TUMOURS OF THE SKULL-BONES 325
INDEX 335
LIST OF ILLUSTRATIONS
FIGS. PAGES
1 and 2. Cranio-cerebral topography 2, 3
3. The cortical motor and sensory areas 8
4 and 5. The scalp-tourniquet 14, 15
6. Cushing’s ‘clips’ 18
7. Hudson’s trephine 20
8. The hand-trephine 21
9 and 10. The technique of trephining 22
11-16. Instruments used in trephining 23, 24
17-19. The formation of an osteoplastic flap 26, 27
20. An occipital cephalocele 33
21. A cephalocele over the anterior fontanelle 35
22. An occipital cephalocele 37
23. A depressed birth-fracture 45
24 A and B. A case of depressed birth-fracture, before and after
operation 47
25. To illustrate the effects and position of a birth-hæmorrhage 53
26. The author’s operation for Hydrocephalus internus 64
27. The conversion of Hydrocephalus internus into cephalocele 65
28. Illustrating the lines along which forces received on the vault
are transmitted to the base 69
29 A and B. The base of the skull and the base as seen on
transillumination 70, 71
30. Plan of the base of the skull 77
31. To illustrate the relation of basic fractures to cranial
nerves 81
32-37. The lines pursued by basic fractures 83-8
38 A and B. To illustrate the probable source of profuse
hæmorrhage from the ear 97
39. To show the relation of a typical basic fracture to the middle
ear and its adjuncts 103
40 and 41. To show the relation of basic fractures to the petrous
bone 104, 105
42. A comminuted fracture of the skull 112
43 A and B. An explosive fracture of the vault of the skull 113
44. A temperature chart illustrating the changes in temperature
observed in head-injuries 117
45-48. Intermusculo-temporal cerebral decompression 122, 123
49 A and B. The elevation of a depressed fracture of the vault 131
50 A and B. The inner aspect of the skull and the same seen on
transillumination 137
51. To illustrate compression of the brain as produced by an
extra-dural hæmorrhage from the middle meningeal artery 141
52 A and B. The operative treatment of middle meningeal
hæmorrhage 144, 145
53. A basic fracture with laceration of both carotid arteries 148
54. A basic fracture with laceration of the cavernous sinus 149
55. A basic fracture with laceration of both lateral sinuses 151
56 A and B. The operative treatment of subdural hæmorrhage 156, 157
57. The areas concerned in speech expression 163
58. The cortical motor and sensory areas 165
59. The König-Müller osteoplastic flap 197
60. The author’s method of covering in a gap in the skull 199
61. A case of traumatic orbital aneurysm 207
62. A glioma of the brain 211
63. A sarcoma of the brain 211
64. An endothelioma of the dura mater 212
65. A fibroma of the dura mater 212
66. An acoustic tumour 213
67. Symmetrical tuberculomata 214
68. The cortical motor and sensory areas 220
69. The visual paths 223
70. A pituitary tumour 226
71 A, B and C. The exposure of a tumour by osteoplastic flap 230, 231
72. Combined flap formation and decompression 235
73 A, B, C and D. The exposure of a cerebellar tumour by
craniectomy 239-41
74 A and B. To illustrate the extension of disease from the tympanic
cavity and the surgical anatomy of that region (after Hunter
Tod) 251
75. A large right-sided temporo-sphenoidal abscess 256
76. To illustrate the pressure effects of a temporo-sphenoidal
abscess 257
77. A cerebellar abscess 259
78. To illustrate diagrammatically the symptoms observed in
cerebellar abscess formation (after Luciani) 261
79. The exposure of a temporo-sphenoidal abscess 265
80. The ‘radical’ mastoid operation (after Hunter Tod) 269
81. Exploration for a temporo-sphenoidal abscess (after Hunter
Tod) 270
82. Exploration for a cerebellar abscess (after Hunter Tod) 271
83. A fracture of the anterior fossa which was followed by the
development of meningitis 275
84. Basal meningitis secondary to temporo-sphenoidal abscess 277
85 A and B. To illustrate the exposure of the lateral sinus (after
Hunter Tod) 285
86. A case of Hernia cerebri and the abscess after removal 292
87. Diagrammatic illustration of the three forms of ‘gutter’
fracture 297
88. Diagrammatic representation of the effects produced on bone
and brain by a perforating bullet-wound 299
89 A and B. Sheen’s bullet probe, forceps, and telephone
bullet-detector 302, 303
90. To illustrate the operations on the Gasserian ganglion 317
91. To illustrate the operations for exposure of the Gasserian
ganglion 321
92. Ivory exostoses of the skull 326
93. The development of the frontal bone 327
94. An exostosis of the orbit 330
95. An extrinsic sarcoma of the skull 331
96. An intrinsic sarcoma of the skull 333
THE SURGERY OF
THE SKULL AND BRAIN
CHAPTER I
CRANIO-CEREBRAL TOPOGRAPHY
The surgeon who is called upon to carry out operations on the skull and
brain must possess an accurate knowledge of the anatomy of the parts
involved. Added to this, he must have at his command some simple method
of depicting on the surface of the skull the more important structures.
The more complicated systems of cranio-cerebral topography are of little
practical value to the surgeon. Simplicity is essential, and the
following outline will be found to furnish an adequate practical guide.
Firstly, the skull can be divided into two lateral halves by the
surface-marking of the superior longitudinal venous sinus.
=The superior longitudinal sinus.= This sinus originates at the crista
galli and, passing backwards along the attached margin of the falx
cerebri, terminates at the internal occipital protuberance. It may be
represented by a line drawn from the base of the nose (the nasion), over
the vertex of the skull, to the external occipital protuberance (the
inion)--this line corresponding in its course to the occasionally
persistent metopic suture between the two halves of the frontal bone, to
the sagittal suture between the parietal bones, and to the middle line
of the upper or tabular portion of the occipital bone.
Secondly, each lateral half of the skull can be subdivided into supra-
and infratentorial regions by a line which marks the external attachment
of the tentorium cerebelli; in other words, by the line of the lateral
sinus.
=The lateral sinus.= This sinus is represented by a line presenting a
slight upward convexity, which is drawn from the external occipital
protuberance to the upper and posterior part of the mastoid process of
the temporal bone.
[Illustration: FIG. 1. CRANIO-CEREBRAL TOPOGRAPHY. 1, The nasion; 2, The
inion; 3, The mid-point between nasion and inion; 4, The Rolandic
fissure; 5, The superior temporal crest; 6, The inferior temporal crest;
7, The Sylvian point; 8, The anterior horizontal limb of the Sylvian
fissure; 9, The vertical limb of the Sylvian fissure; 10, The posterior
horizontal limb of the Sylvian fissure; 11, The parietal prominence; 12,
The malar tubercle; 13, The lambda; 14, The first temporo-sphenoidal
sulcus; 15, The external parieto-occipital sulcus; 16, The lateral
sinus; 17, 17, 17, The level of the base of the cerebrum; 18, The
external auditory meatus; 19, 19, Reid’s base-line. (_Reproduced, by the
permission of Mr. H. K. Lewis, from the author’s work on ‘Landmarks and
Surface-markings’._)]
[Illustration: FIG. 2. CRANIO-CEREBRAL TOPOGRAPHY. 1, 1, Reid’s
base-line; 2, 2, A line parallel to the above at the level of the
supra-orbital margin; 3, The middle meningeal artery; 4, The anterior
branch; 5, 5, 5, The three sites for trephining; 6, The posterior
branch; 7, The site for trephining; 8, The point for trephining to reach
the descending horn of the lateral ventricle; 9, The lateral sinus; 10,
The inion; 11, The mastoid process; 12, Macewen’s suprameatal triangle;
12_a_, The mastoid antrum; 12_b_, The facial nerve; 13, The suprameatal
and supramastoid crests; 14, 14, The temporal crest; 15, The temporal
fossa; 16, The external angular frontal process; 17, The tendo-oculi
attachment; 18, The lachrymal groove. (_Reproduced, by the permission of
Mr. H. K. Lewis, from the author’s work on ‘Landmarks and
Surface-markings’._)]
=The infratentorial region.= The cerebellum lies wholly beneath the
tentorium cerebelli, and it is obvious that, in operations carried out
over this portion of the brain, the surgeon is limited in his field of
exposure, above by the line of the lateral sinus, and on either side by
the posterior border of the mastoid process. The division between the
halves of the cerebellum may be represented by a line drawn vertically
downwards from the external occipital protuberance to the nuchal region.
This line also represents the surface-marking of the occipital sinus and
falx cerebelli.
=The supratentorial region.= Brief allusion must be made to certain
landmarks that aid in the representation of structures situated in this
region:--
(_a_) _The external angular frontal process._ The suture between the
external angular frontal process and the corresponding process of the
malar bone lies immediately above the central point of the outer border
of the orbital cavity.
(_b_) _The malar tubercle._ A slight prominence on the posterior border
of the frontal process of the malar bone, about ¹⁄₄ inch below the
external angular frontal process.
(_c_) _The temporal crest._ A prominent ridge that is directed upwards
and backwards from the external angular frontal process. The crest cuts
across the lower portion of the parietal bone, passing below the
parietal prominence, and curves downwards towards the upper and
posterior portion of the mastoid process. It terminates by becoming
continuous with the upper root of the zygomatic process. The crest
consists of two parts, the upper and lower temporal crests. To the upper
is attached the temporal fascia, to the lower the temporal muscle. The
lower crest is almost invariably the more prominent.
(_d_) _The parietal prominence._ The central and most prominent part of
the parietal bone. It indicates the point at which ossification
commenced, and lies about ³⁄₄ inch above the termination of the
posterior horizontal limb of the fissure of Sylvius.
(_e_) _The zygoma._ When traced in the backward direction, the zygoma is
found to divide immediately in front of the ear into three roots, of
which the anterior, merging into the eminentia articularis, and the
middle, aiding in the formation of the post-glenoid process, are of no
practical utility in surface-marking. The upper or posterior root sweeps
backwards above the external auditory meatus to become continuous with
the suprameatal and supramastoid crests, the former of which forms the
upper boundary of _Macewen’s suprameatal triangle_, a triangular
depression at the upper and posterior border of the external auditory
meatus. This triangle may be taken as representing the opening of the
mastoid antrum into the middle ear.
These landmarks having been determined, the following structures may be
mapped out on the surface of the skull.
=The middle meningeal artery.= This artery is given off from the
internal maxillary; after a short extra-cranial course it enters the
skull through the foramen spinosum, and soon divides into two main
terminal branches. The site of division corresponds to a point situated
just above the centre of the zygoma.
The _anterior branch_ passes at first in a forward and upward direction
towards the anterior inferior angle of the parietal bone, and then turns
upwards and backwards towards the vertex of the skull. The main ‘danger
zone’ in the course of this vessel may be mapped out by taking points
which lie respectively 1, 1¹⁄₂, and 2 inches behind the external angular
frontal process and an equal distance above the upper border of the
zygoma. A line uniting these three points represents that part of the
anterior division of the middle meningeal artery which is most liable to
injury and which therefore most frequently requires exposure.
The uppermost point may, however, be regarded as the ‘site of election’
for exposure of the artery, as, in trephining over either of the two
lower points, difficulty may be experienced in the removal of the disk
of bone, since the posterior border of the great wing of the sphenoid
tails off on to the anterior inferior angle of the parietal bone in such
a manner that to effect a clean removal of the disk is often impossible.
Another disadvantage to trephining low down lies in the fact that in
about 30 to 40 per cent. of cases the artery occupies, in that
situation, a canal in the bone.
The _posterior branch_ passes almost horizontally backwards, parallel to
the zygoma and supramastoid crest, towards the posterior inferior angle
of the parietal bone. The vessel can readily be exposed by trephining
over the point at which a line drawn backwards from the upper border of
the orbit, parallel to Reid’s base-line,[1] cuts another line directed
vertically upwards from the posterior border of the mastoid process.
