Popliteal Artery Entrapment Syndrome: Report of 2 Critical Aspects Cases

Popliteal artery entrapment syndrome

Popliteal artery entrapment syndrome (PAES) is an uncommon cause of lower extremity exertional claudication due to external compression of vascular structures in the popliteal fossa. A developmental anomaly due to an aberrant relationship of the artery with the surrounding myofascial structures contributes to the vascular compromise. PAES presents in younger, athletic patients without atherosclerotic risk factors. Typical presentation of unilateral or bilateral, intermittent claudication in the feet and calves specifically after exercise and relieved by rest in a young person should prompt further evaluation. Early diagnosis and intervention is essential for preventing thromboembolic complication and in worst cases limb loss. Initial tests with Ankle Brachial indices or Doppler ultrasound with provocative maneuvers will prompt more definitive cross sectional imaging studies. CTA or MRA also with provocative maneuvers has a high sensitivity and specificity and will clinch the diagnosis. There are six subtypes based on the relationship of the vascular structure with surround myofascial structures. CTA and MRA can characterize the subtypes and guide surgical planning. Catheter directed thrombolysis may be attempted adjunctively to reduce surgical thrombectomy or resolve distal emboli; however, myotendinous decompression with or without vascular repair is the definitive treatment. Long term surgical outcomes are satisfactory when the distal circulation is preserved.

Trapped by the Entrapment

Introduction

Popliteal entrapment syndrome results from extrinsic compression of the popliteal artery by the surrounding musculotendinous structures and is a rare cause of limb ischaemia. The purpose of this report is to highlight potential mistakes in the management of popliteal entrapment.

Report

In 2000, a 23 year old man underwent a popliteal to popliteal artery bypass surgery for what was initially diagnosed as a traumatic popliteal artery thrombosis. After being initially lost to follow up for 13 years, this “unspecified traumatic” thrombosis led to several inappropriate endovascular and open procedures misinterpreted as being caused by late graft failure. These included thrombectomy, aneurysmorrhaphy, polytetrafluoroethylene covered stent graft, a redo femoropopliteal bypass, and bypass thrombolysis. The diagnosis was reached 19 years after the initial surgery, when the patient underwent a redo bypass using a retrogeniculate approach. An abnormal lateral insertion of the gastrocnemius muscle medial head, and its accessory slip, constricted the artery, and also involved the popliteal vein (Type V), thus explaining previous revascularisation failures. Surgery consisted of resecting the accessory slip and the aneurysmal bypass. The artery was reconstructed with the cephalic vein. The patient was discharged on clopidogrel 75 mg, with no further complication, and a patent bypass at six months. Based on post-operative imaging (duplex ultrasound and magnetic resonance imaging), with forced plantarflexion and dorsiflexion, asymptomatic popliteal entrapment was also present on the contralateral side.

Discussion

The finding of an isolated popliteal artery lesion in a young individual should be considered to be caused by popliteal artery entrapment, unless proven otherwise. Definitive surgical release of the popliteal artery should be favoured over other strategies.

•

Popliteal entrapment may be overlooked by confounding anamnestic factors, leading to inappropriate treatment.

•

Popliteal entrapment should be ruled out in any isolated popliteal artery lesion in a young individual.

Suprageniculate Approach to Release of Popliteal Entrapment without Distal Bypass Despite Preoperative Runoff Thrombosis

BACKGROUND

Popliteal artery entrapment syndrome is an uncommon condition in which anatomic or functional popliteal artery compression causes arterial insufficiency. We present a case of popliteal entrapment with runoff thrombosis treated with suprageniculate release of entrapment without distal bypass.

RESULTS

A 15-year old boy with Klinefelter syndrome presented with right leg claudication severely limiting his activity. He had a palpable femoral pulse, but no palpable popliteal or foot pulses on the right. Noninvasive testing showed a partially thrombosed popliteal artery with an ankle-brachial index (ABI) of 0.69. Computed tomography scan revealed type III popliteal entrapment with distal thromboses and abnormal insertion of gastrocnemius muscle. Popliteal entrapment release was performed via a medial suprageniculate approach in consideration for distal bypass. The soleus was released first; intraoperative angiography showed continued popliteal compression with forced dorsiflexion. This was followed by release of the gastrocnemius and found caudal and medial to the soleus as a tight band. Repeat angiography showed cessation of popliteal artery compression with dorsiflexion. Bypass was not performed due to improvement of distal flow seen on angiography. Postoperative recovery was unremarkable. On 1-month and 9-month follow-up, he had a normal ABI and arterial duplex, was asymptomatic, and had returned to normal activities.

CONCLUSIONS

We describe suprageniculate approach to popliteal release that may be useful if a distal bypass is planned. In this case, bypass was unnecessary despite the abnormal appearance of distal runoff on preoperative imaging, as the child's perfusion improved with entrapment release alone, and arterial remodeling over time resulted in normal perfusion and arterial appearance on duplex imaging.