Recognition and clinical implications of mesenteric and portal vein obstruction in chronic pancreatitis.

While splenic vein obstruction is a well-described feature of chronic pancreatitis, analogous occlusion of the superior mesenteric and/or portal veins (SMV-PV) has not been appreciated. We present 14 instances of SMV-PV obstruction in patients with proved chronic pancreatitis without cancer. Portal hypertension was first suspected because of variceal bleeding (4/14) or unexpected varices at laparotomy (10/14). The angiographic appearance mimicked that of pancreatic cancer. The splenic vein was also occluded in eight of the 13 patients who had angiograms. The liver was normal in all 14 cases. The clinical importance of SMV-PV occlusion in chronic pancreatitis lies in (1) its presentation by variceal bleeding, (2) the probable necessity for nonshunting means of control for bleeding varices, (3) the increased difficulty of operations on the pancreas because of portal hypertension, and (4) the possible confusion with pancreatic cancer.