Resection of large sessile serrated polyps by cold piecemeal endoscopic mucosal resection: Serrated COld Piecemeal Endoscopic mucosal resection (SCOPE)

Sessile serrated adenomas/polyps (SSA/Ps) are frequently found in the proximal colon, where the wall is thinner and easily damaged by diathermy during polypectomy, which also carries a risk of delayed bleeding, perforation, and post-polypectomy syndrome. SSA/Ps are often flat with subtle, irregular edges making endoscopic assessment of their extent difficult [1]. This can lead to incomplete resection and risk of post-colonoscopy cancer [2].

Currently, cold snare resection (CSR) is considered the preferred technique to resect small polyps. It is safe, time efficient, and user friendly [3]. Recently, case series have highlighted the safety and efficiency of CSR for larger adenomas [4] [5]. In this series, we report our preliminary experience in achieving complete resection of large SSA/Ps using a cold piecemeal endoscopic mucosal resection (SCOPE) technique.

Following detection of an SSA/P, the polyp surface was assessed. The polyp was then lifted using a submucosal injection of 0.1 % hyaluronate and methylene blue, and resected using a small cold snare (9 mm, Exacto; US Endoscopy, Mentor, Ohio, USA) in a piecemeal manner ([Video 1]). A gradual increase in snare closure pressure was applied to mechanically transect each polyp piece. Each polyp was resected with a small rim of adjacent normal mucosa (1 – 2 mm) in order to achieve a complete resection margin. The polypectomy defect edges were scrutinized for any remaining polyp and trimmed using the snare, or cold avulsed with a biopsy forceps ([Fig. 1], [Video 1]).

Video 1 A 30-mm sessile serrated polyp was resected using the serrated cold piecemeal endoscopic mucosal resection (SCOPE) technique.

Fig. 1 Resection of a large sessile serrated polyp by cold piecemeal endoscopic mucosal resection (SCOPE) technique. a A 40-mm sessile serrated adenoma/polyp in the ascending colon; the edges are enhanced by chromoendoscopy. b Complete resection was achieved using the SCOPE technique. c No recurrence was observed at follow-up colonoscopy. d Normal mucosa in continuity with a serrated polyp highlights complete resection of the lesion (B1, normal mucosa; B2, serrated polyp).

The SCOPE technique was applied successfully in 10 consecutive patients with 29 large SSA/Ps. We achieved complete resection in all cases ([Table 1]). Minor oozing was noted in almost all cases; however, no hemostatic interventions were required. There were no adverse events during or after resection. Histology showed complete resection of polyps ([Fig. 1]). In one polyp (3.4 %), a small area of residual tissue was observed at the follow-up examination; this was resected using cold snaring.

Table 1 Patient and polyp characteristics.

Case #	Age, years	Location	Number of SSA/P	Size, mm (number of polyps)	Follow-up, months	Outcome
1	64	Ascending colon	1	30	12	No recurrence
2	62	Hepatic flexure	1	30	9	No recurrence
3	68	Ascending colon	1	30	7	5-mm residual polyp; cold snared
4	68	Ascending colon	1	20	7	No recurrence
5	42	Hepatic flexure	1	30	6	No recurrence
6	31	Cecum – transverse colon	7	10 (5), 15 (1), 20 (1)	12	No recurrence
7	39	Cecum – transverse colon	7	10 (4), 20 (3)	6	No recurrence
8	77	Ascending colon	2	12 (1), 18 (1)	8	No recurrence
9	34	Cecum – transverse colon	4	10 (2), 15 (2)	12	No recurrence
10	29	Ascending colon	4	10 (2), 15 (2)	7	No recurrence

SSA/P, sessile serrated adenoma/polyp.

Endoscopy_UCTN_Code_TTT_1AQ_2AD

Competing interests

None

^* These authors contributed equally to this work.

• References

• 1 Kahi CJ, Li X, Eckert GJ. et al. High colonoscopic prevalence of proximal colon serrated polyps in average-risk men and women. Gastrointest Endosc 2012; 75: 515-520
• 2 Zauber AG, Winawer SJ, O’Brien MJ. et al. Colonoscopic polypectomy and long-term prevention of colorectal-cancer deaths. N Engl J Med 2012; 366: 687-696
• 3 Hewett DG. Cold snare polypectomy: optimizing technique and technology (with videos). Gastrointest Endosc 2015; 82: 693-696
• 4 Piraka C, Saeed A, Waljee AK. et al. Cold snare polypectomy for non-pedunculated colon polyps greater than 1 cm. Endosc Int Open 2017; 5: E184-E189
• 5 Muniraj T, Sahakian A, Ciarleglio MM. et al. Cold snare polypectomy for large sessile colonic polyps: a single-center experience. Gastroenterol Res Pract 2015; 2015: 175959