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Bilateral popliteal artery entrapment syndrome secondary to anomalous lateral heads of gastrocnemius Popliteal artery entrapment syndrome (PAES) was first described by Stuart in 18791 and is characterized by extrinsic compression of the popliteal artery by musculotendinous structures within the popliteal fossa. During the embryological development of the lower limb, the popliteal artery forms superficial to the popliteus muscle during the same period that the medial head of gastrocnemius migrates across the popliteal fossa. Congenital abnormalities in the relations of the popliteal artery, medial head of gastrocnemius and popliteus muscles are the most commonly described anomalies in PAES and have subsequently been classified into six categories by Whelan and Love in 1986.2 Mechanical compression of the artery by aberrant muscle fibres can lead to sclerotic and aneurysmal degeneration of the arterial wall resulting in thromboembolism. The incidence of popliteal artery entrapment has not been clearly documented or studied, but figures range from 0.17% to 3.5% of the population.3 Patients with PAES may be asymptomatic, suffer from pain or paraesthesia after exercise, are limited by intermittent claudication or present with limb-threatening ischaemia. Bilateral symptoms are present in 30% of patients with PAES, although with investigation, two-thirds of patients with unilateral symptoms are found to have bilateral anatomic abnormalities. Entrapment by the lateral head of gastrocnemius muscle is indeed so uncommon, that it does not fall into any of the six categories described,4 and to date, only a handful of cases have been reported.5 Kim et al. described two subgroups of the ‘uncommon type’ lateral head of gastrocnemius anomaly; one being an abnormal insertion and the other an aberrant accessory slip
of the muscle.6 We describe a fascinating case of bilateral, symptomatic, popliteal artery entrapment by anomalous medial origins of the lateral heads of gastrocnemius. A 47-year-old man with a past history of alcohol abuse and obesity developed sudden onset paraesthesia of his right foot while training in the gym. On presentation to the emergency department, his foot was found to be cool, pale and pulseless. He was diagnosed with an acutely ischaemic limb and a heparin infusion was commenced. He had no prior history of claudication and had never smoked, but reported foot paraesthesia when exercising in the preceding months. Computer tomography angiogram demonstrated a 5-cm acute occlusion of the right mid-popliteal artery. Magnetic resonance (MR) imaging demonstrated anomalous medial origins of the lateral head of gastrocnemius bilaterally, arising from the posterior aspect of the medial supracondylar femur, immediately superior to the origin of the medial head of gastrocnemius (Fig. 1). There was hypertrophy of the anomalous right lateral head of gastrocnemius, with aneurysmal dilatation and subacute thrombosis of the right mid-popliteal artery, and complete effacement of the right popliteal vein. Digital subtraction angiography was performed, which diagnosed a 5-cm acute right mid-popliteal artery occlusion with preserved three vessel run off (Fig. 2). The patient was treated with an inter-position short saphenous vein bypass graft and release of entrapment performed via a posterior approach. The bulky anomalous lateral head of gastrocnemius was divided from its origin at the medial femoral condyle, and a segment of the lateral head of gastrocnemius was resected. The
Fig. 1. Magnetic resonance image of bilateral knees displaying hypertrophied anomalous medial slip of the lateral head of gastrocnemius attaching to medial supracondylar ridge of femur.
© 2015 Royal Australasian College of Surgeons
ANZ J Surg •• (2015) ••–••
2
Images for surgeons
Fig. 3. Operative image displaying anomalous lateral head of gastrocnemius (left leg).
of the entrapment and arterial reconstruction to be performed successfully, resulting in limb salvage. Popliteal entrapment should be considered as differential diagnosis in any young person with claudication or acute popliteal occlusion. Despite the rare nature of this subgroup, consideration should be given to include a seventh group in the Whelan and Love classification system, for ‘popliteal artery entrapment by lateral head of gastrocnemius muscle’.
References Fig. 2. Digital subtraction angiography left leg displaying popliteal artery compression on active plantar flexion.
