popliteal artery entrapment syndrome

Uncommon

Diseases of The Popliteal Artery: A Pictorial Review. Popliteal artery entrapment syndrome (PAES) in a 52-year-old man with a history of right calf claudication for 2 years. (a) Digital subtraction angiography shows abrupt occlusion of the proximal popliteal artery (solid arrow), which reconstitutes at its midportion (dashed arrow). A cine sequence is presented in Movie 1. PAES was suspected and patient underwent CT angiography. (b) Axial images of CT angiography reveal severe narrowing of the right popliteal artery (arrowhead), with an abnormal muscle slip (red transparent overlap) originating from the medial head of the gastrocnemius muscle and coursing between the popliteal vessels (V = popliteal vein). The contralateral side shows a similar appearance of abnormal muscle slip (red transparent overlap); however, the left popliteal artery is patent (A). Bilateral green transparent areas correspond to normal insertions of the gastrocnemius insertions

insightsimaging.springeropen.com • Open Access

Uncommon

Diseases of The Popliteal Artery: A Pictorial Review. Drawings illustrate the classification scheme for PAES. (a) Type 1: the medial head of the gastrocnemius muscle has normal insertion, displacing the popliteal artery around and beneath the muscle. (b) Type II: the medial head of the gastrocnemius arises from an abnormal position, displacing the popliteal artery medially. (c) Type III: entrapment is caused by an abnormal slip of the gastrocnemius muscle. (d) Type IV: entrapment is caused by a fibrous band or by the popliteal muscle

insightsimaging.springeropen.com • Open Access

Uncommon

Diseases of The Popliteal Artery: A Pictorial Review. Popliteal artery entrapment syndrome (PAES) in a 31-year-old woman admitted to the hospital because of a 6-week history of right calf pain and numbness. Patient also reported half-block claudication. (a) Lower extremity digital subtraction angiography reveals obliteration of the popliteal artery (arrow). Given the lack of risk factors for an arterial thrombus, an anatomic etiology was suspected. (b, c) Axial selective partial inversion recovery (SPIR) MR images of the right knee showing an accessory slip of the lateral head of the gastrocnemius muscle (arrow) crossing anterolateral to the popliteal vessels, with resulting compression of the popliteal artery (arrowhead). The accessory slip (arrow) joins the lateral head of the gastrocnemius distally (star). This finding supports a diagnosis of PAES

insightsimaging.springeropen.com • Open Access

Uncommon

Diseases of The Popliteal Artery: A Pictorial Review. Popliteal artery entrapment syndrome (PAES) in a 38-year-old woman with a 4-week history of right foot pain, admitted to the hospital for gangrenous fourth toe. (a) Digital subtraction angiogram shows total occlusion of the right popliteal artery (arrow), with filling defects of the distal superficial femoral artery (arrowheads) consistent with thrombus, and multiple collaterals around the knee. PAES was suspected and patient underwent CT angiogram. (b) Maximum-intensity projection reconstruction from lower extremity CT angiogram demonstrated total occlusion of the right popliteal artery (arrow) extending into the proximal anterior tibial artery, with distal reconstitution (dashed arrow). (c) Axial CT angiography image shows occlusion of the right popliteal artery (arrow), and an extra slip of muscle lateral to it (red transparent overlap). No comparable structure is seen on the left side, which suggests right PAES. Green transparent overlapping areas of the normal gastrocnemius heads bilaterally are added to display the asymmetrical appearance between right and left knees. (d) Coronal reconstruction of CT angiography showing the gastrocnemius heads (green transparent overlap) with an extra slip of muscle (red transparent overlap) causing asymmetric appearance, and possibly originating from the lateral head

insightsimaging.springeropen.com • Open Access

Vascular

compression disorders • Popliteal artery entrapment syndrome - Ganzer Fall bei Radiopaedia

Dixon, A. Popliteal artery entrapment syndrome. Case study, Radiopaedia.org. (accessed on 09 Nov 2022) https://doi.org/10.53347/rID-9411 • CC by-nc-sa 3.0 (modified)

Popliteal

artery entrapment syndrome • Bilateral popliteal artery entrapment (dynamic angiogram) - Ganzer Fall bei Radiopaedia

Dixon A, Bilateral popliteal artery entrapment (dynamic angiogram). Case study, Radiopaedia.org (Accessed on 05 Jan 2023) https://doi.org/10.53347/rID-9420 • CC by-nc-sa 3.0 (modified)

Popliteal

artery entrapment syndrome • Popliteal artery entrapment syndrome - type II - Ganzer Fall bei Radiopaedia

Ho F, Popliteal artery entrapment syndrome - type II. Case study, Radiopaedia.org (Accessed on 05 Jan 2023) https://doi.org/10.53347/rID-62921 • CC by-nc-sa 3.0 (modified)

