Objective sensory and functional outcomes at the donor site following endoscopic-assisted sural nerve harvest.

Background: The sural nerve is a common choice for a nerve graft. Understanding the potential morbidity associated with its harvest is important. In this study, we describe the objective sensory and functional outcomes associated with endoscopic sural nerve harvest from a combined paediatric and adult population.

Methods: Data were collected prospectively from patients attending for follow-up between August 2015 and January 2016, who had previously undergone an endoscopic sural nerve graft harvest. Sensory loss was evaluated using a 5.07 Semmes-Weinstein monofilament. The lower extremity functional scale was used to evaluate the patients' lower limb function. Statistical comparison was made using the Student's t-test.

Results: The outcomes from 46 sural nerve grafts were evaluated. The mean age of the patients was 18.1 years (range 4-45 years old). The mean time since surgery was 4.3 years. Those aged ≤18 years had a significantly smaller area of sensory loss (p = 0.003), which was not related to a difference in foot size. Those who had undergone surgery >6 months previously had a significantly smaller area of sensory loss than those who had undergone surgery <6 months ago (p = 0.0002). The mean lower extremity functional scale score was 78.7/80.

Conclusion: We demonstrated a significantly reduced post-harvest sensory deficit among a paediatric population compared to that seen in adults. Furthermore, sensory loss reduces with time. Despite the sensory loss resulting from sural nerve graft harvest, there is minimal loss of function. As such, the sural nerve continues to be an excellent donor for a nerve graft procedure.