Intraoperative Duplex and Functional Popliteal Entrapment Syndrome: Strategy for Effective Treatment

Clinical Outcomes of a Diagnostic and Management Protocol for Popliteal Artery Entrapment Syndrome at a Large Referral Center

OBJECTIVE

Popliteal Artery Entrapment Syndrome (PAES) is a rare clinical entity without a standardized algorithm for diagnosis and treatment. The objective of this study was to evaluate the clinical outcomes of a unique diagnostic and management algorithm for patients with PAES managed at a quaternary referral center.

METHODS

We retrospectively reviewed patients diagnosed with PAES at a single institution between 2013 and 2021. Demographics, physical exam findings, non-invasive imaging results, and angiographic images were assessed to validate a diagnostic and management algorithm (Figure 1). Surgical findings, operative technique, post-operative complications, and symptomatic improvement were assessed to validate this clinical algorithm.

RESULTS

There were 35 extremities in 23 patients treated for PAES (Table 1). The mean age was 28 and 82.6% of patients were female. Physical exam revealed a decrement in pedal pulse with provocative maneuvers in 90% of treated limbs. Noninvasive studies to include treadmill exercise testing revealed a mean ABI drop of 0.28 and positional duplex demonstrated that the mean peak systolic velocity (PSV) in the popliteal artery was 78 cm/sec at rest which increased to 175 cm/sec with provocation. Diagnostic arteriography was performed in all patients and revealed well-developed geniculate and sural collaterals in 100% of treated limbs and complete effacement of the popliteal artery with active provocative maneuvers in all treated limbs (Figure 2). Surgical exposure was performed via a posterior approach and intraoperative completion duplex was performed in all cases. Type III PAES was discovered in 89% of cases. Arterial reconstruction was required in 2 patients who presented with an occluded popliteal artery. All but one patient was discharged on post-operative day one. Wound complications occurred in 4 limbs (3 patients) and included seroma and hypertrophic scarring. All patients experienced symptomatic relief with median follow-up of 4 months.

CONCLUSIONS

We report 100% technical and clinical success in patients with PAES diagnosed and managed using our clinical algorithm. Cross-sectional imaging is not necessary for the diagnosis. Dynamic angiography confirms the diagnosis and intraoperative duplex is essential for successful clinical outcome by confirming complete release of the popliteal artery.

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.

Functional popliteal artery entrapment syndrome: A review of diagnostic and management approaches

Functional popliteal artery entrapment syndrome (FPAES) presents a challenge for clinicians in the field today. The relative rarity of the disease coupled with its affliction primarily in young, athletic individuals makes it a difficult condition to diagnose. Treatment modalities have been limited to surgical intervention, with more novel methods being developed over the last several years. We present a case report and review the diagnostic and management approaches for FPAES, shedding light on proposed future interventions.

Response of the popliteal artery to treadmill exercise and stress positioning in patients with and without exertional lower extremity symptoms

OBJECTIVE

Functionally limiting exertional lower extremity pain and neurologic symptoms are commonly encountered in military and civilian settings. Exertional muscle compression of the popliteal artery (PA) and tibial nerve in the proximal calf (the "popliteal outlet") can be associated with these symptoms but is rarely investigated as a cause. Exertional ankle-brachial index (EABI) and dynamic PA ultrasound imaging may be suitable to screen for this syndrome of "functional" popliteal entrapment, but neither has been rigorously studied. Our objective was to characterize the response of the PA to lower extremity exertion and dynamic ankle positioning in symptomatic and asymptomatic limbs.

METHODS

Limbs characterized as symptomatic (n = 29) or asymptomatic (n = 61) had duplex ultrasound PA diameter and peak systolic velocity measurements with the ankle neutral and maximally plantar flexed. EABIs were obtained at rest and 1 minute and 5 minutes after walking (5 minutes, 3 mph, 10-degree incline) and running (5 minutes, 6 mph, 0-degree incline). Significance was set at P ≤ .05. Data are expressed as mean ± standard error of the mean.

RESULTS

Plantar flexion resulted in PA occlusion and changes in diameter and peak systolic velocity in symptomatic (three occluded, -2.4 ± 0.34 mm, +49 cm/s) and asymptomatic (six occluded, -1.6 ± 0.21 mm, +65 cm/s) limbs. The difference in percentage change was significant between groups only for diameter change. EABIs in both groups were similar at rest, decreased with running and walking at 1 minute, and were not fully recovered by 5 minutes. Symptomatic limbs had a greater decrease in ABI than did asymptomatic limbs with both running and walking. The decrease was greatest at 1 minute after running and significantly more pronounced in symptomatic (-0.18) than in asymptomatic (-0.02) limbs.

