Fitting Balloon Overtube-Assisted Colonoscopy (BOAC) Into the Difficult or Failed Colonoscopy Algorithm

We thank Koukias et al for highlighting the recent article from their group that supports our view that balloon overtube-assisted colonoscopy (BOAC) should be available in major endoscopy units as an option for technically challenging colonoscopies.1Despott E.J. et al.Dig Liver Dis. 2017; 49: 507-513Google Scholar In their randomized controlled trial, patients who were predicted to have difficult colonoscopies by using a novel scoring system underwent either a double balloon colonoscopy (DBC) or a conventional colonoscopy (CC) without the use of ancillary equipment. The cecal intubation rate (CIR) was 100% in the DBC group, compared with 59% in the CC group, although the CIR increased to 86% when magnetic endoscopic imaging or a pediatric colonoscope was used. Underwater colonoscopy, use of a gastroscope, or cap-assisted colonoscopy were not tested. With these ancillary devices, there may not have been a detectable difference between both groups. Importantly, patients and endoscopists were more satisfied with DBC than CC. In our meta-analysis2Tan M. et al.Clin Gastroenterol Hepatol. 2017; 15: 1628-1630Abstract Full Text Full Text PDF Scopus (15) Google Scholar of patients who had incomplete CC, the average age was 66.1 years and there was a slight preponderance toward women (53.4%). Approximately half (45.6%) of our patients had a history of abdominopelvic surgery and using the novel colonoscopic difficulty scale described by Despott et al,1Despott E.J. et al.Dig Liver Dis. 2017; 49: 507-513Google Scholar a significant number of our patients would have been eligible to participate in their trial. A recently published prospective cohort study by Rogers et al3Rogers M.C. et al.Endosc Int Open. 2017; 5: E886-E892Google Scholar looked at 175 patients with a prior incomplete colonoscopy. An algorithm was derived with an initial cohort of 50 patients and using the first suggested endoscope (adult or pediatric colonoscope, or gastroscope ± water immersion) selected by the algorithm, a CIR of 90% could be achieved. Therefore, a key question for endoscopists is where BOAC fits in their personal and unit’s algorithm for difficult or failed colonoscopy. It seems clear that alternative scopes, devices, techniques, or endoscopists can bring CIR close to 90%, although this remains short of the 97% (95% CI, 95%–99%) reported in our meta-analysis and supported by the randomized data from Despott et al.1Despott E.J. et al.Dig Liver Dis. 2017; 49: 507-513Google Scholar Because the use of a disposable overtube is required in BOAC, the added cost may be a prohibitive factor in using it as a first-line tool for patients who are suspected to have technically difficult colonoscopies, although this needs to be balanced against a repeat failure. We suggest that in units without a balloon enteroscopy service, the algorithm proposed by Rogers et al3Rogers M.C. et al.Endosc Int Open. 2017; 5: E886-E892Google Scholar may be considered, with referral to a unit for BOAC if complete optical examination and biopsy or therapy is clinically mandated. However, if BOAC is immediately available, endoscopists perhaps should go directly for the most effective and comfortable technique for difficult or failed cases. Efficacy of Double-Balloon Colonoscopy in Technically Difficult Cases: Growing Evidence Favoring its Frontline UseClinical Gastroenterology and HepatologyVol. 16Issue 4PreviewWe read with great interest the results of the meta-analysis by Tan et al1 that highlight the usefulness of balloon overtube-assisted colonoscopy for technically difficult (TD) cases. Interestingly, among the 18 studies included in this meta-analysis,1 only 3 were prospective randomized studies; this underlines the scarcity of higher-quality data regarding this important subject. Full-Text PDF