Outcomes of Popliteal Artery Entrapment Syndrome (PAES)
Popliteal artery entrapment syndrome results from compression by the medial head of the gastrocnemius muscle, leading to thrombosis, limb ischemia, and potential limb loss if left untreated. 1
Clinical Presentation and Progression
PAES is a rare but significant cause of leg ischemia, particularly in young, active individuals without typical atherosclerotic risk factors. The condition presents with:
- Claudication and exercise-induced leg pain
- Coldness in the affected limb
- Decreased blood flow to the leg 2
Natural History and Complications
If left untreated, PAES follows a predictable progression:
- Initial intermittent claudication
- Progressive arterial damage and fibrosis
- Thrombosis formation
- Acute limb ischemia
- Potential limb loss 1, 3
The syndrome accounts for approximately 10% of acute arterial occlusions in elderly men and is commonly mistaken for an embolic event 4. Severe ischemia typically occurs because:
- Thrombosis develops suddenly without collateral circulation
- The popliteal artery is the sole axial artery crossing the knee 4
Diagnostic Considerations
PAES should be suspected in any patient under 50 years with calf claudication. Diagnosis involves:
- Positional stress testing
- Duplex ultrasonography
- CT angiography with the knee in neutral and hyperextended positions 5, 6
CT angiography is particularly valuable as it can:
- Depict arterial changes
- Identify abnormal anatomic structures causing the entrapment 6
Treatment and Outcomes
Early intervention is critical to prevent irreversible damage. Treatment options depend on the degree of arterial damage:
For early cases without significant arterial damage:
- Simple surgical release of the popliteal artery (67.3% of cases in one study)
For cases with arterial wall damage:
- Autogenous saphenous vein patch angioplasty with or without thromboendarterectomy (10.2%)
For cases with complete occlusion or severe damage:
- Autogenous saphenous vein graft interposition or bypass (22.5%) 5
In cases of acute limb ischemia with absent runoff, catheter-directed thrombolysis or mechanical thrombectomy may be necessary to restore distal flow and resolve emboli before definitive surgical treatment 4.
Important Clinical Pearls
- PAES is bilateral in approximately 50% of cases, requiring evaluation of both limbs 4
- The condition occurs predominantly in young adults who lack atherosclerotic risk factors 3
- Early diagnosis and treatment are essential to prevent progression to irreversible arterial damage and limb loss 1
- When acute ischemia occurs in a young patient without risk factors, PAES should be high on the differential diagnosis
Based on the evidence provided, the correct answer to the multiple-choice question is C: Popliteal artery entrapment results from compression by the medial head of the gastrocnemius muscle.