developed in a vein already varicose. The coats of the vessel become
thickened and hardened by interlamellar development of nucleated
fibrous tissue, so that the walls become more or less rigid. This
thickening may be partly at the expense of the lumen of the vein, thus
reducing its calibre, or it may be entirely excentric. The vasa vasorum
are sometimes developed in chronically-inflamed veins to a remarkable
extent. Quincke states that they may attain the size of cuticular
veins.[12]
[Footnote 12: _Ziemssen's Cyclopædia_, art. "Dis. of the Veins."]
Except in the case of superficial veins, in which the vessel may be
felt as a hard cord, the affection cannot be recognized during life. It
may be assumed to exist when the symptoms of acute phlebitis continue
in a less degree, or when tenderness, without other active symptoms, is
found along the course of a vein. Under these circumstances there are
apt to be acute attacks of pain and swelling from the operation of
slight causes, the attacks subsiding, but the chronic condition
remaining through the intervals.
The treatment looks to the avoidance or removal of the causes which
tend to produce acute exacerbations. Rest is of the first importance.
In chronic inflammation of a superficial vein the local use of iodine
or of the ointment of iodide of lead will be of service. A succession
of flying blisters along the course of the vein may be employed with
advantage. When there is chronic enlargement of the limb the persistent
administration of potassium iodide may be useful in promoting the
absorption of effused material. After the subsidence of all
inflammatory action massage may be resorted to.
{849} Dilatation of the Veins.
This condition results either from undue pressure of the blood within
the veins or from impaired resistance of their walls. The former
condition is found in certain forms of heart disease affecting the
right chambers; on the distal side of an obstruction in a vein; when
collateral veins are required to carry on the circulation, the natural
channel being narrowed or obliterated; and in the veins of a limb when
the position is such, a great portion of the time, that the blood is
forced to mount against gravity.
The second condition, that of diminished resistance of the walls, is
found in enfeebled constitutions and in the degeneracy of tissue
incident to advancing age. A familiar example is furnished by the
enlargement of the veins on the back of the hand in old persons.
Excessive dilatation of the veins which go to make up the superior cava
often results from insufficiency of the tricuspid valve. When this
insufficiency exists a proportionate part of the systolic energy is
expended in driving the blood back into the systemic venous
circulation, and the superior cava, from the nearer correspondence of
the axis of its opening with the axis of the auriculo-ventricular
opening, receives the larger share. Hence with every contraction of the
ventricle a direct distending force is exerted upon this vessel and its
branches which they are not fitted anatomically to resist. In such
cases the distended veins may reach an enormous size, and are seen to
pulsate synchronously with the arteries. The distension is greatest in
the neck, but affects also the veins of the chest and of the upper
extremities.
Whenever a vein is obstructed, either by some process taking place
within it or by pressure from without, the distal portion is more or
less dilated. Examples of this are seen in the closure of veins from
phlebitis and by the pressure of abdominal tumors or the gravid uterus.
Under like conditions the tributary veins also, being forced to carry
more than the normal amount of blood, become enlarged. This we see
constantly in the dilated veins of the abdomen when the internal
vessels are pressed upon by large dropsical effusions.
The term caput Medusæ is applied to a collection of enlarged veins
radiating from a common centre or arranged in the form of a corona.
Such collections often occur on a small scale above the ankles, but
under some conditions they assume vast proportions. When there is
obstruction of the inferior cava a great mat or pad of dilated,
convoluted veins may form on the abdomen or thighs. Some of these veins
may be as large as the little finger.
In the erect posture the veins of the lower extremities are subject to
a distending force proportioned to the height of the column of blood
which they have to sustain. For short periods at a time the resistance
of the walls is ordinarily sufficient to bear this pressure without
yielding, but in persons whose occupation requires them to stand a
considerable portion of each day, and especially in those past middle
life, there is a gradual giving way, which results in increasing not
only the diameter but the length of the vein.
