Case Report Abstracts Presented to the Peripheral Vascular Society - Winter Meeting 2009

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1 Case Report Abstracts Presented to the Peripheral Vascular Society - Winter Meeting 2009 Intermittent Foot Claudication with Active Dorsiflexion: The Seminal Case of Dorsalis Pedis Artery Entrapment Katie Weichman, 1 Todd Berland, 1 Brendan MacKay, 2 Kenneth Mroczek, 2 and Mark Adelman, 1 New York, New York Background: Atypical claudication is a relatively uncommon problem within the general population. However, suspicion for the diagnosis is raised when young and athletic patients present with symptoms of claudication during exercise. The most common causes of atypical claudication are anatomical variants, including popliteal artery entrapment syndrome and tarsal tunnel syndrome. These variants result in impaired arterial flow and nerve compression, respectively. In this report, we present a seminal case of dorsalis pedis artery entrapment by the extensor hallucis brevis tendon during active dorsiflexion of the foot. Methods: The patient was a 42-year-old male without significant past medical history, who presented with claudication in both feet upon active dorsiflexion. He underwent dynamic arterial duplex studies that first revealed normal flow in the neutral position and then revealed complete cessation of flow in both duplex and Doppler modes on dorsiflexion of the foot. He also underwent dynamic magnetic resonance angiography of bilateral lower extremities that revealed an incomplete pedal arch with early termination of the posterior tibial artery on static images and termination of the dorsalis pedis artery at notching on the dorsum of the foot during dorsiflexion. The patient was taken to the operating room for bilateral dorsalis pedis artery exploration. During exploration, the patient was found to have entrapment of the dorsalis pedis artery by the extensor hallucis brevis (EHB) tendon. This was documented by both direct visualization and intraoperative cessation of Doppler signal on dorsiflexion. Since the EHB tendon provides only secondary function to the extensor hallucis longus (EHL) tendon, the EHB was transected near its insertion and transposed directly to the EHL tendon. This allowed for normal extensor function of the great toe and restored triphasic Doppler signals during dorsiflexion. Conclusion: Dorsalis pedis arterial entrapment is a novel cause of atypical claudication. It is extremely uncommon as patients must have both abnormal anatomy and an incomplete pedal arch to display symptoms. Similar to other entrapment syndromes, if identified before permanent arterial scarring, the treatment does not require a bypass procedure. Removal of the tendon along with transposition will allow cessation of symptoms without impaired dorsiflexion of the great toe. Intermittent claudication is derived from the Latin word claudicatio and refers to a halt or lameness in a person s walk. Typical etiologies of lower extremity pain are most common in elderly patients with Presented at the 19th Annual Winter Meeting of the Peripheral Vascular Surgery Society, Steamboat Springs, CO, January 30 February 1, Department of Vascular Surgery, New York University, New York, NY. 2 Department of Orthopedic Surgery, New York University Hospital for Joint Diseases, New York, NY. multiple medical comorbidities. These etiologies include both arterial claudication and pseudoclaudication, which consists of musculoskeletal, venous, and neurogenic types. Arterial claudication is defined Correspondence to: Katie Weichman, Department of Surgery, New York University, 560 First Avenue, New York, NY 10016, USA, E mail: weichmank@gmail.com Ann Vasc Surg 2010; 24: 113.e1 113.e5 DOI: /j.avsg Ó Annals of Vascular Surgery Inc. 113.e1

