Risk factors for the development of portal and mesenteric vein thrombosis

ABSTRACT Introduction and Aim: Portal vein thrombosis (PVT) and mesenteric vein thrombosis (MVT) are vascular diseases with high morbidity, which clinically present in various forms ranging from acute intestinal ischemia to chronic portal hypertension. The aim of our study was to reveal the characteristics of patients diagnosed with PVT and MVT. Materials and Methods: The records of patients diagnosed with PVT and/or MVT in our hospital between 01.01.2014 and 31.12.2024 were retrospectively reviewed. Demographic characteristics, accompanying diseases, clinical features, laboratory findings, radiological and endoscopic findings at the time of the initial diagnosis were recorded. Results: During the study period, a total of 74 patients with a mean age of 57.2 ± 18 years, including 47 (63.5%) males and 27 (36.5%) females, were diagnosed with PVT and/or MVT. If the presence of thrombosis in any of the right, left, or main branches of the portal vein in the 74 patients examined is considered as "portal vein thrombosis," thrombosis was detected in the portal vein alone in 35 patients, in both the portal and mesenteric veins in 37 patients, and in the mesenteric vein alone in 2 patients. The most common symptom in our patients was abdominal pain, which was present in 61 (82.4%) of the cases. The cause of thrombosis was cancer in 15 patients (20%), cirrhosis in 9 (12%), myeloproliferative disease in 2 (3%), Factor V Leiden mutation in 4 (5%), prothrombin gene mutation in 1 (1%), and pregnancy in 2 (3%), while the remaining 31 patients (41%) were considered idiopathic. In patients with myeloproliferative disease, unlike those in whom thrombosis developed due to other causes, more extensive thrombosis was present at the same time. It was determined that the presence of portal hypertensive gastropathy was associated with more frequent thrombosis in the left branch of the portal vein (p<0.01) and the main portal vein (p=0.03); the presence of collaterals in the liver hilum was associated with thrombosis in the right branch of the portal vein (p=0.03) and the splenic vein (p=0.02); the absence of an extrahepatic mass was associated with right branch portal vein thrombosis (p=0.02); and the absence of gallstones was associated with superior mesenteric vein thrombosis (p<0.01). No significant relationship was found between the presence of cirrhosis and ascites and the spleen long axis, portal vein diameter, and splenic vein diameter with the localization of thrombosis. Conclusion: In the majority of our cases, malignancies and cirrhosis were responsible for the development of thrombosis, while the idiopathic group had an important place. Thrombophilic conditions such as myeloproliferative diseases, Factor V Leiden mutation, and prothrombin gene mutation were found to be less common than expected. The development of thrombosis in the portal and mesenteric veins at the same time should suggest myeloproliferative diseases. Keywords: Portal vein thrombosis; mesenteric vein thrombosis; risk factors; anticoagulation; retrospective study