Practical pathology

by Aldred Scott Warthin

Under certain conditions other methods must be employed for the examination of the heart. In cases of suspected aneurism, pulmonary embolism, patent ductus arteriosus, etc., the thoracic organs should be removed en masse and dissected on the table. They may be removed in connection with the neck-organs or alone. In the latter case the trachea is cut transversely above the sternum, the fingers of the left hand introduced into the trachea, and, while traction downward is being made with force, the œsophagus and cervical vessels are cut transversely, the trachea and vessels stripped down to the level of the clavicle, and the subclavian vessels cut on both sides. The thoracic organs are then stripped from the vertebræ down to the diaphragm and cut off just above the latter.

The pulmonary artery may be examined in situ before the heart is opened by thrusting a sharp-pointed scalpel through the wall of the artery just beyond the valves and cutting upward to the branches going to the right and left lungs. This incision may be extended downward through the pulmonary valve and the anterior wall of the right ventricle, and the right side of the heart first exposed.

Virchow Method. The heart is rotated toward the left side of the cadaver so as to bring the venæ cavæ into view, and is held by the index-finger and thumb of left hand. An incision is then made in the wall of the right auricle, beginning midway between the two cavæ and extending downward as far as the right auriculoventricular ring, in the direction of the right ventricular ridge. The tricuspid is examined from above. The tricuspid ring may be left uncut and an incision made in the ventricle-wall, beginning just below the valve and extending downward along the right ventricular ridge to the septum, or the incision may be carried down in the same line passing through the tricuspid ring. The long narrow-bladed knife or the enterotome is introduced into the right ventricle and an incision made from the middle of the first incision, just above the insertion of the anterior papillary muscle, through the pulmonary orifice into the pulmonary artery, passing between the two anterior leaflets of the pulmonary valve. The heart is now drawn up on the right edge of the ribs so that the left ventricular border presents uppermost. The left auricle is then opened by an incision beginning in, or just below, the lowermost pulmonary vein and extended in the direction of the left ventricular ridge as far as the auriculoventricular ring. Beginning just below the ring an incision is made through the entire length of the left ventricular ridge as far as the apex and to the septum, which lies usually beyond the apex. A second incision is then made in the left ventricle from the apex, extending through the anterior ventricular wall close to the septum, parallel to the descending branch of the anterior coronary artery and about 1 cm. from it, and passing through the aortic opening between the anterior and the right posterior cusps. This is the more easily accomplished if the pulmonary artery has been dissected away from the aorta, so that the incision can be carried well over to the right. (See Fig. [41].) As the chambers of the heart are opened the contents should be inspected, clots removed, and the valvular orifices examined from the upper side. The coronary arteries are then opened with the fine probe-pointed scissors. When the heart has been removed from the body it may be opened on the board by following the method as given above. The heart is held very conveniently for the Virchow incisions by putting the four fingers of the left hand beneath it and the thumb on the anterior surface; complete pronation puts the heart in the position for opening the right side; complete supination gives the position for opening the left side.

Fig. 40.—Section of right auricle and ventricle, according to Nauwerck.

Fig. 41.—Incision for opening of aortic ring; same for all methods described in text. (After Nauwerck.)

Nauwerck Method. By this method the left auricle, left ventricle, right auricle and right ventricle are opened in succession. The heart is seized in the left hand, and without rotation is drawn upon the right edge of the ribs. Beginning in the upper left pulmonary vein or between the veins an incision is made through the wall of the auricle to the sulcus circularis, avoiding any injury to the coronary vessels. Beginning below the mitral ring an incision is carried along the left ventricular ridge to the apex. The left auricle and ventricle are then cleared of blood and the mitral opening examined. The heart is then put back into its natural position; the left thumb is placed in the apex of the left ventricle and the four fingers passed over the right border of the heart to its posterior surface, rotating the heart to the left until the right auricle is brought uppermost. (See Fig. [40].) Then an incision is made through the wall of the right auricle, beginning midway between the superior and inferior venæ cavæ and extending to the tricuspid ring, then begun again 1 cm. below, is carried along the right border of the heart, or slightly anterior to it, as far as the septum. (See Fig. [40].) The contents of right auricle and ventricle and the tricuspid valves are now inspected. The heart is then removed from the body by lifting it up vertically as far as possible and cutting the vessels from below upward as close as possible to their exits through the pericardial sac. The hydrostatic test is then applied to the aortic and pulmonary valves by pouring water into these vessels, or by immersing the heart an water and then lifting it out. The heart is then laid flat on the board with apex toward the operator. The enterotome is introduced into the right ventricle and through the pulmonary orifice and an incision made through the anterior wall of the right ventricle, beginning just above the anterior papillary muscle at about the middle height of the ventricle, and cutting through the pulmonary conus and pulmonary valve well to the left, close to the septum, following the narrow ridge of fat at the base of the artery so as to pass between the left anterior and posterior segments. The heart is then rotated on its vertical axis so that the right auricle is turned toward the prosector, and the tricuspid ring is opened with the intestinal shears. The auricular appendage is then cut open from the auricular incision. The heart is then held in its former position and an incision is made in the anterior wall of the left ventricle just to the left of the septum, from the apex through the aortic ring and the left wall of the aorta, while the pulmonary artery is pulled to the right. (See Fig. [41].) Care must be taken not to damage the right border of the base of the mitral; the cut should pass half way between the pulmonary orifice and the left auricular appendage, cutting the left aortic flap. If it is desired to save the cusps the pulmonary artery may be dissected from the aorta and the incision carried between the right posterior and the anterior valve-flaps. The heart is again rotated toward the right and the mitral ring is cut with the enterotome, which is introduced from the left auricle into the left ventricle. The left auricular appendage is then cut open. The heart-wall is then examined by means of parallel vertical or horizontal incisions. The papillary muscles are cut longitudinally from apex to base. The coronary vessels and their branches are then examined, partly from the aorta and partly from the incisions through the muscle.

Prausnitz Method. The heart is removed and held in the palm of the left hand and two vertical incisions are made on either side of the septum, parallel with it, and extending from base to apex. Two other incisions are then made from base to apex on the outer borders of the ventricles, connecting at the apex with the first incisions. The ventricles are opened by the triangular flaps of the anterior wall thus formed, these flaps being attached at the base of the heart. The contents of the cavities are examined and removed; the valvular orifices and flaps are examined, and the pulmonary and aortic rings are cut through with the shears by extending the two incisions made on each side of the septum, taking care to pass between the cusps.

The heart can also be opened with the long shears alone. The openings of the two cavæ in the right auricle are connected by an incision. The auricular appendage is opened by a second cut. The shears are then put through the tricuspid ring, and this with the right ventricle is cut, the incision following the right ventricular border. The pulmonary orifice is then opened by a cut made along the right side of the septum. The left heart is opened through the pulmonary veins, cutting first the auricle-wall, then the mitral ring and ventricular wall to the apex. An incision is then made along the left side of the septum, through the aortic orifice into the aorta.