Objective:
Emphasis on extended lymph node dissection during esophagectomy is increasing. Many propose that the best technique to achieve this goal is to approach the mediastinal portion of the operation trans-thoracically. However, this may increase overall surgical morbidity compared to a purely transhiatal technique. Totally laparoscopic transhiatal esophagectomies have been performed but while better than open, the mediastinal dissection remains difficult due to ergonomic challenges while working in a small space with sufficient triangulation and visualization using standard rigid laparoscopic instruments. We hypothesized that the transhiatal mediastinal dissection would be better facilitated using a multitasking flexible endoscopic platform.
Methods:
The operation was performed on a cadaver by two surgeons experienced in minimally invasive esophagecotmy. The Direct Drive Endoscopic System (DDES, Boston Scientific, Natick, MA) platform which combines a flexible endoscope with a pair of separately-controlled articulating instruments through a single, flexible, access system was inserted through the cadaver umbilicus. Two additional 5mm laparoscopic trocars were placed for retraction. The phrenoesophageal ligament was divided circumferentially to mobilize the gastroesophageal junction and enter the mediastinum,
The DDEStm device was advanced to the hiatus and the arms adjusted appropriately. A combination of dissecting graspers, scissors and hook cautery was used. The mediastinal pleura was divided along the azygos vein and carried along its length. . The lymphatic tissue was then mobilized medially from the azygos vein across the aorta in an en bloc fashion mobilizing the posterior esophagus. The dissection was carried laterally and anteriorly at the pleural and pericardial margins. The airway structures were skeletonized and the subcarinal lymph nodes were included in the resection margin. From there the dissection followed the esophagus to the cervical region. The vagus and recurrent laryngeal nerves were identified and preserved.
Results:
Complete transhiatal esophageal mobilization and mediastinal lymphadenectomy was performed on a single human cadaver. The ergonomics and feasibility of the esophagectomy using this device was found to be adequate. Both the surgeons found the visualization of the mediastinum excellent, especially the perihilar vital structures. This facilitated an extended mediastinal lymphadenectomy with superior ability to meticulously dissect the structures in the mediastinum for complete lymphadenectomy.
Conclusions:
Although a totally laparoscopic trans-hiatal esophagectomy avoids the morbidities associated with the trans-thoracic approach. Its drawback is the lack of visualization and difficulty performing extended mediastinal lymph node dissection. The DDEStm is a flexible operating platform that affords excellent visualization of the mediastinum via the hiatus and seems to facilitate an extended thoracic lymphadenectomy improving the oncologic esophageal resection via a transhiatal approach.