The body lying on its back.
The Abdomen being opened by a crucial incision, the parts exposed will be—
1. The Stomach.
2. The Liver and Gall-bladder.
3. The great Omentum descending from the Stomach and hiding the small Intestines; frequently, however, it is more or less puckered up, and exposes them to a variable extent.
4. The Caecum and the lower end of the ascending Colon when distended.
Fix the Liver to the ribs by stitches passed through its substance. Pull down the Pylorus and dissect out the structures in the lesser Omentum, viz.—
1. The Bile duct to the right, above joined by the Cystic and Common Hepatic branches.
2. The Hepatic artery to the left, giving off the Superior Pyloric, Cystic, and Gastro-duodenal branches, the last running down behind the Pylorus, and giving off the Inferior Pyloric branch.
3. The Portal vein behind the preceding, dividing into right and left branches, and the right receiving the Cystic vein. The Gastric vein should be traced into it at the Pylorus. The Gastroepiploic vein, running along the greater curvature of the Stomach, may be traced into the Gastro-duodenal by pulling down the Pylorus, and the junction of this with the Portal after being joined by the Pancreatico-duodenal vein may be seen.
Place the great Omentum on the ribs, and dissect out—
1. The Superior Mesenteric vein by placing the Intestines over on the left side and removing the anterior layer of the Mesentery. The branches from small Intestines, the Ileo-colic, and right Colic branches may be found, and the middle Colic by removing the lower layer of the transverse Mesocolon.
2. The Inferior Mesenteric vein, by placing the Intestines on the right side and removing the Peritoneum covering the left side of the posterior Abdominal wall, whence it passes over the Colon. The left Colic, Sigmoid, and beginning of the Superior Hæmorrhoidal branches will be seen. In this dissection the corresponding arterial branches, the Superior and Inferior Mesenteric plexuses of the Sympathetic nerve and the Mesenteric glands will be seen, and the arteries and veins occupying the following relative positions :— a. Superior Mesenteric vein to the right.
b. Superior Mesenteric artery to the left of preceding.
c. Next the Inferior Mesenteric artery.
d. The Inferior Mesenteric vein, most to the left.
Remove any remaining parts of the posterior layer of the transverse Meso-colon. Divide a small piece of the upper end of the Mesentery opposite the second Lumbar vertebra, in order to get the beginning of the Jejunum to the right, as it overlaps the upper end of the Inferior Mesenteric vein.
Divide the Hepatic flexure of the Colon, and, pulling the divided ends to the right and left sides, pin them there.
1. The Pylorus and Duodenum encircling the Pancreas.
2. The Superior and Inferior Mesenteric arteries and veins passing over the third piece of the Duodenum and beneath the Pancreatic gland.
a. Divide now the head of the Pancreas, and the Duodenum at the junction of its first and second portions. The arteria Pancreatic Magna will be divided as well as the duct.
b. Pull the Stomach and Pancreas over to the left, and place them on the ribs.
c. Remove the Hepatic artery and Bile duct.
The Portal vein and its branches will now be fully seen.