Both branches of the middle meningeal artery possess important relations
to the cortex cerebri, the anterior branch passing upwards in relation
to the precentral or motor area, traversing, from below upwards, the
motor speech area (on the left side of the head), the centres for the
movements of the face, upper extremity, trunk, and lower extremity. The
posterior branch, on the other hand, passes backwards in relation to the
temporo-sphenoidal lobe, one of the so-called ‘silent areas’ of the
brain. Throughout their course the middle meningeal vessels lie between
the dura mater and the bone.
=The lower limit of the cerebrum.= The lower limit of the cerebrum can
be mapped out in the following manner: From a point situated about ¹⁄₂
inch above the nasion a line is drawn outwards which follows the curve
of the upper border of the orbit as far as the external angular frontal
process, thence curving upwards and backwards to the Sylvian point (see
below). The temporo-sphenoidal lobe sweeps forwards to the posterior
border of the malar bone, and its lower limit lies practically flush
with the upper margin of the zygoma. At and behind the ear the lower
limit of the cerebrum corresponds to the suprameatal and supramastoid
crests, subsequently following the curve of the lateral sinus from the
mastoid process to the external occipital protuberance.
=The Sylvian point and fissure.= The Sylvian point represents the site
of divergence of the three limbs of the Sylvian fissure. It lies 1¹⁄₄
inches behind the malar tubercle and 1¹⁄₂ inches above the upper border
of the zygoma. The main posterior horizontal limb passes backwards and
upwards to a second point situated ³⁄₄ inch below the parietal
prominence.
The vertical limb is directed upwards for about 1 inch, whilst the
anterior horizontal limb passes forwards for about the same distance.
=The fissure of Rolando.= This, from a surgical point of view, the most
important fissure of the brain, is represented as follows: A point is
taken in the median antero-posterior line which lies ¹⁄₂ inch behind the
mid-point between nasion and inion, and from this point a line is drawn,
for 3¹⁄₂ to 4 inches, towards the mid-point of the zygoma. This line is
inclined to the median antero-posterior line at an angle of 67¹⁄₂°
(three-quarters of a right angle).
=The parieto-occipital and first temporo-sphenoidal fissures.= In the
representation of these two fissures, two points require to be
determined--the malar tubercle and the lambda. Allusion has already been
made to the former; the latter is usually readily located as the
point of intersection of the sagittal and lambdoid sutures. A line
uniting these two points corresponds in its middle third to the
temporo-sphenoidal fissure, and in its posterior inch or so to the
external parieto-occipital sulcus, a fissure separating the occipital
and parietal lobes of the brain.
=The cortical motor and sensory areas.= The researches of Sherrington
and Grünbaum,[2] Campbell,[3] and others tend to show that the _cortical
motor areas_ are situated entirely anterior to the central fissure or
fissure of Rolando, extending above well over on to the mesial aspect of
the brain, though not so far as the calloso-marginal fissure, and in the
downward direction to within a short distance of the fissure of Sylvius.
In the posterior direction the motor area includes the anterior boundary
and part of the bottom of the fissure of Rolando, whilst in front it
spreads, by means of gyri annectantes, on to that part of the brain
which lies anterior to the precentral sulcus. The anterior termination
is indefinite, but the motor strip is, on an average, not more than ³⁄₄
inch in breadth.
The genua of the Rolandic fissure are said to bear a more or less
definite relation to the motor areas. In my experience, however, they
are too variable, and any importance which might obtain is further
diminished by the fact that the surgeon should never rest content with
that limited exposure of the brain which was so much in vogue till
recent years. The suspected region is widely exposed by osteoplastic
flap, and if doubt exists as to the particular part of cortex exposed
the question is accurately settled by faradization.
This motor strip corresponds, from above downwards, to the movements of
the contralateral lower extremity (toe to hip), trunk, upper extremity
(shoulder to fingers), neck and face. It is a point of some general
utility to bear in mind that the temporal crest intervenes approximately
between the regions responsible for the movements of the upper extremity
(above the crest) and those for the movements of the head and face
(below the crest).
[Illustration: FIG. 3. THE CORTICAL MOTOR AND SENSORY AREAS.]
On the left side of the head--in normal right-handed individuals--the
_motor speech area of Broca_ corresponds to the third left frontal
convolution, in the angle between the anterior and posterior horizontal
limbs of the Sylvian fissure.
The ‘primary registration’ of ‘_common sensation_’ occurs in the
post-central gyrus, immediately posterior to the fissure of Rolando.
This tactile area occupies a position behind the fissure of Rolando
similar in extent to that occupied by the motor area in front. It
commences at the bottom of the fissure of Rolando and extends backwards
over rather more than half the exposed area of the post-central
convolution. It reaches down to near the Sylvian fissure and extends
over on to the mesial aspect of the brain. Furthermore, it is probable
that sensation in any given part lies on more or less the same level as
the corresponding motor area.
Immediately posterior to the tactile area and occupying the posterior
and upper part of the post-central convolution, the area responsible for
_muscle-sense_ is situated.
=Stereognosis=--memory pictures, object perception, &c.--is referred to
the superior parietal lobe.
=Primary visual impressions= are received in the occipital lobe, more
especially on the mesial aspect thereof.
Finally, the four areas concerned in =speech=--motor speech, writing,
reading, and hearing--are anatomically separated from one another and
yet closely associated, so much so that one can hardly be involved
without the other. The motor speech centre of Broca has already been
mentioned as occupying--in right-handed individuals--the posterior part
of the third left frontal convolution. Writing lies immediately above
and in front, in the posterior part of the middle frontal gyrus,
auditory impressions are received in the posterior and upper part of the
first temporo-sphenoidal lobe, whilst the power of reading is dependent
on the integrity of the supramarginal and angular gyri (see also Fig.
57).
=Smell and Taste= lie in close relation to the anterior pole of the
temporo-sphenoidal lobes.
[1] Reid’s base-line is a line drawn around the skull, starting in front
at the lower border of the orbit and passing through the central point
of the external auditory meatus.
[2] _Proceedings and Philosophic Transactions of the Roy. Soc._, 1901.
[3] _Localization of Cerebral Function._ Camb. Univ. Press, 1905.
CHAPTER II
THE SPECIAL TECHNIQUE IN OPERATIONS ON THE SKULL AND BRAIN
=Preparatory treatment.= Where possible at least two or three days
should elapse between the admission of the patient and the day of
operation. During this period the patient should be confined to bed with
all possible cheerful surroundings. The bowels are regulated and the
diet restricted.
The extent to which the scalp should be shaved and the time at which
this procedure should be carried out vary according to the circumstances
of the case. Much depends on the sex and age of the patient and the
nature of the proposed operation. Insomuch, however, as it is always
inadvisable to prolong the period of anæsthesia, it follows that the
shaving should be carried out previous to the operation. With regard to
extent, each case must be judged on its own merits. For instance,
considerable concession must be made in the case of a young woman on
whom the surgeon proposes to carry out a subtemporal decompression
operation, and in the case of a neurotic or elderly patient who is the
subject of trigeminal neuralgia. There can, however, be no question that
the limitation of operative field advocated by some surgeons is fraught
with considerable risk from the point of view of wound infection.
If the question be discussed with the patient the surgeon will find the
ground cut away from beneath his feet, and that he has to make
considerable and inadvisable concessions. Taking everything into
consideration, although it is seldom necessary to shave the whole head,
I am accustomed to order such preparation as will allow of a very wide
margin. To shave the whole head is not only unnecessary but is also
exceedingly distasteful to the patient. The front, back, or side of the
head should be prepared only--on the morning of the operation, so as to
allow of a comfortable night’s rest. After shaving, the scalp is
thoroughly cleansed with soap and water, and the head surrounded by a
sterilized towel. The final skin sterilization is carried out when the
patient is under the anæsthetic.
The iodine method has always given satisfactory results, the skin being
painted, half an hour previous to operation, with a 2¹⁄₂ per cent.
solution of iodine, and again after the administration of the
anæsthetic. Still, I cannot avoid a certain penchant for the older
method--sponging with ether to remove the fats, washing with a 1 in 500
spirit solution of biniodide of mercury, and finally douching with a
weaker mercury solution.
=Precautions against the development of shock.= It is almost inevitable
that all serious head-operations should be associated with some degree
of shock, though, from my experience, I am convinced that, with due
precautions, it is far less serious than is generally supposed. The
development of shock is very largely dependent on the amount of blood
lost during the operative procedures. The various methods adopted to
control hæmorrhage are enumerated later. In addition, attention should
be paid to the following details:--
1. Half an hour before the operation an injection of a quarter of a
grain of morphia should be given hypodermically. The addition of
one-hundredth of a grain of atropin, recommended by some surgeons,
interferes somewhat, by its action on the pupil, with the data deemed
necessary for the administration of the anæsthetic.
2. The theatre should be maintained at a temperature between 65 and 75
degrees Fahrenheit. The table should be suitably warmed.
3. The patient’s body should be covered with warm blankets, and, in the
more serious cases, the lower extremities may be bandaged, from below
upwards.
It has been recommended that the brain, if exposed, should be protected
from the cooling effects of the atmosphere by irrigation with saline
solution at a temperature between 110 and 115 degrees Fahrenheit.
Personally I prefer to keep the operative field as dry as possible.
An assistant should be told off, whose duty lies in keeping a record
both of blood-pressure and pulse-rate. The lowering of blood-pressure is
the surest guide to the surgeon of approaching danger.
It is often considered that rapidity of operation is essential. There
can be no greater error. To ensure success the utmost care must be taken
to control the loss of blood, for which it is essential that each step
of the operation should be carried out deliberately and carefully.
=The anæsthetic.= Needless to say, it is essential that the surgeon
should have at his disposal an anæsthetist of great experience in head
operations.
Ether is regarded with favour in the United States, and in other
countries, but we prefer chloroform on the ground that, by its lowering
effect on the blood-pressure, there is less venous oozing, and added to
this there is probably less tendency to post-operative vomiting. I have
recently had the opportunity of seeing the open ether method as carried
out in the States, on one occasion for an operation lasting four hours,
and in this and in other cases the patient left the operation table in
excellent condition, recovering also rapidly from the effects of the
anæsthetic.
The lowering of blood-pressure as produced by chloroform might be
advanced as an argument against the use of that drug, shock being the
greatest danger to be feared in these operations. Still, I must say that
I prefer chloroform so long as it is administered by a skilled
anæsthetist.
In any case, it is advisable to have oxygen ready to hand.
=The position of the patient.= Special tables have been invented and
special positions advised. Thus, the dental-chair position is
recommended for operations on the Gasserian ganglion, and, in cerebellar
operations, it is urged that the patient should be turned on his face,
the forehead resting on a tripod, the shoulders on supports fastened to
the head of the table. Personally, I do not consider that any special
arrangements are required in the majority of cases. Much can be done
with sand-bags and firm pillows. Even in the exposure of one cerebellar
hemisphere I prefer to utilize the semi-prone position.
In bilateral cerebellar exposure, however, the patient must be placed on
his face, the forehead resting on special supports, and the shoulders on
props or pillows so as to allow of free entry of air into the chest. In
such cases the anæsthetic is administered from below.
I am not enthusiastic over the so-called dental-chair position, but the
operating table should be constructed in such a manner that the head and
shoulders of the patient can be well raised, the body being inclined to
the floor at an angle of about 30-40 degrees.
=Preparation of the operative field.= When the patient is fully under
the anæsthetic, the final cleansing of the scalp is carried out and the
operative field cut off from all possible sources of infection. In the
States, in Cushing’s clinic, the anæsthetist is completely covered with
a large sterilized sheet, which is fastened to the head of the patient.
