P1313 - Evaluation of EverLift in the Performance of Cold Snare Polypectomy (CSP) for 4-9mm Polyps

Mike T. Wei, MD¹, Christine Louie, MD², Yu Chen, MD², Jennifer Y. Pan, MD, MS², Susan Y. Quan, MD², Robert Wong, MD, MS, FACG³, Ryanne Brown, MD, MBA², Melissa Clark, MD¹, Kristin Jensen, MD², Hubert Lau, MD², Shai Friedland, MD^2
1Stanford University Medical Center, Palo Alto, CA; ²VA Palo Alto Health Care System, Palo Alto, CA; ³Stanford University School of Medicine/Veterans Affairs Palo Alto Healthcare System, Palo Alto, CA

Introduction: Currently, CSP without submucosal injection is recommended for removing polyps < 10mm.¹ While submucosal injection of viscous agents has been found to be helpful in the removal of polyps >20mm, no study has evaluated its use in smaller polyps.² In June 2020, EverLift^TM submucosal lifting agent (GI Supply, Mechanicsburg, Pennsylvania) was approved by the United States Food and Drug Administration.³ We investigate the potential role of EverLift^TM in CSP.

Methods: The study is a single-center prospective randomized clinical trial evaluating CSP of nonpedunculated 4-9mm polyps, with or without submucosal injection of EverLift^TM. Patients >18 years of age presenting for colonoscopy were recruited between September 16, 2020 and May 31, 2021. Each eligible polyp identified underwent block randomization to CSP with or without EverLift^TM. Following CSP, two biopsies were performed at the CSP site margin. Data collected included patient demographics, use of anticoagulation, history of liver disease, polyp size and morphology, CSP time, and need for additional snaring or hemostatic clips. The primary outcome was complete resection rate, defined by absence of residual polyp in the margin biopsies.

Results: A total of 159 patients were included, 105 of whom had polyps removed with EverLift^TM and 109 of whom had polyps removed without EverLift^TM. A total of 55 patients had polyps removed both with and without EverLift^TM. The patients had similar distributions in age, sex, race/ethnicity, and body mass index. A total of 291 eligible polyps underwent CSP, with 142 removed using EverLift^TM (Table 1). Polyp sizes were similar between the two cohorts (p=0.949). Use of EverLift^TM significantly increased CSP time (109.8 vs 38.8 seconds, p< 0.0001). There was similar distribution of pathology between the two groups. There was a low rate of positive margins with (1.4%) or without submucosal injection (2.7%), with no significant difference (p=0.428). Hemostatic clips were used more frequently in polyps receiving EverLift^TM (13.4 vs 3.6%, p=0.002).

Discussion: Submucosal injection of EverLift^TM increased time needed and use of hemostatic clips in CSP of 4-9mm polyps. There was high complete resection rate with or without EverLift^TM, with no significant difference between the two cohorts. Overall, this study supports that CSP of 4-9mm polyps can be performed safely and sufficiently without submucosal injection of EverLift^TM (ClinicalTrials.gov ID: NCT04551014).

	With EverLiftTM (N=142)	Without EverLiftTM (N=149)	p-value
Mean polyp size, mm (+SD)	5.3 (1.5)	5.3 (1.5)	0.949
Location of polyp			0.892
Cecum, N (%)	13 (9.2)	13 (8.7)
Ascending, N (%)	39 (27.5)	42 (28.2)
Hepatic flexure, N (%)	5 (3.5)	7 (4.7)
Transverse, N (%)	48 (33.8)	50 (33.6)
Descending, N (%)	19 (13.4)	14 (9.4)
Sigmoid, N (%)	14 (9.9)	20 (13.4)
Rectum, N (%)	4 (2.8)	3 (2.0)
Pathology			0.189
Tubular adenoma, N (%)	124 (87.3)	126 (84.6)
Sessile serrated polyp, N (%)	7 (4.9)	3 (2.0)
Hyperplastic polyp, N (%)	10 (7.0)	15 (10.1)
Normal colonic mucosa, N (%)	1 (0.7)	5 (3.4)
Polyp morphology			0.567
Is, N (%)	122 (85.9)	129 (86.6)
IIa, N (%)	19 (13.4)	19 (12.8)
IIb, N (%)	1 (0.7)	0 (0.0)
Isp, N (%)	0 (0.0)	1 (0.7)
Positive margin, N (%)	2 (1.4)	4 (2.7)	0.428
Additional polypectomy needed, N (%)	6 (4.2)	5 (3.4)	0.697
Polypectomy by fellow, N (%)	13 (9.2)	25 (16.8)	0.054
Hemostatic clip used, N (%)	19 (13.4)	5 (3.6)	0.002
Mean polypectomy time, s (SD)	109.8 (56.0)**	38.8 (54.5)**	< 0.0001