Salvage of an ischaemic ‘kite flap’ by an arterial supercharge: A case report

A 35-year-old industrial worker sustained a crush injury to his dominant right thumb. This resulted in soft tissue loss on the ulnar side, including the lateral nail fold and the ulnar neurovascular bundle. A kite flap was planned and the first dorsal metacarpal artery (FDMA) was identified at the first interosseous space using a Doppler probe. Under general anaesthesia and tourniquet control, the wound was debrided and resulted in an oval-shaped 6×3.5 cm defect (Fig. 1). A flap of appropriate dimensions was marked out and the distal and radial margins of the flap were raised protecting the paratenon over the extensor tendon. Proximally, the radial portion of the extensor hood and a wide rail of fascia overlying the first dorsal interosseous muscle were included in the flap. At this point, it was noted that the ulnar branch of the FDMA seen running under the fascia appeared very tenuous and terminated abruptly 2 cm proximal to the second metacarpophalangeal joint (MCPJ) (Fig. 1). The options available then were to either proceed with harvest of the flap on the assumption that the flap would survive as a random pattern flap or to abandon the flap and consider another flap for cover of the thumb at a later date. Since the ulnar margin of the flap had not been divided, we decided to harvest a segment of the ulnar digital artery along with its dorsal branch as a backup. This was done by including all the subcutaneous tissue down to the paratenon on the ulnar side of the index finger. The ulnar digital nerve was protected and a 2 cm segment of the ulnar digital artery after its bifurcation from the common digital artery was harvested along with the flap (Fig. 1).