Acute Thrombosis of an Aneurysm of the Small Saphenous Vein: A Case Report.

Background: A venous aneurysm (VA) is a focal dilatation of a nonvariceal vein (diameter increased by at least 1.5 times compared to the adjacent upstream or downstream venous segment), which carries a risk of venous thromboembolism (VTE) when located in the deep veins of the lower limbs but also when it affects the veins above the muscle fascia.

Case: We report the case of a 40-year-old woman who presented with a painful and disabling mass-like lesion of the upper third of the right calf. A Doppler ultrasound (DUS) examination revealed a small saphenous vein (SSV) dilated at the saphenopopliteal junction (SPJ) and thrombosed along its entire length. Anticoagulant treatment was initiated but although the thrombosis regressed on DUS, the functional impotence and the persistence of pain prompted a stripping of the SSV. Histology allowed the diagnosis of SSV's primary aneurysm.

Discussion: Dilated segments of the saphenous vein are not always varicose veins (VVs). True VAs can develop on veins located above the muscular fascia and, like deep VAs, may trigger VTE. Small saphenous vein aneurysms have seldom been reported, and only a few clinical observations have described the thrombosis of a SSV aneurysm. Any mass in the popliteal fossa or upper part of the calf should be examined by DUS to look for an SSV aneurysm. Excision of the saphenous vein with junctional ligation is advised if thrombosis is present at the time of diagnosis.