The dilatation takes place irregularly, being greater at one point than
at another, and in one place affecting the entire circumference of the
vessel, while in another it produces a bulging on one side or even a
pouch or diverticulum. Especially just above the valves in the veins of
the lower extremities, where the diameter is naturally a little
greater, the larger area gives rise to greater pressure, and more
marked dilatation results. Their breadth remaining the same, the valves
are no longer able to reach across the vein, and the circulation is
deprived of the aid which it is their office to give. Instead of the
column of blood being divided into a number of portions, each resting
upon the valve beneath it, there is now a continuous column which
exerts its full static pressure. Dilatation is thenceforth doubly
rapid, and at the same {850} time the vein is stretched longitudinally
and becomes tortuous, thus adding another impediment to the
circulation. The nutrient vessels ramifying in the venous walls are
pressed upon, and the nutrition of the several tunica is impaired. From
this arises fatty or calcareous degeneration. Under these combined
influences the walls often become so thinned that rupture takes place.
But it is rare that the blood is effused into the tissues surrounding
the vein, for the overlying integument or mucous membrane, atrophied
from the pressure of the vein beneath, usually gives way at the same
time, affording a means of escape. Even bone is not capable of
resisting the continuous pressure of an enlarged vein, but may be
absorbed in the same way as in the case of arterial aneurism
(Bristowe).
Sometimes the dilated vein becomes thicker instead of thinner by
addition to the outer tunic; probably the result of a slow inflammatory
process, to which, as already stated, varicose veins are peculiarly
liable.
The slow circulation, especially in pouched and tortuous veins, favors
the formation of coagula which frequently close up the vein entirely,
thus bringing about a spontaneous cure. Independently of this, there is
a disposition to recovery when the cause is removed, and the vessel
may, under favorable circumstances, regain its normal condition. If,
however, the valves have atrophied, as they are apt to do after their
efficiency has ceased, entire recovery is impossible.
Oedema is apt to occur in connection with dilated veins if the
impediment to the circulation is considerable. Chronic ulcers of the
legs, accompanied by eczema, are a very common result of a varicose
condition of the superficial veins of the lower limbs; and a permanent
cure can seldom be effected unless the varicose condition is first
removed.
Dilatation of the hemorrhoidal veins is an important factor in
hemorrhoids. But it is far from constituting the disease, as was
formerly supposed, the tumors being largely made up of dilated
capillaries and hypertrophied connective tissue. Indeed, in some of the
worst forms of piles it is not possible to find any evidence of
varicose veins in the extruded mass.
In most cases, however, these varices are present, and may be
distinguished as smooth blue or purple nodules. When a hypodermic
needle is thrust into one of these, the point is felt to be in a free
cavity, which immediately becomes filled with a solid coagulum when a
few drops of a weak solution of carbolic acid are injected--an
operation which usually effects a cure.
Obstruction of the portal circulation predisposes to hemorrhoids; hence
they are a frequent attendant upon diseases of the liver. The habitual
presence of fecal accumulations in the rectum, pressing upon the veins,
operates directly to impede the return circulation, while the straining
at stool which accompanies this condition greatly aggravates the
difficulty.
The TREATMENT of external varicose veins belongs properly to the
province of surgery. When the dilatation can be traced to changes
occurring in any of the internal organs, treatment should be directed
to removing the cause or mitigating its effects. A constipated habit
should be corrected and the hepatic circulation be promoted.
The presence of ascites will call for the use of diuretics or
purgatives or of the aspirator. In cases having a cardiac origin much
good may often be accomplished, for a time, by the judicious use of
digitalis.
In all cases advantage is to be taken of position to aid the
circulation as far as possible.
In the case of superficial veins the application of moderate and
evenly-distributed pressure is of much service.
{851} Narrowing of a Vein.
This condition may occur as the result of inflammation which has
stopped short of occlusion.
Under the name of hypovenosity has been described a condition of the
saphenous system in which there is a deficiency in the number and size
of the veins. The outlines of the limb (bone, muscle, etc.) are
effaced, the skin is dusky, the limb brawny, and there are no veins
visible. The motion of the limb is painful and difficult. There is
degeneration of the superficial veins, collateral dilatation of the
deep veins, and ultimately atrophy of the muscles.
