Superficial ulnar artery flap.

Superficial ulnar artery is a known abnormality. It replaces the normal ulnar artery and has a superficial course. Its accidental division during the raising of the radial forearm flap can seriously jeopardize hand circulation. The presence of this vessel can be diagnosed preoperatively by careful palpation, and its course can be confirmed by vascular Doppler. This abnormality was found in 9.38 percent of upper limbs in cadaver dissections. A similar incidence of 9.12 percent was observed in clinical practice. Superficial ulnar artery gives several good-sized fasciocutaneous branches in the forearm. A type C fasciocutaneous flap, similar to a radial forearm flap, can be raised with safety on this anomalous vessel. Over the past 4 years, six such flaps have been raised. The largest fap was 24 x 12 cm. The flaps can be made neurosensory. Palmaris longus muscle can be raised with the flap for bulk or as an active motor unit. The extralong pedicle with good-sized vessels makes free-flap transfer safe. The donor site heals uneventfully. The presence of this abnormality can be a trap to an unsuspecting surgeon but is in fact a boon if diagnosed in time.