Popliteal artery entrapment syndrome (PAES) is a rare vascular condition typically characterized by an aberrant relationship of the popliteal artery with its surrounding myofascial structures in the popliteal fossa.1,2 It results in compression of the popliteal artery in the popliteal fossa, predominantly during plantarflexion.1-3 PAES primarily affects young adult males without a previous history of cardiovascular risk factors.1-3 As a diagnosis that tends to be missed, the overall incidence of PAES ranges widely from 0.17% to 3.5% in the general population.4-6 Furthermore, 30% of patients with PAES experience bilateral symptoms.7 Patients with PAES typically present with intermittent claudication occurring primarily during exercise and dissipating at rest.1,2 Should PAES be left untreated or go undiagnosed, complications including popliteal artery stenosis (PAS), popliteal artery thrombosis (PAT), and distal arterial thromboembolism (DAT) may occur.1,2 Even though PAES is rare, it is an often overlooked cause of morbidity in this patient cohort. We present a case of PAES in a patient with a prior history of multiple unsuccessful diagnoses and treatments.
A 45-year-old Caucasian male presented with over a decade of progressively worsening lower left extremity claudication. In the last twelve months, claudication occurred with accompanying symptoms of left foot cyanosis, paresthesia, and intermittent pain, prompting vascular evaluation. The patient is an avid runner and lifts weights, and he reported exacerbation of symptoms during exercise. His past medical history is significant for multiple events of left leg deep venous thrombosis (DVT), dyslipidemia, and gastroesophageal reflux disease (GERD). He is a lifetime non-smoker, and denies any alcohol or recreational drug use. The patient was maintained on rivaroxaban (Xarelto, Janssen) for his DVT history, but tested negative for hypercoagulable workup. His physical exam was unremarkable. Bilateral resting and exercise lower extremity arterial Doppler studies and ankle brachial indexes were normal. Due to worsening symptoms, a computed tomography angiography (CTA) with bilateral runoff was performed and showed a focal left popliteal vasculitis with mild to moderate obstruction. A rheumatologic workup was done and was unremarkable. Ultimately, a high index of clinical suspicion for PAES led the patient to magnetic resonance imaging (MRI) without contrast of the left knee in plantarflexion. MRI showed a few slips of the medial head of the gastrocnemius coursing around the lateral margin of the popliteal artery between the artery and vein, before inserting on the posterior distal femur (Figure 1A-B). This imaging is consistent with Type III PAES, with the accessory slip of the medial head of the gastrocnemius arising more laterally, compressing the popliteal artery. However, given that the patient had vein involvement due to his DVT history, it is more appropriately categorized as Type V PAES. A selective descending abdominal aortic arteriogram with bilateral iliac artery runoff was done with provocative maneuvers. An Omni Flush catheter (AngioDynamics) was advanced over the aortoiliac bifurcation with the tip of the catheter in the left external iliac artery. An angiogram with runoff was performed, with angiographic images obtained in the neutral, dorsiflex, and plantar flexed positions. The patient, under conscious sedation, was instructed to perform these non-resisted provocative maneuvers. Reviewed interpretation of angiographic findings was performed. Imaging of plantarflexion in the left leg confirmed PAES with complete obliteration of the popliteal artery and substantial collateral circulation formation (Figure 2A-C). The procedure was replicated for the right leg and angiographic findings confirmed PAES to a lesser extent when compared to the left; however, the findings were still significant (Figure 3A-B). Intravascular ultrasound (IVUS) (Philips) was used to evaluate for intra-arterial injury due to PAES. The patient was instructed to perform the provocative maneuver of non-resisted plantarflexion of the left ankle. During plantarflexion, IVUS showed complete obliteration of the left popliteal artery. There was extensive intimal and medial injury, as well as a small burden of thrombus (Figure 4, Video 1). The patient was formally diagnosed with bilateral PAES, left worse than right. The patient underwent successful left leg gastrocnemius tendinous release to ameliorate his immediate symptoms, with the recommendation to undergo contralateral release in the near future. He was continued on Xarelto for chronic DVT despite undergoing release.
