MAIN INCISION: THORAX AND ABDOMEN.
I. METHOD OF OPENING TRUNK.
1. =The Main Incision.= After the examination of the cranium has been
completed, the skull-cap is replaced and the anterior flap of the
scalp drawn up over it, to hold it in place until the close of the
autopsy. The head is then wrapped in a towel to protect the face and
hair.
The prosector then stands at the right side of the cadaver (if
left-handed, on the left side), the body being brought as near as
possible to the edge of the table. The cartilage-knife is then held
in the palm of the right hand and with it an incision is made through
the skin in the median line of the body, extending from just below
the thyroid cartilage to the base of the penis in the male, and to
the anterior commissure in the female, passing to the left of the
umbilicus. If pathologic conditions (hernia, surgical wound, tumor,
etc.) are present in the median line the main-incision should deviate
to right or left as expedient. The incision in the suprasternal notch
is made with the point of the knife, the thumb and fingers of the
left hand being used to put the skin of the neck on a stretch. Over
the sternum the knife is held horizontally and the tissues cut to the
bone. As soon as the epigastrium is reached less force is used, and
the cut should not be deeper than through the skin and subcutaneous
tissue over the abdominal portion of the incision. At the end of the
incision the knife is raised, vertically and the cut finished with
the point of the knife. The incision is then carefully deepened in
the epigastrium, just below the ensiform, until a small opening is
made through the peritoneum into the abdominal cavity. To determine
the presence of gas within the peritoneal cavity the peritoneum
should first be nicked with the point of the knife to make a very
small opening through which the escape of any free gas within the
cavity can be easily noted. When bacteriologic examinations of the
peritoneal fluid are to be made, the incision should be extended down
to the peritoneum, which should then be seared, and the fluid secured
by means of a sterile pipette forced through the seared portion. If
it is more expedient to secure the fluid through an incision, the
opening should be made with a sterilized knife and the fingers should
not be put into the cavity, but are used to lift up the abdominal
wall at the sides of the incision. In cutting through the peritoneum
great care should be taken not to injure the stomach or intestines,
which, often greatly distended, are pressed tightly against the
peritoneum. If the opening is made just below the ensiform the knife,
should it slip through unexpectedly, usually strikes the liver
without causing any damage.
[Illustration:
FIG. 36.—The main incision completed. Lines show incisions through
costal cartilages, and for disarticulation of sternoclavicular
joints. (After Nauwerck.) The incision in the neck is begun higher
than is usual in this country.
]
The abdominal incision is now extended downward to the pubis. The
first and second fingers of the left hand are introduced into the
peritoneal cavity and used as directors to lift up the abdominal
wall and to keep the intestines from the knife, the latter cutting
between them in the line of the first incision through the skin and
subcutaneous fascia. When the main incision is complete the knife
is introduced into the abdominal cavity with cutting edge directed
outward and the abdominal muscles are divided on either side just
above the pubis by cuts extending outward to the skin. (See Fig. 36.)
Care should be taken not to cut the latter. These transverse cuts
made from the peritoneal surface permit the opening of the peritoneal
cavity to the necessary extent, so that transverse incisions through
the skin are not necessary.
The main incision is carried to the left of the umbilicus and then
back to the median line, in order not to injure the umbilical
vessels, the ligamentum teres of the liver, or a concealed hernia
or persistent omphalomesenteric duct. In the case of the new-born
the incision to the left of the umbilicus is extended to the pubis
in an oblique line diverging from the median line. After the
examination of the umbilical vessels through the main incision
a second diverging cut is made from just above the umbilicus,
passing to its right, across the umbilical vessels and hepatic
ligament down to the pubis, forming a triangular flap including the
umbilicus, urachus and umbilical arteries.
The abdominal flaps are now held back and a thorough inspection of
the cavity made, noting particularly the position of the abdominal
organs, contents of cavity, condition of peritoneum and appendix,
occurrence of perforations, etc. The position of the diaphragm is
then determined on both sides, by passing the right hand up under
the ribs to the highest part of the dome of the diaphragm and then
pressing outward against the chest-wall so that the height can be
estimated by rib or interspace.
