Hot Snare Polypectomy Vs. Hot Snare Polypectomy After Saline Injection for the Complete Resection of Neoplastic Colorectal Polyps: Prospective, Randomized Controlled Trial
Phase: NA
Conditions: Polyp of Large Intestine
Sponsor: Bo-In Lee

Hot snare polypectomy versus endoscopic mucosal resection for small colorectal polyps: a 
randomized controlled trial (HSP vs HSPSI) 
NCT No. : NCT 02239536 
Document date : August 30, 2019 
 
 

Methods 
The study is a prospective randomized-controlled trial and was performed at two academic 
hospitals (Seoul St. Mary’s Hospital and Incheon St. Mary’s Hospital) from June 2014 to 
December 2017. The study protocol was approved by the Institutional Review Board of the 
Catholic Medical Center (Assignment No. XC14TIMI0039K) and registered with 
clinicaltrials.gov (NCT 02761213). Informed consent was obtained from all patients before 
they were enrolled.  
Study population 
Patients who underwent a screening, surveillance, or diagnostic colonoscopy were 
prospectively enrolled in the study. The inclusion criteria were patients with over the age of 30 
years who provided informed consent and who had at least one small colorectal polyp (5-10 
mm) with neoplastic features on narrow band imaging (NICE classification II). 
Patients were excluded if they have a bleeding tendency or ever taken antiplatelet or 
anticoagulation therapy within 1 week before undergoing the procedure, an inflammatory 
bowel disease such as Crohn’s disease and ulcerative colitis, a polyposis syndrome, or an 
inability to provide informed consent. When detecting the ineligible polyps with NICE 
classification I/III or more than a size of 10 mm, they were treated as per usual clinical protocol. 
Procedures 
All patients were prepared with a 2-L polyethylene glycol plus ascorbic acid solution 
(Coolprep®, Taejoon Pharm., Seoul, Korea). All colonoscopy was performed by two highly 
experienced endoscopists (L.B.I. and K.J.S.) using a high-definition endoscope (CF-HQ290I, 
CF-H260AI, or PCF-Q260AZI; Olympus Co, Japan). The morphology of the polyp was 
described by Paris classification. The size of a detected polyp was measured using the opening 
width of the biopsy forceps. When an eligible polyp (a 5-10 mm polyp with NICE classification 
II) were detected, it was randomly allocated to either HSP or EMR group. An oval snare 
(SnareMaster®, Olympus Co, Japan or Optimos®, Taewoong Co, Korea) with Endocut or 
Forced Coagulation current of an electrosurgical unit (VIO300D; Erbe Elektromedizin GmbH, 
Tubingen, Germany) was used for polypectomy. When the polyp was assigned to EMR group, 
submucosal injection with normal saline was performed in advance of polypectomy. The 
resected specimen was retrieved using endoscope suction channel. Two biopsies were obtained 

from the most probable residual tissue at the polypectomy site after irrigation, air inflation, and 
close observation with white-light and narrow-band imaging. Each patient was allowed for 
enrollment of a maximum of 2 sequential polyps from the cecum. 
Immediate bleeding indicates continuous bleeding over 30 seconds requiring any form of 
endoscopic hemostasis (epinephrine injection, clipping or coagulation) immediately or within 
24 hours after polypectomy whereas delayed bleeding was defined as bleeding from the post-
polypectomy site between 24 hours and 2 weeks after polypectomy.  
The resected specimens and biopsy specimens were reviewed by 3 highly-experienced 
gastrointestinal pathologists who were blinded to the clinical information and resection 
techniques for evaluation the involvement of adenomatous tissue at the resection margin. 
Complete resection was defined as absence of neoplastic tissue from the two additional biopsies 
of the polypectomy site whereas involvement of resection margin was defined as absence of 
neoplastic tissue at the margin of the resected specimen. When the involvement of resection 
margin could not be determined because of electrocautery effect or tangential tissue section, it 
was classified as “inconclusive.” 
Study outcomes 
The primary study outcome was a comparison of complete resection rates between two 
polypectomy techniques.  
The secondary outcomes included involvement of resection margin and post-polypectomy 
adverse events including immediate/delayed bleeding and perforation between the two groups.  
Sample size calculation and statistical analysis 
There was no exact report of the incomplete resection rate of HSP and EMR for 5-10 mm 
neoplastic polyps at the time of the study design. We assumed the incomplete resection rate of 
HSP to be 15% and that of EMR was 5%. Estimated sample size was 310 polyps (155 per 
group) with a α-value of 0.05, power of 80%, and a 10% of dropout rate.  
Chi-square test or the Fisher’s exact test was used to compare categorical variables. The 
unpaired 2-sample t test was used for continuous variables. Binary logistic regression was used 
for multivariate analysis. All data analyses were performed by using Statistical Package for the 
Social Science for Windows (version 24, IBM corp. SPSS Inc, Chicago, Ill, US).