Person:

Brugge, William

Background: With conventional EMR, specimens are fragmented, metaplasia may be left behind, and invasive lesions could be missed because of incomplete sampling. Concentric subtotal esophageal mucosectomy would address these limitations. Objective: To examine en bloc esophageal mucosectomy (EEM). Design: A prospective case series. Setting: An academic hospital. Subjects: Nine swine. Interventions: Conventional EMR was performed in the proximal esophagus. The submucosal space was entered, and the distal two thirds of the esophageal mucosa was freed with blunt dissection. A snare was threaded over the column of mucosa to the gastroesophageal junction. The column was resected, and the mucosa was retrieved. Main Outcome and Measurements: Clinical examination, follow-up endoscopy, necropsy, and gross and histopathologic examination. Results: EEM permitted subtotal esophageal mucosectomy in 9 of 9 swine (tissue specimens removed ranged 9-15 cm in length). The mean procedure duration was 110 minutes. In the survival series, 4 of 4 swine thrived after surgery, for 9 to 13 days. At 9 days, there was no evidence of a perforation, stricture, or leak. At 13 days, 2 swine had a mild proximal stricture, which was easily traversed with a 9.8-mm gastroscope. On necropsy, the mediastinal and thoracic cavities were unremarkable in 3 of 4 swine. One swine was found to have a contained abscess containing cellulose, presumably secondary to ingestion of wood-chip bedding material postoperatively. Reepithelialization was present on histologic examination. Limitations: An animal study. Conclusions: EEM is feasible and enabled concentric subtotal esophageal mucosal resection. The technique could completely and circumferentially excise intramucosal lesions. Longer follow-up and larger studies are needed to evaluate infection, stricture, and safety.

Background: Thoracoscopy and mediastinoscopy are common procedures with painful incisions and prominent scars. A natural orifice transesophageal endoscopic surgical (NOTES) approach could reduce pain, eliminate intercostal neuralgia, provide access to the posterior mediastinal compartment, and improve cosmesis. In addition NOTES esophageal access routes also have the potential to replace conventional thoracoscopic approaches for medial or hilar lesions. Methods: Five healthy Yorkshire swine underwent nonsurvival natural orifice transesophageal mediastinoscopy and thoracoscopy under general anesthesia. An 8- to 9.8-mm video endoscope was introduced into the esophagus, and a 10-cm submucosal tunnel was created with blunt dissection. The endoscope then was passed through the muscular layers of the esophagus into the mediastinal space. The mediastinal compartment, pleura, lung, mediastinal lymph nodes, thoracic duct, vagus nerves, and exterior surface of the esophagus were identified. Mediastinal lymph node resection was easily accomplished. For thoracoscopy, a small incision was created through the pleura, and the endoscope was introduced into the thoracic cavity. The lung, chest wall, pleura, pericardium, and diaphragmatic surface were identified. Pleural biopsies were obtained with endoscopic forceps. The endoscope was withdrawn and the procedure terminated. Results: Mediastinal and thoracic structures could be identified without difficulty via a transesophageal approach. Lymph node resection was easily accomplished. Pleural biopsy under direct visualization was feasible. Selective mainstem bronchus intubation and collapse of the ipsilateral lung facilitated thoracoscopy. In one animal, an inadvertent 4-mm lung incision resulted in a pneumothorax. This was decompressed with a small venting intercostal incision, and the remainder of the procedure was completed without difficulty. Conclusions: Transesophageal endoscopic mediastinoscopy, lymph node resection, thoracoscopy, and pleural biopsy are feasible and provide excellent visualization of mediastinal and intrathoracic structures. Survival studies will be needed to confirm the safety of this approach.

Introduction: Transesophageal endoscopic mediastinoscopy (MX) and thoracoscopy (TX) could reduce pain, eliminate intercostal neuralgia, provide better access to the posterior mediastinal compartment and pulmonary hilum, and improve cosmesis. The purpose of this study was to demonstrate the feasibility of transesophageal natural orifice translumenal endoscopic surgery (NOTES) and to determine the complications that might be seen in surviving animals. Methods: Using cap endoscopic mucosal resection and blunt dissection, a 15–20 cm submucosal tunnel was created in the esophagus and an endoscope passed through the tunnel into the mediastinum. One swine underwent MX; three swine underwent both MX and TX. The mediastinal compartment, hilar lymph nodes, pleura, lung, and esophagus were identified. Esophageal closure was obtained via submucosal tunnel flap-valve alone (two swine) or reinforcement with mucosal clips (two swine). The esophagus, mediastinum, and thorax were examined at necropsy. The esophagus was excised and sent for pathological examination. Results: NOTES MX and TX provided excellent visualization of mediastinal and thoracic structures. Pleural biopsy was easily accomplished. All animals survived the procedure, ate well, and showed no ill effects. Swine were sacrificed at either 8 or 12 days postoperatively. At necropsy, mild atelectasis was noted in each animal. One animal (mucosal clip closure) developed a fluid collection in the submucosal tunnel. There was no evidence of mediastinitis or thoracic contamination in any animals. Conclusions: Transesophageal endoscopic mediastinoscopy and thoracoscopy provide excellent visualization of mediastinal and intrathoracic structures. Pleural biopsy can be easily obtained under direct visualization. Structures that are difficult to visualize via traditional cervical mediastinoscopy and thoracoscopy are seen well with this approach. The submucosal tunnel creates a flap-valve that, alone, may be sufficient for preventing esophageal leak. These procedures can be performed safely in swine with short-term survival. Further study with a larger sample size and longer survival is warranted.