venvägar

Venvägar is a Swedish term used in medical literature to describe collateral venous pathways or alternative routes that develop to drain blood when primary venous channels are obstructed or under high pressure. These venous shortcuts can form within the portal, systemic, or pulmonary venous systems and are an important aspect of how the body adapts to venous impairment.

Collaterals arise in response to conditions such as venous thrombosis, tumor compression, postoperative changes, or chronic liver disease with portal hypertension. They often develop along preexisting venous network segments or through new anastomoses between venous systems. The result is a network of vessels that helps preserve venous drainage but can also give rise to clinically significant problems.

Common examples occur in portal hypertension, where portosystemic collaterals can lead to variceal formation in the esophagus and stomach, caput medusae around the abdomen, and hemorrhoidal plexuses. Other contexts include systemic-to-pulmonary or pulmonary-to-systemic collateral pathways in congenital heart disease or after endurance changes to the venous circulation. The presence and extent of venvägar influence bleeding risk, liver function considerations, and overall prognosis.

Diagnosis typically involves imaging modalities such as duplex ultrasonography, computed tomography venography, or magnetic resonance venography to map collateral networks and assess flow. Treatment focuses on addressing the underlying cause of obstruction or elevated pressure, which may include anticoagulation or thrombolysis for thrombosis, endovascular stenting, or shunt procedures such as a transjugular intrahepatic portosystemic shunt (TIPS) to reduce portal pressure. Management is individualized based on the location and hemodynamic impact of the venvägar. See also collateral circulation, varices, portal hypertension, and venous anatomy.