[Cystic degeneration of the adventitia of the popliteal artery as a possible sequela of entrapment syndrome].

We report two cases of cystic adventitial degeneration of the popliteal artery in young sportsmen. The pathogenetic role of microtrauma is suggested by the localisation of the adventitial cysts, the clinical symptoms, as well as the immunohistochemical demonstration of foamy macrophages instead of endothelial cells in the wall of the cysts. In one case the cause of the intermittent claudication could be verified by duplex sonography and comparison of the arterial pressure of both legs with a Doppler method only after physical exercise. As expected, an angiodilatation has only a temporary effect. Therefore a surgical resection of the cyst or of the involved arterial segment had be performed.