Popliteal

artery entrapment syndrome • Popliteal artery entrapment syndrome - Ganzer Fall bei Radiopaedia

Rizk M, Popliteal artery entrapment syndrome. Case study, Radiopaedia.org (Accessed on 18 Apr 2024) https://doi.org/10.53347/rID-168668 • CC by-nc-sa 3.0 (modified)

Popliteal

artery entrapment syndrome diagnosed with multislice CT angiography. Axial CTA image reveals the occluded left popliteal artery entrapped by a more hypertrophic medial head of the left gastrocnemius that is located more laterally.

www.eurorad.org • CC by-nc-sa-4.0

Popliteal

artery entrapment syndrome diagnosed with multislice CT angiography. Axial CTA image shows the entrapment and compression of the non-opacified left popliteal artery by the more laterally inserted medial head of the gastrocnemius muscle.

www.eurorad.org • CC by-nc-sa-4.0

Popliteal

artery entrapment syndrome diagnosed with multislice CT angiography. Digital subtraction angiography (DSA) shows the collateral vessels that supply the distal part of the popliteal artery.

www.eurorad.org • CC by-nc-sa-4.0

Popliteal

artery entrapment syndrome diagnosed with multislice CT angiography. Digital subtraction angiography (DSA) shows the collateral vessels that supply the distal part of the popliteal artery.

www.eurorad.org • CC by-nc-sa-4.0

Popliteal

artery entrapment syndrome diagnosed with multislice CT angiography. 3D Volume rendering reconstruction, on posterior view, shows the abrupt interruption of the left femoral artery and the collateral vessels that supply the more distal part of the popliteal artery.

www.eurorad.org • CC by-nc-sa-4.0

Radiopaedia • CC-by-nc-sa 3.0 • de

Popliteal artery entrapment syndrome refers to symptomatic compression or occlusion of the popliteal artery due to a developmentally abnormal positioning of the popliteal artery in relation to its surrounding structures such as with the medial head of gastrocnemius or less commonly with popliteus or fibrous bands.

Epidemiology

The anatomic anomalies may be seen in up to 3-3.5% of the population and are often bilateral (~2/3 of cases). Most individuals; however, are asymptomatic, and the true clinical syndrome is far less common. Individuals with well-developed muscles are more likely to be symptomatic, which probably explains why the syndrome is most often found in young sportspersons (~60 % in those <30 years) with a male to female ratio of 15:1 .

Clinical presentation

Symptoms are typically those of intermittent claudication. Physical examination can reveal signs of arterial compromise, particularly when the ankle is plantarflexed. Chronic repeated arterial compression can lead to acute thrombus formation and presentation with acute limb-threatening ischemia in those with poorly developed collateral vessels.

Pathology

Arterial compression can result in chronic vascular microtrauma, local premature arteriosclerosis, and thrombus formation. This can result in distal ischemia. Stenosis and turbulent flow may lead to post-stenotic ectasia or aneurysm formation.

Five anatomic types of entrapment are typically described :

type I: popliteal artery has an aberrant medial course around the medial head of gastrocnemius
type II: artery is not displaced, but the medial head of gastrocnemius inserts more lateral than usual; the artery passes medial and beneath the muscle
type III: an accessory slip of medial head of gastrocnemius slings around the artery
type IV: artery lies deep in popliteal fossa entrapped by popliteus or fibrous band
type V: both popliteal artery and vein are entrapped

Another method of classification is the Heidelburg classification system .

type I: the popliteal artery has an atypical course
type II: the muscular insertion is atypical
type III: both conditions are present

Radiographic features

Ultrasound

May show arterial compression elicited by maneuvers such as plantar flexion and dorsiflexion . Doppler may demonstrate an increase in peak velocity .

CT

CT angiography can help identify abnormal tendinous or muscular structures, diastasis between the popliteal artery and vein, an insertion anomaly and/or arterial deviation. Aberrant muscular and fibrous attachments can be different in almost every case and it best evaluated on axial images.

MRI

MRI is the best imaging modality to demonstrate the underlying anatomic type of entrapment, which helps guide surgical management . A medial slip of the medial head of the gastrocnemius may be seen, compressing the popliteal artery.

Angiography (DSA)

Lower limb angiography usually demonstrates medial deviation/compression of the popliteal artery when the ankle is plantarflexed. Occlusion of the vessels with thrombus can be seen in the acute presentation. Usually, collateral vessels are present. Even slight irregularity of the vessel can indicate a degree of entrapment .

Treatment and prognosis

Acute limb-threatening thrombosis requires urgent bypass surgery. Intermittent occlusion can usually be cured with the release of the popliteal artery alone or with saphenous vein bypass .