The role of splenomesenteric vein anastomosis after division of the splenic vein in pancreatoduodenectomy

Division of the splenic vein was performed in 29 patients who underwent pancreatoduodenectomy to achieve lymph node dissection and neural resection around the superior mesenteric artery. The basic protocol for the splenic vein reconstruction to reduce congestion of the spleen and stomach is as follows. When the inferior mesenteric vein (IMV) drained into the splenic vein, the confluence was preserved without reconstruction of the splenic vein. When the IMV drained into the superior mesenteric vein (SMV) or the splenomesenteric angle, the division of the IMV and spleno-IMV anastomosis were performed. In postoperative venography, nine patients showed downward flow (from the splenic vein to the IMV) and three patients showed upward flow (from the IMV to the splenic vein). Postoperative computed tomography scans showed venous dilatation and splenomegaly in the upward flow group; there were no patients in the downward flow group. In selected patients, splenic vein reconstruction is necessary to reduce congestion of the spleen and stomach. When the flow is downward, spleno-IMV flow should be preserved. When the flow is upward, spleno-SMV anastomosis is necessary instead of spleno-IMV anastomosis.