Popliteal artery entrapment: MR findings

THE CONUNDRUM OF CLAUDICATION

Stable claudication has traditionally been treated conservatively by many clinicians as operative therapies involve considerable risk for a condition that is often slowly progressive and non-fatal. The relative safety of less invasive endovascular techniques brings potential survival benefits from the increased exercise tolerance that result. We aimed to revisit and clarify the aetiologies of intermittent claudication in a review of the rarer causes that can mimic atherosclerotic occlusive disease. An extensive search of Medline, Embase and the Cochrane databases was carried out to compile published work addressing the aetiology of claudication and specific non-atherosclerotic causes. The reference lists of these manuscripts were also searched for relevant articles. There are several vasculogenic and neurogenic causes for intermittent claudication, many of which are unrelated to atherosclerosis. Recognition of these rarer syndromes is essential when planning endovascular or operative management strategies. Consideration of non-atherosclerotic differential diagnoses is recommended when assessing the patient with intermittent claudication. This is particularly critical in the young patient whose pattern of symptoms and risk factors may not fit precisely with atherosclerosis.

Diagnosis and surgical management of popliteal artery entrapment syndrome

BACKGROUND

The purpose of the present study was to report the authors' experience of surgically treating eight limbs in six patients for popliteal artery entrapment syndrome (PAES), over a 10-year period.

METHODS

From 1995 to 2004, six patients (eight limbs) underwent surgery for PAES at a single institution. The patients' data were collected retrospectively from the case records and operative notes.

RESULTS

There were six patients with a mean age of 34 years (range, 27-38 years) at diagnosis and five of them were male. Two patients were found to have bilateral involvement. Both patients had symptoms involving both limbs and underwent bilateral surgery. Intermittent claudication was the most frequent presenting symptom (seven of eight limbs). All the patients had Delaney's type III PAES. Popliteal artery release was performed in all eight limbs and this was combined with a vein patch or a reversed long saphenous vein bypass graft in four limbs because the arteries in these four limbs were diseased or occluded. At a median follow up of 15 months (range, 40 days-9 years), five (seven limbs) of the six patients (eight limbs) were cured of their symptoms. One patient who presented late with rest pain and dusky toes underwent popliteal artery release, endarterectomy and a vein patch repair for an occluded popliteal artery. However, her limb could not be salvaged and her affected limb had to be amputated.

CONCLUSION

Popliteal artery entrapment syndrome is a rare but important cause of peripheral vascular insufficiency especially in young patients. Early diagnosis and surgical intervention is imperative for good operative outcome and to prevent limb loss.

Leg pain in the running athlete

Leg pain is a common complaint among recreational and professional athletes who compete in running sports. Evaluation of the individual with intermittent or constant leg pain should be well organized and inclusive. Duration of the pain, its relation to injury, intensity of the pain, and its pattern are important factors. Additionally, changes in the training regimen, its level, intensity, or duration, or in the nature of the routine are critical components of the assessment. Physical examination can help differentiate bony from soft-tissue etiologies. Studies are dictated by the differential diagnosis but include radiographs in almost all patients and selected use of other modalities. These include bone scans and magnetic resonance imaging for medial tibial stress syndrome and stress fractures and intracompartmental pressure measurements for chronic compartment syndrome. Treatment often requires either rest or a change in training regimen. Surgery for conditions such as chronic compartment syndrome frequently allows a return to preinjury activities.

Popliteal artery entrapment syndrome

Popliteal artery entrapment syndrome is a condition caused by direct compression of the popliteal artery as it passes within or exits the popliteal fossa. It is surprisingly uncommon and usually affects young patients, typically men, and often presenting with symptoms of claudication, or more rarely acute limb ischemia, calf cramps, or a picture of compartment syndrome. The diagnosis should be considered early within the differential diagnosis of all patients presenting with these problems in this age group. The key to management of this condition lies in a high index of suspicion. The treatment of popliteal artery entrapment syndrome is surgical. When the condition is detected at an early stage surgery may be limited to release of the artery alone. However, if the artery has been compressed for some time the resulting intimal damage necessitates bypass of the affected segment. There are numerous reports of thrombectomy with simple vein patching, but the results are inferior to interpositional vein grafting. Reports have also been published of attempts made at endovascular treatment. At present, this mode of management adds little to the definitive treatment of affected limbs and appears limited to use as a bridging procedure in cases presenting with limb ischemia. Unfortunately, an effective clinical screening test does not exist and imaging remains the mainstay in the diagnosis of symptomatic limbs and the screening of asymptomatic limbs. The exact modality of imaging remains unclear, but for the moment duplex scanning, angiography, computed tomography, and magnetic resonance imaging all appear to have their place.

