Postoperative outcomes and reliability of "sensation-sparing" sural nerve biopsy.

Sural nerve biopsy is a valuable tool for the diagnosis of neuropathic disorders. However, concerns of persisting pain and numbness resulting from traditional whole sural nerve biopsy have led to interfascicular dissection techniques with inconsistent benefits over whole nerve biopsy. In this study we describe a novel technique of atraumatic anterior fascicular sural nerve biopsy designed to preserve calcaneal sensation while maintaining diagnostic benefit, without requiring significant interfascicular dissection. A 10-year chart review was conducted to identify patients who underwent anterior fascicular sural nerve biopsy. Pathology reports were reviewed to confirm specimen adequacy, and clinical notes were reviewed to determine if a diagnosis was rendered. Retrospective questionnaires were conducted to evaluate perioperative and long-term sequelae and patient satisfaction. The proportion of patients with symptoms involving the heel versus the dorsolateral foot was evaluated with Fisher's exact test. Specimens from all 53 patients were acceptable and permitted a diagnosis. Twenty-two patients completed the retrospective survey with an average follow-up of 5 years (1.2-11.4 years). Eight patients (34%) experienced numbness of the dorsolateral foot, and 1 patient (4.5%) reported numbness of the lateral heel that lasted >6 months (P = 0.001). Persistent dorsolateral foot pain and cold sensitivity were reported by 5 patients (22.7%), but no patients reported lateral heel symptoms (P = 0.04). Symptoms were noted by patients most commonly while standing or walking, but they did not result in functional impairment in any case. Atraumatic anterior fascicular sural nerve biopsy predictably preserved essential lateral heel sensation in patients with neuropathic disorders while providing diagnostic utility.