| Background:In recent years,cold snare polypectomy(CSP)has been gradually applied to the treatment of small colorectal polyps(<10mm).The European Society of Gastrointest-inal Endoscopy(ESGE)in 2017 and the United States Multi-Society Task Force on Colorectal Cancer(USMSTF)recommends CSP resection for colorectal micropolyps(≤5 mm)and small polyps(6-9 mm).A number of studies have shown that the histological complete resection rate of CSP was similar to that of HSP,but lower than that of conventional hot snare endoscopic mucosal resection(HS-EMR).Cold snare endoscopic mucosal resection(CS-EMR)is based on CSP technology combined with submucosal injection water pads.The literature reports the histological complete resection rate of CS-EMR and HS-EMR for 6-10 mm nonpedunculated colorectal polyps was similar.Although there have been a large number of research reports about cold snare polypectomy in Europe,the United States and Japan,in actual clinical work,due to the operating habits of endoscopists and the knowledge of cold snare polypectomy techniques are still insufficient.A large sample of investigations and studies have shown that cold snare polypectomy has not been fully applied in clinical practice,and only 26.6%-55.2% of small colorectal polyps have been used the cold snare polypectomy technique.China,s latest questionnaire survey research also shows that for 7mm nonpedunculated polyps,only 19.3% of endoscopists choose cold snare polypectomy.Therefore,we still need to further study and understandthe technique of cold snare polypectomy.Objective:To compare the effectiveness and safety of CS-EMR and HS-EMR in the treatment of 6-15 mm nonpedunculated colorectal polyps.Methods:From January 2019 to December 2020,consecutive hospitalized patients who underwent colorectal polypectomy at the Digestive Endoscopy Center of our hospital,were found the polyps that meet the inclusion criteria.Divide the polyps into groups of 6-9mm and 10-15 mm,and each group will be randomly assigned to the CS-EMR and HS-EMR groups in a 1:1 manner according to the random number table.When a polyp that did not meet the standard was detected,the second clinical treatment was usually booked according to the size of the polyp.The rates of histological complete resection of polyps,immediate postpolypectomy bleeding(IPPB),delayed postpolypectomy bleeding(DPPB),enbloc resection,and other adverse events were observed.Use SPSS25.0 statistical software to perform statistical analysis on the data.Results:1、Baseline information:According to the inclusion and exclusion criteria,201 patients with a total of 288 polyps were screened,115 males(57.2%)and 86 females,aged 30-82 years old,with an average of 58.1±11.1 years old.The baseline informations of polyps in the CS-EMR and HS-EMR treatment groups were shown in Table 1.There were no statistically significant differences in polyp size,location,Paris type,and histology between the CS-EMR and HS-EMR groups(p>0.05).The average size of polyps(±SD)was 8.8±2.5 mm.2、Comparison of histological complete resection rate: In the 6-9mm polyp group the histological complete resection rates of CS-EMR and HS-EMR were 91.7%(88/96)and 95.7%(88/92)(difference 4.0%;95% CI:-3.51-11.71),and in the10-15 mm polyp group that were 89.8%(44/49)and 92.2%(47/51)(difference 2.4%;95% CI:-9.76—14.85).The histological complete resection rates of CS-EMR and HS-EMR of 6-15 mm polyps were 91.0%(132/145)and 94.4%(135/143)respectively(a difference of 3.4%;95% CI:-2.87-9.75).All the lower limit of the 95% CI of the difference were greater than the cutoff value of-10%,indicating that the CS-EMR was noninferior to the conventional EMR.In the CS-EMR and HS-EMR groups,the histological complete resection rates decreased with the increase of polyps diameter,but the difference between the two groups was not statistically significant(p>0.05).3、Comparison of IPPB and DPPB: In the CS-EMR and HS-EMR groups,the immediate postpolypectomy bleeding rates were 2.8% and 1.4%,and the delayed postpolypectomy bleeding rates were 0% and 2.8% respectively.For 6-9mm polyps the immediate postpolypectomy bleeding rates of the CS-EMR and HS-EMR groups were 1.0% and 0% respectively,while for 10-15 mm polyps were 6.1% and 3.9%.For6-9mm polyps the immediate postpolypectomy bleeding rates of the CS-EMR and HS-EMR groups were 1.0% and 0% respectively,while for 10-15 mm polyps were6.1% and 3.9%.As the diameter of the polyp increases,the immediate postpolypectomy bleeding rates increased,but the differences wer’e not statistically significant(p>0.05).All patients with immediate postpolypectomy bleeding and delayed postpolypectomy bleeding were successfully stopped by metal clamps under endoscopy.4、Comparison of polyp enbloc resection rate: The overall polyp enbloc resection rates were 96.2%(277/288),the CS-EMR group and the conventional EMR group were 95.9%(139/145)and 96.5%(138/143)respectively.The differences between the two groups were not statistically significant(p = 0.776).5、Other postoperative adverse events: Adverse events were observed and followed up by telephone within 2 weeks after the operation.No patient in the whole group had perforation during or after operation.In the whole group,there were five patients had abdominal pain and five patients had melena after operation.6、Follow-up: The patients of this group were followed up for 6 months,and the last follow-up time was February 2021.Because some patients did not reach the follow-up period,119 patients with 197 polyps were followed up,and no recurrence was found.Conclusion:1、In the 6-9mm and 10-15 mm polyps,the histological complete resection rates of CS-EMR were noninferior to that of HS-EMR.2、The overal limmediate postpolypectomy bleeding rates of CS-EMR were slightly higher than that of HS-EMR.With the increase of polyp diameter,the immediate postpolypectomy bleeding rates increased,but there was no statistical difference.All the bleeding polyps were successfully stopped by endoscopic metal clamps.3、The delayed postpolypectomy bleeding rates in the CS-EMR group were lower than HS-EMR.There was no perforation occurred in the whole group,and the incidence of other adverse events were low.4、CS-EMR is a safe and effective measure for the treatment of 6-15 mm nonpedunculated colorectal polyps,and it is worthy of clinical choice. |
