Abstract
Background and study aims Complex colorectal polyps or those positioned in difficult anatomic locations are
an endoscopic therapeutic challenge. Underwater endoscopic submucosal dissection (UESD)
is a potential technical solution to facilitate efficient polyp removal. In addition,
endoscopic tissue retraction has been confined to limited methods of varying efficacy
and complexity. The aim of this study was to evaluate the efficiency of a unique UESD
technique for removing complex polyps using double-balloon-assisted retraction (R).
Materials and methods Using fresh ex-vivo porcine rectum, 4-cm polyps were created using electrosurgery
and positioned at “6 o’clock” within an established ESD model. Six resections were
performed in each group. Underwater techniques were facilitated using a novel double-balloon
platform (Dilumen, Lumendi, Westport, Connecticut, United States).
Three different polypectomy methods were compared: 1. UESD with retraction (UESD-R),
2. UESD, 3. Traditional cap-assisted ESD technique.
Results UESD-R had a significantly shorter total procedural time than cap-assisted ESD and
UESD alone (24 vs. 58 vs. 56 mins). UESD-R produced a dissection time on average of
5 minutes, attributed to the retraction provided. There was also a subjective significant
reduction in electrosurgical smoke with the underwater techniques contributing to
improved visualization.
Conclusions Here we report the first ex-vivo experience of a unique double-balloon endoscopic
platform optimized for UESD with tissue traction capability. UESD-R removed complex
lesions in significantly shorter time than conventional means. The combined benefits
of UESD and retraction appeared to be additive when tackling complex polyps and should
be studied further.
