Michael P Meara, MD, MBA, Edward L Jones, MD, Jeffrey W Hazey, MD, Kyle A Perry, MD. The Ohio State University Wexner Medical Center
BACKGROUND: Like Laparoscopic Heller Myotomies (LHM), Per Oral Endoscopic Myotomy (POEM) has proven to be a viable therapeutic modality for the treatment of idiopathic achalasia. Similarly, POEM failure is related to distal extent of the myotomy onto the stomach resulting in an incomplete myotomy.
Evaluation of the extent of the POEM myotomy has been performed in a variety of methods. First, the extent of the dissection is visualized within the mucosal tunnel. The distal extent of the myotomy is approximated by observation of the transition of the circular and longitudinal muscular fibers typically observed in the esophagus to the less organized fibers seen on the stomach. The extent of the myotomy is also noted by rough measurement of the distance the endoscope has been advanced into the submucosal tunnel from the incisors. After completion of the dissection, indigo carmine dye is injected into the distal extent of the dissection. The dye is observed from the luminal view upon retroflexion and observation of the gastroesophageal junction. The EndoFlipTM Catheter has been used to provide real time evaluation of the completion of the myotomy, but this device requires additional instrumentation that is not available at all institutions. The purpose of this video presentation is to provide a novel modality for evaluation of the distal extent of the myotomy under direct visualization.
METHODS: After performing routine endoscopy, the POEM dissection is undertaken and the extent of the submucosal tunnel is taken down to and past the gastroesophageal junction. The dissecting scope is left in place and the light on the endoscope is then dimmed. A second, smaller nasopharyngeal endoscope is introduced into the esophagus, advanced past the mucusotomy, and into the stomach. The stomach is insufflated and the nasopharyngeal endoscope is placed in the retroflexion view. The light on the nasopharyngeal scope is dimmed and the light on the dissecting scope is brightened until this can be observed past the gastroesophageal junction. If it cannot be easily observed, the extent of the myotomy should be extended. If it is observed without issue, the stomach is desufflated and the pediatric scope is removed. The light of the dissecting endoscope may be left on and dimmed during introduction of the nasopharyngeal scope and may be observed in the distal esophagus if the dissection has been difficult and incomplete.
CONCLUSIONS: This maneuver can be completed rapidly and provides excellent visualization of the distal extent of the POEM tunnel dissection. This maneuver can be performed with little to no added cost and with instrumentation already owned. This mitigates the need to purchase additional equipment and without the need for additional training.
KEY WORDS: Achalasia — Per Oral Endoscopic Myotomy — POEM — Myotomy –Endoscopic Retroflexion – Myotomy Extent