The skin and muscles are now stripped from the thoracic wall on
both sides of the median incision, beginning first on the right.
(See Fig. 36.) The right flap of the abdominal wall is taken in the
left hand just above the umbilicus and turned over the right lower
border of the ribs, and pulled forcibly upward and outward to the
right, putting the peritoneum, the ligamentum teres of the liver and
abdominal muscles upon a stretch over the edge of the ribs. These are
then cut by the cartilage-knife in an incision extending from the
median line along the edge of the ribs deep down into the flank. The
loosened flap of skin and muscle is then pulled over to the right
with the left hand, while the right hand holds the cartilage-knife,
with its cutting edge turned obliquely to the surface of the ribs,
and makes long, sweeping cuts from above downward, severing the
thoracic muscles and fascia as closely as possible to the costal
cartilages and ribs. The skin and muscles are thus stripped off from
below upward until the right side is laid bare as far back as the
anterior axillary line and to the middle of the clavicle above. (See
Fig. 36.)
In stripping the muscles from the ribs it is necessary only
to do it sufficiently to show the costal cartilages and their
articulations with the ribs. Too clean dissecting is not necessary.
On the other hand, careless slashing cuts should be avoided, as
they might cut through into the pleural cavity.
The right mammary gland is next examined. The index-finger of the
left hand is put upon the nipple, the skin-flap turned over, and an
incision made from the inner surface, extending through the gland to
the nipple. Parallel incisions may then be made. The axillary glands
may be examined by carrying the skin and muscle flap farther down
into the axilla. The thoracic wall is then laid bare on the left
side, in exactly the same way as on the right, except that the right
hand works underneath the left, as the latter pulls the flap over to
the left. When the left side is stripped, the left mamma is examined
in the same way as the right.
The thorax is now opened, beginning with the right second costal
cartilage. This is cut with the belly of the cartilage-knife about
½-1 cm. from the costal articulation so as to leave as much of the
cartilage attached to the sternum as possible. (See Fig. 36.) The
cut is made with a rocking motion so that the knife-blade will
strike upon the next lower cartilage instead of going through into
the thoracic cavity. The cartilages and intercostal muscles are cut
in this manner in succession down to the tenth, the cut flaring
outward below with the outward curve of the costal articulations.
The cartilages forming the lower edge of the ribs are left uncut at
this time. When the first opening into the pleural cavity is made
attention should always be paid to the possible escape of gas or
air (pneumothorax). When pneumothorax is suspected the opening may
be made through a little pocket of water formed by holding up the
skin-flap and filling the hollow with water. A similar incision is
then made through the cartilages on the left side from the second
to the tenth. The lower right edge of the ribs is now lifted with
the right hand, and the cartilage-knife, held on the flat, with
cutting edge toward the abdomen, is put through the opening of the
incision through the cartilage and through the diaphragm, and the
last cartilages cut by a stroke made outward and slightly upward to
avoid injuring the abdominal organs. The last cartilages on the left
side are then cut by putting the blade of the cartilage-knife, held
on the flat with cutting edge outward, through the diaphragm from the
abdominal side, into the incision through the cartilages, and cutting
through the lower edge of the ribs in the same manner as on the right.
The lower part of the sternum and cartilages is then lifted in the
left hand and the diaphragm trimmed off closely beneath it. Still
lifting the sternum the tissues of the anterior mediastinum are
cut close to its under surface, care being taken not to cut the
pericardial sac. The sternum is thus freed up to the cartilage of the
first ribs and the sternoclavicular attachments. With the sternum
lifted as high as it is possible to do so without breaking it the
cartilages of the first ribs are now cut with the blade of the
cartilage-knife turned outward to avoid cutting the large vessels
and flooding the part with blood from the distended veins. This
is possible since the cartilages of the first ribs extend farther
outward than those of the second ribs. (See Fig. 36.)
