Functional Popliteal Entrapment Syndrome

Abstract

Background: Classic popliteal artery entrapment is caused by the abnormal relationship between the popliteal artery and the medial head of the gastrocnemius, resulting in repetitive arterial compression and trauma. There is, however, a distinct subset of calf claudicants who have an anatomically normal popliteal fossa but can occlude the popliteal artery by repetitive vigorous exercise which involves active plantar flexion with or without extension at the knee joint. Methods: Eight patients who led a vigorous athletic lifestyle were evaluated with duplex scan and biplane angiogram after being referred for bilateral calf claudication. They were found to have significant stenosis or occlusion of the popliteal artery with active plantar flexion. All patients had transection of the medial head of the gastrocnemius muscle with release of any vascular bands tethering the popliteal artery. Results: Seven of the eight patients had complete relief. One patient noticed return of claudication at long distances, but a postoperative angiogram was normal. In all patients postoperative duplex scan showed no stenosis or occlusion of the popliteal vessels with the foot in active plantar flexion and the knee in extension. Conclusions: Functional popliteal artery entrapment is becoming a significant cause of disabling claudication in young athletic individuals and needs to be diagnosed accurately for appropriate treatment. This condition is becoming well known with the incorporation of sports in the daily routine of most young people.

Popliteal entrapment syndrome

“…Functional popliteal artery entrapment was reported by nine of 30 studies, and this subset comprised a median 23% of entrapments (range, 6.25%-87.5%). 22,25,29,40,43,44,47,49,51 Of the remaining 21 studies, 14 provided sufficient detail about anatomic types to conclude that functional entrapment was not present in any of the reported patients. Although the most commonly used definition of functional popliteal entrapment was that proposed by Rignault et al 66 (compression due to muscular hypertrophy), two other interpretations of functional popliteal entrapment were encountered.…”

Functional popliteal artery entrapment syndrome: A poorly understood and often missed diagnosis that is frequently mistreated

“…They were much younger and also fit the same activity profile that characterizes individuals with CRECS. 10,11 The major difference between the functional and anatomic entrapment syndrome was the absence of musculotendinous anomalies or vascular complications and the proportion of women affected (25 of 30 [83%]).…”

Functional Popliteal Artery Entrapment Syndrome: A Review of the Anatomy and Pathophysiology

“…The prevalence is unknown although this group is felt to be far more common than anatomical PAES [5,6,9]. The progression of disease is also unknown but it may be that these patients develop arterial injury more gradually with onset of more significant symptoms later in life.…”

“…Asymptomatic occluders tend to occlude their popliteal artery bilaterally [4]. Active knee extension and ankle plantarflexion seems to be the usual position that will provoke occlusion [4,5]. Given the incidence of occlusion in healthy individuals, reliance solely on radiologic demonstration of vascular occlusion for diagnosis of PAES in symptomatic patients is likely to yield a significant number of falsepositive results [3,6].…”

“…Complicating this further is the fact that there are a large number of patients who are seemingly asymptomatic but who can occlude their popliteal artery by placing the leg into sustained provocative positions (typically a combination of knee extension and plantarflexion) [4,5]. What is unknown is whether these asymptomatic patients are at risk of developing symptoms and arterial pathology with time [6].…”