Lateral Decubitus Improves Transoral Endoscopic Access to the Lateral and Posterior Aspects of the Thorax

Yun-Hen Liu, MD, Po-Jen Ko, MD, Yi-Cheng Wu, MD, Tzu-Ping Chen, MD, Ming-Shian Lu, MD. Laboratory Animal Center, Department of Surgery, Chang Gung Memorial Hospital, Linko, Chang Gung University

Backgroud: Natural orifice transluminal endoscopic surgery (NOTES) is a relatively new technique for accessing the thoracic and abdominal cavities. Here, we report the preliminary findings of the transoral approach to access the thoracic cavity of 2 dogs placed in the supine and lateral decubitus positions.Method: Two dogs (weight, 8.1 and 8.4 kg) were used for this experiment. The left thoracic cavity was approached through a right vestibular incision in Dog 1, and the right thoracic cavity, via a left vestibular incision in Dog 2. A homemade metallic tube was used to create a working tract via the pretracheal and substernal planes to approach the thoracic cavity under endoscopic guidance. A flexible bronchoscope was then passed through the metallic tube into the pleural cavity to perform a minor thoracic procedure, involving dorsal sympathectomy, endoscopic lung biopsy, and pericardial window creation.Results: The operative times for Dog 1 and Dog 2 were 115 and 80 min, respectively. The anterior and lateral aspects of the thoracic cavity and mediastinum were adequately accessible with the animals in the supine position. However, the posterior hemithorax was accessible only when both subjects were placed in the lateral decubitus position. With the contralateral transoral approach, the middle and posterior portions of the posterior hemithorax could be easily accessed, and the thoracic procedures (sympathectomy, lung biopsy, and pericardial window) were completed without the need for further assistance. Both animals survived the surgery and were sacrificed 30 min after the completion of pericardial window creation. Necropsy revealed that lung biopsy, pericardial window creation, and bilateral dorsal sympathectomy (left partial sympathectomy and right complete sympathectomy) had been successfully performed. No evidence of injury to the thoracic entrance, mediastinum, or thorax was noted in both animals. In conclusion, we believe that the lack of good exposure to the posterior aspect of the thorax in the canine that is encountered because of the supine position can be overcome by the placing the subject in the lateral decubitus position.