"Sural nerve splitting in reverse sural artery perforator flap: Anatomical study in 40 cadaver legs".

BACKGROUND: The reverse sural artery perforator flap (RSAPF) has been widely used in reconstructions of the lower extremity. However, along with the high rate of flap necrosis, sural nerve (SN) injury is one of the most frequent complications. This cadaveric study investigated a simple SN preservation technique during RSAPF.

METHODS: Anatomic dissection of the sural nerve was performed on 40 lower legs, from 20 cadavers, to investigate the pattern of SN distribution. The points where the lateral sural cutaneous (LSCN) and medial sural cutaneous (MSCN) nerves penetrate the deep fascia were measured. The converging point of these nerves into the SN was also recorded. Further, the SN was split until no tethering was observed, during flap transposition, to simulate SN-sparing RSAPF.

RESULTS: Twenty-nine legs (72.5%) showed the LSCN and MSCN converging to become the SN (combined pattern); 7 (17.5%) and 4 legs (10.0%) demonstrated the diminished and parallel types, respectively. The distances between the lateral malleolus and the fascia-penetrating point of the LSCN and MSCN were 29.9 ± 3.3 cm and 18.8 ± 5.6 cm, respectively. In the combined type, the point of the LSCN and MSCN convergence was 13.6 ± 4.2 cm from the lateral malleolus. Nerve splitting was successfully performed in all combined cases, without injuring the nerve fascicles.

CONCLUSIONS: The MSCN enters the deep fascia significantly more distally than does the LSCN. Further, using nerve splitting, the MSCN can be kept intact during RSAPF in cases demonstrating the combined type of SN.