Gas-chamber mediastinoscopy for dissection of the upper esophagus

Mediastinoscopy has the potential to bring under view the upper mediastinum, the area most difficult to dissect during transhiatal esophagectomy. The aim of the present study was to evaluate in an animal model the feasibility of the gas-chamber mediastinoscopy technique for dissection of the upper esophagus.

Operations were performed in nine Landrace pigs using a 30 degrees laparoscope and conventional 35-cm laparoscopic instruments. Through a left collar incision a virtual space was created with sharp and blunt dissection around the cervical esophagus and insufflated with CO2 at a pressure of 5 mmHg. Using one 10-mm optical trocar and two 5-mm working trocars dissection advanced in the periesophageal space with the aim to reach at least to the tracheal bifurcation.

Performed under visual control, the procedure was accurate and safe, the level of tracheal bifurcation being reached in all cases. Anatomical structures such as trachea and its bifurcation, pleura, pericardium, arch of the azygos vein and periesophageal lymph nodes were visible during the operation. There were no major intraoperative incidents and blood loss was minimal.

The technique of gas-chamber mediastinoscopy is feasible. It allows a fair amount of freedom of movement for the working instruments and offers a good view on the operative field for a controlled and accurate dissection. Further evaluation in experimental and clinical studies is required to establish the role of this procedure in esophageal surgery.