A pooled analysis of published studies of perforation rates was reported during a Digestive Disease Week session on May 31.  Including 17 different studies covering more than a quarter million colonoscopies, the perforation rate for therapeutic colonoscopy was 1 in 1,500 exams.  In purely screening or diagnostic tests, perforations occured in only 1 in 6,000 tests.  Perforation risk is about three times higher when polyps are removed during the colonoscopy.

Analysis showed a trend toward decreasing rates of perforations over time.

The study team defined a diagnostic colonoscopy as one where no polyps needed to be removed and biopsies of  suspicious areas were simple and didn’t require cauterization.  When cauterization or removal of polyps with a snare (polypectomy) was necessary during the procedure, it was called a therapeutic colonoscopy.

Syed M Abbas Fehmi and the team at the University of Michigan concluded,

This is the largest meta-analysis to quantitatively pool colonoscopy perforation rates for diagnostic and therapeutic colonoscopy. Colonoscopy perforation rates for diagnostic and therapeutic colonoscopies are quite low and reported rates are decreasing in recent studies.

SOURCE: Fehmi et al., Risk of Perforation During Colonoscopy: a Systematic Review and Meta-Analysis, Abstract 210, Digestive Disease Week 2009.