popliteal artery was aneurysmal and surrounded by scar tissue (aneurysmal dilatation is a rare but documented complication of entrapped popliteal artery).7 The surgery was uncomplicated, and the patient recovered well. He was discharged on aspirin. At outpatient review 6 weeks post-operatively, the patient complained of mild tingling in his left foot and left leg claudication during high-intensity training. An ultrasound failed to demonstrate compression of the left popliteal artery with dynamic manoeuvres, therefore an angiogram was performed via a retrograde right femoral puncture. This demonstrated left popliteal artery occlusion with active plantar flexion, while the right popliteal vein graft remained widely patent, confirming successful decompression. The patient subsequently underwent left popliteal artery release; at operation, the anomalous lateral head of gastrocnemius was found to attach to the medial femoral condyle (as seen on MR imaging). Left popliteal artery was normal (Fig. 3). As with the right side, the anomalous lateral head of gastrocnemius was dissected at its origin and taken down, and a portion of the muscle was resected. The patient is now symptom-free 1 year post-operatively, with a patent right popliteal artery inter-position graft and patent native left popliteal artery. This case illustrates a rare variant of popliteal entrapment caused by bilateral anomalous lateral heads of gastrocnemius, resulting in an acute right popliteal artery occlusion and acute limb ischaemia. The underlying pathology was correctly identified, enabling release
1. Stuart TP. Note on a variation in the course of the popliteal artery. J. Anat. Physiol. 1879; 13 (Pt 2): 162. 2. Whelan TJ, Love J. Popliteal artery entrapment syndrome. In: Haimovici H (ed.). Vascular Surgery, Principles and Techniques, 2nd edn. New York, NY: McGraw-Hill, 1986; 557–67. 3. Gourgiotis S, Aggelakas J, Nikolaos S, Charalabos E, Charalabos G. Diagnosis and surgical approach of popliteal artery entrapment syndrome: a retrospective study. Vasc. Health Risk Manag. 2008; 4: 83–8. 4. Öztoprak Ì, Gümüs¸ C, Eg˘ilmez H, Manduz S, Oztoprak B, Emrecan B. Multidetector computed tomographic angiography findings in a rare case of popliteal artery entrapment syndrome. Ann. Vasc. Surg. 2008; 22: 130–3. 5. Liu PT, Moyer AC, Huettl EA, Fowl RJ, Stone WM. Popliteal vascular entrapment syndrome caused by a rare anomalous slip of the lateral head of the gastrocnemius muscle. Skeletal Radiol. 2005; 34: 359–63. 6. Kim HK, Shin MJ, Kim SM, Lee SH, Hong HJ. Popliteal artery entrapment syndrome: morphological classification utilizing MR imaging. Skeletal Radiol. 2006; 35: 648–58. 7. Karaman B, Battal B, Akgun V, Hamcan S, Bozkurt Y, Bozlar U. Popliteal artery entrapment syndrome with thrombosed popliteal aneurysm: multidetector computed tomography angiography findings of a case. Clin. Imaging 2012; 36: 850–3.
Melanie D. Chang,* MBBS (Hons), DipSurgAnat Anna Steer,* MBBS Warren Perera,† MBBS, FRANZCR Domenic R. Robinson,* MBBS, FRACS *Vascular Surgery, St Vincent’s Hospital, Melbourne, Victoria, Australia and †Medical Imaging, St Vincent’s Hospital, Melbourne, Victoria, Australia doi: 10.1111/ans.13047
© 2015 Royal Australasian College of Surgeons
Bilateral popliteal artery entrapment syndrome secondary to anomalous lateral heads of gastrocnemius Popliteal artery entrapment syndrome (PAES) was first described by Stuart in 18791 and is characterized by extrinsic compression of the popliteal artery by musculotendinous structures within the popliteal fossa. During the embryological development of the lower limb, the popliteal artery forms superficial to the popliteus muscle during the same period that the medial head of gastrocnemius migrates across the popliteal fossa. Congenital abnormalities in the relations of the popliteal artery, medial head of gastrocnemius and popliteus muscles are the most commonly described anomalies in PAES and have subsequently been classified into six categories by Whelan and Love in 1986.2 Mechanical compression of the artery by aberrant muscle fibres can lead to sclerotic and aneurysmal degeneration of the arterial wall resulting in thromboembolism. The incidence of popliteal artery entrapment has not been clearly documented or studied, but figures range from 0.17% to 3.5% of the population.3 Patients with PAES may be asymptomatic, suffer from pain or paraesthesia after exercise, are limited by intermittent claudication or present with limb-threatening ischaemia. Bilateral symptoms are present in 30% of patients with PAES, although with investigation, two-thirds of patients with unilateral symptoms are found to have bilateral anatomic abnormalities. Entrapment by the lateral head of gastrocnemius muscle is indeed so uncommon, that it does not fall into any of the six categories described,4 and to date, only a handful of cases have been reported.5 Kim et al. described two subgroups of the ‘uncommon type’ lateral head of gastrocnemius anomaly; one being an abnormal insertion and the other an aberrant accessory slip
of the muscle.6 We describe a fascinating case of bilateral, symptomatic, popliteal artery entrapment by anomalous medial origins of the lateral heads of gastrocnemius. A 47-year-old man with a past history of alcohol abuse and obesity developed sudden onset paraesthesia of his right foot while training in the gym. On presentation to the emergency department, his foot was found to be cool, pale and pulseless. He was diagnosed with an acutely ischaemic limb and a heparin infusion was commenced. He had no prior history of claudication and had never smoked, but reported foot paraesthesia when exercising in the preceding months. Computer tomography angiogram demonstrated a 5-cm acute occlusion of the right mid-popliteal artery. Magnetic resonance (MR) imaging demonstrated anomalous medial origins of the lateral head of gastrocnemius bilaterally, arising from the posterior aspect of the medial supracondylar femur, immediately superior to the origin of the medial head of gastrocnemius (Fig. 1). There was hypertrophy of the anomalous right lateral head of gastrocnemius, with aneurysmal dilatation and subacute thrombosis of the right mid-popliteal artery, and complete effacement of the right popliteal vein. Digital subtraction angiography was performed, which diagnosed a 5-cm acute right mid-popliteal artery occlusion with preserved three vessel run off (Fig. 2). The patient was treated with an inter-position short saphenous vein bypass graft and release of entrapment performed via a posterior approach. The bulky anomalous lateral head of gastrocnemius was divided from its origin at the medial femoral condyle, and a segment of the lateral head of gastrocnemius was resected. The
Fig. 1. Magnetic resonance image of bilateral knees displaying hypertrophied anomalous medial slip of the lateral head of gastrocnemius attaching to medial supracondylar ridge of femur.
