A new animal training model for thoracoscopic esophagectomy in a prone position

Soji Ozawa, MD, PhD, Takashi Akaishi, MD, PhD, Haruhiro Inoue, MD, PhD, Masayuki Higashino, MD, PhD, Takashi Kamei, MD, PhD, Natsuya Katada, MD, PhD, Tatsuyuki Kawano, MD, PhD, Yuko Kitagawa, MD, PhD, Masahiko Murakami, MD, PhD, Shunichi Okushiba, MD, PhD, Nobuo Omura, MD, PhD, Harushi Osugi, MD, PhD

Japan Study Group for Endoscopic Esophageal Surgery

INTRODUCTION In the latest annual report published in 2010, the rate of thoracoscopic esophagectomy for the treatment of esophageal cancer was about 24% in Japan. Although this rate has been gradually increasing, it remains relatively low, probably because of the difficulty in maintaining a good surgical field and because of the meticulous procedures that are required. A thoracoscopic esophagectomy performed while the patient is in a prone position may overcome the above problems. However, no animal training model for thoracoscopic esophagectomy in a prone position exists to date. The purpose of this study was to establish and evaluate a new animal training model for thoracoscopic esophagectomy in a prone position.

METHODS A domestic pig was intubated, with the tube being advanced into the left lung, and placed in a prone position. Five trocars were inserted into the right thoracic cavity. Only the left lung was ventilated, and a pneumothorax in the right chest was created using 6 mmHg of CO2 gas. The first step in the training was the dissection of the lymph nodes beneath the costocervical vein, the second step was the division of the costocervical vein, the third step was the dissection of the lymph nodes around the right recurrent laryngeal nerve, the fourth step was the mobilization of the middle and lower esophagus, the fifth step was the mobilization of the upper esophagus, and the sixth step was the dissection of the lymph nodes around the left recurrent laryngeal nerve. Finally, the animals were euthanized. After establishing the animal training model described above, we held six training courses for thoracoscopic esophagectomy using an animal model between June 2010 and June 2012. A total of 48 animals weighing about 40 kg were involved, and 117 participating surgeons answered questions regarding the training. The new animal training model was prospectively evaluated from the point of view of the animal’s condition during the operation, the achievement of the training steps, and the significance of this model as a method of training.

RESULTS Forty-seven of the 48 animals (98%) survived the procedure, while one animal died because of heart failure during the operation. All the participants (100%) completed the six steps of the training procedure. Regarding the usefulness of this training course using a new animal model, 63% of the participants provided a response of “excellent” and 33% provided a response of “good”. Regarding which methods were necessary for a participant to introduce thoracoscopic esophagectomy at his/her hospital, 78% of the participants responded that “visiting and viewing an actual operation performed by an expert surgeon” was necessary, and 42% responded that “this training course using a new animal model” was necessary.

CONCLUSION This new animal training model for thoracoscopic esophagectomy in a prone position is a feasible and useful means of training surgeons who wish to start performing thoracoscopic esophagectomy.

Session: Poster Presentation

Program Number: P156