Exercise, frictions, and hot applications are to be employed. Rest and
bandaging as a mode of treatment aggravate the disease.[13] The
affection is of rare occurrence.
[Footnote 13: J. Gay, _Lancet_, Nov., 1871.]
Occlusion of Veins.
Venous occlusion results very frequently from adhesive phlebitis. It is
also brought about by the presence of cancerous or other tumors. The
complete arrest of the current of blood through a vein rarely produces
the serious results which may occur from a like obstruction of an
artery. The aggregate diameter of the venous system is much greater
than that of the arterial, and the venous walls are much thinner and
more distensible. Hence an adequate collateral circulation is more
readily established. In a healthy individual and in a healthy condition
of the part simple occlusion of a vein produces only a moderate oedema
of the tissues on the distal side of the obstruction. In unhealthy
conditions, however, as already pointed out in discussing phlegmasia
dolens, very serious results may follow.
Occlusion of either the superior or the inferior vena cava is of not
very rare occurrence. It may be the result of pressure from a cancerous
or other growth,[14] which is the most frequent cause, or in the case
of the inferior cava it may be brought about by a thrombus gradually
extending upward in one of the iliac veins until it reaches the
bifurcation, when a thrombus in the other iliac is occasioned by the
partial obstruction of its entrance into the cava. These united thrombi
then extend upward into the cava, producing complete occlusion. This is
an occasional event in phlegmasia dolens.
[Footnote 14: Watson describes a case arising from pressure from
hydatids of the liver.]
Occlusion of the superior cava is less frequent than that of the
ascending. It is nearly always the result of pressure from an
intra-thoracic tumor, and its symptoms are more or less masked by those
directly referable to the growth. There are, however, great dilatation
of the veins and oedema of the tissues of the head and neck and of the
upper part of the thorax. These symptoms in a case in which there are
physical signs of a substernal growth would afford a strong presumption
of obstruction of the cava.[15]
[Footnote 15: Stocks, _Med. Times and Gaz._, April 22, 1876; Williams,
_Tr. Dublin Path. Soc'y_, July, 1878.]
The glandulæ concatenatæ of the neck are apt to be enlarged from the
chronic engorgement. Watson mentions a case in which this added so much
to the volume of the neck as to give a superficial resemblance to
goitre.
Occlusion of the inferior vena cava produces, if life is continued, an
immense dilatation of the veins of the abdomen and of the thighs. By
compressing the abdominal veins it can be seen that the blood-current
is reversed, flowing upward through vessels anastomosing with the
intercostal and internal mammary veins. Internally, the circulation is
carried on chiefly by the azygos, which may become as large as the
normal cava.
{852} There is usually, but not always,[16] an extreme degree of
ascites, together with anasarca of the lower half of the body. After a
time, however, as the tributary circulation becomes established, the
effusion will be reabsorbed.
[Footnote 16: _Le Progrès Médical_, May 26, 1877; _Med. Record_, July
28, 1877.]
If the obstruction involves the portal vein, the ascites will be still
more marked. In this case there is also enlargement of the spleen. When
the cava is occluded above the point at which it receives the renal
veins, congestion of the kidneys results, which in time produces
interstitial change. Yet even here the establishment of the collateral
circulation may be sufficiently prompt to avert the danger.
Anomalies of the cava are occasionally observed. Osler has reported a
case in which the inferior cava was represented only by a fibrous cord.
The condition was probably congenital.[17] Greenfield mentions a case
in which the descending cava was absent, both brachio-cephalic trunks
passing into the heart by the coronary sinus.[18]
[Footnote 17: _Journal of Anatomy and Physiology_, April, 1879.]
[Footnote 18: _Med. Times and Gazette_, April 22, 1876.]
If the cause of the occlusion of either cava be not such as of itself
to destroy life, the patient may get on with some degree of comfort for
many years. The establishment of the collateral circulation sometimes
keeps pace with the increasing obstruction, so that little or no
ascites or oedema occurs.[19]
[Footnote 19: Turpin, "Obliteration Inf. Vena Cava," _N. O. Med. and
Surg. Journal_, 1881, p. 575.]
