Transesophageal Endoscopic Myotomy (teem) for Achalasia- Recognizing Potential Pitfalls Before Clinical Application

Mahmoud Abu Gazala, MD, Abed Khalaila, MD, Noam Shussman, MD, Samir Abu Gazala, MD, Ram Elazary, MD, Oleg Ponomernco, MD, Gideon Zamir, MD, Avraham I Rivkind, MD FACS, Yoav Mintz, MD. Hadassah Ein Kerem Medical Center

Objective
Laparoscopic Heller esophagomyotomy is the standard of care for achalasia treatment. General anesthesia is mandatory and mucosal perforations occur up to 15% of cases. Our aim was to developed a method to perform Transesophageal Endoscopic EsophagoMyotomy (TEEM) which would obviate the need for general anesthesia as well as any external incisions. This technique may offer lower intra-operative complications, reduce the post-operative morbidity and shorten hospital stay up to office procedures. This technique however, has several pitfalls which need to be recognized in order to avoid serious complications.

Methods
TEEM was performed on 8 pigs. Two were performed to develop the surgical technique, and 6 for survival purposes. Following general anesthesia a mid esophageal mucosal incision was performed using an endoscope. A plane was created in between the esophageal mucosa and the circular muscle fibers. The LES muscle fibers were clearly visualized and divided. The endoscope was then retrieved and the mucosal incision was closed using biological glue. Following two weeks of survival a gastrografin swallow study and necropsy were performed.

Results
TEEM procedure was successfully performed in all 8 porcine animal models. The myotomy included the LES fibers and extended 4-6cm proximally to the esophagus. A temporary pneumothorax was created in all cases. The proximal gastric muscle was divided up to 1-2cm but not full thickness. No injuries to the abdominal or mediastinal structures occurred. One pig died on POD1 due to unrecognized pneumothorax. Two pigs had ischemic ulcers at the myotomy site, one of them with mediastinal sepsis and the last three pigs had perfect results. All survived pigs healed completely the mucosal incision site and except for the pig with mediastinal sepsis all ate heartily from the day following surgery and gained weight as expected.

Discussion/Conclusion

TEEM procedure is technically feasible and easy. Having the endoscope in between the esophageal mucosa and muscle fibers clearly avoids mucosal perforation at the site of the Myotomy. In the first three pigs we performed a 30cm submucosal tunnel and used a 12mm dual channel endoscope. This by itself caused a large area of denuded mucosa and followed by ulceration. We modified our technique and created a 10cm tunnel with a 9.8cm gastroscope and avoided this complication. Full thickness division of the esophageal muscle without prior dissection in the mediastinum results in inevitable pneumothorax. Although air can be suctioned prior to mucosal closure, care should be taken not to injure the underlying lung. In the same fashion full thickness division of the gastric portion of the LES can result in liver injury and therefore specially designed instruments should be used which will divide the circular layer only, leaving the longitudinal layer intact. Injury to deeper structures will be avoided and reflux may be prevented. In case of reflux, endolumenal fundoplication may be performed as a second stage. We conclude that TEEM is not yet ready for prime time and perfection of the technique is mandatory prior to safely translating this method to human patients.