Supraclavicular artery island flap innervation: anatomical studies and clinical implications

Recently, the supraclavicular artery island flap has gained popularity as a regional flap for head and neck reconstruction. During clinical follow-up, some patients report referred sensation to the shoulder when there is contact with the flap skin island surface. The authors examine the anatomical origin/characteristics of the supraclavicular nerves (C3-4) to this flap and its relationship to the flap pedicle and anatomical boundaries.

SAI flap harvest and nerve dissection was performed in seven fresh frozen cadavers (n = 10) using loupe magnification in order to further elucidate the sensory nerve branches in a typical SAI flap.

Branches of the supraclavicular nerve innervating the SAI flap were found to emerge from the deep fascia at a separate location from the vascular pedicle with the major nerve root exiting underneath the sternocleidomastoid muscle near the midpoint of the muscle belly. The nerve branches proximal to the pedicle with one branch exiting anterior to the flap and another running axially along the length of the flap. The majority (9/10) flaps had a major cutaneous nerves located 1-2 cm anterior to the pedicle. One (1/10) of the flaps had a major cutaneous nerve located 1-2 cm posterior to the pedicle toward the trapezius muscle. In 3 of the 10 flaps, smaller cutaneous nerves were also found posterior to the pedicle in a more distal location of the flap.

The supraclavicular nerves innervating the SAI flap are easily identifiable and can be preserved or ligated, depending on the desired flap function, when present close to the pedicle. Further clinical investigation is warranted to confirm the potential benefit of using the SAI flap as a neurotized regional flap for head/neck reconstruction.