The TREATMENT of obstruction of either of the venæ cavæ can, as a rule,
be only palliative. In the great majority of cases the cause is
entirely beyond our reach. All violent muscular exertion, making an
excessive demand upon the circulation, should be avoided. While the
blood should not be impoverished, as that would favor dropsical
effusions, the patient, on the other hand, should not be allowed to
become plethoric through the influence of his enforced sedentary
habits. The diet should therefore be light and digestible, and
over-feeding should be carefully avoided. The occasional use of saline
purgatives may be required. Dropsical accumulations may call for the
administration of diuretics or drastic cathartics, and perhaps for
tapping.
Occlusion of the vena portæ, by obstructing the return of the blood
from the intestines, gives rise to rapid and abundant effusion into the
abdominal cavity. As the gastric vein cannot empty itself, there is
congestion of the stomach, often ending in hemorrhage, the blood being
both vomited and passed by stool. The spleen also is enlarged by
passive engorgement, its vein depending upon the portal for an outlet.
This assemblage of symptoms renders the diagnosis almost positive.[20]
There is no enlargement of the liver unless the hepatic vein is also
involved.
[Footnote 20: An interesting case is reported by A. A. Smith in the
_N.Y. Med. Journal_, January, 1880.]
Paget maintains that the occlusion of the principal vein of a limb may
result in an increased growth of some of the tissues, especially of the
muscles.
Degenerations.
Fatty degeneration is rarely observed in the veins, but it occasionally
occurs in those which have long been subjected to excessive strain,
which by compressing the nutrient vessels affects the nutrition of the
walls.
Calcification is less rare. It results in the formation of plates or
rings which closely resemble bone in their structure. Such plates may
not unfrequently be felt in old superficial varicose veins. Sometimes
these formations project as spines into the lumen of the vessel, and,
coagula forming about them, a thrombus is the result.[21]
[Footnote 21: See preceding reference.]
{853} Cancer of the veins is rare as a primary affection, but it is not
uncommon when the vessel traverses a cancerous mass. The morbid process
readily penetrates the thin wall of the vessel, and cancerous nodules
form on the inside and become the starting-point of thrombi which are
soon permeated and supplanted by the heterologous growth. This is
sometimes moulded to the shape of the vein, and fills it for some
distance in the form of a cylindrical plug. Fragments may be swept away
in the blood-current and give rise to secondary cancer at the point of
arrest in the liver or lungs. Virchow has described a case of primary
sarcoma of the inferior cava.
The existence of syphilitic lesions in the veins has not been
satisfactorily demonstrated. It is positively denied by some
authorities, while certain appearances found in the veins, especially
of new-born children, are attributed by other writers to syphilitic
inheritance.
Phlebolithes.
Vein-stones are roundish, oval, or cylindrical bodies found in the
veins or in pouches connected with the veins, or sometimes in the
connective tissue adjacent to a vein. Their size varies from that of a
hempseed to that of a nutmeg. Externally they are white, but when
divided they are found of a yellowish color at the centre. There is
generally a central cavity, around which are disposed concentric laminæ
such as are observed in vesical calculi. Chemically, these bodies are
composed of an animal substance in which are deposited phosphate and
carbonate of lime, and sometimes magnesia. The inner part is hard and
brittle, the outer softer and more earthy.
Usually, phlebolithes are found loose in the vein, but if large they
may be firmly impacted in the vessel, causing complete obstruction.
Sometimes the outer portion is of a gelatinous texture, from which a
delicate mesh extends to the wall of the vein and becomes incorporated
with it.
Frequently these concretions occupy sacs or diverticula connected with
the vein. Occasionally these sacs become detached from the vessel and
are absorbed and removed, and the stone, then entirely outside of the
vein, becomes enveloped in a fibrous cyst formed from the surrounding
connective tissue.