In this country we prefer that our anæsthetist should have full
knowledge of the progress of the operation, and I think that the
advantages are with us. In any case, the whole head is enveloped in
gauze, two or three layers thick and about 18 inches square. This sheet
is thrown over the patient’s head and maintained in position by means of
the scalp-tourniquet (see pp. 14, 15). Around this sterilized towels are
arranged, either fastened to one another or stitched to the scalp. When
the operation is conducted in the temporal region the towels, unless
fastened to the skin by means of a few sutures or safety-pins, tend to
become displaced, and by so doing add to the risk of wound infection.
THE CONTROL OF HÆMORRHAGE
=Hæmorrhage from vessels of the scalp.= All surgeons must have
appreciated the difficulty attendant on the application of forceps to,
and the ligature of, divided scalp-vessels. The patient may lose a
considerable quantity of blood, and much valuable time will be wasted
before the more essential part of the operation is commenced. All this
can, under ordinary circumstances, be avoided by the use of the
scalp-tourniquet. As used by Cushing it consists of a rubber ring
fashioned after the style of an Esmarch’s tourniquet, encircling the
head and passing from the lower frontal region in front, above the ears,
to the lower occipital region behind. A median tape, passing from
glabella to occiput, prevents any tendency for the tourniquet to slip
down over the eyes, at the same time acting as a convenient landmark for
the superior longitudinal sinus.
The tourniquet, when applied with the correct pressure, should, under
ordinary circumstances, completely control all hæmorrhage from the
divided scalp-vessels. It should be noted, however, that bleeding will
be rather increased than otherwise if the tourniquet be so loosely
applied as to impede the venous return without compressing the scalp
arteries. A little experience will soon enable the operator to gauge the
requisite pressure.
[Illustration: FIG. 4. THE SCALP-TOURNIQUET. _Front View._]
[Illustration: FIG. 5. THE SCALP-TOURNIQUET. _Back View._]
There is one other exception to the satisfactory working of the
scalp-tourniquet. In the presence of a superficial cerebral tumour,
especially when of a malignant nature, the normal communication between
the intra- and extra-cranial vascular systems may be so exaggerated that
those scalp-vessels which receive diploic and emissary venous
communications will give rise to some trouble. This difficulty should be
overcome--not by rapidity in the formation and turning down of the
flap--but by clipping each vessel as exposed or divided, by the
application of pressure and by foraminal occlusion (see also p. 17).
I found Cushing’s tourniquet rather inconvenient in its application,
and, after various modifications, am accustomed to use the one depicted
in the illustration. It consists of two flat metal bands connected
posteriorly by a strong rubber connecting link, the two bands passing in
front through a metal fixation piece possessing a screw which, when
tightened up, allows of the maintenance of the desired pressure. The
median tape, previously mentioned, helps to keep the tourniquet in
position.
The tourniquet is applied as follows: the whole head is enveloped in
gauze--two or three layers thick, and cut to the size and shape of a
large handkerchief. The tourniquet is slipped over the head, as low
down as possible, and then tightened up. The median tape, having a loop
behind through which the tourniquet passes, is laid in the middle line
and tied round the screw on the fixation piece.
The gauze should then be moistened with saline solution or some mild
antiseptic, so that it clings tightly to the underlying scalp and
becomes sufficiently translucent to allow of the recognition of any
underlying landmarks that may have been previously mapped out with the
scalpel, iodine, silver nitrate, or aniline pencil.
The scalp-flap is then framed by incisions carried down to the bone,
through gauze and scalp, in one sweep. The flap is turned down and
covered with gauze. By the adoption of this method hæmorrhage from
scalp-vessels is efficiently controlled and the risk of wound infection
is reduced to a minimum.
After the completion of the operation, the scalp-flap is approximated
and sewn into position, first by numerous buried fine silk sutures
bringing together the aponeurotic layer of the scalp, and finally by a
few silk or salmon-gut sutures passed through the skin itself. Gauze
dressings are applied, the tourniquet loosened, and a roll-gauze bandage
quickly applied circumferentially around the head, low down over the
forehead and occipital region. This roll bandage in reality takes the
place of the tourniquet, but is, of course, applied with moderate
pressure only.
If the wool and bandage now applied over all should include the ears,
these two organs should be well covered with vaseline. Few things are
more uncomfortable to the patient than the contact of wool and bandage
to the ears.
The tourniquet should be utilized whenever possible. In operations,
however, that are conducted near the base of the skull--subtemporal
decompression, cerebellar exploration, &c.--the surgeon, in his effort
at hæmostasis, must rely on the application of digital pressure on
either side of the incision, the more careful exposure of the vessels,
and the application of forceps as soon as they are seen or divided, or
by the utilization of Vorschütz’s hæmostatic safety-pins.
Other methods of controlling scalp-bleeding are as follows:--
1. Kredel’s hæmostatic sutures, passed with a large curved needle which
slides along the bone and emerges about 5 to 7 cm. from the point of
introduction. The silk ligatures are then tied over metal plates, so
curved as to lie flush with the surface of the skull in the particular
region involved. Four of these plates would be used in the formation of
an osteoplastic flap, one on the distal side of each of the three scalp
incisions, and one along the base of the flap.
2. The enclosure of the proposed incision by a running suture which,
passing down to the bone, emerges about 1 inch further on, then so to
speak repeating itself in part until the whole region is surrounded. The
ligatures are then tightened up. This method takes some time in its
application, and presents no advantages over the scalp-tourniquet.
3. The blocking of the main arterial supply--temporal, occipital, and
supra-orbital vessels--by modified safety-pins, mass ligatures, &c.
Arterial compression by means of the modified safety-pin as suggested by
Vorschütz will be found most useful in those operations in which the
scalp-tourniquet cannot be utilized--subtemporal decompression, &c.
=Hæmorrhage from the bone.= Severe bleeding may take place from the
mastoid and other emissary veins, and from the open mouths of those
abnormally dilated diploic and emissary veins so often encountered in
the exposure of an underlying dural or superficial cerebral tumour. The
foramina in the bone, when exposed, must be occluded as quickly as
possible. For this purpose we have the following methods at our
disposal--plugging with small bone or wooden pegs, blockage with minute
plugs of cotton-wool, and the utilization of Horsley’s wax, smeared over
the part and well pressed home.
Hæmorrhage may also occur from the bone during trephining, more
especially when the operation is conducted over that part of the
anterior division of the middle meningeal artery which runs through a
channel in the spheno-parietal region. Here the disk of bone should be
removed as quickly as possible and the channel plugged with pegs,
cotton-wool, or wax.
Oozing from the raw surface of the cut bone is controlled by rubbing in
aseptic wax, or by the crushing together of the inner and outer tables.
=Hæmorrhage from the dural vessels.= In this case the bleeding may occur
from three sources, meningeal veins--often of considerable size when
related to neighbouring tumour-formation--the middle meningeal artery,
and the venous sinuses of the brain.
Hæmorrhage from meningeal veins may be arrested by one or other of the
following methods:--
1. Gentle pressure as applied either by dry gauze, or wet gauze soaked
in saline solution at a temperature between 110 and 115 degrees
Fahrenheit.
2. The application of a piece of muscle to the bleeding-point. This
method was, I believe, first introduced by Sir Victor Horsley. Some
muscle is usually available for the purpose, usually the temporal
muscle. A small portion of muscle is snipped off, spread out as a flat
muscular pad, the bleeding area dried, and the graft quickly applied. It
soon adheres, and usually arrests the hæmorrhage.
3. The application of a ligature. This method is placed last, being the
most difficult. It is usually necessary to underrun the bleeding-point
with a fine needle threaded with the finest of silk. It presents the
disadvantage in that the needle may perforate the dura mater and
puncture one of the superficial cerebral veins.
[Illustration: FIG. 6. CUSHING’S CLIPS. A, The holder of the clips; B, A
clip ready to be applied; C, Two clips applied to the middle meningeal
artery.]
Hæmorrhage from the middle meningeal artery may be controlled by
ligature or torsion, and added to these methods we have one other,
recently introduced by Cushing--silver wire ‘clips’. These clips are
U-shaped, loaded on a magazine, picked up as required in the jaws of a
specially indented forceps, and clipped on to the vessel--usually one on
either side of the bleeding-point.
Hæmorrhage from venous sinuses is dealt with on p. 150.
=Hæmorrhage from the superficial vessels of the brain.= This form of
hæmorrhage, one of the most troublesome complications arising in
head-operations, most commonly results from hasty or careless opening of
the dura mater. Thus, when the dura is incised in a case of greatly
increased intracranial pressure, the brain herniates suddenly outwards,
and the incautious use of the knife will damage one of the dilated
superficial cortical veins. The dura should always be opened with the
greatest care, the knife being passed lightly over the membrane till the
pia-arachnoid is exposed, when the dural margins are lifted up with
small tenaculum forceps and the membrane slit up with blunt-pointed
scissors or on a grooved director.
In the event of injury, the bleeding may often be controlled by light
pressure with dry gauze, or wet gauze wrung out in hot saline solution
as described above. If this fails, a very fine silk ligature may be
passed beneath the vessel on either side of the site of bleeding. This
procedure is not easy to accomplish, the tissues are so soft and
friable. However, every effort must be made to arrest the bleeding, for
not only does the hæmorrhage obscure the field of operation, but the
presence of a blood-clot beneath the dura mater will lead at a later
date to the formation of adhesions between the various membranes of the
brain--a potent cause of headache, epilepsy, &c.
THE OPENING OF THE SKULL
Two methods are adopted in the exposure of meninges and
brain--craniectomy and craniotomy.
=Craniectomy= implies the formation of a scalp-flap, exposure of the
bone, trephining of the skull, and enlargement of the gap to the
required size and shape.
=Craniotomy= implies the formation of a flap of scalp and bone in one,
and the exposure of an area of dura and brain directly proportionate to
the size of the bone-flap.
=Craniectomy.= After the application of protective gauze and tourniquet,
the scalp-flap is framed according to the requirements of the case. If
the tourniquet is used, the knife is entered at one extremity of the
proposed flap, carried down to the bone--through gauze and scalp in
one--and the incision completed in a single sweep. Under other
circumstances, digital pressure is applied to the main flap-supplying
vessel, e.g. the temporal artery over the base of the zygoma, or else
Kredel’s clamps or Vorschütz’s hæmostatic safety-pins are passed in such
a manner as to control bleeding from the main supplying vessel. In the
event of bleeding, the surgeon goes along quietly, deepening his
incision and seizing each vessel as exposed.
In turning down the scalp-flap it is usually recommended that the
pericranium should be included. This is quite unnecessary, and, under
certain circumstances, should certainly be omitted (see p. 129). It
should be stripped away from the underlying bone as required.
[Illustration: FIG. 7. HUDSON’S TREPHINE. Showing the usual method of
using the spiral perforator, spiral follower, and enlarging burr.]
The trephining may be carried out with the hand-trephine, or by means of
saws, burrs, and trephines driven by electricity. With the exception of
a few words on Hudson’s trephine, I do not propose to discuss the
relative advantages and disadvantages of these mechanically-driven
instruments. I hold the opinion that the hand-driven instrument is
sufficiently rapid in its work, that it is infinitely safer, and that
the surgeon should accustom and perfect himself with those instruments
which are to him most convenient and most portable. He will not always
be conducting his operations in a perfectly equipped hospital, much of
his work will be carried out in the nursing home or in the country.
Whatever method be adopted, the operator should use those instruments to
which he is most accustomed.
