Features of Vocal Fold Adductor Paralysis and the Management of Posterior Muscle in Thyroplasty.

OBJECTIVE: To present the pathologic characteristics of unilateral recurrent nerve adductor branch paralysis (AdBP), and to investigate the management of posterior cricoarytenoid (PCA) muscle on the basis of our experience of surgical treatment for AdBP.

STUDY DESIGN: This is a retrospective review of clinical records

METHODS: Four cases of AdBP, in which surgical treatment was performed, are presented. AdBP shows disorders of vocal fold adduction because of paralysis of the thyroarytenoid and lateral cricoarytenoid muscles. The PCA muscle, dominated by the recurrent nerve PCA muscle branch, does not show paralysis. Thus, this type of partial recurrent nerve paresis retains the abductive function and is difficult to distinguish from arytenoid cartilage dislocation because of their similar endoscopic findings. The features include acute onset, and all cases were idiopathic etiology. Thyroarytenoid muscle paralysis was determined by electromyography and stroboscopic findings. The adduction and abduction of paralytic arytenoids were evaluated from 3 dimensional computed tomography (3DCT).

RESULTS: In all cases, surgical treatments were arytenoid adduction combined with thyroplasty. When we adducted the arytenoid cartilage during inspiration, strong resistance was observed. In the two cases where we could cut the PCA muscle sufficiently, the maximum phonation time was improved to ≥30 seconds after surgery, from 2 to 3 seconds preoperatively, providing good postoperative voices. In contrast, in the two cases of insufficient resection, the surgical outcomes were poorer.

CONCLUSIONS: Because the preoperative voice in AdBP patients is typically very coarse, surgical treatment is needed, as well as ordinary recurrent nerve paralysis. In our experience, adequate PCA muscle resection might be helpful in surgical treatment of AdBP.