Some doubt exists as to the manner in which these concretions are
formed, but the probability is that a small clot first forms in the
vessel, and that around this, as a nucleus, successive layers are
deposited from the plasma of the blood. These layers then undergo
chalky transformation by the deposit within them of salts of lime and
magnesia. These formations seem to be conditioned by a slow current in
a dilated vein. Hence they are most frequently found in the enlarged
pelvic veins of old people, and especially about the neck of the
bladder in those suffering from prostatic enlargement. They are also
found in the varicose veins of the extremities.
Except in superficial situations they are usually not recognized during
life. They seldom produce discomfort, and therefore rarely call for
treatment. When accessible they may be excised if requisite, the vein
being secured above and below if not already permanently occluded.[22]
[Footnote 22: Rokitansky, _Path. Anat._, Philadelphia, 1858.]
{854}
THE CAISSON DISEASE.[1]
BY ANDREW H. SMITH, M.D.
[Footnote 1: This article is mostly drawn from a report by the writer
on _The Effects of High Atmospheric Pressure, including the Caisson
Disease_, published in 1873 by the New York and Brooklyn Bridge
Company.]
Persons exposed for a considerable time to a greatly increased
atmospheric pressure are liable, after the pressure is removed, to
certain morbid effects which comprise what is known as the caisson
disease. It is observed principally in those employed in submarine
operations by the aid of compressed air, and who labor for hours
together in what is termed by engineers a caisson. The pressure varies
with the depth at which the work is carried on, and reaches sometimes
fifty or more pounds to the square inch. The disease rarely if ever
occurs when the pressure is less than fifteen pounds, and its severity
is, other things being equal, in direct ratio to the increase in the
density of the atmosphere.
SYMPTOMS.--These are, in the order of their frequency, intense
neuralgic pain in one or more of the extremities, and sometimes in the
trunk; epigastric pain; nausea and vomiting; more or less complete
paralysis, which may be local or general; headache; vertigo; and coma.
The pain, which is often very severe, is usually paroxysmal,
exacerbations and remissions occurring at short intervals. It may come
on suddenly in its full severity, or it may be slight at first and
rapidly increase until it becomes absolutely intolerable, "as if the
flesh were being torn from the bones." The pain begins most frequently
in the knees, extending rapidly to the legs and thighs, but the upper
extremities may be first attacked. Sometimes the most severe pain is
felt in the spine, and especially in the lumbar region. There is
usually some tenderness with the pain, and a stiffness of the muscles
of the affected limbs.
Epigastric pain occurs in a considerable proportion of the cases. It is
often very severe, and if not relieved by treatment is liable to be
followed by nausea and vomiting. The vomiting is usually limited to the
ejection of the contents of the stomach, but it may persist, sometimes
even after the pain has ceased. Vomiting accompanied by giddiness may
occur without epigastric pain, and is then probably of cerebral origin.
Paralysis, to a greater or less degree, occurs with considerable
frequency, the percentage of cases increasing in proportion to the
pressure of the atmosphere to which the patients have been exposed and
the duration of the exposure. It affects most frequently the lower half
of the body, but it may include the trunk or one or both arms. In rare
cases an arm alone is affected.
The paralysis is of sensation as well as motion. It comes on soon after
the invasion of the pains, but affords no relief from them. Thus, while
pinching or pricking occasions no pain, the part may still be the seat
of exquisite suffering. Paralysis may, however, occur in cases in which
the pain is very slight or entirely absent. The paralysis varies in
degree from a transient {855} weakness of the limbs and slightly
impaired sensation to complete loss of motion and sensation in the
affected part. Even the minor degrees generally affect the bladder.
Symptoms of a transient character are often observed depending upon
changes in the brain. They consist of headache, dizziness, double
vision, incoherence of speech, and sometimes syncope. They usually pass
off in a few hours. In fatal cases, however, coma is the usual
forerunner of death.
The duration of the caisson disease is from three or four hours to six
or eight days. When paralysis occurs it may continue for weeks, or it
may pass off within twelve hours. The cases marked only by neuralgic
pains do not generally last more than six to twelve hours, though some
continue five or six days. Death occurs only in cases which are severe
from the first and show symptoms of cerebral or spinal effusion.