History and findings: A 52-year-old patient complained of progressively increasing pain in his left leg when walking. The pain-free walking distance was 50-100 m. He was smoking about 20 cigarettes daily. No pulses were palpable in the left leg below the inguinal fossa. Recapillarisation time was normal in both legs and there were no trophic changes.
Investigations: The Doppler perfusion pressure values were up to 40 mm Hg less in the left than the right leg. Ankle oscillography record showed a definite stenosis curve on the left. Digital subtraction angiography of the left leg showed a short occlusion of the popliteal artery with many collaterals and atypical medical deviation of the artery. The findings were interpreted as indicating peripheral arterial vascular disease.
Treatment and course: Laser-assisted percutaneous transluminal angioplasty with balloon dilatation merely achieved a narrow lumen which again closed on plantar flexion of the left foot. The reversible occlusion suggested popliteal artery entrapment. At operation the popliteal artery coursed atypically over the dorsal medial aspect of the medial head of the gastrocnemius muscle. The arterial segment in the stenotic area was replaced by an autologous venous graft and the gastrocnemius muscle fixed laterally. The patients no longer experienced any impairment on walking and repeat angiography showed unimpeded flow through the graft even on plantar flexion.
Conclusion: Popliteal artery entrapment is rare in the elderly and may be overlooked without provocation test and complete visualisation of the leg and pelvic arteries.