CONCLUSIONS

EABI decrease at 1 minute after running and PA diameter decrease with dynamic ankle plantar flexion are significantly greater in limbs with than without exertional lower extremity symptoms. These noninvasive measurements may be valuable in the workup of such symptoms. PA and tibial nerve compression at the popliteal outlet may be a more frequent cause of functionally limiting exertional lower extremity pain and neurologic symptoms than previously recognized.

Nonatherosclerotic PAD: Approach to Exertional Pain in the Lower Extremities

Atherosclerotic peripheral artery disease is the most common cause of intermittent claudication. Nonatherosclerotic peripheral artery disease is a heterogeneous collection of diseases affecting the extracoronary arteries which is not due to atherosclerosis. These diseases include, but are not limited to, popliteal artery entrapment syndrome, cystic adventitial disease, external iliac endofibrosis, and thromboangiitis obliterans. Due to its relatively low prevalence, nonatherosclerotic peripheral artery disease may be misdiagnosed leading to the mismanagement of potentially treatable conditions. The proper and timely diagnosis of these conditions is paramount to the prevention of adverse outcomes as treatments widely vary. The diagnostic approach to patients presenting with intermittent claudication must take into account both atherosclerotic as well as nonatherosclerotic causes of peripheral artery disease making the differential vital to clinical practice.

Intraoperative duplex ultrasound criteria for performing interposition bypass in the treatment of popliteal artery entrapment syndrome

We present a case series of 3 surgical procedures (2 patients) in which intraoperative duplex ultrasound (IDUS) was used to determine whether the chronic compression of the popliteal artery caused by popliteal artery entrapment syndrome had injured the artery to such a degree that interposition bypass was required. Patients initially underwent standard clinical evaluation including history and physical examination and noninvasive diagnostic testing including postexercise ankle-brachial indexes and angiography with evocative maneuvers before surgery. IDUS was performed. Doppler was used to calculate peak systolic velocities (PSVs) and velocity ratios (VRs) across areas of suspected injury. B-mode was used to assess arterial wall thickness (AWT) and sclerotic changes. Patients were followed in the postoperative period with surveillance duplex ultrasound (US). Three limbs (2 patients) underwent IDUS evaluation after popliteal decompression. Limb 1 demonstrated an elevated intraoperative PSV of 295 cm/sec with an elevated VR of 2.52 (295/117 cm/sec) and AWT of 1.1 mm. Interposition bypass was performed after popliteal decompression. Postoperative surveillance duplex US revealed a reduction of the PSV to 90 cm/sec. Limb 2 showed a mildly elevated intraoperative PSV of 211.5 cm/sec with a VR of 1.86 (211.5/114 cm/sec) and AWT of 0.8 mm. An interposition bypass was not performed. Limb 3 demonstrated an elevated intraoperative PSV of 300 cm/sec with an elevated VR of 2.51 (300/119.5 cm/sec) and AWT of 1.0. Interposition bypass was performed. Postoperative surveillance duplex US revealed a reduction of the PSV to 115 cm/sec. IDUS was very helpful in the operative management and intraoperative decision making process for popliteal artery entrapment. An elevated PSV of 250-275 cm/sec or greater on IDUS and a VR of 2.0 or greater, in conjunction with B-mode demonstration of arterial wall injury, was useful in identifying severely injured popliteal arterial segments. Additional prospective studies are warranted to further investigate objective criteria that indicate the need for bypass.

Delayed presentations of popliteal artery entrapment syndrome in a middle-aged military population

Popliteal artery entrapment syndrome (PAES) is a rare but significant cause of disability usually diagnosed in young, healthy adults. Advancements in diagnostic imaging modalities have prompted a current report of our recent experience with PAES in a middle-aged military population at the Walter Reed National Military Medical Center. The addition of computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) permit accurate and facile diagnosis of this complex syndrome.

Vascular disorders in athletes

Athletes rarely present with symptoms or clinical findings suggestive of vascular disease. However, vascular etiologies should be considered when an athlete complains of persistent symptoms which are refractory to conservative therapies commonly used for presumed musculoskeletal injuries. A comprehensive history should be performed, with special consideration to the postures the athlete assumes repeatedly during their chosen sport. Musculoskeletal anatomy surrounding the vascular bed of interest should be thoroughly reviewed. Physical examination should include provocative maneuvers specific to the suspected vascular disorder. The proper use of noninvasive diagnostic studies, including duplex ultrasonography, computerized tomography (CT), and magnetic resonance imaging (MRI), along with catheter-based angiography, when indicated, can ensure prompt diagnosis. Appropriate, multifaceted treatment of an athlete affected by a vascular disorder can facilitate an expeditious return to previous levels of activity.