After the first costal cartilages have been cut on both sides,
the sternum is lifted nearly perpendicularly and twisted slightly
toward the right so that the capsule of the left sternoclavicular
articulation can be put upon a stretch. The latter is then opened
from below until the joint is exposed. With the sternum still
pulled firmly upward and toward the right the left sternoclavicular
articulation is completely severed, the left sternocleidomastoid
and other muscles and fascia attached to the sternum are cut from
left to right; and the sternum, twisted over to the right, is
disarticulated in the same manner from the right clavicle, and the
right sternocleidomastoid cut. The freed sternum is now examined. It
may be cut through in the median line with the saw, or cuts made into
it with knife or chisel.
[Illustration: FIG. 37.—Method of disarticulating sternoclavicular
articulation and cutting cartilage of first rib from above. (After
Nauwerck.)]
Ossification of the cartilages of the ribs is very common in late
middle life and old age, more rarely in younger persons. The first
cartilages, particularly the left one, and the lower ones usually
show it in the most marked degree. It may be impossible to cut
them with a knife, and the hand-saw must be used. Ankylosis of the
sternoclavicular articulation is also not rare, and it is sometimes
necessary to saw through the clavicles. The sternoclavicular
articulation and the cartilage of first rib may also be opened from
above downward with a long, narrow-bladed scalpel, the incision
following the articular surfaces.
Many prosectors prefer this method. (See Fig. 37.) The
location of the joint and the direction of the incision may be
ascertained by moving the arm and shoulder of the cadaver. The
sternocleidomastoids may be cut when the skin-flaps are stripped
off. In case bacteriologic examination is to be made of the
contents of the pleural cavity the incisions into the cavity should
be made with a sterilized knife, or the material for culture may
be obtained by means of a pipette introduced through a seared
interspace.
2. POINTS TO BE NOTED IN THE MAIN INCISION.
1. =Panniculus.= Note thickness at different points in the incision,
color (straw-color, rosy or almost white in early life, orange or
reddish-yellow in atrophy or old age, brown in severe anæmias),
moisture (œdema, serous or purulent inflammation, transfusion; the
latter should not be mistaken for pathologic œdema), dryness in
atrophy, long-continued fevers, cachexias, etc., number of bleeding
points (passive congestion, hypostasis), hemorrhages (recent, old,
pigmented).
2. =Musculature.= The muscles of the neck, thorax and abdomen are
examined with reference to the following points: size (atrophy,
hypertrophy), color (normally bright brownish-red, may be paler
than normal, deep brown, yellow or grayish), consistence (pale
muscle usually tears easily, brownish muscle usually tears less
easily), moisture (moist in œdema, inflammation, and as a result
of transfusion; dry in anæmias, severe diarrhœas, long-continued
fevers), translucency (increased in Zenker’s necrosis, fatty
infiltration, fatty degeneration, atrophy, anæmia; diminished
in cloudy swelling and simple necrosis), blood-content (anæmia,
hyperæmia), hemorrhages (trauma, surgical, hypodermic injections,
toxic, infective, hæmatoma of abdominal rectus in typhoid fever),
inflammation (acute, chronic, focal, diffuse, primary, secondary,
abscess, fibroid, etc.), bony formations (myositis ossificans),
parasites (trichina the most common, especially frequent in muscles
of neck and in the intercostals and diaphragm, small whitish, oval
bodies looking and feeling like grains of sand; echinococcus and
cysticercus are more rare), neoplasms (not common, the spindle-cell
fibrosarcoma or “recurrent fibroid” of abdominal wall the most
frequent form). Zenker’s necrosis (hyaline, waxy or “fish-flesh”
degeneration) is of frequent occurrence in the abdominal muscles
in typhoid and other severe fevers and intoxications. Anomalies of
sternal and pectoral muscles are not rare.
