Balloon-assisted colonoscopy after incomplete conventional colonoscopy - experience from two European centres with a comprehensive review of the literature

Background: Conventional colonoscopy (CC) allows access for colonic investigation and intervention; in the small group in whom CC is unsuccessful alternative imaging is often sufficient. There remains a subset, however, requiring full colonic visualisation or intervention. Balloon-assisted colonoscopy (BAC) gives a further option when access is difficult. Aims: This study aims to present the experience with BAC of two European tertiary referral centres. Methods: Procedures were carried out under local protocol over 15-years (2006–2020). Markers of procedural quality such as caecal intubation, complications and comfort were retrospectively compiled and analysed. Published evidence was summarised for comparison. Results: 122 procedures were undertaken, with polyps the most frequent indication and 90.2% having at least one previously incomplete CC. Features associated with difficult colonoscopy were common, including intraabdominal surgery (32.0%). 92.6% reached the caecum; completion was higher (96.3%) in those failing CC due to discomfort and lower in those failing due to anatomical difficulties (90.7%) or previous surgery (84.6%). Mean time to the caecum was 20.9 minutes and mean midazolam and fentanyl doses were 2.6 mg and 49.9 µg with low discomfort scores. Conclusion(s): Balloon-assisted colonoscopy is successful in >90% of patients, is well-tolerated, and is safe.