Ansa to recurrent laryngeal neurorrhaphy in the setting of laryngeal nerve sacrifice: a cadaveric study to evaluate a reconstructive option.

OBJECTIVE: In certain cases, the recurrent laryngeal nerve (RLN) has to be sacrificed. This often results in an inadequate length of residual RLN to be used in a reinnervation procedure. We investigated the length of the distal stump of the RLN from the inferior border of the inferior pharyngeal constrictor muscle (IPCM), where it is frequently compromised, to its entrance into the larynx. Our objective was to determine whether this residual nerve stock was sufficient for margin clearance and neurorrhaphy. STUDY DESIGN: Cadaveric study METHODS: Recurrent laryngeal nerves were identified in fresh frozen cadavers. The IPCM was divided, revealing the distal stump of the RLN, which was measured. RESULTS: Dissection was performed in 20 cadavers (40 nerves). The average length of the right RLN and the left RLN from the IPCM until it entered the larynx was 15mm and 14mm, respectively. All residual RLN remnants were of sufficient length for neurorrhaphy. CONCLUSION: Concomitant RLN reinnervation procedures in the setting of nerve sacrifice are not well described. A barrier to reinnervation in this setting may be insufficient residual nerve length for a neurorrhaphy. Often, when the RLN is sacrificed intraoperatively either iatrogenically or due to tumor invasion, it is close to the cricoarytenoid joint, at the inferior border of the IPCM. This study demonstrates that by splitting the IPCM, sufficient length can be obtained for neurorrhaphy.