Esophageal submucosal dissection under steady pressure automatically controlled endoscopy (SPACE): A clinical feasibility study

Background and study aims: Steady pressure automatically controlled endoscopy (SPACE) is a new insufflation system that provides constant carbon dioxide (CO₂) insufflation pressure during prolonged procedures. The system consists of an overtube, a surgical insufflator, and a newly developed leak-proof valve. The aims of this study were to validate the feasibility and safety of SPACE for esophageal endoscopic submucosal dissection (ESD). Patients and methods: This was a clinical phase I trial, involving 10 patients who underwent esophageal ESD. The primary end point was the rate of adverse events within 30 days (grade 0 to 4). Secondary end points were changes in partial pressure of carbon dioxide (PaCO₂) and vital signs during ESD, completion rate of ESD, and degree of abdominal distension by patient assessment and radiographic grading. Results: All adverse events were Grade 2 or less. Mild PaCO₂elevation after ESD was noted; however, no associated symptoms were reported. The procedure was completed under SPACE alone in 8 of 10 patients. Minimal post-procedural bowel distension was observed. Conclusions: In this small pilot study, SPACE was feasible and appeared to be safe. Further study with larger case numbers is required to demonstrate efficacy and safety. Clinical trial registration: UMIN000005434.