Single- Versus Double-Balloon-Assisted Colonoscopy After Previous Incomplete Standard Colonoscopy

Abstract

Colonoscopy is the principle screening tool used for the detection of colorectal cancer and removal of colorectal adenomatous polyps [1, 2]. Recently, a large clinical study showed that colonoscopic removal of adenomatous polyps reduced mortality from colorectal cancer by 53 % [3]. While complete colonic evaluation is essential for screening colonoscopy, the rate of incomplete colonoscopy using a conventional standard colonoscope has been reported to be 5–10 % [4–6]. A study conducted in Ontario found that 43,483 (13.1 %) of 331,608 screening colonoscopies failed to evaluate the entire colon [7]. In this population-based cohort study, the factors associated with incomplete colonoscopy were increased patient age, female sex, a history of prior abdominal or pelvic surgery, and having the procedure done in a private office. Other predictors of incomplete colonoscopy include decreased functional status of the patient [8] and anatomic factors such as colonic elongation, tortuosity, and severe diverticulosis [9]. Malignant and pre-malignant lesions may go undetected in patients that are not completely evaluated by screening colonoscopy. In a population-based cohort study, 4.3 % of advanced colonic neoplasms were missed by incomplete colonoscopy [10]. Since 33–50 % of advanced neoplasms are found only in the proximal colon [11–13], additional efforts should be made to adequately visualize the remaining colon after an incomplete colonoscopy. An alternative diagnostic modality such as computed tomographic colonography has been utilized in these cases, however, its usefulness is limited by low sensitivity for small polyps, radiation exposure, and the inability to perform histologic biopsy and therapeutic procedures including polypectomy [14, 15]. As a result, endoscopic approaches are still favored after incomplete standard colonoscopy. Additional endoscopic techniques using gastroscope, variable stiffness colonoscope, pediatric or cap-pitted colonoscope have been tried, but failed to achieve an adequate cecal intubation rate. More recently, a balloon-assisted technique, which was originally introduced to investigate the small bowel, has been applied in patients with previous failed or incomplete colonoscopy. For a balloon-assisted colonoscopy, two types of balloon enteroscopes are available; the double-balloon enteroscope developed by Yamamoto et al. [16], and the single-balloon enteroscope developed by Tsujikawa et al. [17]. The reported success rates of single(SBC) or doubleballoon-assisted colonoscopy (DBC) in patients with previous incomplete conventional colonoscopy range from 88 to 100 % [18–23]. In the current issue of Digestive Diseases and Sciences, Dzeletovic et al. [24] compared the performance outcomes of SBC and DBC in patients with previous incomplete conventional colonoscopy. In this study, the authors retrospectively reviewed 26 cases of SBC and 27 cases of DBC in patients whom underwent failed conventional colonoscopy. The current study showed that cecal intubation was successful in 96 % of patients using either SBC or DBC (100 % with SBC vs. 93 % with DBC, p = 0.049). The median cecal intubation time and total procedure time using SBC and DBC were 17 min vs. 20 min (p = 0.37) and 43.5 min vs. 46.0 min (p = 0.32), respectively. While SBC required less time than DBC, the difference was not statistically significant. Balloon-assisted colonoscopy revealed additional colonic polyps in 35 % of patients in the SBC group and 30 % of patients in the DBC group. Despite the J. U. Lim J. M. Cha (&) Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, 149 Sangil-dong, Gangdong-gu, Seoul 134-727, Korea e-mail: drcha@khu.ac.kr