Resection of Mesenteric Tumors

Abstract

In removing a portion of the large bowel for adenocarcinoma, the en bloc resection of the appropriate corresponding portion of the mesocolon has been standardized, according to the location of the particular colon cancer, such as right hemicolectomy, left hemicolectomy, sigmoid resection, and so forth. For carcinoma of the small intestine, it is also well known and adequately standardized that in addition to removing an adequate length of small bowel proximal and distal to the tumor, the corresponding mesentery should be removed in a triangular shape from the mesenteric border of the small bowel at the points of its intended proximal and distal division to the base of the mesentery. When primary tumors involve the mesentery itself, however, particularly when the base of the mesentery is involved close to the proximal loops of small bowel, methods of dealing surgically with the situation are not clear. One finds in perusing the literature that often the resectability of tumors at the base of the mesentery is decided upon mere palpatory or visual examination, the rationale being that tumors at the base of the mesentery in this proximal portion probably involve the superior mesenteric vessels, so an attempt at resection poses the risk of complete devascularization of the small bowel and the right colon. The result for the patient would be a permanent need for intravenous hyperalimentation due to short-bowel syndrome. We have found, however, that in cases of desmoid tumors involving the small bowel or mesentery or retroperitoneal sarcomas located at the base of the mesentery (often causing bowel obstruction), dissection at the base of the mesentery and exposure of the superior mesenteric vessels allows preservation of the latter and resection of most of these tumors. The exposure of the superior mesenteric vessels to establish the presence or absence of actual involvement by the tumor of these vessels is the definitive way to decide deliberately whether the tumor can be removed safely.