THE FIRST U.S. EXPERIENCE OF PERORAL ENDOSCOPIC MYOTOMY WITH FUNDOPLICATION (POEM-F): LESSONS LEARNED

BACKGROUND: Recently, high rates of post-peroral endoscopic myotomy (POEM) gastroesophageal reflux disease have been reported. A novel POEM with fundoplication (POEM-F) has been described to address this issue. This case series presents our experience performing POEM-F and highlights the lessons learned. CASE: 13 patients (age 46.6+10.7yrs; 7M) were included; most (76.9%) of them had type II achalasia, and the mean baseline Eckardt score (ES) was 8.2+2.9. ENDOSCOPIC METHODS: After an initial standard anterior myotomy, transmural dissection was done to enter the peritoneum. Next, an ultraslim scope was advanced into the stomach and the fundus was grasped and retracted into the tunnel to simulate the fundoplication wrap (monitored by the ultraslim scope). Thereafter, a loop ligating device was anchored to the fundus of the stomach and the myotomy edge and then gradually tightened to form a fundoplication wrap. Following are the lessons learned while performing POEM-F. Lesson 1: To prevent injury to extraperitoneal blood vessels, float the fat to improve the visualization of these vessels. Lesson 2: To prevent the loss of an adequate wrap position: 1) Choose a position far from the peritoneal fat, 2) Note the orientation to the liver and the presence and appearance of nearby vessels on the fundic serosa, 3) Abrade the serosa to increase visualization. Lesson 3: To prevent the loss of the loop ligating device while anchoring at the fundic serosa, slowly open the endoclip while maintaining forward pressure and ensure adequate loop slack. Lesson 4: To avoid using a Veress needle, continuously use the scope to suction peritoneal CO2 whenever the scope is within the peritoneal cavity and before it is retracted into the submucosal tunnel. Lesson 5: To prevent shearing of surrounding structures: 1) Make a generous incision at the esophageal mucosa and the peritoneal lining, 2) Keep the catheter of the loop ligating device close to the gastroscope, 3) Pass the assembled loop through the mucosal incision, submucosal tunnel and into the peritoneal cavity under direct visualization. The technical success was 92%, mean procedural duration and fundoplication time was 105.17+12 and 55+11.82mins, respectively. At the median follow-up of 134 (IQR 133-175) days, the mean ES was 0.2+0.45 and an intact wrap was seen in 4/5 patients. No high-grade dysplasia was noted and an abnormal esophageal acid exposure time was seen in 1/5 of patients. CONCLUSION: POEM-F is safe and technically feasible with excellent short-term outcomes. Greater experience, procedural standardization and the development of dedicated tools are likely to refine this procedure further. Larger prospective studies with long-term follow-up are critical to validate this procedure further.