Free neurosensory flap based on the accompanying vessels of lateral sural cutaneous nerve: anatomic study and preliminary clinical applications.

Background: The posterior aspect of the leg is an ideal donor site for flap surgery. In this study, the anatomy was investigated of the lateral sural cutaneous nerve (LSCN) and its accompanying artery, superficial lateral sural artery (SLSA), and a lateral sural neurocutaneous flap was designed.

Methods: Five fresh adult cadaver legs perfused with red latex were dissected to observe the course and relationship between LSCN and SLSA. The outer diameter of SLSA at its origin was measured. Then a lateral sural neurocutaneous flap was designed and used to repair soft tissue defects in six patients.

Results: The anatomic results showed that the SLSA gave rise to branches that followed the LSCN and ramified into terminals at the ramification of the nerve. It originated directly from the popliteal artery 4.2 ± 0.2 mm above the fibular head, where its outer diameter was 0.96 ± 0.23 mm. Several perforators penetrated from the crural fascia and anastomosed to the SLSA, creating a fine anastomotic network. The clinical results showed that the size of the flap ranged from 12 × 6 cm to 25 × 8 cm. All six flaps survived completely without complications. Follow-up ranged from 6 to 18 months with 11 months on average. The overall contour and sensory recovery of the flap were satisfied.

Conclusion: A free innervated flap may be elevated safely based on the LSCN and its accompanying vessels. It provides an alternative in reconstruction of soft tissue defects where sensory recovery is important.