Prevention of a Foot Amputation: A Large Arteriovenous Malformation Reconstructed with a Composite Free Flap

Abstract

A case of a patient with a large arteriovenous malformation in the medial plantar aspect and dorsum of the foot is presented. Embolization and surgical management of the malformation allowed a successful outcome, avoiding amputation of the foot and preventing recurrence of the lesion. Although arteriovenous malformations are not frequent entities, they have to be considered in the differential diagnosis of lesions that may affect the lower extremities. The earlier the diagnosis and treatment of these malformations, the lower the morbidity. In large arteriovenous malformations, before radical treatment is envisaged, surgery combined with embolization may achieve good results. CASE REPORTA 33-year-old man with an unremarkable medical history had been diagnosed with arteriovenous malformation of the right foot ( Fig. 1). The patient presented an interdigital ulceration in the first space between the toes, not related to previous trauma. Four years previously, a competent deep venous system had been visualized by echography-Doppler, and saphenectomy and ulcer debridement of the ulceration were performed. However, the ulcer reappeared after the wound was grafted. Two years later, arteriography was performed and provided diagnosis of an arteriovenous malformation located on the dorsum and medial plantar aspect of the right foot. The arteriovenous malformation was dependent on the posterior tibial artery and dorsalis pedis artery.In our department, the patient reported an increasing limitation of daily activities and the inability to wear shoes because of ulceration in the distal dorsal aspect of the right foot. Amputation of the right foot had been advised at another center. Physical examination showed a 4 ϫ 2-cm ulceration with local signs of infection in the first interdigital space of the foot, which extended to the dorsal area ( Fig. 1, above, left). A firm soft-tissue mass was palpable in the medial side of the plantar right foot, extending from the metatarsophalangeal joints to the distal border of the talus (Fig. 1, above, right). It was not pulsatile and the mass lacked a bruit or thrill. There were hyperpigmented changes overlying the lesion in the plantar side of the foot. The extremities were equal and symmetrical in size and appearance. Digital subtraction arteriography showed a high-flow arteriovenous malformation affecting the soft tissue of the dorsal and medial plantar aspects of the right foot (Fig. 1, below, left).The vessels involved in the arteriovenous malformation were the metatarsal plantar branches of the posterior tibial artery and dorsalis pedis artery branches. The posterior tibial artery showed a lobular and tortuous morphology, with aneurysmatic dilatations. Once the extent of the nidus, its blood supply, and its collateral supply had been mapped using digital subtraction arteriography, surgical excision of the lesion was proposed. Magnetic resonance images showed an enlargement of vessels into the flexor muscles of the foot together with an increased signal from the skin paddle (Fig. 1, be...