Vascular complications of pancreatitis.

Hemorrhage is one of the most life-threatening complications of pancreatitis. It is usually due to erosion of a major pancreatic or peripancreatic vessel with massive bleeding into the gastrointestinal tract or abdominal cavity, or to formation and subsequent rupture of an arterial pseudoaneurysm. In addition, the inflammatory process of pancreatitis may cause thrombosis of the portal vein or its main tributaries, the splenic and superior mesenteric veins, resulting in compartmental portal hypertension with gastric, mesenteric, or colonic varices. Variceal hemorrhage is not an uncommon vascular complication of pancreatitis. The use of the newer, noninvasive imaging modalities of US, duplex Doppler US, and bolus-dynamic CT; earlier use of diagnostic and therapeutic angiography; and a more aggressive surgical approach have led to significant reductions in morbidity and mortality rates for patients with vascular complications secondary to pancreatitis. The radiologic diagnosis of vascular complications can be accomplished with US, CT, and angiography. US and CT may show formation of arterial pseudoaneurysms, evidence of hemorrhage into a pancreatic pseudocyst or fluid collection, or portal venous thrombosis with development of varices. The presence of flow in a pseudoaneurysm, or absence of flow due to portal venous thrombosis, can be confirmed by contrast-enhanced dynamic CT or duplex Doppler US. Angiography should be utilized in all patients, if possible, to show the precise site and source of bleeding. Although active bleeding can be diagnosed only by detection of contrast extravasation, the source of bleeding often can be identified by demonstration of an underlying vascular abnormality, such as a pseudoaneurysm or varices. Patients who are hemodynamically stable and who have angiographic evidence of bleeding can be treated with transcatheter embolization. This may result in permanent control of the bleeding, providing definitive treatment, or temporary control, thus allowing surgery to be performed on an elective or semi-emergent basis. Patients who are unstable or who have vascular involvement that is not amenable to transcatheter embolization should have emergency surgery. Preoperative angiography should be performed prior to surgery, if possible. Angiography can show the surgeon the exact vessel involved, as well as the surrounding vascular anatomy, thus facilitating the surgical approach. In selected patients, occlusion balloon catheters can be employed to obtain hemostasis during or after pancreatic surgery.