Hudson’s trephine is shaped after the style of the carpenter’s brace and
is fitted with three cutting heads--the perforator, the follower, and
the enlarging burr. It is claimed that injury to the dura and brain is
impossible, the instrument becoming automatically locked so soon as the
resistance of the internal table is overcome, a thin film of bone being
pushed in front of the advancing head. I have had the opportunity of
using this instrument, and so far as my experience goes it answers all
requirements. Still, I prefer the ordinary hand-trephine so long as it
satisfies certain requirements. It must be of simple mechanism and
strong, the handle of good size and shaped to fit the hand, the shaft
and head so interlocked as to allow of no independent movement, and the
hollow head sharply toothed and bevelled externally, in continuity with
the teeth, for a distance of half an inch. The bevelling is so arranged
that the actual cutting process is only effected during supination of
the hand and forearm. The pin of the trephine should not project beyond
the cutting edge for a greater distance than about ·2cm. This pin should
be readily removable.
[Illustration: FIG. 8. THE HAND-TREPHINE.]
The pattern which I am accustomed to use is depicted in Fig. 8. The
trephines are kept in three sizes--diameter ¹⁄₂, 1, and 1¹⁄₂ inches. The
intermediate size is used for ordinary trephining, the small one for the
formation of the osteoplastic flap, the large for the removal of a disk
of bone which includes within its circumference the area involved in
some depressed and punctured fractures (see p. 133).
[Illustration: FIG. 9.
FIG. 10.
TO SHOW THE TECHNIQUE OF TREPHINING. Fig. 9 illustrates the act of
trephining for cerebellar exposure. Fig. 10 shows a trephine-disk to one
side of a depressed fracture.]
The site of trephining may be fixed by the introduction of a bradawl
through the scalp, so indenting the external table that the spot can be
verified on turning down the scalp-flap. The pin of the trephine is
there applied, and the trephine directed at right angles to the
surface of the skull, or at that angle which is suited to the region
attacked. The pin is discarded when a sufficient groove has been
attained. The trephine must be kept under perfect control, muscular
effort only being required during the act of supination.
[Illustration: FIG. 11. HORSLEY’S DISK OR BONE ELEVATOR.]
[Illustration: FIG. 12. HORSLEY’S DURAL SEPARATOR.]
[Illustration: FIG. 13. KEEN-HOFFMANN’S CRANIECTOMY FORCEPS.]
The firm nature of the external table will be readily appreciated; so
soon as this resistance is overcome the trephine will be felt to be
cutting its way through a softer structure, whilst the increased
bone-dust and venous oozing will make it evident that the instrument is
biting its way through the diploic tissue. Greater resistance is again
encountered on meeting the internal table, warning the operator that the
time has come when greater care must be exercised. The bone-dust must be
wiped away, the teeth of the trephine cleansed with nail-brush or
sponge, and the depth of the groove estimated. The groove should be of
the same depth throughout its circumference, or of that depth which is
suited to the part involved.
The readiness of the disk for removal is best demonstrated by digital
pressure. When it gives to that pressure, whether in whole or in part,
the elevator may be applied and the fragment removed.
In the temporal and cerebellar regions special care is required by
reason of the absence of diploic tissue.
It is impossible to lay too much stress on the necessity of avoiding
injury to underlying dura and meningeal vessels. Injury to these
structures not infrequently upsets the whole plan of campaign.
[Illustration: FIG. 14.
LANE’S FULCRUM CRANIECTOMY FORCEPS.]
[Illustration: FIG. 15.
HORSLEY’S GOUGE FORCEPS.]
[Illustration: FIG. 16. DE VILBISS’S CRANIECTOMY FORCEPS.]
_The enlargement of the trephine hole to the required size and shape._
Previous to any attempt at enlargement of the trephine hole, the dura
mater must be separated from the bone with the aid of Horsley’s dural
separator or other suitable instrument. Of the many patterns of
craniectomy forceps, the following will be found to suit all
requirements:--
_Keen-Hoffmann._ The visceral blade is introduced between the dura and
the bone and ‘morcellement’ carried out. It is essential that the
surgeon should not be too greedy, resting content with the removal of
small fragments at a time.
_Lane’s fulcrum forceps._ They possess great mechanical advantage and
are mainly suited for the rapid removal of large portions of bone.
_Horsley’s nibbling or rongeur forceps._ This instrument is mainly
utilized in the smoothing and refreshing of sharp edges of bone, and in
the ‘morcellement’ of the thinner portions of the skull--temporal and
cerebellar regions.
_De Vilbiss’s forceps._ A clever contrivance whereby the operator is
enabled to cut a narrow channel in the bone. Mainly utilized in the
formation of the osteoplastic flap.
=Craniotomy.= Craniotomy, or osteoplastic resection of the skull, was
first carried out by Wagner. It is proposed to describe that method only
which, by experience, has been found to meet all requirements--the
formation of the osteoplastic flap by means of the hand-trephine,
Gigli’s saw, and de Vilbiss’s forceps.
The protective gauze dressing and scalp-tourniquet are applied as
before. A large
______
\ / -shaped
\ /
incision is made in such a manner as to include the area which it is
desired to expose. The two vertical limbs of the incision should
converge to such a degree as to allow of the subsequent ready fracture
of the flap along its base. The knife is entered at one extremity,
carried down to the bone, and the three incisions rapidly made, one
after the other. Along the line of each of the three incisions, the
pericranium is stripped away from the bone so as to allow of adequate
exposure. At the anterior and posterior angles of the flap the tissues
are retracted a little more, permitting the application of a half-inch
diameter trephine. Here the two trephine-holes are bored--with the usual
precautions against damage to the dura mater--and the two disks of bone
elevated and removed.
Between these two trephine-holes the dura mater is separated from the
bone and the special director introduced, entering at the one hole,
emerging at the other, and lying throughout between the dura and the
bone. The saw is now passed along the groove of the director, the
handles affixed, and the bone intervening between the two trephine-holes
divided, not straight out to the surface, but bevelled or cut in such an
oblique manner that the bone-flap, when replaced, rests on a ledge (see
Figs. 17-19). The sawing process generates considerable heat, and the
assistant should be instructed to keep up irrigation with saline
solution or sterilized water. The sawing is carried out by steady
side-to-side traction, without jerks; if the saw breaks, the special
handle may be attached, thus obviating the necessity of introducing a
new saw.
[Illustration: FIG. 17. FIRST STAGE IN THE FORMATION OF AN OSTEOPLASTIC
FLAP. Gigli’s saw, protected from the dura mater by the special
director, passing between the two trephine-holes. For further
description, see text.]
[Illustration: FIG. 18. SECOND STAGE IN THE FORMATION OF AN OSTEOPLASTIC
FLAP. The bone-flap turned down and the dura mater exposed.]
[Illustration: FIG. 19. THIRD STAGE IN THE FORMATION OF AN OSTEOPLASTIC
FLAP. The dural flap turned down and the brain exposed. Note the
relation of the scalp, bone, and dural incisions to one another.]
The dura is now separated from the bone along the line of the two
vertical incisions, and the visceral blade of de Vilbiss’s forceps
insinuated beneath the bone, starting at one trephine-hole and working
downwards to the lower limit of the incision. It is essential that the
operator should be satisfied with the ‘morcellement’ of small portions
of bone at each bite of the instrument. At the lower end of each of
the vertical incisions the forceps is directed inwards for ¹⁄₄ to ¹⁄₂
inch so as to weaken the base of the flap.
To lift up the osteoplastic flap, a stout elevator or spatula is
introduced beneath the bone at its upper part, leverage applied, and, as
soon as sufficient elevation has been attained, the dura mater carefully
separated from the whole of the under aspect of the flap. The flap is
then grasped at its upper part with both hands and, with a quick but
forcible jerk, broken across at its base, the assistant at the same time
aiding the correct linear fracture of the bone by a flat spatula applied
to the outer aspect of the base of the flap. Insomuch as the flap is
most usually framed in the parieto-temporal region--for the exposure of
the motor area--the base of the flap, being formed from the squamous
portion of the temporal bone, is comparatively weak. Fracture is then
readily obtained. Under other circumstances the base may be sufficiently
weakened by the application of the de Vilbiss forceps or by the use of
the Gigli saw.
The bone-flap is thrown back and enveloped in gauze. Its basal region is
examined for a possible injury to meningeal vessels. In the event of
such complications the bleeding vessel is clipped, ligatured, or
underrun. Possibly some branch of the anterior division of the middle
meningeal artery, running in an osseous canal, may require to be
controlled by foraminal occlusion--with a wooden match, bone peg,
cotton-wool, or aseptic wax.
In comparing the =relative advantages and disadvantages= of craniectomy
and craniotomy, although there are certain definite contra-indications
to the latter method, yet craniotomy should always be carried out when
the surgeon desires to expose a large surface area of brain, more
especially in the exposure of a tumour diagnosed to lie in relation to
the motor cortex. Even if the operator should be unsuccessful in his
exploration, or, if finding the tumour, should deem it irremovable, the
dura can be sewn up and the bone-flap replaced, resting on its bevelled
edge, with little defect in the skull and a normal surface contour.
The three main disadvantages to craniotomy are as follows:--(1) the
operation can seldom be done under much less than thirty minutes; (2)
there is some slight risk of complication through injury to the middle
meningeal artery; and (3) the dura mater may be so adherent to the bone
as to be torn in the process of flap-elevation. Time, however, is
usually of little importance; bleeding from the middle meningeal artery
may be controlled, and dural lesions may be avoided by careful
technique. In general, the advantages of osteoplastic resection greatly
outweigh the disadvantages.
The more definite contra-indications to the formation of the bone-flap
are as follows:--
1. This operation is unnecessarily severe in most cases of intracranial
hæmorrhage, e. g. from the middle meningeal artery. It is also usually
impracticable by reason of the associated damage to the bones of the
vault and base.
2. It is contra-indicated in operations conducted for the exposure of
the Gasserian ganglion, its root and its branches (trigeminal
neuralgia). In these operations it is essential that the operator should
get down as low as possible towards the base of the skull.
3. It is contra-indicated in operations conducted in the cerebellar
region. Even after cerebellar exposure by craniectomy, the surgeon is
working in a sufficiently confined space. The presence of a bone-flap
only adds further difficulty and complication. Added to this is the fact
that the thin wall of the cerebellar fossa is not adapted to
osteoplastic flap-formation.
=Opening the dura mater.= Reference has already been made to the great
importance of opening the dura in such a manner as to avoid injury to
the underlying superficial cerebral vessels (see p. 19). It may be
incised in a crucial manner or by flap-formation. Flaps are usually to
be preferred if the surgeon desires to have the widest possible view of
the brain surface. In the formation of the flap, advantage should be
taken of the vessels that minister to its vitality. Thus, in the lateral
region of the head, the base lies below, the middle meningeal artery
supplying the flap. Under special circumstances, the blood-supply may be
disregarded; the flap never sloughs, so far as my experience goes.
=Sewing up the dura mater.= Considerable difficulty may be experienced
in sewing up the dura--by reason of the bulging of the brain. How these
difficulties may be overcome is dealt with on p. 236. The edges should
be united by numerous fine silk sutures.
=Replacement of the osteoplastic flap and sewing up.= The flap is
replaced, care being taken that its lower or fractured edge does not
injure the dura mater. The aponeurotic and subcutaneous tissues of the
scalp-flap are sewn up in the manner stated on p. 16.
=After-treatment.= Whether the operation be carried out by craniectomy
or craniotomy, the patient is put back to bed in the so-called head-down
position, the lower end of the bed being raised at least a foot above
the level of the head. In the event of shock, a hypodermic injection of
a ¹⁄₄ gr. of morphia should be given, the lower extremities may be
bandaged firmly from below upwards, and saline infusions administered,
preferably per rectum.
CHAPTER III
CEPHALOCELES. BIRTH-HÆMORRHAGES. BIRTH-FRACTURES. DERMOIDS.