2 113.e2 Case reports Annals of Vascular Surgery as reproducible pain or weakness in a muscle group that is induced by exercise and relieved by rest. This type of intermittent claudication most commonly affects the lower extremity and results in a severely impaired quality of life for its many sufferers. There is, also, a unique subset of young, healthy, athletic patients who experience atypical claudication. The most widely recognized and documented causes of atypical claudication are chronic compartment syndrome, popliteal artery entrapment syndrome, and tarsal tunnel syndrome. 1,2 These syndromes are the result of anatomical constraints on arteries and nerves that initiate symptomatic intermittent claudication. There are no other documented musculotendinous compressions of distal arteries reported in the literature. In this report, we present a case of atypical lower extremity claudication caused by entrapment of the dorsalis pedis artery by the extensor hallucis brevis tendon on active dorsiflexion of the foot in a patient with an incomplete pedal arch. CASE REPORT Our patient was a 43 year old male, nonsmoker, with no significant past medical history, who presented to the vascular surgery office complaining of bilateral foot pain and numbness during dorsiflexion and exercise. Histori cally, the symptoms initiated when he was a child and had not lessened or worsened over the past 30 years. He noted that they were most noticeably reproducible over a constant time interval during bicycle riding, uphill walking, or running or when his foot was in dorsiflexion for a sustained period of time. He denied any symptoms at rest, including pain, burning, numbness, and nonheal ing ulcers. He also denied any family history of similar complaints or peripheral vascular disease. Of note, many doctors in various countries had seen the patient over a number of years and no definitive diagnosis had been made. In the absence of objective data explaining his symptoms, a psychiatric disorder was even suggested. His physical exam was unremarkable at rest. He dis played palpable 2+ pulses in bilateral femoral, popliteal, dor salis pedis, and posterior tibial vessels. However, upon active pedal dorsiflexion, the dorsalis pedis pulse became nonpalp able, signifying more than one anatomical problem. If the patient had only dorsalis pedis occlusion with dorsiflexion, retrograde flow from the pedal arch should restore a dorsalis pedis pulse. Since the pulse did not restore, there must also be pathology related to the posterior tibial artery or the pedal arch in conjunction with the abnormality in the dorsal pedal anatomy. He displayed no obvious bony or musculotendi nous abnormalities. Sensation was intact in superficial peroneal, deep peroneal, sural, and medial/lateral plantar distributions. Strength in bilateral lower extremities was 5/5 and symmetrical. During the initial work up, he underwent a noninva sive vascular arterial duplex scan. This study, at rest, Fig. 1. Arterial Duplex Scan obtained at rest. revealed an ankle brachial index (ABI) of 1.00 and tripha sic pulse volume recordings in bilateral lower extremities (Fig. 1). However, arterial duplex scanning, during active dorsiflexion, demonstrated an absent ABI and a flat pulse volume recording (Fig. 2). Of note, during passive dorsi flexion of the feet, the point of occlusion was not identi fied and the patient maintained an ABI of 1.00 and normal triphasic flow to the foot. He subsequently underwent magnetic resonance angiography (MRA) of bilateral lower extremities that

3 Vol. 24, No. 1, January 2010 Case reports 113.e3 Fig. 3. MRA of Bilateral Lower Extremity. Fig. 2. Arterial Duplex Scan obtained during active dorsiflexion of the foot. revealed three vessel (anterior tibial, peroneal, and poste rior tibial) runoff to bilateral lower extremities. While the inflow to the foot appeared normal, the images showed a discontinuous pedal arch, with early termination of the posterior tibial artery and minimal notching of bilat eral dorsalis pedis arteries in the mid forefoot (Fig. 3). These unusual findings prompted a dynamic angio gram to be obtained of bilateral lower extremities. This Fig. 4. Angiogram of Right Lower Extremity in Neutral Position. study revealed normal runoff to the foot through the dor salis pedis artery in the neutral position (Fig. 4). However, on active dorsiflexion, this arterial flow through the dor salis pedis artery was abruptly interrupted with absent distal runoff to the foot (Fig. 5). Given the patient s symptoms and objective evidence of compression on active dorsiflexion, he was taken to

4 113.e4 Case reports Annals of Vascular Surgery Fig. 5. Angiogram of Right Lower Extremity during Active Dorsiflexion of Foot. Fig. 7. Normal Pedal Anatomy: Ext. Hallucis Brevis tendon crossing 2nd to 1st Metatarsal to insert on the Ext. Hallucis Longus tendon. Fig. 6. Intraoperative Photo: transection and transposition of Extensor Hallucis Brevis to Extensor hallucis Longus. the operating room for exploration of bilateral dorsalis pedis arteries under local anesthesia. The patient was minimally sedated and injected with lidocaine over the incision site, to facilitate active dorsiflexion after surgical exposure. The right dorsalis pedis artery was visualized in its usual course after a longitudinal incision was made over the dorsum of the foot. A normal triphasic signal was identified with the use of an arterial Doppler. Audible occlusion of the dorsalis pedis was then appreciated during active dorsiflexion of the foot. Upon further distal expo sure, a musculotendinous structure was visualized, com pressing the dorsalis pedis artery. This structure was located over the intermediate (second) cuneiform bone and inserted onto the proximal first metatarsal head. This structure was identified as the extensor hallucis bre vis, with a normal origin on calcaneus and insertion onto the first proximal phalanx. Since there was no evidence of gross abnormalities in the vessel, a decision was made to transect the extensor hallucis brevis tendon at its abnormal insertion and transpose it to the extensor hallu cis longus tendon proximally (Fig. 6) using a nonabsorb able proline suture. After transection and transposition of the tendon, the Doppler was used again during active dorsiflexion of the foot and it displayed a triphasic signal. At this time, care was taken to expose the left dorsalis pedis artery through an identical incision. Similar pathology was visualized upon mobilization, and again the extensor hallucis brevis tendon was transected at its insertion and transposed to the extensor hallucis longus tendon. Confirmation of resolution of compression was obtained through a tripha sic Doppler signal on dorsiflexion of the foot. The incisions were then closed, and a repeat Doppler was performed, which confirmed triphasic flow. Postoperatively, the patient did well and regained function and mobility within 4 days. He currently is living in Indonesia and communicating through e mails and notes that after 6 months he has great improvement in the symptoms of claudication and has no difficulty with dorsiflexion of the great toe. He is unwilling to return for follow up at this time.

