Resection of small colonic polyps in anticoagulated patients: prospective randomized study comparing conventional polypectomy versus cold loop resection

Source: Gastrointestinal Endoscopy

Comment

Currently, the ASGE (American Society of Gastrointestinal Endoscopy) guidelines consider conventional or cold loop polypectomy as a high-risk procedure in anticoagulated patients, and therefore recommend the suspension of anticoagulation before the procedure is performed.

This recommendation is based on the available evidence that establishes that the risk of post-polypectomy bleeding in anticoagulated patients is approximately 10%. However, the risk of thromboembolic events after discontinuation of anticoagulation is approximately 3%.

In this study published in the journal Gastrointestinal Endoscopy by a Japanese group, the risk of conventional polypectomy versus cold loop polypectomy in anticoagulated patients without suspension of anticoagulation is raised as a question.

This is a prospective randomized study carried out in a single center in Japan, in which patients over 20 years of age who were anticoagulated and who presented polyps smaller than 10 mm in a screening colonoscopy were included for 10 months. Exclusion criteria were: pregnant women, ASA III or IV, obesity (>100 kg), allergy to propofol or insufficient preparation that prevented observation of at least 90% of the colon. The primary outcome was delayed bleeding (bleeding within the first 2 weeks of the procedure that would have required endoscopic intervention) and the secondary outcome was immediate bleeding (oozing bleeding during the procedure for more than 30 seconds that would have required hemostatic clip placement).

The estimated sample calculation was 53 patients in each group; however, an intermediate analysis was performed during the course of the study which showed a high rate of bleeding with conventional polypectomy (40%) and the study was stopped. Finally, 77 patients were prospectively included, of which 7 were excluded because they presented lesions larger than 10 mm. All patients were randomized, leaving 35 patients in the conventional group (CG) and another 35 in the cold loop group (GF). Both groups were similar with respect to demographic characteristics.

In the GF group 78 polyps were resected with an average size of 6.5 mm and in the CG group 81 polyps were resected with an average size of 6.8 mm. Regarding delayed bleeding, a significant difference was observed between both groups, being 14% (5/35) in the GF vs. 0% (0/15) in the GF; P=0.027. Immediate bleeding was 5.7% (2/35) vs. 23% (8/35) respectively; P=0.042. The Odds ratio for post-polypectomy bleeding in the GF was 6.5 (95% CI, 1.9-22.5). Regarding the histopathological study of the polyps, there was no difference in the rate of complete resection between the two groups. A statistically significant difference was observed in the presence of submucosal arteries in the samples analyzed: GC 47% vs GF 32%, P=0.049. Likewise, the presence of injured submucosal arteries was also higher in the GC: 22% vs 39%, P=0.023.
In conclusion, this study shows that cold loop polypectomy seems to be a useful and safe resource in anticoagulated patients, since immediate bleeding could be effectively controlled with hemostatic clips or other methods. As for delayed bleeding, it would appear to be much less than that estimated with conventional polypectomy, making it a safe method that could avoid the suspension of anticoagulation, thus avoiding possible thromboembolic events. A possible explanation for the differences observed between both techniques could be linked to the injury of submucosal arteries, a situation more frequently observed in conventional polypectomy. Although this is a small sample study, future larger and multicenter studies could be important to corroborate these results.

Carried out by: Dr. Ramiro C. González Sueyro

Original article:
Removal of small colorectal polyps in anticoagulated patients: a prospective randomized comparison of cold snare and conventional polypectomy.
Akira Horiuchi, MD,1 Yoshiko Nakayama, MD,1,2 Masashi Kajiyama, MD,1 Naoki Tanaka, MD,1 Kenji Sano, MD,3 David Y. Graham, MD.
Gastrointest Endosc. 2014 Mar;79(3):417-23.