A novel volume-reduced CT colonography regimen using hypertonic laxative (polyethylene glycol with ascorbic acid): randomized controlled trial

Abstract

ObjectivesThe aim of this study is to investigate the feasibility of bowel preparation using a hypertonic laxative (polyethylene glycol with ascorbic acid, PEG + Asc) for CT colonography (CTC) and to examine the volume limit of laxative.MethodsIn one institution, patients who met the indications for CTC were enrolled and randomly assigned to CTC with regimen A (800\xa0ml PEG + Asc), B (600\xa0ml PEG + Asc), or C (400\xa0ml PEG + Asc). Sodium diatrizoate was given orally for fecal tagging. On the previous day, patients ate low-residue meals and took the assigned lavage solution after dinner. A reader blinded to the preparation graded residual stool/fluid and fecal tagging quality in six segments of the colorectum. The primary outcome was a proportion of colon segments without stool. One hundred twenty segments in 20 patients with each regimen were needed to show a non-inferiority margin of 15%, assuming 85% of no stool.ResultsA total of 360 segments in 60 patients were analyzed. There were 83% of segments with no stool in regimen A, 89% in regimen B, and 88% in regimen C. Using the delta method, the 95% confidence interval of the risk difference (6.7%) between regimens A and B was −\u20092.2% to 15.6%, and the risk difference (5.0%) between regimens A and C was −\u20094.1% to 14%, both within the non-inferiority margin. Residual fluid and fecal tagging quality were also within the non-inferiority margin. No adverse events occurred.ConclusionsA novel CTC regimen using hypertonic laxative demonstrated optimal colon cleansing effectiveness even with the lowest volume of laxative (UMIN000022851).Key Points• A novel CTC regimen using a hypertonic laxative is feasible.• The lowest volume of laxative provides excellent colon imaging.• However, the lowest volume of laxative did not improve patient acceptance.