Thyroarytenoid cross-innervation by the external branch of the superior laryngeal nerve in the porcine model.

OBJECTIVES/HYPOTHESIS: Cross-innervation patterns to the thyroarytenoid (TA) muscle have long been sought after. We have identified in the porcine model, cross-innervation by way of the external branch of the superior laryngeal nerve (eSLN).

STUDY DESIGN: Experimental study.

METHODS: TA contraction was electromyographically recorded when electrically stimulating the eSLN in six porcine necks. The recurrent laryngeal nerve (RLN) was subsequently transected. The insertion of the cricothyroid (CT) muscle on the cricoid was then subsequently removed as well.

RESULTS: Stimulation of the eSLN rendered a response from the TA muscle in 6/6 subject necks, with a mean latency of 2.76 msec. TA muscle contraction by way of eSLN stimulation persisted after the RLN was transected and after CT insertion release.

CONCLUSIONS: The TA muscle is directly cross-innervated by a branch of the eSLN in the porcine model. This finding may have implications regarding possible future laryngeal pacing strategies and could be a target nerve for rehabilitation.