PRESENTED AT THE VANCOUVER ISLAND VASCULAR SYMPOSIUM
APRIL 7, 2001
Dr. Jim Dooner FRCS(C), FACS
Case Presentation
A 19 year old female complained of severe cramping pain in the right calf with walking more than a block and was unable to participate in sports, notably soccer
and baseball. She was a non smoker with no history of diabetes. She had started experiencing these symptoms two years before and Popliteal Artery Entrapment
Syndrome (PAES) was suspected. An MRI at that time had suggested lateral displacement of the Popliteal artery and a more lateral insertion of the medial head of
the gastrocnemius. Her symptoms seemed to improve slightly and while surgery had been tentatively discussed she deferred surgical intervention. The symptoms became
worse and she was re-referred.
Objective findings were minimal. She had normal palpable pedal pulses but both the PT and DP disappeared bilaterally with plantar and dorsiflexion. A resting Doppler
with PG revealed normal waveforms and ABI. Damping of the digital waveforms in both legs occurred with resisted plantarflexion and passive dorsiflexion. An exercise
Doppler revealed no post exercise gradient indicating there was no fixed obstructive lesion. An angiogram revealed normal looking vessels but dramatic narrowing of
the popliteal artery between the femoral condyles with plantar and dorsiflexion.
Surgery was carried out to explore the popliteal fossa through a posterior approach and release the lateral portion of the gastrocnemius insertion. No other restrictive
elements were found i.e. aberrant bands, aberrant popliteus tendon. She was mobile with assisted weight bearing the next day and wounds healed well. Pulses were normal
at rest. Walking distance improved dramatically. Resumption of sports is anticipated soon.
History of PAES
The first description of the entity was by T.P. Anderson Stuart, and Edinburgh University medical student, in 1879. He described an abnormal medial course of the
artery in a gangrenous limb[1]. Description of the clinical syndrome was elaborated by Hamming in the Netherlands (1959) Servello in Italy (1962) and Carter and Eban in
England (1964).[2] Despite this there have been only 400 cases reported in the world literature as of 1999.[3]
The incidence has been largely skewed towards males (15:1) perhaps due to greater muscle bulk, however with the rise in women's competitive athletics the ratio may be
expected to change.
Clinical Presentation
Claudication in a young, athletic individual should raise the suspicion of PAES. The history of the problem is critical due to the lack of physical findings. If the
lesion is not detected and the problem is left uncorrected an occlusive process may develop resulting in embolic phenomena or frank thrombosis with either claudication
or limb-threatening ischemia. The pulses in uncomplicated PAES will be intact and resting and exercise dopplers will be normal. If the entity is suspected, passive
dorsiflexion and resisted plantar flexion should be included in the clinical and doppler evaluation. This tenses the gastrocnemius across the artery. MRI is emerging as
the most valuable test. It is able to accurately detect anatomical aberrations which account for the entrapment. Angiography is important and in this case confirms the
impingement. It is particularly valuable in longer standing cases where evaluation of endofibrotic lesions is necessary. The surgical approach will be affected by the
presence or absence of any fixed lesions in the vessel.
Classification
Type I: Popliteal artery deviates medially around a normally placed medial head of the gastrocnemius muscle.
Type II: Medial head arises from a point more lateral than normal. The artery descends in a relatively straight course but still passes medial and beneath the muscle.
Type III: The popliteal artery is compressed by an accessory slip of muscle from the medial head, which arises more laterally than the medial head.
Type IV: Popliteus muscle or a fibrous band passes over the artery below the level of the tibial plateau.
Functional: No clear anatomical abnormality defined by MRI, CT or exploration.
Operative Intervention
A prone posterior approach with a 'S' shaped incision is preferred. This allows visualization of the entire popliteal fossa and does not necessitate division of any
unnecessary musculo-tendinous structures to accomplish the exposure. The constricting element defined by MRI can be divided. If there is no anatomic abnormality
consistent with the above classification the entrapment is defined as 'functional'. The medial head should be mobilized and the popliteal space cleared from the adductor
canal to the Anterior tibial artery. Care should be taken to avoid compromising geniculate collaterals. If the preoperative assessment has shown a fixed occlusion,
revascularization may be necessary. In all cases musculo-tendinous release should precede the revascularization procedure. Saphenous vein bypass may be necessary or a
short segment excision and interposition may suffice if the anatomy is appropriate.
In straightforward cases assisted weight bearing should be started early, within 24 hours and objective analysis with treadmill testing repeated at about 6 weeks.
Results are excellent if the lesion is detected before endofibrosis or occlusion develops.
Note on a variation in the course of the popliteal artery.
References
1. Journal of Anatomy and Physiology 1879; 13:162.
2. Whelan Thomas J: Popliteal Artery Entrapment in Rutherford: Vascular Surgery, WB Saunders 1989, 779.
3. Lambert AW and Wilkins DC: Popliteal Artery Entrapment Syndrome, Br J Surg 1999,86,1365-1370.
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