The gallbladder, antrum of the stomach, head of the pancreas, and duodenum have been separated to call attention to the various relationships, including the blood vessels that must be ligated in this procedure. These structures are numbered for convenient identification. The gallbladder is removed since there is a tendency for gallstone formation in case of long survival. To facilitate the anastomosis, as much of the common duct as possible should be saved below the junction of the cystic duct except in cases of possible cholangiocarcinoma. The common hepatic artery and its branches must be identified carefully. The right gastric and the pancreaticoduodenal vessels are identified and ligated in order to gain access to the region of the portal vein. Since no vessels enter at the anterior surface of the portal vein, this is the logical point for dividing the head of the pancreas from the body and tail. A number of pancreatic veins enter at the lateral border of the portal vein opposite the point where the splenic vein joins the superior mesenteric to form the portal vein. The middle colic artery and vein should be preserved.
Before the blood supply of the head of the pancreas is compromised, the antrum of the stomach is transected, using the landmarks for hemigastrectomy (see Plate 19). If a pyloric-sparing anastomosis is planned, the first portion of the duodenum is divided. Otherwise, the antrum is transected. Either of these divisions provides a direct approach to the pancreas in the region of the portal vein.
The pancreatic duct varies in size, depending on the amount of obstruction that may have occurred as a result of a prolonged block by calculi or tumor formation. If it is quite small, direct implantation of the duct is impossible, and direct implantation of the tail of the pancreas into the lumen of the jejunum can be carried out. Usually, there is one blood vessel that needs to be ligated above the pancreatic duct in the substance of the gland and two below. In the presence of adenocarcinoma of the pancreas, consideration should be given to the desirability of total pancreatectomy.
Since marginal peptic ulceration may occur in a prolonged survival, the ability of the stomach to produce acid may be controlled with truncal vagotomy and by removing the entire antrum of the stomach. The latter can be accomplished by hemigastrectomy, selecting as the point of division the stomach at the level of the third vein on the lesser curvature and the point on the greater curvature where the epiploic vessels are nearest the gastric wall (see Plate 19). Alternatively patient's may be treated with lifelong acid reducing medication.
One of the most difficult parts of the procedure is the freeing of the third part of the duodenum, because of the short mesentery in this area. A portion of the upper jejunum should be resected along with the duodenum to ensure free mobilization of the upper jejunum, which is to be brought through the opening in the mesentery to the right of the middle colic vessel.