CHAPTER VII.
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.
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.
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.