3. =Abdominal Cavity.= Watch carefully for the escape of gas when
the first cut through the peritoneum is made. A lighted match may
be held over the opening, or the skin incision may be filled with
water and the peritoneum opened through the water, noting the escape
of bubbles. The odor (sour, sweetish, yeasty, fécal, putrid, etc.)
should be noted. Abnormal contents of the peritoneal cavity are to
be measured and described as to color (amber, greenish-yellow, color
of bile, red, bloody, brown, gray, creamy, milky, opalescent, etc.),
consistence (thin, clear, watery, serous, pea-soup-like, gruel-like,
creamy, jelly-like, colloid, semi-solid, etc.), odor (fécal or foul,
due usually to the presence of the colon bacillus; acid or yeasty
in perforation of stomach; fruity in diabetes, acute hemorrhagic
pancreatitis; odor of ether, chloroform, alcohol, etc.), contents
(blood, bile, féces, stomach-contents [distinguish perforations due
to postmortem digestion], fibrin, fat, chyle, pus, foreign-bodies,
mucin or pseudomucin, parasites) and reaction (acid, alkaline).
Non-inflammatory ascites occurs in portal stasis, hepatic cirrhosis,
thrombosis or compression of portal or splenic veins, chronic
passive congestion, chronic valvular lesions with incompensation,
nephritis, severe anæmia, obstruction or rupture of thoracic
duct, etc. The fluid of transudates is usually clear, odorless,
alkaline, low specific gravity (below 1.016), small albumin- and
fibrin-content, few flocculi, and relatively small number of white
cells. Inflammatory exudates are turbid, often foul-smelling, usually
acid, specific gravity over 1.016, high albumin-, fibrin- and
urea-content, numerous thick flocculi and numerous cells. In early
peritoneal tuberculosis the fluid may be clear and resemble that of
a transudate. Milky and opalescent fluids are found in diabetes,
lipæmia, new-growths of the peritoneum, obstruction or rupture of
thoracic duct or receptaculum. Hemorrhagic exudates may be traumatic
(rupture of spleen, liver, intestines, extra-uterine pregnancy,
etc.), inflammatory (severe acute peritonitis), or due to new-growths
or tuberculosis of the peritoneum, extreme portal stasis, perforation
of gastric or typhoid ulcers, severe intoxications, chronic icterus,
etc. Red effusions may be due to diffused hæmoglobin. In such cases
there is no settling of the color, and coagulation may not occur.
When red cells are present settling takes place on standing. Rupture
of gall-bladder or bile-ducts may lead to presence of free bile
in the peritoneal cavity. Postmortem diffusion of bile through
the gall-bladder wall should not be mistaken for a pathologic
condition. In normal conditions there is just enough fluid in the
peritoneal fluid to make the surfaces moist, and about a teaspoonful
in all may be collected from the flanks and pelvis. The amount
may be greatly increased just before death in all cases of slowly
progressive cardiac weakness. Note character of peritoneum (normally
moist-shining, grayish, translucent, cloudy, dry, lustreless,
thickened, hyaline (“iced” or “Zuckerguss”) in chronic inflammation.)
4. =Omentum.= Note position of lower border, amount of fat, condition
of blood-vessels, dry or moist-shining surface, adhesions (to
appendix, cæcum, oviducts), indurations, contractions (edges rolled
up), character of lymphnodes, cysts, tubercles, secondary tumors,
snared-off tumors from ovary or uterus (parasitic cysts, fibroids),
encysted foreign bodies, etc., exudates on surface, fat-necrosis,
accessory spleens, encysted parasites, hernia, etc. Most common
pathologic conditions are inflammation (secondary to appendicitis,
salpingitis, etc.), metastic carcinoma and tuberculosis.
5. =Position of Abdominal Organs.= Note situs viscerum inversus,
gastro-enteroptosis, displacements due to spinal curvatures and
deformities, and hernia, anomalies or malformations, locate organs by
usual landmarks (edge of ribs, ensiform, umbilicus, etc.), position
of lower and left borders of liver, gall-bladder, spleen, pylorus and
fundus of stomach, appendix, colon, etc. Malposition of transverse
colon especially common. Note volvulus, ileus, invaginations,
etc. Examine stomach and intestines carefully for perforations.
