Hemilaryngeal Transplantation in the Canine Model: Technique and Implications Robert J. Andrews, MD,* Gera]d S. Berke, MD,* Keith E. BIackwe]], MD,* MichaeI Jakobsen, MD, * Marilene B. Wang, MD, * and Joel A. Sercarz, MD, *~- Purpose: There is no ideal method for reconstruction of hemilaryngeal defects because there is no autologous flap or graft that can reproduce the unique structural properties of the larynx. In this article, the technique, potential research, and clinical applications of hemilaryngeal transplantation are addressed. Materials and Methods: In a canine model, transplantation of a hemilarynx was performed. The thyroarytenoid muscle was reinnervated, and an arytenoid adduction was performed to ensure a competent larynx during the early postoperative period. Results: The canine tolerated the procedure well and the transplanted larynx remained healthy and well vascularized during the postoperative period. Electromyography of the transplanted thyroarytenoid muscle verified reinnervation 2 months after the procedure. During induced phonation, vibration was symmetrical with a normal-appearing laryngeal geometry. Conclusions: Preliminary experience indicates that this technique has unique advantages compared with other available techniques for laryngeal reconstruction. Only with additional progress in transplantation medicine could this procedure be considered an option for reconstruction of human partial laryngeal defects. (Am J Otolaryngo12000;21:85-91. Copyright © 2000 by W.B. Saunders Company) Optimal phonation is possible when both vocal folds have similar muscular and muco- sal properties. There are many potential causes of asymmetric vocal fold vibration including paralysis, neoplasms, and pesttraumatic scar- ring. After reconstruction of hemilaryngeal defects, the remaining vocal cord typically vibrates opposite a reconstructed pseudocord consisting of mucosa, cartilage, or myofascia] flaps. These methods seek to optimize phona- tion while allowing airway patency and protec- tion. However, most conventional reconstruc- tion techniques provide a suboptimal solution for replacement of the physical properties and 3-dimensional configuration of the excised laryngeal tissue. We have recently developed a technique of From the *Division of Head and Neck Surgery, UCLA Medical Center, Los Angeles, CA, and -I-Division of Head and Neck Surgery, Harbor-UCLA Medical Center, Tor- rance, CA. Supported by a VA Merit Review Grant, Washington, DC. Address reprint requests to Joel Sercarz, MD, Division of Head and Neck Surgery, UCLA Medical Center, 10833 Le Conte Ave, Los Angeles, CA 90095. Copyright © 2000 by W.B. Saunders Company 0196-0709/00/2102-0003510.00/0 hemilaryngeal transplantation (HLT). This is an outgrowth of previous research in the field of whole organ laryngeal transplantation (LT) and experiments conducted to compare vocal function resulting from several hemilaryngeal reconstruction methods. 1-3 Although the proce- dure was compared with other hemilaryngeal reconstruction approaches in a previous study, the technique has not been previously de- scribed in detail. Because no current method of autologous laryngeal repair can precisely replicate the layered structure of the larynx, HLT was included in a hemilaryngeal recon- struction protocol as a theoretical ideal for an anatomically accurate repair method. In this article, HLT is described in a canine subject. The procedure included an arytenoid adduction with reinnervation of the donor thyroarytenoid muscle using the anterior branch of the recurrent laryngeal nerve (RLN). HLT provided an opportunity to investigate the feasibility of partial organ transplantation and compare this method with the perfor- mance of other reconstruction techniques. The future role of HLT in the treatment of patients after vertical hemilaryngectomy is discussed. American Journal of Otolaryngology,Vo121, No 2 (March-April),2000: pp 85-91 85