Practical pathology

by Aldred Scott Warthin

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.