Surgical Indications for Type II Thyroplasty in Adductor Spasmodic Dysphonia: A Scoping Review.

This scoping review mapped evidence on surgical eligibility criteria, efficacy, durability, and safety of Type II thyroplasty with titanium bridges for adductor spasmodic dysphonia to identify gaps and inconsistencies among studies and propose preliminary international surgical indication criteria and a core outcome set for future validation. PubMed/MEDLINE and Cochrane Library were searched from inception to January 5, 2026. Two independent reviewers evaluated full-text articles based on eligibility criteria. Risk of bias was assessed using ROBINS-I V2. Overall, 32 studies were identified and 15 met the inclusion criteria. Surgical indications were heterogeneous, including patients with inadequate response to botulinum toxin injection and those who responded well but sought a permanent alternative to repeated injections. Mean Voice Handicap Index-10 scores improved from 26.3-30.4 preoperatively to 4.1-14.0 postoperatively, with sustained improvement up to 8.4 years. Perceptual, acoustic, and aerodynamic parameters significantly improved postoperatively. Revision rates ranged from 2% to 7%, and complications were minor and transient. Titanium bridge fractures were not consistently associated with symptom recurrence. Type II thyroplasty with titanium bridges provides durable and clinically meaningful voice outcomes in adductor spasmodic dysphonia, with low revision rates and acceptable safety. The evidence supports a preliminary framework for surgical eligibility based on standardized diagnosis, symptom chronicity, prior conservative therapy, and exclusion of other voice disorders. Development and validation of international surgical indication criteria and a core outcome set are necessary to support comparability and global implementation. N/A.