Reply: Sural Nerve Splitting in Reverse Sural Artery Perforator Flap
In our parallel type, the medial and lateral sural cutaneous nerves seemed to converge together, but actually ran parallel with separate epineuria until they reached the level of the lateral malleolus. We did not have to divide the medial and lateral sural cutaneous nerves to obtain a sufficient rotation arc while the reverse sural artery perforator flap was elevated. Unfortunately, we could not take any high-quality photographs that showed the anatomical course of the parallel type sural nerve.
Dr. Hwang’s other comment is about the point of the lateral sural cutaneous nerve, based on the Japanese cadaveric study conducted by Nuri et al.3 They described the endpoint of the lateral sural cutaneous nerve, which was located 172 mm (range, 110 to 230 mm) higher than the lateral malleolus, and 9.3 mm (range, 0 to 50 mm) lateral to the midline. However, we measured the points where the lateral sural cutaneous nerve penetrated the deep fascia, and found that the fascia-penetrating point of the lateral sural cutaneous nerve is located proximal to the endpoint of the lateral sural cutaneous nerve. This difference in definition of the lateral sural cutaneous nerve point could explain the reason why the lateral sural cutaneous nerve was located more proximally (29.9 ± 3.3 cm from the lateral malleolus) by us than by Nuri et al.