Background and aims: A new external additional working channel (AWC) was recently introduced by which endoscopic submucosal dissection (ESD) can be converted to a technique termed "ESD+ ". We aim to systematically evaluate this novel technique in flat gastric lesions and compare it to classical ESD.
Methods: The study was prospectively conducted in a pre-clinical ex vivo animal model (EASIE-R simulator) with porcine stomachs. Prior to intervention, we set standardized lesions measuring 3 cm or 4 cm in antegrade as well as in retrograde positions.
Results: Overall, 64 procedures were performed by an experienced endoscopist. Both techniques were reliable and showed en bloc resection rates of 100%. Overall, ESD+ reduced time of procedure compared to ESD (24.5 vs. 32.5 min, p = 0.025*). Particularly, ESD+ was significantly faster in retrograde lesions with a median of 22.5 vs. 34.0 min in 3 cm retrograde lesions (p = 0.002*) and 34.5 vs. 41.0 min (p = 0.011*) in 4 cm retrograde lesions. There were 0 perforations with both techniques. In ESD+ , 1 muscularis damage occurred (3.13%) compared to 6 muscularis damages with ESD (18.75%, p = 0.045*).
Conclusions: By its grasp-and-mobilize technique, ESD+ allows potentially faster and safer resections of flat gastric lesions compared to conventional ESD in an ex vivo porcine model. The potential advantages of ESD+ in terms of procedure time may be particularly relevant for difficult lesions in retrograde positions.
Keywords: Additional working channel (AWC); Animal model; EASIE-R model; EMR+; ESD+ technique (ESD+); Endoscopic mucosal resection (EMR); Endoscopic submucosal dissection (ESD); RESECT+.