Cystic adventitial degeneration as a cause of dynamic stenosis of the popliteal artery: a case report.

Cystic adventitial degeneration, which is generally localized in the popliteal artery, leads to a dynamic, exercise-dependent flow inhibition. The cysts of the adventitia, which increase in size with exercise, cause an increasing degree of stenosis which can be completely reversed after a longer period if rest. Angiographic presentation may therefore be misleading. Functional examination with Doppler sonography is able to identify the obstruction in such cases. Resection of the involved vessel and restoration of flow by interposition of a vein graft is the therapy of first choice.