Connector-Assisted Repair of Transected Inferior Alveolar and Lingual Nerves Using Photochemical Tissue Bonding.

BACKGROUND

Inferior alveolar nerve (IAN) and lingual nerve (LN) injury are recognized complications of oral and maxillofacial trauma or surgical procedures, often requiring subsequent microsurgical repair. This study explores the potential of photochemical tissue bonding (PTB), a light-activated technique that forms molecular crosslinks between collagen molecules, to seal a commercial nerve connector in place for IAN and LN nerve repair.

PURPOSE: The purpose of this study was to measure and compare the repair strength of conventional suture and PTB repair in a nerve transection model.

STUDY DESIGN, SETTING, AND SAMPLE: This was an ex vivo study conducted on IAN and LN harvested from independently euthanized Yorkshire pigs. The nerves were transected and then repaired by a single operator at Massachusetts General Hospital. Both repair techniques were performed on nerves retrieved from the same donor animal to minimize variability. Intraoral PTB repair of both IAN and LN was also simulated in a euthanized swine model.

PREDICTOR VARIABLE: The predictor variable was the nerve repair technique. Transected IAN and LN nerves were repaired using 4 simple interrupted 10-0 polyamide monofilament sutures or photochemical crosslinked porcine small intestinal submucosa (SIS) (Axoguard Nerve Connector).

MAIN OUTCOME VARIABLE(S): The primary outcome variable was mechanical repair strength, measured as maximal load to failure and maximum stress at failure, using an ADMET mechanical microtester.

COVARIATES: Nerve cross-sectional area was included as a covariate.

ANALYSES: Paired t tests were used to compare maximal load to failure and maximum stress at failure between the 2 repair methods. Statistical significance was set at P < .05.

RESULTS

A total of 14 nerves were repaired. The maximal load to failure was 2.76 ± 1.01 N and 0.39 ± 0.28 N for the PTB with porcine SIS conduits and suture repair groups, respectively (P = .0006). The maximum stress at failure was 0.490 ± 0.319 N/mm2 and 0.125 ± 0.181 N/mm2 for the PTB with porcine SIS conduits and suture repair groups, respectively (P = .0039).

CONCLUSIONS AND RELEVANCE: The results of this study suggest that photosealed porcine SIS across the transected nerve provides greater mechanical strength than that of suture repair alone. Given the known benefits of PTB, this technique has high potential to enhance and streamline nerve repair in oral and maxillofacial surgery.