Hybrid endoscopic thymectomy: combined transesophageal and transthoracic approach in a survival porcine model with cadaver assessment
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Video-assisted thoracoscopic surgery thymectomy has been used in the treatment of Myastenia Gravis and thymomas (coexisting or not). In natural orifice transluminal endoscopic surgery, new approaches to the thorax are emerging as alternatives to the classic transthoracic endoscopic surgery. The aim of this study was to assess the feasibility and reliability of hybrid endoscopic thymectomy (HET) using a combined transthoracic and transesophageal approach.
Twelve consecutive in vivo experiments were undertaken in the porcine model (4 acute and 8 survival). The same procedure was assessed in a human cadaver afterward. For HET, an 11-mm trocar was inserted in the 2nd intercostal space in the left anterior axillary line. A 0° 10-mm thoracoscope with a 5-mm working channel was introduced. Transesophageal access was created through a submucosal tunnel using a flexible gastroscope with a single working channel introduced through the mouth. Using both flexible (gastroscope) and rigid (thoracoscope) instruments, the mediastinum was opened; the thymus was dissected, and the vessels were ligated using electrocautery alone.
Submucosal tunnel creation and esophagotomy were performed safely without incidents in all animals. Complete thymectomy was achieved in all experiments. All animals in the survival group lived for 14 days. Thoracoscopic and postmortem examination revealed pleural adhesions on site of the surgical procedure with no signs of infection. Histological analysis of the proximal third of the esophagus revealed complete cicatrization of both mucosal defect and myotomy site. In the human cadaver, we were able to replicate all the procedure even though we were not able to identify the thymus.
Hybrid endoscopic thymectomy is feasible and reliable. HET could be regarded as a possible alternative to classic thoracoscopic approach for patients requiring thymectomy.
KeywordsGeneral Oesophageal Surgical Technical Endoscopy Thoracoscopy
This project was funded by the FCT Grants project PTDC/SAU-OSM/105578/2008.
J Correia-Pinto is a consultant for Karl Storz GmbH. Aníbal Ferreira, Alice Miranda, Carla Rolanda have no conflict of interest.
Supplementary material Video 1. Transesophageal access creation. Main image represents thoracoscopic view, and inset represents gastroscopic view. An operative thoracoscope with a 5-mm working channel was introduced through an 11-mm trocar inserted in the 2nd intercostal space in the left anterior axillary line. A forward-viewing, single-channel gastroscope was advanced into the esophagus, identifying the position of the thoracoscope and determining the esophagotomy site. 5 mL of saline solution was injected into the submucosa, 8 cm proximal to the esophagotomy position. An 1-cm longitudinal incision was made in the mucosa using an endoscopic needle-knife. Then, an 8- to 9-cm long submucosal tunnel was created by blunt dissection. While the submucosal tunnel was being created in the esophagus, the left mediastinal pleura was opened and the left posterior limits of the thymus dissected using rigid instruments introduced through the transthoracic trocar. (MPG 9368 kb)
Supplementary material Video 2. Thymus dissection. Main image represents thoracoscopic view, and inset represents gastroscopic view. Dissection of the thymus was completed using both flexible (gastroscope) instruments and rigid (thoracoscope) instruments. The vessels were ligated using electrocautery alone, connected through the coagulation grasper introduced through the gastroscope or the rigid dissector entering through the thoracoscope working channel. (MPG 7722 kb)
Supplementary material Video 3. Specimens retrieval. Image represents gastroscopic view. The thymus was retrieved through an endoscopic bag introduced through the transthoracic trocar. For that, the surgeon handling the gastroscope had to grasp the specimens and put it inside the endoscopic bag. (MPG 2326 kb)
Supplementary material Video 4. Esophageal closure. Image represents gastroscopic view. The esophageal mucosa was closed at the proximal edge of the submucosal tunnel by using 4 to 5 flexible hemoclips (MPG 1196 kb)
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