Popliteal artery entrapment syndrome

BACKGROUND

Popliteal artery entrapment syndrome (PAES) is rare and may be underdiagnosed. Improved specialized, non-invasive imaging techniques are producing detailed topographical evidence of the anomaly.

METHODS

A historical review of the literature and Medline search was performed with reference to the diagnosis and treatment of the condition. In addition, embryologically based theories for the condition have been postulated.

RESULTS AND CONCLUSION

PAES may be the result of abnormal development of the popliteal artery or a consequence of excessive cranial migration of the medial head of the gastrocnemius muscle. Magnetic resonance imaging appears to be the most useful single investigation to demonstrate the anomaly. Popliteal artery release alone or with vein bypass is the treatment of choice when intervention is indicated.

Popliteal artery entrapment syndrome: arteriographic findings and thrombolytic therapy

PURPOSE

To review the arteriographic appearance of popliteal artery entrapment syndrome (PAES) and functional popliteal artery entrapment, and determine the role of thrombolysis in the treatment of these disorders.

MATERIALS AND METHODS

Retrospective review of hospital records from 1991 to 1998.

RESULTS

Seven patients with PAES and one with functional entrapment were identified. The popliteal artery was occluded in two limbs and compressed in 13. Active plantar flexion was necessary to demonstrate impingement in nine limbs. Medial deviation of the popliteal artery was evident in six of 14 patent popliteal arteries, and lateral deviation was observed in one limb. "Classic" abrupt medial angulation of the popliteal artery was observed in one limb. Both limbs were involved in all six patients who underwent bilateral popliteal exploration. Thrombolytic therapy was performed in three limbs. In two instances, it permitted a less extensive surgical procedure than would otherwise have been required.

CONCLUSIONS

There is considerable variability in the arteriographic appearance of PAES, which is arteriographically indistinguishable from functional entrapment. It is frequently bilateral. Thrombolytic therapy does not obviate surgery but may permit a less extensive procedure to be performed.

A new therapeutic approach to popliteal artery entrapment syndrome (PAES)

OBJECTIVES

An alternative therapeutic approach to popliteal artery entrapment syndrome (PAES) with vascular complications.

MATERIALS

Three male patients (16, 42 and 68 years) with thrombotic and/or embolic obstructions of popliteal or crural vessels as a consequence of popliteal entrapment syndrome.

METHODS

Combined catheter treatment consisting of percutaneous transluminal thrombembolectomy (PTEE), local thrombolysis (LTL) and percutaneous transluminal dilatation (PTA) was performed for thrombotic and embolic obstructions of popliteal or crural vessels. The aberrant tendomuscular structures were surgically corrected at a later date.

RESULTS

After the procedure systolic ankle/arm pressure ratios in the three patients improved from 0.66 to 1.13, 0.57 to 1.07 and 0.46 to 1.10. Twelve, 8 and 4 months later the patients were asymptomatic. None of the patients showed popliteal artery compression during plantar flexion on Duplex scanning.

CONCLUSIONS

This new therapeutic approach avoids direct vascular surgery with bypass or patch implantation in patients with PAES who are often young. The long term results remain to be evaluated.

Demonstration of popliteal artery entrapment on leg muscle scintigraphy with 99mTc MIBI and single photon emission tomography

Popliteal artery entrapment is difficult to diagnose even at surgery. Early diagnosis is important as the prognosis is better if detected before the onset of complications. There is no sensitive method for the evaluation of this condition. We describe three cases detected by a new technique using 99mTc methoxy isobutyl isonitrile (MIBI) with single photon emission tomography. The scintigraphic features of entrapment and the advantage of MIBI leg scintigraphy over other methods are discussed.

Three-dimensional reconstruction of a levator claviculae muscle

During routine radiological examination of a 72 year-old woman a soft-tissue shadow in the left posterior triangle of the neck was observed. Three-dimensional reconstruction of this structure suggested that it might be a muscular variant: a levator claviculae muscle. In our case it took origin from the upper part of the cervical column and was inserted into the lateral third of the clavicle. With this example as a background, the general significance of anatomical muscular variants for modern imaging techniques is discussed.

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young health volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.