Popliteal artery entrapment: an evolving syndrome.

Popliteal artery entrapment can result in claudication and limb-threatening ischemia in the young adult. The purpose of this study was to evaluate prospectively those patients with popliteal artery entrapment. To define the syndrome, the methods used in diagnosis and the type of anatomic anomaly were established for each patient. From 1977 to 1988, 12 patients were found to have popliteal artery entrapment. The average age was 27 years, with all but three patients under age 40 years. All patients complained of calf claudication, and one had acute ischemia. The ankle pulses decreased with maneuvers in 10 patients; four patients had a resting ankle/brachial index less than one. All had diminished ankle/brachial indexes when a treadmill test was performed at 4.2 mph, 10% grade, for 10 minutes. All patients had biplanar arteriography with passive dorsiflexion and active plantar flexion. All results showed abnormal extrinsic compression or occlusion of the popliteal artery. Twenty limbs were affected; eight of 12 patients (67%) had bilateral entrapment. Type IV (37%) lesions were the most common, with type II (32%) and type III (26%) following closely. One (5%) type I lesion and no type V lesions were found. This is the largest single series of patients with popliteal entrapment in the United States. A treadmill test followed by biplanar arteriography established the diagnosis in all patients. Bilateral involvement was twice that reported in previous studies. Popliteal artery entrapment should be considered in the young adult with claudication and may be seen with greater frequency in an increasingly active population.