Popliteal artery occlusion caused by cystic adventitial disease: successful treatment by urokinase followed by nonresectional cystotomy. Preoperative diagnosis of an occluded popliteal artery caused by cystic adventitial disease allowed use of urokinase to successfully dissolve secondary thrombosis. Subsequent non-resectional adventitial cystotomy and evacuation of cyst contents allowed lasting restoration of a patent arterial lumen and return of normal distal pulses. This nongrafting technique may serve as a model for future patients with occluded arteries caused by this condition. 