Authors
C. DE VLOO (1), W. MEERSSEMAN (2), G. MALEUX (3), S. HOUTHOOFD (4), K. OP DE BEECK (5), W. LALEMAN (1), F. NEVENS (1), L. VERBEKE (1), H. VAN MALENSTEIN (1), S. VAN DER MERWE (1), C. VERSLYPE (1) / [1] UZ Leuven, Leuven, Belgium, Department of Hepatology , [2] UZ Leuven, Leuven, Belgium, Internal Medicine , [3] UZ Leuven, Leuven, Belgium, Interventional Radiology , [4] UZ Leuven, Leuven, Belgium, Vascular surgery, [5] UZ Leuven, Leuven, Belgium, Radiology
Case
A 67-year-old man was admitted at the emergency with abdominal pain, located in the upper abdomen (mostly in the right upper quadrant), but not with features of a colic. There was no nausea, changes in stools, or fever. His medical history included only metabolic syndrome with diabetes mellitus, obesity and arterial hypertension. His abdomen was soft and not tender without organomegaly, ascites, abdominal masses. No stigmata from chronic liver disease, nor vascular abnormalities. Laboratory values showed only an elevated CRP (77 mg/L), with normal full blood count, kidney function and liver enzyme tests. Color Doppler ultrasonography showed a portal vein thrombosis and a hyporeflective mass of 5.2 cm next to the pancreas (no previous US to compare). Computed tomography (CT) scans confirmed an extension of the diameter of the portal vein up to 5.5 cm on the level of the splenic-portal confluence, complicated with total thrombosis of portal vein, expanding to the splenic vein and the superior mesenteric vein. Furthermore a nodule in the corpus of the pancreas was seen, There were no signs of cirrhosis or chronic pancreatitis. Further diagnostic excluded all known thrombophilic factors (including JAK2-mutation) and a bone marrow aspirate reveiled no signs of myeloproliferative diseases. Upper endosocpy was negative for varices. A liver biopsy showed a picture of regenerative nodular hyperplasia. EUS with FNA of the small pancreatic nodule showed a low grade neuroendocrine tumor with Ki 0.67%. After multidisciplinary discussion conservative management for this thrombosed portal vein aneurysm was adopted, and therapy with low molecular weight heparin was started. Portal vein aneurysm is an unusual vascular dilatation of the portal vein. Since first described by Barzilai and Kleckner in 1956, less than 200 cases have been reported, mainly as case reports or small surgical series. Portal vein aneurysm is defined as a portal vein diameter exceeding 1.9 cm in cirrhotic patients and 1.5 cm in normal livers. Most patients are asymptomatic, but approximately 50% have nonspecific abdominal pain as a major symptom. Etiology is still unclear, however congenital or acquired causes have been proposed. An incomplete regression of the right primitive distal vitelline vein can explain the congenital variant. Portal hypertension represents the main cause of the acquired version (others are necrotizing pancreatitis, abdominal trauma, surgery or malignancy). Most common locations for aneurysms of the portal venous system are splenomesenteric venous confluence, the main portal trunk or the intrahepatic portal vein branches at bifurcation sites (rarest locations are the splenic, mesenteric and umbilical vein). Complications of portal vein aneurysm are thrombosis, portal hypertension, rupture (rare because of the low portal venous pressure), gastrointestinal bleeding, duodenal compression, inferior vena cava obstruction or compression of common bile duct causing jaundice, cholestasis and cholelithiasis. The management remains somewhat controversial (no clear evidence or comparative studies). Conservative management with regular follow-up by ultrasound is the best option for the majority of patients. Surgical intervention (trombectomy, aneurysmectomy, or even liver transplantation) has been proposed, but remain controversial.
