Professor Michael Bourke
Prophylactic endoscopic clipping does not prevent delayed postpolypectomy bleeding (DPPB) in the context of screening colonoscopy.
According to a large Canadian study of 8,366 colonoscopies involving polypectomy, only 95 (1.1%) led to delayed bleeding events.
There were 50 bleeding events in patients with clips and 45 bleeding events in patients who were not clipped.
“After adjusting for clinically relevant covariates, the adjusted odds ratio (AOR) of DPPB between the clipped and unclipped groups was not statistically significant, at 1.27 (95% CI, 0.83–1.96),” the study said.
The study also found no evidence of a beneficial effect with clipping based on the polyp size.
While the AORs of delayed bleeding after clipping were less than 1 for larger polyps ≥20 mm and for proximal polyps ≥20 mm in the single-polyp cohort (0.64 and 0.55 respectively), these failed to reach statistical significance.
The study, co-authored by Australian endoscopist Professor Michael Bourke, said the results were consistent with several meta-analyses.
“What the study shows is that in routine clinical practice for average risk patients undergoing screening colonoscopy and then polypectomy, in polyps less than 10mm there is no benefit to prophylactically clip the polypectomy site to prevent delayed bleeding,” Professor Bourke told the limbic.
“The risk of delayed bleeding is remote (<1%) and prophylactic clipping offers no benefit but just adds to the expense of the procedure,” he said.
He noted the study was done between 2008 and 2014 when most polyps were removed using diathermy which is known to increase the risk of postpolypectomy bleeding.
“So even under those circumstances, where most of the polyps were removed by diathermy… there was no benefit from clipping.”
“Now, most of the world has changed to cold snare excision for small polyps less than 10mm and the risk of bleeding is even lower – virtually negligible for polypectomy under those circumstances.”
“So there is doubling down on the message that there is virtually no role for prophylactic clipping in average risk individuals undergoing polypectomy for small polyps in routine practice.”
However the jury might still be out on a role for clipping larger defects to reduce bleeding.
“Despite reviewing over 10,000 colonoscopies, our study was ultimately underpowered to demonstrate a difference in DPPB in procedures with a single proximal polyp ≥20 mm, although we did observe an odds ratio of 0.55 (95% CI, 0.10–2.66),” the study said.
“Although entirely statistically nonsignificant with a wide CI, this point estimate was nevertheless below 1.0 in a direction indicating a lower odds of bleeding, and thus quite different than the odds ratios seen for other subgroups.”
“Ultimately, we would have had to capture over 1,400 procedures with proximal polyps ≥20 mm in our study to show a statistically significant protective benefit of clipping.”
They noted the small number of patients who do develop DPPB can usually be managed conservatively.
“Thus, it may be more efficient to apply widespread efforts towards optimizing periendoscopic conditions including antiplatelet/anticoagulant management and application of evidence-based polypectomy techniques to reduce the risk of DPPB while dealing with relatively rare and treatable bleeding events when they present.”