Differentiate postmortem perforations and those due to pathologic
conditions. (Edges of postmortem perforations soft, slimy, without
evidences of disease.) The appendix should also be carefully examined
at this time. Note also peritoneal surface (color, thickness,
translucency, tubercles, adhesions), color and blood-content of all
abdominal organs before acted upon by exposure to air. In the female
examine pelvic organs. Do not mistake postmortem perforations of
stomach or intestine, postmortem imbibition and diffusion of bile
in region of gall-bladder, postmortem contraction of intestines,
dilatations of lymphatics with lymph or chyle, agonal transudates,
accessory spleens, etc., for pathologic conditions.
6. =Position of Diaphragm.= Normally fourth rib or interspace on
right, fifth rib on left, higher in the young, lower in old age.
Raised in conditions of increased abdominal pressure (pregnancy,
ascites, enlargement of liver or spleen, subdiaphragmatic abscess,
dilatation of stomach, urinary or gall-bladder, tumors of any
abdominal or pelvic organ, especially ovarian cysts, etc.), low
in increase of intrathoracic pressure (pleuritic effusions,
pneumothorax, pericardial effusion, hypertrophy of heart, tumors,
aneurism, etc.).
7. =Mammae.= Condition varies according to age, pregnancy, lactation,
etc. In resting glands the structure is lobulated, connective-tissue
white with yellow fat between; in the white connective-tissue are
small grayish-red nodules of gland-tissue (“breast-grains”). During
lactation the fat disappears entirely or to a large extent, the
entire organ consisting of a more homogeneous grayish-white glandular
tissue, distinctly granular on section, and resembling the section
of a salivary gland. Note size of ducts, presence of secretion
(colostrum or milk) on pressure, congestion, œdema, abscess, fistula,
caseous tubercles or gummata, cysts (milk, “soap,” “butter,”
senile, new growths), neoplasms, atrophy, hypoplasia, hypertrophy,
accessory nipples, parasites (echinococcus). The most common tumors
are adenofibromata and carcinomata. Tuberculosis is not rare. In
the male breast hypertrophy has been noted in association with
malignant chorio-epithelioma of the testis; and in the female with
pseudopregnancy and tumors of the genital tract. Adenofibroma, gumma
and tuberculosis are the most common conditions of the mammæ in males.
8. =Costal Cartilages.= Note color (ochronosis), degree of
ossification, anomalies, separations, fractures, caries,
tuberculosis, alteration in shape (pigeon-breast, emphysema, Pott’s
Disease, erosions of tumors or aneurisms, rickets, etc.). The
costochondral edges are thickened as a result of rachitis (rachitic
rosary). In old age the costal cartilages may undergo the so-called
“asbestos-like” degeneration, becoming yellowish- or grayish-brown,
streaked with shining whitish granules, with calcification or
ossification and new-formation of blood-vessels. Degeneration cysts
(senile) are not infrequent, and the cartilages sometimes appear as
if soaked with oil, soft and translucent. Fibroid or calcified areas
may be present. Spaces and clefts within the cartilage may be filled
with new-formed bone-marrow.
9. =Sternum.= Note shape (pigeon-breast, “shoemaker’s,” rounded,
scaphoid, bifid, anomalies of ensiform, etc.), fractures (in
marked osteoporosis the bones may break during removal), erosions
(aneurisms, tumors), tuberculous and syphilitic caries, gummata,
perforations, etc. Under surface of sternum should be smooth,
shining, translucent and grayish. In chloroma the under surface
may present a uniform greenish layer ½-1 cm. thick. Bone-marrow of
sternum is normally red and lymphoid in character; may be green
in chloroma, pyoid in leukæmia, hyperplastic in severe anæmias.
Sclerosis and osteoporosis of sternal bones are not rare. In the
former condition the marrow may be entirely absent; in the latter
hyperplastic.