The portal vein is formed by the confluence of the splenic and superior mesenteric veins, which drain the spleen and small intestine, respectively (figure 1). Occlusion of the portal vein by thrombus (portal vein thrombosis [PVT]) typically occurs in patients with cirrhosis and/or prothrombotic disorders (table 1). Chronic PVT develops in patients with acute PVT that does not resolve (with or without treatment). Patients with chronic PVT develop collateral blood vessels that bring blood in a hepatopetal manner around the area of obstruction, known as cavernous transformation of the portal vein or portal cavernoma. When seen in a transverse section, as on a computed tomographic (CT) scan, cavernous transformation gives the appearance of multiple caveolar orifices (image 1). Complications of chronic PVT include portal hypertension and portal cholangiopathy.
This topic will review the clinical manifestations, diagnosis, and management of chronic PVT. The epidemiology and pathogenesis of PVT, the approach to patients with acute PVT, and other causes of noncirrhotic portal hypertension are discussed elsewhere. (See "Epidemiology and pathogenesis of portal vein thrombosis in adults" and "Acute portal vein thrombosis in adults: Clinical manifestations, diagnosis, and management" and "Causes of noncirrhotic portal hypertension".)
The approach to patients with PVT has also been reviewed in 2009 guidelines from the American Association for the Study of Liver Diseases . The discussion that follows is generally consistent with those guidelines.
Chronic portal vein thrombosis (PVT) may be asymptomatic and discovered incidentally when abdominal imaging is obtained for other reasons, or patients may present with symptoms related to portal hypertension or portal cholangiopathy, two of the complications of chronic PVT. Patients with chronic PVT may also develop intestinal ischemia and infarction if there is extension of the clot into the superior mesenteric vein, though the risk is small . Patients with chronic PVT may also have clinical manifestations related underlying conditions that predisposed to PVT, such as cirrhosis (table 1). (See "Epidemiology and pathogenesis of portal vein thrombosis in adults", section on 'Portal hypertension' and "Epidemiology and pathogenesis of portal vein thrombosis in adults", section on 'Portal cholangiopathy' and "Cirrhosis in adults: Etiologies, clinical manifestations, and diagnosis", section on 'Clinical manifestations'.)
Patients with chronic PVT, even if asymptomatic, frequently have esophageal or gastric varices, and the most common clinical presentation is gastrointestinal bleeding [3-6]. In a retrospective series that included 40 patients with chronic PVT, at the time of diagnosis, esophageal varices were present in 35 patients (88 percent), gastric varices in 20 patients (50 percent), portal hypertensive gastropathy in 19 patients (48 percent), and gastrointestinal bleeding in 19 patients (48 percent) .