title: Development of a canine model for recurrent laryngeal injury by harmonic scalpel.
abstract: Various energy devices had been used in thyroid surgery. Aim of study is to develop canine model for recurrent laryngeal nerve injury by harmonic scalpel and to evaluate feasibility of using this model for evaluating the safety use of harmonic scalpel during thyroid surgery. Nine dogs were divided into 3 groups according to distance between harmonic scalpel application and recurrent laryngeal nerve; group 1 (1 mm), 2 (2 mm), and 3 (3 mm). Vocal cord function was assessed pre- and postoperatively using video laryngoscopy. Harmonic scalpel was applied adjacent to left recurrent laryngeal nerve and, two weeks later, right recurrent laryngeal nerve at assigned distances. Recurrent laryngeal nerves were evaluated for subacute and acute morphologic changes. Laryngoscopy demonstrated 3 abnormal vocal cords in group 1, 1 in group 2, and no in group 3 (P=0.020). Subacute histologic changes were observed in nerves with abnormal function. Acute histologic changes were observed 5/8 (62.5%) in group 1, 1/7 (14.3%) in group 2, and not in group 3. We developed canine model for recurrent laryngeal injury. The functional outcomes matched with the histologic changes. These warrant further study to determine the safety margin for energy device in vicinity of recurrent laryngeal nerve.
authors: Department of Surgery, Seoul National University Hospital & College of Medicine, Seoul, Korea. ; Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors: Kyu-Eun
authors: KE
authors: Lee
authors: Hyeon-Gun
authors: HG
authors: Jee
authors: Hoon-Yub
authors: HY
authors: Kim
authors: Won-Seo
authors: WS
authors: Park
authors: Sung-Hye
authors: SH
authors: Park
authors: Yeo-Kyu
authors: YK
authors: Youn
keywords: Recurrent laryngeal nerve; canine model; harmonic scalpel; nerve damage; safety margin; ultrasonic shears