Is Prophylactic Clipping Effective in Preventing Post-Polypectomy Bleeding?

Polypectomy is routinely performed during colonoscopy. It is not uncommon for gastroenterologists to prophylactically place hemoclips after removal of a polyp to prevent both immediate and future bleeding. However, the decision of whether or not to place a prophylactic clip is multifactorial in nature and can vary between gastroenterologists. Factors such as polyp size, location, anticoagulation status as well as patient co-morbidities can all contribute to the choice of whether to proceed with prophylactic clipping. 

Despite the routine utilization of post-polypectomy (PP) clipping, studies on the use of the procedure show mixed results. Most recently, Spadaccini et al conducted a meta-analysis to evaluate prophylactic clipping in preventing post-polypectomy bleeding (PPB). Results were published in Gastroenterology.¹

The authors identified 9 randomized trials that met inclusion criteria and performed a meta-analysis and systematic review. They analyzed a total of 7197 colorectal lesions from 4557 patients within these studies. The mean percentage of proximal polyps was 49.2% with a mean polyp size of 18.6 mm.   

Risk of PPB was similar between groups, with 3.3% (95% CI, 1.9-5.7%) in the control group and 2.2% (95% CI, 1.2-3.9%) in the clipping group. When authors applied a random-effects model, they found no significant difference between the 2 groups with respect to PPB (RR [relative risk], 0.69; 95% CI, 0.45-1.08; P =.072). 

In a meta-regression analysis, the authors found that as the percentage of large lesions increased, prophylactic clipping resulted in reduced PPB. This was determined by calculating the meta-regression coefficient for the percentage of large (> 20 mm) lesions. The resulting coefficient was 0.92 (95% CI, 0.85-0.98). This figure indicated that for every 10% increase in large lesions removed, the RR of PPB decreased by 8% (95% CI, 2-15%) if prophylactic clipping was utilized. 

A sub-group analysis found no benefit in using prophylactic clips in polyps < 20 mm (RR, 1.04; 95% CI, 0.60-1.79). However, there was a benefit in clipping polyps > 20 mm (RR, 0.51; 95% CI, 0.33-0.78).  In patients with polyps < 20 mm, the estimated rates of PPB were 1.4% in the prophylactic clipping group and 1.8% in the control group.  Conversely, in patients with lesions > 20 mm, the estimated PPB rates were 4.3% in the prophylactic clipping group compared with 7.6% in the control group. 

When evaluating the impact of prophylactic clipping based on polyp location, there was a statistically significant association with decreased PPB in the proximal colon (RR, 0.53; 95% CI, 0.35-0.81) but not in distal colon (RR, 1.01; 95% CI, 0.43-2.37).  The association observed in the proximal colon was found regardless of the definition of “proximal” used (cecum, ascending colon, hepatic flexure vs all structures proximal to the splenic flexure). 

Another multilevel random-effects meta-regression analysis found that the rate of PPB in proximal lesions was 3.0% in the prophylactic clipping group and 6.2% in the control group. The rate of PPB in distal lesions was 3.3% in the prophylactic clipping group compared with 2.7% in the control group. When these findings were adjusted for the prevalence of large lesions, the benefit of prophylactic clipping was only seen in large proximal lesions (OR, 0.37; 95% CI, 0.22-0.61; P =.021) but not small lesions (OR, 0.88; 95% CI, 0.48-1.62; P =.581). There was no benefit found in prophylactically clipping large distal lesions, although this data was more limited. In addition, there were no statistical differences between groups with respect to perforation. 

The authors concluded that although there was no routine benefit to prophylactic clipping in reducing PPB overall, there is evidence to support prophylactic clipping in larger, more proximal lesions. However, it is important to note that the study was a meta-analysis and that there was heterogeneity between many of the trials, although this was factored into the design. In addition, there was no detailed information regarding patient anticoagulation status and polypharmacy, both of which can play a significant role in PPB.  Many of the studies included in the meta-analysis were low to moderate quality, which could obviously impact the outcomes.

Another interesting consideration is the financial impact of prophylactic clipping, especially in larger, more proximal lesions. Depending on the practice site, some gastroenterologists may be hesitant to use prophylactic clipping due to the cost associated with the procedure. In addition, it was not clear if there was any difference in additional hemostasis techniques used (such as epinephrine or electrocautery) or in the number of clips. The authors note that additional studies should include more prospective trials focusing on patient anticoagulation status and medications, certain laboratory parameters, as well as number and type of hemoclips used.

Reference

Yang E, Panaccione N, Whitmire N, et al. Efficacy and safety of simultaneous treatment with two biologic medications in refractory Crohn’s disease [e-pub, ahead of print]. Aliment Pharmacol Ther. 2020;51(11):1031‐1038. doi:10.1111/apt.15719