MedicalResearch.com Interview with:
Dr Franco Radaelli
Division of Digestive Endoscopy and Gastroenterology
Medical Research: What is the background for this study?
Dr. Radaelli: Split regimens of bowel preparation are strongly recommended by European and American Guidelines as they have been associated with a higher level of colon cleansing. However, there is still uncertainty on whether the higher level of cleansing associated with a split regimen also results in a higher proportion of subjects with at least one adenoma (adenoma detection rate, ADR), that represents by far a more relevant quality indicator than the level of cleansing itself.
On this background, we designed a randomized investigator-blinded controlled trial to evaluate whether a “split regimen” of low-volume 2-L PEG-ascorbate solution was superior to the traditional “full dose, the day before regimen” in terms of ADR. Differently from other studies on bowel preparation, we considered adenoma detection rate instead of the level of colon cleansing, the primary study end-point, and we designed the sample size accordingly. A precise estimation of the sample size was facilitated by including an homogeneous population of asymptomatic subjects undergoing first colonoscopy after positive-FIT within CRC organized screening program. Besides, ADR represents a very solid end-point due to the very low inter-pathology variability in the differential diagnosis between neoplastic and non-neoplastic lesions, while the assessment of the level of cleansing is hampered by unavoidable degree of subjectivity and higher degree of inter-operator variability.
Medical Research: What are the main findings?
Dr. Radaelli: We showed that the adoption of a split regimen of bowel preparation increased the proportion of subjects with at least one adenoma and one advanced adenoma by 22% and 35%, respectively, when compared with a day-before regimen. The adoption of a split regimen also resulted in higher mean number of adenomas, advanced adenomas, proximal and flat lesions, including SSP, at per polyp analysis. Last but not least, we showed that the favorable effect of a split regimen on the detection of neoplastic lesions was associated with a better cleansing level as compared with the ‘day-before’ arm, providing a biologic plausibility to the efficacy of a split regimen on adenoma detection rate. We may postulate that the improved cleansing led to a more meticulous exploration of the colorectal mucosa, increasing the detection of polypoid and flat lesions at both per patient and per polyp analysis.
Medical Research: What should clinicians and patients take away from your report?
Dr. Radaelli: The adoption of a split regimen for screening and diagnostic colonoscopy results into a higher adenoma detection rate, that is strictly associated with lower risk of interval cancer. Such evidence offers a superior rationale than the higher level of cleansing, as currently done in the available guidelines, to recommend the adoption of a split regimen for colonoscopy in clinical practice.
Dr Franco Radaelli (2015). Split Bowel Prep For Colonoscopy Results In More Polyps Detected