HYDROCEPHALUS
CEPHALOCELES
The term ‘Cephalocele’ has been applied to all those tumours which
project through a gap or deficiency in the bones of the vault and base
of the skull. The tumour may be congenital or traumatic in origin: the
membranes of the brain may alone protrude (meningocele), or the tumour
may be composed of normal or altered brain-substance: all the varying
conditions, however, are included under one term--=cephalocele=.
Congenital and traumatic cephaloceles differ, however, so markedly from
one another, both with regard to their pathology and treatment, that
they must be considered separately.
=Congenital cephaloceles.= Billroth and the late Professor von Bergmann
were the first to narrate cases in which this deformity was present,
Lyssenkow[4] added much to the previous records, and de Quèrvain,[5] by
prolonged researches, drew further attention to the subject.
Lyssenkow divided the congenital variety into two main
groups--exencephaly and cephalocele--the former resulting from a general
error in development (the ‘Acrania’ of Muscatelle), the latter a partial
or local developmental failure. In =exencephaly= there is an extensive
gap in the vault of the skull, the remainder of the skull being
microcephalic in nature, the brain projecting outwards in a varying
degree, and the ventricular spaces distended with fluid. In
=cephaloceles= the hole in the skull is usually circumscribed, although
the sutures may be widely separated and the ventricles distended with
fluid, yet both skull and brain may be normally developed in all other
respects.
=Exencephaly= presents but few points of surgical interest, insomuch as
the condition is barely compatible with life.
=Cephaloceles= occupy a very different position. The condition is by no
means confined to man, and many instances are recorded as occurring
throughout the animal kingdom. Norsa Gurrieri,[6] for instance, records
a case occurring in the embryo of Mus decumanus vel albinus. The same
writer insists that the developmental error involves bones of either
cartilaginous or membranous origin, and that the atrophic condition of
the bone is the primary cause and the ectopia of the brain a secondary
result.
Lyssenkow,[7] after careful investigation of tumours removed by
operation and after death, found scattered nerve-fibres, fat-cells,
striated muscle and vessels--the products, therefore, of both ectoderm
and mesoderm. He also observed the frequent occurrence of an intimate
union or fusion between the cephalocele and the overlying integument,
and, in consequence, the theory was formulated that the greater number
of cephaloceles were in reality cephalomata or true teratoid tumours.
It would appear, therefore, that a cephalocele results from the
incomplete cutting off of the neural canal in the head region of the
embryo from the overlying epiblast, with consequent fusion between the
primary neural tube (from which the brain is developed) with the
primordial mesoblastic membranous cranium (from which the membranes are
developed), and with the overlying epiblastic layer (from which the
epidermal portion of the scalp is developed). In consequence of this
localized fusion of layers, the outer dermic coat (from which the
membranous skull is developed) fails to form. Bony defects therefore
exist through which brain-matter protrudes, the projecting portion often
being intimately attached to the skin, and containing not only
epiblastic elements, but also mesoblastic tissue from irregular
occlusion of the same. The mesoblastic involvement is proved by the
presence in the tumour of muscle tissue, vessels, &c.
=Position of the tumour.= The tumour may project through the vault or
base of the skull. In the former case, it is almost invariably situated
in close relation to the middle line of the skull, from nasion to below
the inion.
[Illustration: FIG. 20. AN OCCIPITAL CEPHALOCELE. (For further
description, see text.)]
1. _Occipital cephaloceles_--the commonest variety--occupy,
anatomically, two positions (1) between the two lower segments of the
occipital bone (inferior occipital cephaloceles), often involving the
foramen magnum and sometimes complicated by a condition of cervical
spina bifida, and (2) between the two upper segments of the occipital
bone (superior occipital cephaloceles), occasionally involving the
posterior fontanelle.
The tumour may possess a broad base or may be definitely pedunculated.
In the former instance the gap in the bone may be of considerable size
and the margins everted: in the latter case, the hole may be quite
small.
The deformity is frequently associated with other congenital
defects--hydrocephalus, microcephalus, spina bifida, hare lip, hernia,
and talipes.
2. _Sincipital cephaloceles_ occur next in order of frequency. The
tumour projects between the nasal bones and the nasal process of the
superior maxilla (naso-frontal), between the nasal process of the
maxilla and the orbital plates of the ethmoid (naso-ethmoidal), or
between the nasal bones (nasal).
[Illustration: FIG. 21. A CEPHALOCELE OVER THE ANTERIOR FONTANELLE.
(For further description, see text.)]
3. More rarely, the tumour overlies the _anterior or posterior
fontanelle_. A case of this nature is depicted in Fig. 21, the tumour,
situated over the anterior fontanelle, bulging over the temporal and
frontal regions to a remarkable extent.
4. _Basal cephaloceles_ protrude through the cartilaginous base of the
skull, either through the cribriform plate of the ethmoid, between the
pre- and basi-sphenoid, or between the basi-sphenoid and basi-occiput,
often projecting as a polypoid growth in the nose or naso-pharynx.
An interesting case of basal hernia was reported by von Mayer.[8] The
child, 3 days old, was admitted with a tumour projecting into the
right nostril, covered with mucous membrane, translucent, encrusted
with scabs, pedunculated, and closely resembling a nasal polypus. The
possibilities were fully recognized and all necessary precautions
taken. The right half of the nose was turned back as a flap, the
tumour isolated, ligatured, and removed. Death occurred after six
weeks. An oval hole was found in the left half of the cribriform plate
through which the dura mater projected and to the margins of which the
membrane was firmly adherent. The pedicle contained ganglion-cells and
nerve-fibres, whilst the parts removed showed, from without inwards,
mucous membrane, dura mater, arachnoid, pia, and glial tissue.
=Size, structure, and contents.= Sincipital cephaloceles are usually
quite small, but the occipital variety and those situated in the region
of the anterior fontanelle frequently attain a great size (see Figs.
20-22).
[Illustration: FIG. 22. AN OCCIPITAL CEPHALOCELE. (For further
description, see text.)]
It is not always possible to determine whether the tumour consists
of a mere outward protrusion of membranes (meningocele), or
whether brain-matter enters into the formation of the tumour
(meningo-encephalocele). Fluctuation, translucency, and pulsation are
all points to be investigated. All these features are, however,
deceptive, and several cases are on record in which operative measures
were carried out under the impression that the surgeon had to deal with
a pure meningocele, and in which it was afterwards found that
brain-matter formed the basis of the swelling.
When the tumour is large, the skin adherent, when no pedicle is present,
when fluctuation and pulsation are absent, and when the tumour is of
firm consistency, then it is practically certain that brain-matter
shares largely in the formation of the tumour. On the other hand, it is
not unusual to find that the brain projects markedly outwards without
resulting in any symptoms of brain irritation: fluctuation and pulsation
are also not infallible signs, since the brain may occupy the base of
the tumour, ‘corking-up’ the gap in the bone, or the brain may be so
thinned by ventricular distension that a mere shell of cerebral matter
lies beneath the scalp-covering.
Looking at the question from all points of view, it may be accepted that
most cephaloceles contain either true brain-matter or the mixed
epiblastic and mesoblastic elements described by Lyssenkow.
The following case serves to illustrate some of these facts:[9]--
The child was 3 months old, and presented a tumour, the size of an
orange, situated between the occipital protuberance and the nape of
the neck. The mass was pedunculated, the stalk being about the size of
a four-shilling piece in diameter. It was soft, translucent,
irreducible, and swelled up on coughing. An attempt at removal was
carried out, and, after incising the outermost layers, three ounces of
cerebro-spinal fluid escaped. A second tumour was then found occupying
the base of the swelling. This was also punctured, more fluid
escaping. Both sacs were cut away and the wound sewn up. Death
occurred on the third day, preceded by convulsions, retraction of the
head and neck, and high fever. The autopsy showed that the fontanelles
were widely open, the anterior measuring 4 inches from side to side
and 2¹⁄₂ from before backwards. The bones of the vault were markedly
thinned. In the subdural space there was a quantity of fluid, and the
cerebral substance was soft and diffluent, the convolutions flattened,
and the ventricles distended. There was a broad gap in the occipital
bone, extending downwards into the foramen magnum, and in this
situation the cerebellum had bulged backwards into the protruding
mass. (See Fig. 22).
For _differential diagnosis_, _see_ p. 57.
_Treatment._ In considering the question of treatment, the late
Professor von Bergmann[10] divided the cases into two groups:--
1. _Inoperable cases._ When associated with premature synostosis and
microcephaly.
When associated with hydrocephalus or marked deformity.
When the tumour is situated below the occipital protuberance.
2. _Operable cases._ Limited protrusions with none of the above
defects and disadvantages.
This classification undoubtedly forms a practical basis on which to
estimate the feasibility of operative measures, and it would appear that
sincipital and small occipital cephaloceles are the only cases that come
within the realms of operative treatment. In estimating the possibility
of operation, however, due consideration must be paid to the fact that,
in the very great majority of cases, the tumour tends to increase in
size, the bones become further thinned, the margins of the gap more
everted, and the development of the brain suffers correspondingly.
Again, in spite of the fact that some few cases have survived to adult
age, yet it is the general rule for the patient to die within a few
weeks or months of birth. For desperate ills, corresponding measures
must be undertaken, and in the consideration of the more serious cases
the surgeon should be biased in favour of operation unless the general
condition of the child shows clearly that no success is possible. The
best results have been attained in cases of pure meningocele.
=Operation.= The unhealthy condition of the overlying integument,
especially at the apex of the tumour, prohibits any extensive
preparatory cleansing, this process being carried out for the most part
when the child is under the anæsthetic.
Scalp-flaps are framed from the region of the base of the tumour,
advantage being taken of the more healthy parts. These flaps must be so
sized and framed that accurate approximation and complete covering to
the gap will be attained at the termination of the operation. The flaps
are dissected back to their base. The pedicle of the tumour is defined
and an endeavour made to detach it completely from the margins of the
osseous defect. This is often a matter requiring considerable patience.
The sac of the tumour should then be tapped with trocar and cannula, and
the fluid contents allowed to escape slowly, after which the opening
into the sac is enlarged and the membranes slit up towards the base of
the protrusion.
When dealing with a pure meningocele, the membranous protrusion is cut
away in such a manner that sufficient tissue is left to allow of closure
of the dural gap. This closure can be carried out either by means of a
purse-string suture or by the union of two lateral flaps. In either
case, accurate approximation is essential in order to prevent as far as
possible the further escape of cerebro-spinal fluid.
If the sac should contain an irregular mass of neuroblastic and
mesoblastic tissue, apparently not true cerebral or cerebellar
substance, this material can be dissected from the membranous sac,
ligatured at its base, and freely cut away.
If the sac should contain true brain substance, the possibility of
excision can be raised. In the cerebellar region such measures are
contra-indicated, and the surgeon must remain content with an attempt
at replacing the cerebellar substance within the cranial cavity. This
attempt at reposition will be aided by elevation of the head and,
occasionally, by lumbar puncture. If the protrusion corresponds to a
region which has no known important function, it may be ligatured and
cut away flush with the surface of the gap. Hæmorrhage may be
considerable, but can be controlled by ligature, pressure, and
irrigation with hot water at a temperature between 110 and 115 degrees
Fahrenheit. The degree of shock attendant on the operation may be
severe, necessitating the most complete attention to preliminary,
operative, and post-operative details (see Chap. I).
To _remedy the defect of the bone_ Lyssenkow recommends an osteoplastic
operation, a flap composed of pericranium, together with the external
table of the skull, being framed from the bone above the defect.
The flap is then turned down in such a way that the pericranial surface
faces towards the dura, and the fragment is suspended by the continuity
of the pericranium. He reports 72 cases so treated, with 37 recoveries
and 35 deaths.
König and von Bergmann oppose this osteoplastic operation on the ground
that the extreme thinness of the bone seldom permits of the necessary
splitting off of the external table of the skull, and that, even when
such a course is feasible, the fragment undergoes necrosis.