Exertional or positional limb pain in younger patients usually leads to diagnoses consistent with musculoskeletal pathologies. The differential diagnoses to consider for patients presenting with symptoms of claudication is vast. However, information elicited from the patient’s history and physical exam can often clearly elucidate the etiology. PAES is a diagnosis to consider when a vascular pathology cannot readily be ascertained with conventional workup for claudication. PAES is divided into six types, I-VI, that are based on the anatomical variations of surrounding structures causing entrapment (Table 1).1,2
Etiologically, different mechanisms for PAES development have been suggested.1,3 Analysis of human embryological development has shown that the popliteal artery and the medial head of the gastrocnemius muscle arise at approximately the same time.1,3 The medial head of the gastrocnemius may develop an aberrant migration during development, in which the positioning of the muscle in conjunction with the nearby vessels can result in potential vascular compromise.1,3 Depending on the aberrant migration and resultant attachments of the medial head, varying types of PAES can occur (Table 1).1,3 Most individuals with this aberrant migration remain asymptomatic.1,8 Symptomatic presentation is likely attributable to the change in primary use of the gastrocnemius for activities such as running.1,8 This change typically causes muscle hypertrophy, with resultant gastrocnemius medial head compression and impingement of the popliteal artery.1,8
A focused history and physical is necessary to establish a high degree of clinical suspicion for PAES.1-3 Symptoms typically present insidiously during young adulthood. In addition to the common complaints of claudication, patients may also note numbness, discoloration, pallor, and coolness in the affected lower extremity.1-3 Findings on physical exam that also warrant suspicion for PAES in the appropriate clinical setting may be hypertrophy of the calf muscles, as well as diminished, unequal, or absent pulses in the lower extremity upon dorsiflexion/plantarflexion.1-3
A high degree of clinical suspicion must trigger further evaluation in order to establish a diagnosis of PAES.1,9 Studies have shown that, in order to achieve a high sensitivity for the detection of PAES, radiological tests must be used to analyze both the functional/anatomical makeup of the popliteal artery as well as the structural layout of the popliteal fossa.9 Thus far, the diagnostic studies best suited for further evaluation have been determined to be a combination of MRI and duplex arterial ultrasonography (DAU) using provocative maneuvers.9 Angiography may also be performed using provocative maneuvers, but testing with CTA or magnetic resonance angiography (MRA) does not always allow for provocative testing.10 CTA and MRA may provide confirmation of PAES primarily in the setting of arterial occlusion.10
Management of PAES is dependent upon whether the patient is symptomatic.3,5 Expectant management is usually practiced in asymptomatic individuals who have incidental findings of entrapment.3,5 Surgical correction is typically the alternative for symptomatic individuals, as this allows for popliteal artery release and reinstitution of normal anatomy.3,5 Surgical correction has been shown to provide the best outcomes in addressing PAES, as well as providing direct assessment of the popliteal artery for repair or bypass in the event of damage.3,5 The approach for open surgical repair varies based on the patient’s type of PAES.3,5
PAES is a rare but potentially significant cause of lower limb-threatening vascular disease in the younger population. Earlier diagnosis of PAES and consequent treatment can prevent future morbidity from disease progression and abate complications from radical surgical treatments.
Disclosures: The authors report no conflicts of interest regarding the content herein.
The authors can be contacted via Mushaf Haque, MS, OMS-IV, at email@example.com
- Carneiro Júnior FCF, Carrijo ENDA, Araújo ST, et al. Popliteal artery entrapment syndrome: a case report and review of the literature. Am J Case Rep. 2018 Jan 9; 19: 29-34. doi: 10.12659/ajcr.905170
- Davis DD, Shaw PM. Popliteal artery entrapment syndrome. In: StatPearls. Treasure Island, Florida: StatPearls Publishing; 2020.
- Shahi N, Arosemena M, Kwon J, et al. Functional popliteal artery entrapment syndrome: a review of diagnosis and management. Ann Vasc Surg. 2019; 59: 259-267.
- Radonić V, Koplić S, Giunio L, et al. Popliteal artery entrapment syndrome: diagnosis and management, with report of three cases. Tex Heart Inst J. 2000; 27(1): 3-13.
- Gokkus K, Sagtas E, Bakalim T, et al. Popliteal entrapment syndrome. A systematic review of the literature and case presentation. Muscles Ligaments Tendons J. 2014; 4(2): 141-148.
- O’Leary DP, O’Brien G, Fulton G. Popliteal artery entrapment syndrome. Int J Surg Case Rep. 2010; 1(2): 13-15. doi: 10.1016/j.ijscr.2010.07.003
- Drigny J, Reboursière E, Desvergée A, et al. Concurrent exertional compartment syndrome and functional popliteal artery entrapment syndrome: a case report. PM R. 2019 Jun; 11(6): 669-672. doi: 10.1002/pmrj.12081
- Hameed M, Coupland A, Davies AH. Popliteal artery entrapment syndrome: an approach to diagnosis and management. Br J Sports Med. 2018; 52(16): 1073-1074.
- Williams C, Kennedy D, Bastian-Jordan M, et al. A new diagnostic approach to popliteal artery entrapment syndrome. J Med Radiat Sci. 2015; 62(3): 226-229.
- Hai Z, Guangrui S, Yuan Z, et al. CT angiography and MRI in patients with popliteal artery entrapment syndrome. AJR Am J Roentgenol. 2008; 191(6): 1760-1766.
- Mustapha JA, Saab F, Danielson K, et al. Popliteal artery entrapment syndrome: a case series with variable timing of diagnosis and outcome. Vascular Disease Management. 2017; 14(9): E202-E207. Accessed February 10, 2021. Available online at https://www.vasculardiseasemanagement.com/content/popliteal- artery-entrapment-syndrome-case-series-variable-timing- diagnosis-and-outcome