Mind the Vocal Process Level Gap! A Telltale Sign for Arytenoid Adduction

Background: Unilateral vocal fold paralysis (UVFP) often results from neoplastic or iatrogenic damage to the recurrent laryngeal nerve or vagus nerve.It can have harmful effects on the patient's quality of life owing to dysphonia and aspiration.The configuration of glottic closure in patients with UVFP is variable and unique in each case depending on the position of the immobile vocal fold, which is determined by factors such as intact nerve supply to the muscles, the extent of reinnervation, synkinesis, and compensatory laryngeal postures.Medialization thyroplasty and arytenoid adduction (AA) are effective treatments for medializing the paralyzed vocal cord; nevertheless, the indications and benefits of each procedure remain controversial.Historically, AA has been indicated for patients with vertical height mismatch and those with a maximum phonatory duration of <6 seconds.The success of laryngeal framework surgery largely depends on achieving an excellent phonatory closure.Pathophysiologically, AA stimulates the action of lateral cricoarytenoid muscle (LCA). Objectives:(1) To study the prevalence of different types of phonatory gaps in patients presenting with unilateral vocal fold palsy; (2) to identify whether a gap at the vocal process level is the most predictive factor preoperatively regarding whether AA is required or not. Materials and methods:The retrospective cohort study was done from the digital data archives of the senior author containing the laryngoscopic findings of unilateral vocal fold palsy patients in whom type I thyroplasty with or without arytenoid rotation was done during a period of 2021-2022.The laryngoscopic findings of these patients were compared both pre-and postoperatively to assess for the closure of phonatory gap at different levels.Results: Of the 30 study subjects, males were 40% and females were 60%.In most cases, 73.3% had a phonatory gap at the thyroarytenoid (TA) and vocal process level, followed by 16.7% having a gap at the TA level, and 6.7% gap at the vocal process level only and 3.3% gap at the body of arytenoid level only.Around 66.7% of the subjects underwent arytenoid rotation and medialization thyroplasty, whereas 33.3% underwent type I thyroplasty alone.Out of the 19 patients who underwent AA, the gap at the vocal process level was closed in 17 patients with a p-value of 0.006, which is statistically significant (Fischer's exact test). Conclusion:The gap at the level of the vocal process of arytenoid may predict the patients who require AA and help in the preoperative planning of patients regarding the type of laryngeal framework surgery to be selected.