Popliteal artery aneurysm with popliteal artery entrapment syndrome: a case report and literature review

Background: Popliteal artery entrapment syndrome (PAES) is a rare anatomical anomaly that may rarely lead to secondary popliteal artery aneurysm (PAA). We present a case in which chronic extrinsic compression culminated in a giant PAA, highlighting the diagnostic workflow and surgical strategy. Case presentation: A 50-year-old man presented with a 2-year history of exercise-induced pain and numbness in the right lower limb. On examination, popliteal and distal pulses were absent. Duplex ultrasound showed a 4.1 cm saccular popliteal artery aneurysm (PAA) containing a 15 mm mural thrombus; CT angiography revealed moderate-to-severe stenosis of the proximal popliteal artery. Intra-operatively, the popliteal artery was found compressed and occluded by the medial head of the gastrocnemius, confirming popliteal artery entrapment syndrome; after partial myotomy to release the vessel, only the eccentric aneurysmal sac wall was excised while the macroscopically normal-appearing arterial wall was preserved, and the artery was reconstructed with an autologous small-saphenous-vein patch angioplasty. Discussion: PAES-induced PAA is uncommon; failure to recognise the underlying entrapment risks could lead to incorrect endovascular treatment. Open decompression combined with venous bypass remains the gold standard when the artery is structurally damaged. Conclusion: Clinicians encountering an isolated PAA in a relatively young patient should actively exclude PAES. Timely surgical decompression and revascularisation can prevent thrombo-embolic complications and limb loss.