Lingual Nerve Microsurgery Outcomes Using 2 Different Conduits: A Retrospective Cohort Study

Purpose This study compared a type 1 collagen conduit (NeuraGen) with a porcine small intestinal submucosa conduit (AxoGuard) when used in lingual nerve microsurgery and any differences in achieving functional sensory recovery (FSR). Patients and Methods All patients who underwent lingual nerve microsurgery performed by 1 surgeon (V.B.Z.) from 2007 to 2014 had their surgical information obtained by a retrospective review of hospital records and office charts after institutional review board approval. Those patients whose surgery included the use of a nerve conduit were included in the study. Subjective neurosensory recovery was determined by neurosensory testing, including responses to hot, cold, wisp, brush, and pinprick. Objective recovery was determined by testing 2-point discrimination and fine touch threshold with von Frey fibers. The objective findings were correlated to a Medical Research Council System score, with grades S3, S3+, and S4 indicating FSR. Results The conduits were compared using a Student t test with a 2-tailed hypothesis. The von Frey fiber test had a preoperative mean of 6.29 (standard deviation [SD], 0.95), which improved to 3.97 (SD, 0.67) for the NeuraGen and 4.17 (SD, 0.56) for the AxoGuard. Two-point discrimination improved from a mean higher than 19.42 to 9.32 mm (SD, 2.96 mm) for the NeuraGen and 9.67 mm (SD, 2.13 mm) for the AxoGuard. The mean FSR was S3+. Conclusions There were no meaningful differences in outcomes between the 2 conduits studied, and all patients achieved FSR according to the Medical Research Council Scale.