5 Vol. 24, No. 1, January 2010 Case reports 113.e5 Fig. 8. Abnormal Pedal Anatomy: Ext. Hallucis Brevis tendon crossing Cunneiform bones to insert proximally on Ext. Hallucis Longus tendon. DISCUSSION Dorsalis pedis arterial entrapment by the extensor hallucis brevis tendon is a novel etiology for atypical claudication in the lower extremity that has not yet been described in the literature. Similar to other etiologies of atypical intermittent claudication of the lower extremity, the cause was an aberrant anatomical relationship. In young patients who present with atypical intermittent claudication of the lower extremity, the differential diagnosis should include, but is not limited to, popliteal artery entrapment syndrome, tarsal tunnel syndrome, and chronic compartment syndrome. The normal anatomical location of the dorsalis pedis artery is well described in the literature. Routinely, it is lateral to the extensor hallucis longus tendon in the proximal forefoot. It is a continuation of the anterior tibial artery at the ankle joint. The posterior border is made up of the articular capsule of the ankle joint and the talus, navicular, and second cuneiform bones. Its anterior border consists of the integument, fascia, and cruciate ligament. It is known to be crossed near its termination by the first tendon of the extensor digitorum brevis and extensor hallucis brevis. On the tibial side, the border is the extensor hallucis longus tendon, while the fibular side is bordered by the first tendon of the extensor digitorum longus. 3 This anatomical relationship was intact except for the extensor hallucis brevis position. Normally, it traverses across the dorsalis pedis artery distal to the branching of both the arcuate artery and deep plantar artery and over the second and first metatarsal bones (Fig. 7). In this case the extensor hallucis brevis tendon traversed the dorsalis pedis artery proximal to these branch points and over the cuneiforms (Fig. 8). As a consequence, there is no room to displace the artery to the plantar surface of the foot and, therefore, compression results. This abnormality is not described in the literature. In addition to the abnormal tendinous insertion, the patient had abnormal arterial anatomy. He had an incomplete arterial arch in the foot, with early termination of the posterior tibial artery. Typically, single-vessel runoff in the calf allows adequate perfusion to the foot through the plantar arch. However, since the arch was incomplete when the dorsalis pedis flow was interrupted by the extensor hallucis brevis tendon, ischemia resulted and the patient experienced symptoms of claudication. Unlike popliteal artery entrapment syndrome, which requires bypass procedure for a chronically injured vessel, this vessel did not display any gross abnormalities; therefore, a bypass was not indicated. 4 In addition, the extensor hallucis brevis was easily transected and transposed because its function is only synergistic with the extensor hallucis longus tendon and long-term disability was unlikely. CONCLUSION This unique case of anatomical variation in both arterial and musculotendinous insertion resulted in a distinct cause of atypical lower extremity claudication that was successfully treated with surgical intervention. SUPPLEMENTARY DATA Supplementary data associated with this article can be found, in the online version, at doi: / j.avsg Indicates video presentation available online REFERENCES 1. Turnipseed WD. Clinical review of patients with atypical clau dication: a 28 year experience. J Vasc Surg 2004; Turnipseed WD. Popliteal entrapment syndrome. J Vasc Surg 2002;35: Standring S. Gray s Anatomy: the Anatomical Basis of Clin ical Practice, Expert Consult. Edinburgh: Churchill Livingstone, Stager A. Popliteal artery entrapment syndrome. Sports Med 1999;28:61 70.