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

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).

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.

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+.

There were no meaningful differences in outcomes between the 2 conduits studied, and all patients achieved FSR according to the Medical Research Council Scale.