Introduction
Cold snare polypectomy (CSP) for polyps 10-14 mm is unsatisfactory, with higher rates of unclear/positive histologic margins compared to small polyps,1 which is similar for CSP with submucosal injection.2 Therefore, hot snare polypectomy (HSP) or endoscopic mucosal resection (EMR) has been widely performed for polyps measuring ≥10 mm.3 However, these procedures often cause adverse events such as delayed bleeding and perforation due to deep thermal injury related to the use of electrocautery.4 A recent large-scale study reported a low incidence (0.9%) of invasive cancer in 10-19 mm colorectal polyps.5 Therefore, the development of less invasive therapeutic options for this size category is demanding.
Thus, we have developed HSP with low power pure-cut current (LPPC-HSP), a polypectomy technique with low power, low voltage, and no coagulation current (UMIN Clinical Trials Registry; UMIN000037678). This method uses pure-cut current and reduces the power of electrocautery, expecting less deep thermal damage compared with conventional HSP with blend or coagulation current, resulting in a lower risk of perforation and bleeding. This study aimed to evaluate the efficacy and safety of LPPC-HSP for colorectal polyps 10 to 14 mm, compared with conventional EMR.
Aims & Methods
In this multicenter, retrospective, observational study, records of patients who underwent EMR or LPPC-HSP for nonpedunculated colorectal polyps 10 to 14 mm at two Japanese institutions between January 2021 and March 2022 were evaluated consecutively. EMR was performed with blend cut current (Endocut Q; effect 3, time interval 2, time duration 2), while LPPC-HSP with a low power pure-cut current (Autocut; effect 1, 10 W in VIO300D or Autocut; effect 0.4 [Pmax 13 W] in VIO3). We analyzed the treatment outcomes of the two techniques using propensity score matching to reduce selection bias. The following variables expected to affect treatment outcomes were selected: age, sex, polyp size, morphology, lesion location, endoscopists (experienced endoscopists or gastrointestinal fellows), and antithrombotic agents. R0 resection was defined as en bloc resection with histologically tumor-free margins.
Results
We retrospectively enrolled 203 EMR (168 patients, 203 lesions) and 208 LPPC-HSP (169 patients, 208 lesions) cases. After propensity score matching, the baseline characteristics between the groups were comparable, with 131 pairs. The en bloc and R0 resection rates were not significantly different between EMR and LPPC-HSP groups (93.9% vs. 96.9%, P=0.38; 90.8% vs. 91.6%, P=1.00). The vertical margin was negative in all lesions except one in the EMR group. Immediate bleeding requiring hemostasis was observed in 10.7% of cases in the EMR group versus 2.3% in the LPPC-HSP group (P=0.010). The rates of delayed bleeding and perforation didn’t differ between the groups (0% vs. 0.8%, P=1.00; 0% vs. 0%).
Table 1. Baseline characteristics and treatment outcomes after propensity score matching
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| Baseline characteristics | EMR n=131 | LPPC-HSP n=131 | P value | standardized difference |
| Treatment outcomes | EMR n=131 | LPPC-HSP n=131 | P value |
| Age, years (interquartile range) | 72 (67-76) | 72 (68-78) | 0.29 | 0.105 |
| En bloc resection (%) | 123 (93.9) | 127 (96.9) | 0.38 |
| Male sex (%) | 91 (70) | 96 (73) | 0.59 | 0.085 |
| R0 resection (%) | 119 (90.8) | 120 (91.6) | 1.00 |
| Lesion size, mm (interquartile range) | 10 (10-12) | 10 (10-12) | 0.93 | 0.017 |
| Immediate bleeding (%) | 14 (10.7) | 3 (2.3) | 0.01 |
| Location right colon/left colon/rectum (%) | 61 (47) / 53 (41) / 17 (13) | 63 (48) / 53 (41) / 15 (12) | 0.95 | 0.049 |
| Delayed bleeding (%) | 0 (0) | 1 (0.8) | 1.00 |
| Morphology 0-Is/0-IIa (%) | 89 (68) / 42 (32) | 87 (66) / 44 (34) | 0.90 | 0.033 |
| Perforation (%) | 0 (0) | 0 (0) | N/A |
| Antithrombotic agents (%) | 24 (18) | 35 (27) | 0.14 | 0.202 |
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| Gastrointestinal fellows performed (%) | 42 (32) | 44 (34) | 0.90 | 0.033 |
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Conclusion
LPPC-HSP showed treatment outcomes comparable to conventional EMR, with fewer adverse events. These results suggest that this technique is a safe and effective treatment for nonpedunculated colorectal polyps 10 to 14 mm.
References
1. Hirose R, Yoshida N, Murakami T, et al. Histopathological analysis of cold snare polypectomy and its indication for colorectal polyps 10-14 mm in diameter. Dig Endosc 2017;29:594-601.
2. Yabuuchi Y, Imai K, Hotta K, et al. Efficacy and safety of cold-snare endoscopic mucosal resection for colorectal adenomas 10 to 14 mm in size: a prospective observational study. Gastrointest Endosc 2020;92:1239-1246.
3. Ferlitsch M, Moss A, Hassan C, et al. Colorectal polypectomy and endoscopic mucosal resection (EMR): European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline. Endoscopy 2017;49:270-297.
4. Oka S, Tanaka S, Kanao H, et al. Current status in the occurrence of postoperative bleeding, perforation and residual/local recurrence during colonoscopic treatment in Japan. Dig Endosc 2010;22:376-380.
5. Parsa N, Ponugoti P, Broadley H, et al. Risk of cancer in 10 - 19 mm endoscopically detected colorectal lesions. Endoscopy 2019;51:452-457.
Disclosure
Authors declare no Conflict of Interests for this study.