Cold Snare Polypectomy Safe Without
Heparin Bridge?

Marcia Frellick

July 15, 2019

Patients who had cold snare polypectomy (CSP) for small polyps while remaining on anticoagulants were not at higher risk of severe bleeding compared with those who underwent hot snare polypectomy plus heparin bridging, according to results from a multicenter, randomized controlled trial published online today in Annals of Internal Medicine.

CSP, which does not involve electrocautery and may be performed without the complications of heparin bridging (HB), is recommended by the European Society of Gastrointestinal Endoscopy as standard care for subcentimeter polyps.

Yoji Takeuchi, MD, of the Department of Gastrointestinal Oncology at Osaka International Cancer Institute in Japan, and colleagues assigned 182 patients at 30 centers in Japan to two treatment groups in an open-label trial. Overall, 631 lesions were detected and 611 lesions were removed from 168 patients. All patients were hospitalized for their procedures.

The first group remained on anticoagulants (warfarin or direct oral anticoagulants) and underwent cold snare polypectomy (continuous anticoagulants [CA] +CSP). The other group stopped the anticoagulants and received heparin bridging a few days before and after hot snare polypectomy (HB+HSP).

The incidence of major bleeding in the HB+HSP group was 12.0% (95% confidence interval [CI], 5.0% - 19.1%) vs 4.7% (CI, 0.2% to 9.2%) in the CA+CSP group.

No uncontrolled bleeding was observed in either group, according to the study.

Average procedure time and hospital stays were longer in the HB+HSP group than in the cold snare group.

The authors note that guidelines vary on how to manage anticoagulants for patients having polypectomy and options have been controversial. Whereas anticoagulants increase the risk for hemorrhage, stopping them for colonoscopy increases the risk for thromboembolic events.

Jeffrey L. Tokar, MD, and Michael J. Bartel, MD, both with the Fox Chase Cancer Center in Philadelphia, Pennsylvania, write in an accompanying editorial, "This study adds to emerging evidence that small colorectal polyps may be resected safely with CSP while oral anticoagulation continues and provides the first comparative evidence that this strategy may be safer than HB+HSP."

"A fundamental question for gastroenterologists is whether discontinuation of antithrombotic treatment (with or without HB), which exposes patients to thromboembolic risk, is justifiable for all patients receiving anticoagulants who are undergoing colonoscopy solely on the basis that polypectomy might be performed," they say.

Heparin bridging has been linked to a higher rate of bleeding after polyp removal. And recent evidence, Tokar and Bartel write, "suggests that [heparin bridging] is not as beneficial as once believed and may actually be harmful."

These concerns have led some physicians to use heparin bridging only with patients at highest risk for thromboembolism and to stop blood thinners without heparin bridging for the rest.

"However, what if HB is effective in preventing thromboembolism in some patients? Is it fair to expose any patient to thromboembolic risk, regardless of how infrequently thromboembolism might occur?" the editorialists ask.

Tokar and Bartel highlight some limitations of the study. One is that the design  was open-label and lack of blinding may introduce bias. Blinding wasn’t possible because clinicians needed to know which procedure patients had to monitor and assess them.

Another was that the study was inadequately powered "to fully characterize either class-specific risks for postpolypectomy bleeding in patients using warfarin versus those receiving direct oral anticoagulants or the rate of residual adenoma (incomplete polyp resection), which are important considerations in clinical practice."

The authors acknowledge that because they tested two factors at once — the snare methods and anticoagulant strategies — it may be hard to discern the effect of each on the outcomes.

Given these results, other studies are warranted, the editorialists write, such as whether CA+CSP could be effective with incomplete polyp resection, removal of larger polyps, and when used with other classes of antithrombotic medications, such as thienopyridines.

The Japanese Gastroenterological Association provided primary funding for the study. The study authors and the editorialists have disclosed no relevant financial relationships.

Annals of Internal Medicine. Published online July 15, 2019. Abstract, Editorial

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