Isolated, Idiopathic Splenic Vein Thrombosis, Presenting with Massive Lower GI Bleeding.

Isolated, also called idiopathic, splenic vein thrombosis (SVT) is a very rare clinical condition, which usually results in left-sided portal hypertension and isolated fundal varices. This syndrome is a rare cause of mostly upper, gastrointestinal bleeding. There are only a few hundreds of cases reported in the literature. Colonic varices are even much rarer, 0.07% post mortem autopsies, and 0.2% in a prospective large endoscopic trials. Pancreatic disorders, including malignancies are the most common underlying causes for SVT. Congenital aneurysm of the splenic vein is one of the theoretical explanations of the Isolated, Idiopathic SVT.

Case report: A 53 year old Caucasian female with history of hypertension, and no history of smoking or alcohol abuse, presented with chronic lower gastrointestinal bleeding. Upper endoscopy and flexible colonoscopy revealed perigastric varices without any source of acute bleeding. A bleeding scan demonstrated marked splenomegaly and source of bleeding from left colon. Mesenteric angiogram during venous phase showed splenic vein thrombosis and extensive perigastric varices. In addition, a single large left colonic varix from the lower pole of the spleen was identified as the source of bleeding. The patient was treated with splenic artery embolization with coils, followed by splenectomy, without any major complication. Coagulation studies 8 weeks after the procedure did not show any hypercoagulable state.

Conclusion: The Isolated, Idiopathic SVT, itself is a very rare syndrome. Our center has reported four cases of SVT, secondary to medical conditions, such as; pancreatic malignancy, MRSA sepsis, and multi-organ failure. Upper gastrointestinal bleeding has been more frequently reported than lower bleeding. Interestingly, in our case report, a single colonic varix secondary to SVT was proved to be the cause of chronic lower gastrointestinal bleeding. SVT should be suspected in any patient with a triad of gastric varices, splenomegaly, and normal liver function tests, who presents with gastrointestinal bleeding secondary to left sided or so called “sinistral” portal hypertension. Mesenteric angiography with venous phase is the gold standard for the diagnosis of SVT, as endoscopic studies may not be diagnostic of this syndrome. Splenectomy is the only and definitive procedure of choice in the patients with isolated SVT, followed by post splenectomy vaccination.