Is capsule colonoscopy the solution for incomplete conventional colonoscopy?

Abstract

The era of colon capsule endoscopy (CCE) started in 2007 (1). Few years later second-generation CCE (CCE-2) (Medtronic, Minneapolis, USA) was launched, featuring an improved optical system allowing for nearly 360° coverage via two 172° angle cameras, and adaptive frame rate function (ranging from 4 to 35 images per second depending on capsule motion).At present the main clinical indications for CCE are: a) completion of incomplete colonoscopy; b) polyp detection; and c) investigation of inflammatory bowel disease (IBD).Colon capsule endoscopy (CCE-2) was shown to be a reliable tool for the detection of colonic lesions such as polyps and tumors. The ability of CCE to identify colonic polyps and colorectal cancer (CCR) has been the goal of several studies, which were recently subjected to a meta-analysis pooling data from 14 studies (2). The accuracy of first-generation CCE (CCE-1) was tested in 7 studies involving 1,128 patients. CCE-2 was studied in 1,292 patients included in another series of 7 studies. This analysis showed that, while the sensitivity values for polyp detection achieved by CCE-1 studies were relatively low (58% and 54% for ≥ 6 mm and ≥ 10 mm polyps, respectively), those reported in CCE-2 studies were more acceptable (i.e., sensitivity of 86% and 87% for ≥ 6 mm and ≥ 10 mm polyps, respectively; specificity of 88.1% and 95.3% for ≥ 6 mm and 10 mm polyps, respectively). In addition, CCE-2 identified all 11 invasive cancers that were detected by colonoscopy. The authors concluded that high specificity values for polyp detection seem to be achievable by CCE-2 with a 10 mm cutoff in a screening setting.Conventional colonoscopy is the gold-standard procedure for the screening of bowel cancer. While complete examination of the large bowel is essential to detect abnormalities, incomplete colonoscopies (ICs) do occur. Population-based studies have found that, in clinical practice, cecal intubation rates (CIR) are variable between centers within the range of 80-95% (3), far from the targets established by different national and international specialty associations (4,5).The consequences of incomplete colonoscopy may be unfortunate. The term "post-colonoscopy colo-rectal cancer" (PCCRC) has been coined for interval cancers in patients having undergone colonoscopy. PCCRCs may represent a missed cancer, a cancer arising in a missed or incompletely treated adenoma, or a cancer that started to develop after colonoscopy. Missed cancers may result from several factors, including poor bowel preparation or reduced withdrawal time, but most important is incomplete colonoscopy. Higher post-colonoscopy colorectal cancer (PCCRC) rates are found for endoscopists with a lower CIR (6), and in cases of incomplete colonoscopy (7), with PCCRCs being more frequent in the right side of the colon.These data make it clear that all patients with incomplete screening colonoscopy should be re-examined. Several alternatives may be used. Patients may undergo a successful repeat colonoscopy at a tertiary referral center with dedicate...

What Is the Optimal Bowel Preparation for Capsule Colonoscopy and Pan-intestinal Capsule Endoscopy? A Systematic Review and Meta-Analysis

“…These capsules have two cameras in opposite sides, with a wide field of view (2 × 172°), a high frame rate of image capture (up to 35 endoscopic images per second) and extended battery duration (more than 12 h), and were demonstrated to be safe and effective, ensuring high diagnostic accuracy both for the small bowel and the colon mucosal evaluation [1][2][3]. To date, they have mostly been used in cases of previous incomplete conventional colonoscopy (due to redundant colon, loops, or acute bends preventing successful cecum intubation) or in patients with inflammatory bowel disease, mainly Crohn's Disease involving both the small bowel and the colon [4][5][6].…”