Endoscopic removal of a colorectal polyp involving a diverticulum is challenging owing
to the risk of perforation from lack of the muscularis propria [1] and concerns over incomplete resection associated with the difficult access [2].
A 70-year-old man was referred to our department for management of a difficult polyp
identified at a previous colonoscopy performed for positive fecal occult blood tests.
Colonoscopy revealed a 15-mm, flat, elevated polyp extending deep into a diverticulum
in the ascending colon. Narrow-band imaging (NBI) magnifying endoscopy was indicative
of an adenoma ([Fig. 1a]). Inspection of the entire polyp was difficult under CO2 insufflation. Water immersion using the “continuous irrigation” technique with magnifying
NBI facilitated identification of the tumor margin within the diverticulum ([Fig. 1 b, c]) [3]. A snare tip was fixed in the normal mucosa within the diverticulum and the polyp
was introduced into the snare (15-mm Captivator II; Boston Scientific, Tokyo, Japan)
using the “rapid water deflation” technique. Underwater endoscopic mucosal resection
(UEMR) achieved en bloc removal without perforation ([Fig. 1 d]; [Video 1]). Histopathology revealed a low grade adenoma with negative margins ([Fig. 2]).
Fig. 1 Colonoscopic images showing: a a 15-mm, flat, elevated polyp extending into a diverticulum in the ascending colon,
where identification of the border of the lesion was difficult owing to its extension
into the diverticulum; b good visualization with magnifying narrow-band imaging (NBI) endoscopy with water
immersion, which enables identification of the margin of the lesion; c irregular brown vessels surrounding a tubular white structure on magnifying NBI, suggesting
Japan NBI Expert Team (JNET) classification type 2A; d after the area near the diverticulum has been fixed with a snare tip, the floating
effect enabled easy capture of the entire polyp, so that underwater endoscopic mucosal
resection (UEMR) could then be performed without any complications.
Video 1 A 15-mm laterally spreading tumor resected completely by underwater endoscopic mucosal
resection. Water immersion enables visualization of the diverticulum margin; furthermore,
it facilitates snaring of the entire lesion due to “floating” and “massive deflation.”
Fig. 2 Histopathological appearance showing an adenoma with negative resection margins.
Although complex and time-consuming, traction-assisted endoscopic submucosal dissection
(ESD) is efficacious in the management of colonic tumors involving a diverticulum
[4]. In UEMR, the “floating” and “heat-sink” effects can facilitate grasping of large
or scarred polyps, respectively, and reduce the risk of perforation [5]. In this case, the “continuous irrigation” technique improved polyp visualization
within the diverticulum. The “floating” effects could be maximized by the distended
colonic wall using the “rapid water deflation” technique to secure the polyp involving
the diverticulum. The “heat-sink” effect decreased the risk of perforation, even for
a diverticulum-related polyp. This is the first case demonstrating the usefulness
of UEMR in the management of an adenoma extending into a diverticulum. UEMR may be
considered for complete removal of adenomas extending into a diverticulum.
Endoscopy_UCTN_Code_TTT_1AQ_2AD
Endoscopy E-Videos is a free access online section, reporting on interesting cases and new techniques
in gastroenterological endoscopy. All papers include a high
quality video and all contributions are
freely accessible online.
This section has its own submission
website at
https://mc.manuscriptcentral.com/e-videos