© 2015 Royal Australasian College of Surgeons
ANZ J Surg •• (2015) ••–••
2
Images for surgeons
Fig. 3. Operative image displaying anomalous lateral head of gastrocnemius (left leg).
of the entrapment and arterial reconstruction to be performed successfully, resulting in limb salvage. Popliteal entrapment should be considered as differential diagnosis in any young person with claudication or acute popliteal occlusion. Despite the rare nature of this subgroup, consideration should be given to include a seventh group in the Whelan and Love classification system, for ‘popliteal artery entrapment by lateral head of gastrocnemius muscle’.
References Fig. 2. Digital subtraction angiography left leg displaying popliteal artery compression on active plantar flexion.
popliteal artery was aneurysmal and surrounded by scar tissue (aneurysmal dilatation is a rare but documented complication of entrapped popliteal artery).7 The surgery was uncomplicated, and the patient recovered well. He was discharged on aspirin. At outpatient review 6 weeks post-operatively, the patient complained of mild tingling in his left foot and left leg claudication during high-intensity training. An ultrasound failed to demonstrate compression of the left popliteal artery with dynamic manoeuvres, therefore an angiogram was performed via a retrograde right femoral puncture. This demonstrated left popliteal artery occlusion with active plantar flexion, while the right popliteal vein graft remained widely patent, confirming successful decompression. The patient subsequently underwent left popliteal artery release; at operation, the anomalous lateral head of gastrocnemius was found to attach to the medial femoral condyle (as seen on MR imaging). Left popliteal artery was normal (Fig. 3). As with the right side, the anomalous lateral head of gastrocnemius was dissected at its origin and taken down, and a portion of the muscle was resected. The patient is now symptom-free 1 year post-operatively, with a patent right popliteal artery inter-position graft and patent native left popliteal artery. This case illustrates a rare variant of popliteal entrapment caused by bilateral anomalous lateral heads of gastrocnemius, resulting in an acute right popliteal artery occlusion and acute limb ischaemia. The underlying pathology was correctly identified, enabling release
1. Stuart TP. Note on a variation in the course of the popliteal artery. J. Anat. Physiol. 1879; 13 (Pt 2): 162. 2. Whelan TJ, Love J. Popliteal artery entrapment syndrome. In: Haimovici H (ed.). Vascular Surgery, Principles and Techniques, 2nd edn. New York, NY: McGraw-Hill, 1986; 557–67. 3. Gourgiotis S, Aggelakas J, Nikolaos S, Charalabos E, Charalabos G. Diagnosis and surgical approach of popliteal artery entrapment syndrome: a retrospective study. Vasc. Health Risk Manag. 2008; 4: 83–8. 4. Öztoprak Ì, Gümüs¸ C, Eg˘ilmez H, Manduz S, Oztoprak B, Emrecan B. Multidetector computed tomographic angiography findings in a rare case of popliteal artery entrapment syndrome. Ann. Vasc. Surg. 2008; 22: 130–3. 5. Liu PT, Moyer AC, Huettl EA, Fowl RJ, Stone WM. Popliteal vascular entrapment syndrome caused by a rare anomalous slip of the lateral head of the gastrocnemius muscle. Skeletal Radiol. 2005; 34: 359–63. 6. Kim HK, Shin MJ, Kim SM, Lee SH, Hong HJ. Popliteal artery entrapment syndrome: morphological classification utilizing MR imaging. Skeletal Radiol. 2006; 35: 648–58. 7. Karaman B, Battal B, Akgun V, Hamcan S, Bozkurt Y, Bozlar U. Popliteal artery entrapment syndrome with thrombosed popliteal aneurysm: multidetector computed tomography angiography findings of a case. Clin. Imaging 2012; 36: 850–3.
Melanie D. Chang,* MBBS (Hons), DipSurgAnat Anna Steer,* MBBS Warren Perera,† MBBS, FRANZCR Domenic R. Robinson,* MBBS, FRACS *Vascular Surgery, St Vincent’s Hospital, Melbourne, Victoria, Australia and †Medical Imaging, St Vincent’s Hospital, Melbourne, Victoria, Australia doi: 10.1111/ans.13047
© 2015 Royal Australasian College of Surgeons
