Intestinal Obstruction as Initial Presentation of Idiopathic Portal and Mesenteric Venous Thrombosis: Diagnosis, Management, and Literature Review.

It is quite common for portal vein thrombosis to occur in subjects who present predisposing conditions such as cirrhosis, hepatobiliary malignancies, infectious or inflammatory abdominal diseases, or hematologic disorders. The incidence of idiopathic portal vein thrombosis in non-cirrhotic patients remains low, and despite the intensive workup that is performed in these cases, in up to 25% of cases, there is no identifiable cause. If portal vein thrombosis is untreated, complications arise and include portal hypertension, cavernous transformation of the portal vein, gastroesophageal and even small intestinal varices, septic thrombosis, or intestinal ischemia. However, intestinal ischemia develops as a consequence of arterial thrombosis or embolism, and the thrombosis of the mesenteric vein accounts for about 10% of cases of intestinal ischemia. Although acute superior mesenteric vein thrombosis can cause acute intestinal ischemia, its chronic form is less likely to cause acute intestinal ischemia, considering the possibility of developing collateral drainage. Ileus due to mesenteric venous thrombosis is rare, and only a small number of cases have been reported to date. Most patients experience a distinct episode of acute abdominal pain due to ischemia, and in the second phase, they develop an obstruction/ileus. Acute superior mesenteric venous thrombosis is a rare condition that is still associated with a high mortality rate. The management of such cases of superior mesenteric venous thrombosis is clinically challenging due to their insidious onset and rapid development. A prompt and accurate diagnosis followed by a timely surgical treatment is important to save patient lives, improve the patient survival rate, and conserve as much of the patient's bowel as possible, thus leading to fewer sequelae.