Society: ASGE

LIVE STREAM SESSION

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.

Background: Colonoscopy is widely performed for direct visualization and therapeutic intervention in the colon. While colonoscopy is a relatively safe procedure, there are several limitations due to the unintuitive drive mechanism and mechanical design of current conventional colonoscopes (CC). These include sedation related events, patient discomfort due to looping, perforation/colon trauma, long learning curve/training time, variable quality, and endoscopist injury due to poor ergonomics. To overcome these limitations, endoscopy as currently practiced would require a dramatic transformation in both endoscope design and technique used for actuation. The Magnetic Flexible Endoscope (MFE) was developed to address these limitations, as a highly flexible, single-use, robot-assisted, magnetically-manipulated endoscope. The MFE is composed of a handheld controller, a robot manipulator with magnetic end effector, and a magnetic flexible endoscope to maintain the functionality of a CC. Unlike CC's that are pushed for advancement, the MFE is driven by magnetic coupling to enable a “front-pull” actuation mechanism. The forward drive mechanism prevents buckling of the insertion tube, looping, and colon wall stress; reducing the risk of perforation and pain during the procedure. With integration of robotic assistance and autonomous function, the challenging task of endoscope navigation becomes simplified. In-vivo validation of colon navigation for diagnostic and therapeutic colonoscopy is now tested.

Methods: The MFE was tested in-vivo using two 37-kg female, Danish Duroc, large white-Landrace cross-swines to evaluate system safety, core functionality, navigation, and capacity for therapeutic interventions. Main outcome measure was safety (trauma/premature demise). The MFE was navigated through the colon and withdrawn five times. Autonomous navigation and endoscopic maneuvers, retroflexion, biopsy, and endoscopic mucosal resection (EMR), were performed.

Results: The MFE successfully and safely navigated the swine colon with good visibility. There was no gross colon trauma. Autonomous navigation of the MFE was successful at autonomously detecting lumen center and orienting the endoscope for biopsy. The detection algorithm tracked the target location while motion control software aligned the endoscope tip with the biopsy forceps for tissue acquisition. During all EMR trials, the MFE system maintained hardware integrity and camera visualization. There was no submucosal trauma/perforation. 3D magnetic field sensing and manipulation was also successful.

Conclusion: The MFE is a novel platform capable of diagnostic and therapeutic colonoscopy, as demonstrated through benchtop evaluation and in-vivo swine trials. There was no gross trauma, perforation, or adverse event. The MFE platform functioned well and preparations for first-in-human in-vivo trials are underway.

Venkataraman Subramanian

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