Transplantation of decalcified and calcined bone, silver and celluloid
plates, have all been tried, with no great amount of success.
Ssamoylenko proposes paraffin and vaseline injections, especially for
the sincipital variety of cephalocele.
When the surrounding bone is of such a nature that it is possible to
form an osteoplastic flap, that course should be adopted. Under other
circumstances, it would appear preferable to postpone any attempt to
close in or protect the gap in the bone in the hope that nature will
remedy the defect in part, the surgeon stepping in at a later date with
one of the measures advocated for the protection of gaps in the skull
(see p. 196).
TRAUMATIC CEPHALOCELES
Many cases have been recorded in which a cephalocele developed after an
injury to the skull. In such conditions it is necessary that a
comminuted or fissured fracture of the vault should be present, that the
underlying dura mater should be torn, and that the adjacent brain
substance should be severely contused or lacerated. Cerebro-spinal fluid
may alone escape through the gap in the skull to the subaponeurotic and
subcutaneous regions, leading to the formation of a _false traumatic
meningocele_. When the brain shares in the outward protrusion the
condition is known as _false traumatic meningo-encephalocele_. This
protrusion of the brain is dependent on the fact that the
injury--necessarily a severe one--leads to considerable brain lesion,
with subsequent œdema and localized or general increase in the
intracranial pressure.
Occasionally, the external accumulation of cerebro-spinal fluid
communicates with one of the horns of the lateral ventricle. A
meningo-encephalocele, having such connexions, is produced in the
following manner:--the protruded brain includes that part of the
cerebral substance which bounds one of the horns of the lateral
ventricle, usually the descending cornu. The ventricular channel becomes
elongated in the outward direction, towards and through the gap in the
skull, whilst the increased intraventricular tension gradually dilates
up the new channel, and, in course of time, still further spreads out
and thins that part of its cerebral boundary which lies external to the
skull deficiency.
There can be no question that after the patient has reached the age of
three years traumatic cephaloceles are of exceedingly rare occurrence.
This special liability in quite young children has been ascribed to the
greater elasticity of the infant skull, and to the supposed greater
adherence of the dura mater. Though these factors may exercise some
influence on the production of the tumour, it seems more probable that
the development of a cephalocele is dependent to a greater degree on the
general vitality of the child. Thus, a blow that produces in the adult a
comminuted or widely fissured fracture of the skull, with laceration of
the dura mater and injury to the underlying brain, frequently leads to a
fatal result, whilst the child often recovers. Again, in the adult, the
force required to produce such a lesion usually suffices to lacerate the
integument. Consequently a compound comminuted fracture of the vault
with hernia cerebri is relatively more common in the adult than in the
infant.
The right side of the head is more frequently affected than the left,
and, of all bones in the skull, the parietal is the one most constantly
involved.
=Symptoms.= During the first few days subsequent to the injury
the child merely suffers from the symptoms common to all severe
head-injuries--concussion and brain irritation. The osseous lesion is
obscured by the presence of a well-marked cephalhæmatoma. After the
lapse of a short time--usually one to two weeks--the partial resolution
of the hæmatoma allows one to observe, for the first time, that a
definite tumour remains. This tumour is irreducible, pulsates freely,
and may be translucent. If the protruding brain substance includes the
precentral region--the motor area--definite weakness or paralysis of the
opposite face and extremities may be observed. Usually, however, no such
symptoms are forthcoming, and the child appears but little the worse for
the accident. Shortly afterwards the tumour becomes more defined in
outline, and careful palpation will reveal the defined margins of an
osseous deficiency. Compression of the protruded mass will often throw
the child into general convulsions, or induce a state of compression
with dilated pupils, slow pulse, and stertorous respiration.
Compression, however, seldom results in any marked diminution in the
size of the tumour. The conditions may remain stationary, but, as a
general rule, the hernial protrusion slowly increases in size and the
child dies in general convulsions, preceded by symptoms of brain
irritation or compression.
=Treatment.= Three courses are available in the treatment of this
condition:--
1. Expectant treatment, combined with the application of pressure.
2. Aspiration and puncture.
3. Free exposure and further treatment according to the conditions
found.
In the majority of cases the local conditions preclude any attempt at
radical cure--the gap in the skull is large, the margins of the
deficiency are thinned and everted, and the brain enters largely into
the formation of the projecting mass. Furthermore, the dura mater is
torn and in a tag-like condition. Only in the most favourable
cases--when the tumour is small and the gap narrow--can radical
treatment be advocated.
The application of pressure--without previous aspiration--exercises but
little effect on the size of the tumour and, under such treatment, the
danger of brain-compression is always present.
Aspiration with the object of removing the fluid constituents of the
tumour, and thus of reducing its size, has occasionally been followed by
disastrous results. Still, many cases were so treated in the pre-aseptic
days, and the modern methods of cleanliness should allow of better
results. One or more aspirations may be carried out, this treatment to
be followed by the application of steady and uniform pressure,
preferably with the aid of elastic bandages, the degree of compression
depending on the size and constituents of the tumour. The patient must
be watched most carefully, in order to guard against the development of
symptoms pointing to cerebral compression. Irritating injections should
never be used.
One must acknowledge that this mode of treatment has--except in a few
isolated cases--not produced very satisfactory results. Still, since an
open operation is usually out of the question, no other course remains.
The after-history of these cases is not very encouraging. In one of
Weinlecher’s cases the child was living 5 years later, but pulsation was
still present. In Lucas’s case the patient died 21 months later from
meningitis. In Sir T. Smith’s case, pulsation was present 3 years after
the accident, and in Silcock’s there was no marked change for the better
after 11 years. On the other hand, a case reported by Golding Bird
steadily improved, and a second case reported by the same writer gave
every promise of a permanent cure. The two following cases have come
under my own observation:--
1. A female child, 11 months old, was knocked down by a van, and, on
admission, a large hæmatoma was seen situated over the right
temporo-parietal region. The child was semi-comatose, but recovered
consciousness next day. The hæmatoma softening, a gap in the bone was
felt, one-third of an inch wide, and extending from the occipital
bone upwards and inwards to the middle line. The swelling increased in
size when the child cried. Pulsation was present and translucency was
obtained. The tumour increased in size for some days, but no untoward
symptoms developed. For over one month pressure was applied, but
without much benefit, though the general condition of the child was
good. The edges of the gap became thickened. The child was then
removed from the hospital.
2. A male child fell 19 feet on to his head. He was concussed, and, on
admission, presented a hæmatoma over the right fronto-parietal region,
and subconjunctival hæmorrhage in the left orbit. Four days later he
was apathetic and there was some paresis of the left arm and leg. As
the hæmatoma became softer, pulsation was noticed over a small area,
and, in this situation, the swelling increased in size on straining. A
fracture was detected later, one-third of an inch in diameter, and
extending across the left frontal bone to the right temporal region.
Pressure was applied, the tumour steadily decreased in size, and
eventually the gap was completely closed.
=Synopsis of 38 cases of traumatic cephalocele.=
_Sex._ Males, 16. Females, 13. Sex not stated, 9.
_Age at time of accident._
2 cases at birth.
9 in the first 6 months.
9 in the second 6 months.
14 between 1 and 2 years of age.
1 between 3 and 10.
1 between 10 and 15.
1 between 15 and 20.
1 between 20 and 30.
_Region affected._
Right parietal, 17 cases.
Left parietal, 4 cases.
Other bones, right and left, 8 cases.
Parietal with others, 9 cases.
Parietal bone involved in 30 out of 38 cases.
Right side involved in 27 out of 38 cases.
_Date of appearance of tumour._
7 cases in the first week.
11 cases in the second week.
4 cases in the third week.
4 cases between 2 and 18 months.
In the remainder, date uncertain.
=Fractures of the skull resulting from injuries received at or shortly
after birth.= In the consideration of injuries to the skull and brain in
babies the following points should be noted:--
1. The bones of the skull are elastic and pliable, and consequently a
blow may lead to a ‘bending-in’, either temporary or permanent. Slight
depressions may exist without any associated fracture, but all major
depressions are accompanied by a fracture of the bone, especially
evident on examination of the internal table.
2. The fibrous tissue intervening between the component parts of the
vault tends to cause a limitation of the fracture to the particular bone
affected. Downward extension to the base is of infrequent occurrence,
but, when that region is involved, the fracture usually follows the
transbasic lines described in the section dealing with fracture of the
base of the skull (p. 82).
3. The dura is said to be more adherent to the inner table of the skull
than in adults. The relative infrequency in the young of extra-dural
hæmorrhage has been ascribed to this peculiarity. It would appear,
however, more probable that the rarity of such hæmorrhages results from
the bending-in, _without splintering_, of the bone.
4. The brain of the infant is equally--if not more--liable to bruising
and laceration, but the results are far less definite than in adults.
There can be no question that extensive cerebral injury may exist in the
child without leading to the development of any definite localizing
symptoms.
FRACTURES OF THE VAULT
(_a_) =Depressed fractures.= Depressed fractures either result from
injury received during the birth of the child--whether from forceps
delivery or from the pressure exerted on the head by a contracted
pelvis--or from blows received shortly after birth.
[Illustration: FIG. 23. A DEPRESSED BIRTH-FRACTURE.]
The depression, varying greatly in depth and extent, may be situated
over any part of the skull, but commonly involves the fronto-parietal
region. It is often obscured in the early stages by the presence of an
overlying hæmatoma, the condition perhaps only being discovered after
the absorption of the blood-clot. In many cases no symptoms result,
partly owing to the shallowness of the depression and partly due to the
situation of the lesion over one of the so-called ‘silent’ areas of the
brain. Under other circumstances the child may evidence the general
increase in the intracranial pressure by cyanosis, difficulty in
respiration, unconsciousness, and slow pulse. The anterior fontanelle
will be tense, and pulsation will be absent or greatly diminished--a
feature of the greatest diagnostic value. Localizing symptoms ensue when
an extensive depression is situated over the motor area, the extremities
of the opposite side being flaccid, or evidencing irritation by
twitchings and convulsions. The ready response of the infant to cortical
irritation frequently results in the early transformation of local
twitchings into general convulsions.
=Course and treatment.= It is often stated that these depressed
fractures remedy themselves in the course of time, the development of
the underlying cortex curing the depression by the outward leverage
exerted. In the minor degrees of depression there may be some chance of
such spontaneous cure. I am, however, entirely opposed to the view that
spontaneous cure is the rule, and there can be no question that the more
severe types of depression remain as permanent defects unless surgical
remedies are adopted. Furthermore, even if the deformity should cure
itself in time, the intermediate dangers are not to be disregarded,
for, during the process of spontaneous cure, there is a decided
liability for the depressed cortex to lag behind in the process of
development, or to undergo degenerative changes as the result of the
pressure exerted--with disastrous results on the parts supplied by the
region compressed. Mental deficiency, paralyses, and contractures will
result, and there is every reason to believe that some cases of
infantile paralysis are dependent on this lesion.
The following case, recently under my care, adds further proof to the
statement that spontaneous cure is usually out of the question:--
The child, 10 weeks old, was admitted with a depressed fracture over
the parieto-frontal region, oval in shape, and about 3¹⁄₂ inches in
its long antero-posterior diameter. The centre of the depression lay
about 1¹⁄₂ inches below a normal surface. The injury was produced at
birth (contracted pelvis), and frequent convulsions were observed
during the first few days of life. The fits then ceased, but the
depression became, if anything, more marked day by day. The child was
then brought up to see me. The depression was exposed by a suitable
scalp-flap and a small trephine hole made immediately posterior to the
depression. The dura mater was stripped away from the under surface of
the bone and every effort made to remedy the depression. No impression
was thus made on the defect. The whole depressed area was then cut out
with a pair of scissors, the segment removed, wrapped up in a piece of
gauze, and forcibly manipulated in the hope that the depression could
be overcome and the segment placed back in the normal position. This
attempt was also greeted with failure. The segment was then placed
back in the inverted position, the dural surface external and vice
versa. The segment required some trimming with the scissors before it
fitted accurately in position. The scalp-flap was then replaced. The
child suffered but very slightly from the operation, firm union was
present in two weeks, and, six months later, examination of the skull
showed that the two sides were absolutely symmetrical.
It should be noted that, although the child was only 10 weeks old, and
in spite of the fact that the depression was fully exposed, it was
quite impossible to lever up the depressed bone. This hardly coincides
with the views of those who maintain that birth-depressions undergo
spontaneous cure.
Taking all these facts into consideration, it would appear advisable to
adopt the following course:--slight depressions, situated in the region
of ‘silent’ areas of the brain, may be left for one or two weeks, and,
in the event of failure at spontaneous cure, the depression must be
elevated. In all the more serious cases, whether associated with
symptoms of brain-pressure or not, surgical interference is imperative.
[Illustration: A
B
FIG. 24. A CASE OF DEPRESSED BIRTH-FRACTURE. A, Before operation; B,
After operation. (For further description, see text.)]
=Operation.= The baby would be well wrapped up and, after shaving and
cleansing of the scalp, the scalp-tourniquet applied. Babies stand these
operations exceedingly well so long as hæmorrhage is but slight. A
scalp-flap is turned down and a small trephine (¹⁄₂-inch diameter)
applied immediately to one side of the depression, the trephine circle
including the outer margin of the depressed area. The dura is stripped
away and a flat periosteal elevator introduced so that its apex
corresponds to the apex of the depression. An attempt is then made to
lever the depressed area in the outward direction. If that result be
attained, well and good. The flap is replaced and dressings applied. In
many cases, however, the elevated region promptly assumes its original
depressed position as soon as the elevator is removed, and, in other
cases, all attempts at rectification of the deformity are of no avail.
Under these circumstances, it is advisable to carry out the method
advocated by Nicholl--adopted in the case described above--the whole of
the depressed area being cut out with blunt-pointed scissors, reduced to
a more normal curvature by manipulation between layers of gauze, and
replaced in the inverted position, the original dural surface becoming
now external. This inversion is requisite, as it is usually quite
impossible--even under considerable pressure--to reduce the depression
to a permanently satisfactory degree.
Nicholl reports on 23 cases, the ages of the patients varying from 3
weeks to 8 years. The first 13 cases were treated by elevation. The
results obtained were most unsatisfactory, complete reduction of the
deformity seldom being attained, whilst recurrence, of a greater or
lesser degree, was the rule.
In the last 10 cases the inversion method was carried out, with, in all
cases, satisfactory results. Bony union was present in 10 days.
Four cases of depressed birth-fractures have come under my own care. In
two cases the depression was elevated--in both cases with considerable
difficulty--whilst in the other two cases, after failure of leverage,
Nicholl’s method was carried out, in both cases with eminently
satisfactory results.
(_b_) =Fissured fractures.= Fissured fractures are especially prone to
involve the parietal bone, and, in their direction, to follow the lines
of ossification. Thus, in the case of the parietal bone, the fissures
will radiate from the parietal prominence. There is also a certain
tendency for the fracture to remain limited to the particular bone
affected.
The presence and extent of the fracture is commonly obscured by the
overlying hæmatoma, which is either subpericranial or subaponeurotic. On
the other hand, the hæmatoma may, from its size and shape, supply
evidence as to the nature of the underlying lesion. Thus, when confined
to the parietal bone, it may be inferred that the fracture is also
limited to that region. Again, when linear, the presumption is that the
fracture is of a similar nature. A definite diagnosis may be impossible
without aspiration or till after absorption of the hæmatoma. The fissure
will then be found to vary in extent from a mere crack in the bone to a
wide gap as broad or broader than the width of the finger. In a case
recently under my care the fissure, over half an inch in breadth,
extended from the vertex to the base, whilst throughout the whole extent
of the gap pulsation was readily obtained.
Fissured fractures in the very young possess another point of interest
in that the cleft often tends to increase, this being notably the case
when the fracture is associated with injury to underlying dura and
brain. The local and general increase of intracranial pressure not only
widens the gap, but also leads to thinning and eversion of the margins
of the deficiency with possible herniation of brain-matter--traumatic
cephalocele.
=Symptoms.= In many cases--in spite of the severity of the lesion--there
are no symptoms, the child appearing but little the worse for the
accident. In most cases, however, the child evidences symptoms of
brain-concussion, irritation, or compression, for which conditions
reference should be made to the sections dealing with those subjects.
It should be noted, however, that the anterior fontanelle supplies
evidence as to increase or decrease of intracranial pressure. In
concussion the fontanelle is depressed, in compression it is tense and
pulsation is absent or diminished. Irritation of the brain is evidenced
by irritability and general convulsions.
=Treatment.= In the absence of symptoms, or when the fracture is
associated with concussion or irritation, operative measures are
contra-indicated, the patient being treated after the general principles
laid down for those conditions.
When associated with symptoms of brain-compression, exploration is
almost always advisable, the scalp-tourniquet being applied and the
injured region exposed by a suitable scalp-flap. Depressed bone is
elevated, or the trephine applied so as to fully expose the underlying
dura mater. A bulging, non-pulsatile, and plum-coloured membrane points
to the existence of a subdural hæmatoma. The membrane is then incised
and the clot evacuated. Whenever possible the dura mater should be sewn
up and the scalp-flap replaced without drainage.
Operative measures are also indicated when a linear fracture gapes
widely--especially when the gap shows a tendency to increase in width.
The steps of such an operation are as follows:--
1. Expose the fracture throughout its whole length.
2. Cut away all pericranium or fibrous tissue that intervenes between
the margins of the cleft.
3. Separate the dura mater from the bone on either side of the cleft for
a distance of about ¹⁄₂ inch, at the same time sewing up any rents in
the membrane.
4. Bore a few holes through the skull--using an ordinary bradawl--on
either side of the cleft, the holes being placed about ¹⁄₂ inch apart.
5. Approximate and lace the margins of the cleft by means of fine silver
wire or strong catgut.
6. Sew up the flap without drainage.
BIRTH-HÆMORRHAGES
=Extracranial hæmorrhages.= As the result of injury sustained during
protracted labour, hæmatomata may develop beneath the aponeurosis of the
occipito-frontalis or underneath the pericranium, the latter being the
more common situation. The right side of the head is the more frequently
involved, and the parietal region is the part usually affected.
Occasionally these hæmatomata are bilateral and symmetrical.
The two varieties of cephalhæmatoma--subaponeurotic and
subpericranial--possess certain peculiarities that aid materially in
their differential diagnosis.
_Subaponeurotic hæmatomata._ The blood, though spreading widely
throughout the subaponeurotic space, tends to gravitate towards the
lower confines of that space, and, from the position assumed by the
patient, is most evident in the occipital region. The presence of the
blood is evidenced by œdema, doughiness, and ecchymosis.
_Subpericranial hæmatomata._ The blood is confined to the region of the
particular bone affected, usually the right parietal bone. This is due
to the fact that the pericranium blends at the margins of the bone with
the tissue intervening between that bone and the neighbouring parts of
the skull.
Subpericranial hæmatomata present further peculiarities. The tumour is
usually more or less circular in outline, and fluctuates freely. It may
arise immediately after the birth of the child, but, more commonly, some
two or three days elapse before attention is drawn to its existence.
Within a few days clotting occurs at the periphery of the hæmatoma with
the formation of a circumferential ridge. The central portion of the
clot remains soft but tense, so much so that firm pressure is required
before the examining finger is enabled to feel the underlying bone.
These cephalhæmatomata are not infrequently mistaken for depressed
fractures, but no difficulty should be experienced if the existence of
the circumferential ridge be appreciated and if the underlying bone can
be felt at the centre of the tumour. In cases of doubt the blood should
be drawn off by aspiration and the swelling again examined.
For _differential diagnosis_, see p. 57.
=Treatment.= The less extensive hæmatomata require no active surgical
treatment, the absorption of the clot being aided by protection of the
part and by cooling lotions.
Similar expectant treatment is generally advised with regard to the
extensive subpericranial hæmatomata, but as infection of the clot may
take place, and as its resolution invariably requires a considerable
period of time--often many weeks--more active measures can be adopted.
The region of the hæmatoma is carefully shaved and cleansed, and, under
local anæsthesia, a small incision made through the scalp, the clot
squeezed out, and firm pressure applied. Under this form of treatment
the patient is well within a few days.
=Intracranial birth-hæmorrhages.= Attention was first drawn to the
question of intracranial birth-hæmorrhages by Little, who showed that a
history of difficult labour could be obtained in a large percentage of
cases in which children in after-life suffered from uni- or bilateral
spastic paraplegia; hence the name, ‘Little’s disease’ or birth palsy.
Further information was supplied by Sarah MacNutt, and the whole
question was fully investigated by Harvey Cushing.
In all cases a history of difficult and protracted labour can be
obtained, with considerable post-partum respiratory difficulties, the
child being described as ‘blue in the face’ for some hours after birth.
The stress and strain which the advancing head undergoes, and the
consequent moulding and overlapping of the various segments of the
skull, exposes the brain to great alterations of pressure, and throws
considerable tension on the intracranial veins. It is, in fact, rather
surprising that birth-hæmorrhages are not more common.
The hæmorrhages may be wholly within the meshes of the pia-arachnoid
system, but, in the great majority of cases, the lesion is more serious,
and the extravasation comes to lie within the subdural space.
Occasionally the bleeding takes place beneath the tentorium cerebelli,
the blood-clot lying in relation to the pons and medulla. Such
hæmorrhages are said to be observed only in vertex presentations. The
more common supratentorial hæmorrhages--usually resulting from difficult
breech presentations--either remain more or less localized to a certain
region of the cortex, or become widely diffused over the surface and
base of the brain.
It is probable that Cushing is correct in his observations with respect
to the source of these supratentorial hæmorrhages. He states that the
blood is derived from one or more radicles of the superior longitudinal
sinus, especially from those veins which, in their upward passage in the
sulci of the brain, leave their cerebral beds for a short and
comparatively unprotected course, immediately previous to their entry
into the lacunæ laterales of the superior longitudinal sinus.
In addition, he points to the very important fact that the localized
hæmorrhages are commonly situated in relation to the mid-cerebral
cortex, close to the sinus, and on one or both sides of the falx
cerebri. In addition, therefore, to the symptoms of general cerebral
compression, certain definite localizing symptoms are to be observed,
these being in direct proportion to the size of the clot.
In an analysis of 74 autopsies on infants still-born or dying within the
first few days, Archibald[11] found ‘intrameningeal’ hæmorrhage in 32,
in 19 of which it was of considerable extent: and in 5 others there was
extra-dural hæmorrhage. In only two or three was effused blood found
within the cerebral cortex. The importance of these facts from a
surgical point of view cannot be over-estimated.
[Illustration: FIG. 25. DIAGRAM TO ILLUSTRATE THE EFFECTS AND POSITION
OF A BIRTH-HÆMORRHAGE. _sc._, Scalp; _b._, Bone; _d.m._, Dura mater;
_br._, Brain; _s.l.s._, Superior longitudinal sinus; _c.v._¹, The
protected part of a superficial cerebral vein; _c.v._², The unprotected
part of a superficial cerebral vein; _c._, The subdural clot, exercising
pressure on (1) the cortical leg arm, (2) the arm area, and (3) the face
area.]
=Symptoms.= Besides the history of protracted labour and the ‘blue’
asphyxiated appearance of the baby, other evidence is to hand with
respect to both general and local increase of brain-pressure.
The _general_ increase is evidenced first and foremost by the bulging
and non-pulsatile anterior fontanelle. The fontanelle may be regarded as
an index of intracranial pressure. The margins of the fontanelle are
outlined with some difficulty, and, owing to the free communication
between the intra- and extra-cranial venous systems, the scalp-veins are
unduly prominent. The general condition of the child varies according to
rise of intracranial pressure. In the more serious cases it may be
impossible to arouse the patient: in the slighter hæmorrhages the child
may appear but little the worse, with the exception, perhaps, of being
rather more irritable than usual.
The effect of the pressure on the medullary centres is shown by
respiratory difficulties--irregularities of rhythm, &c.--some
retardation in pulse-rate, and increase in blood-pressure. The reflexes
are increased and the child is readily thrown into general convulsions.
The effect of the _localized_ pressure on the upper Rolandic centres
seldom becomes evident till after the lapse of a few days--and often
after a longer period--when muscular weakness, twitchings, rigidity, or
paralysis--more especially of the contralateral lower extremity--becomes
apparent. The mother often draws attention to the fact that the child
does not move one of its legs properly.
When the extravasation is extensive, spreading downwards over other
motor areas, the upper extremities and even the face may be involved.
When a small hæmorrhage is present, situated on either side of the falx
cerebri, both lower extremities suffer and diplegia results.
In some cases, chemosis of the conjunction, œdema of the lids, and
proptosis have been observed. In any case an ophthalmoscopic examination
should be carried out. Frequently some fullness of the retinal veins and
diminution in the calibre of the arteries supply confirmatory evidence.
In the event of doubt in diagnosis, lumbar puncture should be carried
out. It should be noted, however, that although the positive evidence of
free blood corpuscles points to subdural hæmorrhage, yet that absence of
blood in the fluid withdrawn does not exclude the possibility of a
localized and more or less encapsulated hæmorrhage. In the event of
failure at recognition of the serious lesion present, disastrous results
will ensue--monoplegia, diplegia, hemiplegia, epilepsy, and idiocy.
=Treatment.= The age of the patient must not be allowed to weigh in the
balance against operative treatment, for, if due precautions be taken,
the new-born child stands operation well. Cushing points out that ‘the
possibilities of surgical relief are limited to the first week or two
after the hæmorrhage has occurred, for old cortical scars can neither be
helped by medicine nor by the scalpel’.
The clot can be exposed by craniectomy or by craniotomy. The latter
operation results in a more complete exposure, but the shock is
undoubtedly more severe. Exposure by craniotomy is advocated by Cushing,
and carried out in the following manner: ‘An omega-shaped incision just
within the outer margin of the parietal bone is carried down to the bone
through the scalp and pericranium, and the latter is scraped away so as
to expose the thin serrated edge of the parietal bone. Under this a
blunt dissector is passed, so that the edge of the bone is tilted up,
and then, with a proper cutting instrument (strong blunt-pointed
scissors suffice), the bone is incised in a line conforming with the
skin incision 1 centimetre or more within the parietal margin. The
parietal bone is then broken across at its base. The dura is opened by a
curved incision some distance within the bony margin, and the
superficial clot broken away or lifted off in fragments, or irrigated
away with a gentle stream of warm saline solution. The dura should be
accurately sutured, the bone replaced, and the skin closed with suture.’
He reports on 9 cases so treated, with 4 recoveries, apparently complete
and permanent. The fatal cases were all associated with extensive
extravasation over the entire hemisphere. In 3 cases bilateral exposure
was necessitated.
Taking, however, the question into more general consideration, it would
appear that equally satisfactory results can be obtained, with a lesser
degree of operative danger, by carrying out craniectomy in the manner
described in the treatment of ‘traumatic subdural hæmorrhage’ (see p.
156).
DERMOIDS
Dermoids, in this region of the body, are almost invariably situated in
the middle line between nasion and inion, though cases have been
described in which congenital tumours, dermoid-like in nature, were
situated over the mastoid process and in other regions.
They occur with the greatest frequency over the anterior fontanelle and
in the region of the external occipital protuberance. In the latter
situation they are specially prone to possess those deep attachments to
the dura mater which are further alluded to below. In the great majority
of cases careful examination will show that the tumour occupies a
depression in the bone, saucer-like in nature, in which the tumour
rests. They are seldom freely movable, and are often markedly fixed,
being either attached to the pericranium or to deeper structures. They
are not attached to the overlying skin. The tumour is irreducible, and
pulsation is absent except in those rare cases where, in the presence of
a wide gap in the skull, transmitted pulsation may be obtained.
On careful dissection it may be found that the tumour communicates, by
means of a small hole in the skull, with the underlying membranes. In
more exceptional cases a wide gap in the skull may be found by means of
which the dermoid obtains extensive connexion with the dura mater and
even with the brain. In rare cases the dermoid may be pedunculated.
Bland Sutton drew attention to this frequent connexion between the
dermoid and the membranes of the brain, showing further that the entire
tumour may lie on the inner side of the occipital bone.
The following account affords further information as to the nature and
origin of cephalic dermoids.
‘Morphologically considered, the bony framework of the skull is an
additional element to the primitive cranium which is represented by
the dura mater, and the term extra-cranial should be applied to all
tissues outside the dura mater. Early in embryological life the dura
mater and skin are in contact; gradually the base and portions of the
side wall of the membranous cranium chondrify, thus separating the
skin from the dura mater. In the vault of the skull, bone developes
between the dura mater and its cutaneous cap, but the skin and dura
mater remain in contact along the various sutures even for a year or
more after birth. This relation persists longest in the region of the
anterior fontanelle and the neighbourhood of the inion. Should the
skin be imperfectly separated, or a portion remain persistently
adherent to the dura mater, it would act precisely as a tumour germ
and give rise to a dermoid. Such a tumour may retain its original
attachment to the dura mater, and its pedicle become surrounded by
bone; the dermoid would lie outside the bone but be lodged in a
depression on the surface, with an aperture transmitting its pedicle.
On the other hand, the tumour may become separated from the skin by
bone; it would then project on the inner surface or between the layers
of the dura mater. If this view of the origin of dermoids be accepted,
we must modify our teaching and say that the depressions in which
dermoids of the cranium are lodged arise as imperfections in the
developmental process, and are not due to absorption induced by
pressure; further, the fibrous connexion of such dermoids with the
dura mater is primary, not accidental.’[12]
=Treatment.= When of inconsiderable size, and when intracranial
connexions are absent, of doubtful existence, or of slight extent, the
sooner the tumour is removed the better. The dura mater should not be
opened unless absolutely necessary, in which case it should be carefully
sewn up and the scalp-flap replaced without drainage.
When possessing deep and extensive connexions, careful dissection may
still allow of the complete removal of the dermoid. It is impossible to
foretell with certainty whether it is possible to remove the tumour
until its basal portion is exposed. The operation may be a formidable
one.
SOME POINTS IN THE DIFFERENTIAL DIAGNOSIS BETWEEN CEPHALOCELES,
DERMOIDS, AND CEPHALHÆMATOMATA
----------------------+------------------------+----------------------
_Cephaloceles | _Dermoids._ | _Cephalhæmatomata._
(congenital)._ | |
----------------------+------------------------+----------------------
Present at birth. |Present at birth. |Usually appears
| |after birth.
| |
In middle line, |In middle line, |Always to one side of
especially over |especially over anterior|the middle line, and
occiput and base of |fontanelle. |usually over the
nose. | |parietal bone.
| |
Firm or fluctuating. |Firm. |Fluctuation over
| |central part only.
| |
Perhaps translucent. |Not translucent. |Not translucent.
| |
Perhaps pulsates. |Does not pulsate. |Does not pulsate.
| |
Perhaps reducible, in |Irreducible. |Very slightly, if at
whole or in part. | |all.
| |
Perhaps swells up |No alteration. |Very slightly, if at
on straining. | |all.
| |
Perhaps associated |No cerebral symptoms. |No cerebral symptoms.
with cerebral | |
symptoms. | |
| |
Gap in skull felt. |Depression in bone |Deceptive raised
|common, actual gap |margin, no actual
|comparatively rare. |central depression.
----------------------+------------------------+----------------------
HYDROCEPHALUS
The conditions that lead up to internal hydrocephalus are classified by
Parkes Weber[13] in the following manner:--
1. ‘Cases secondary to and part of the phenomena of tuberculous or any
suppurative meningitis, comparable to pleural effusions due to
tuberculous or any septic invasions of the pleura.
2. Cases resulting from the presence of tumours, &c., analogous to the
pleuritic effusions accompanying tumours, &c., situated close to or
involving the pleura.
3. Ordinary infantile or congenital hydrocephalus, which is, in some
cases at least, due to intra-uterine meningitis.
4. Internal hydrocephalus supervening on the epidemic or sporadic type
of posterior basic non-suppurative meningitis.
6. Simple idiopathic internal hydrocephalus of adults or older children
due to serous ependymitis or ventricular meningitis.
7. Traumatic cases.’
This classification possibly includes all the various grades and degrees
of internal hydrocephalus, but for all practical purposes the cases may
be grouped into two classes, congenital and acquired, both of which may
be either acute or chronic.
=Congenital internal hydrocephalus.= The condition may be recognized
soon after the birth of the child, or the enlargement of the head may
only become apparent some weeks or months later. The slow development
and the insidious nature of the enlargement, as observed in many cases,
may lead to some confusion between the late congenital and the early
acquired varieties. However, the absence of any symptoms pointing to
meningeal inflammation between the time of the birth of the child and
the hydrocephalic development usually allows of correct classification.
It is doubtful whether congenital internal hydrocephalus can be ascribed
to malformation of the inter-ventricular channels and occlusion of the
passages by means of which the cerebro-spinal fluid escapes into the
cerebral subarachnoid space, or whether the development is dependent on
hypersecretion from the ependyma and choroid plexuses. Virchow showed
that occasionally there was an actual formation of small grey-red
masses, about the size of a hemp-seed or cherry, in the walls of the
ventricles, but other authorities deny the existence of such changes,
and consider that the hydrocephalic condition is entirely dependent on
congenital malformation.
It would, however, seem more probable that we have to deal with two
distinct varieties of congenital internal hydrocephalus, one resulting
from intra-uterine ependymal inflammation (? syphilitic), the other
dependent on congenital malformations, especially in the region of the
fourth ventricle, where the foramina of Majendie, Key, and Retzius are
regarded as permitting the outward escape of the fluid secreted from the
lining membrane and choroid plexuses of the ventricles.
=Acquired hydrocephalus.= Acquired hydrocephalus, whether acute or
chronic, presents certain antecedents or associations which enable us to
have a more clear idea as to the pathological conditions present.
In the majority of cases it is secondary to basic meningitis which,
whether tuberculous or not, results in matting of membranes and in the
development of adhesions. The normal flow of cerebro-spinal fluid from
the ventricular to the cerebral subarachnoid spaces is thus impeded.
Similar interference to the flow of cerebro-spinal fluid may be caused
by the growth of a tumour, especially those which originate in the
subtentorial region.
=Progress of the case.= Whether the progress of the case be acute or
chronic, the ultimate results are much the same. The fluid in the
ventricular spaces may be increased up to 1,000 c.c. or more, pressure
effects being exerted on the surrounding parts, with the following
results:--
_A._ The soft cerebral substance is slowly but surely compressed, with
the result that the sulci on the surface of the brain are more or less
obliterated, distinction between the white and grey matter may be lost,
the ventricular spaces are enormously dilated, and, in the most marked
cases, a mere shell of brain may intervene between the ventricles and
the surface of the brain.
This cerebral compression results in the development of two main groups
of symptoms, those referable to the general increase in the
intraventricular pressure and those due to regional compression.