Accuracy of Detecting Colorectal Polyps Utilizing Colon Capsule Endoscopy 2: A Meta-analysis

Abstract

Introduction: Colorectal cancer (CRC) is the 3rd most commonly diagnosed cancer in USA. Optical colonoscopy (OC) is considered the gold standard for CRC screening but is invasive with inherent complications, requires sedation and has poor patient compliance. Colon Capsule Endoscopy (CCE) was first introduced back in 2006 (Given Imaging, Israel) as an alternative to OC; however, sensitivity of 1st generation colon capsule endoscopy (CCE1) was suboptimal. So a 2nd generation colon capsule endoscopy (CCE2) was developed. The role of CCE in CRC screening has been studied with variable results. The aim of this study is to assess sensitivity and specificity of CCE2 in comparison to OC. Methods: Literature from 2006 to May 2015 was reviewed using PUBMED and COCHRANE databases. Studies reporting per patient analysis for detection of colorectal polyps by CCE2 confirmed by OC were included. One abstract from Gastrointestinal endoscopy was also included. Microsoft Excel was utilized for data entry and statistical analysis. Two independent reviewers reviewed the data and conflicts were resolved by discussion. Results: Our search strategy yielded 4 studies with sample size of 1127 patients. Mean age of study population was 56.5yrs. Pooled data for polyps >6mm showed per patient CCE2 sensitivity and specificity with 95% CI of 85.8% (81.2 to 89.6) and 90.6% (88.5 to 92.5), respectively. Pooled data for polyps >10mm showed per patient CCE2 sensitivity and specificity of 85.9% (78.8 to 91.3) and 96.5% (95.2 to 97.6), respectively. Colon cleansing rate for CCE 2 was 81.9%. CCE2 excretion rate within 10hrs in 902 patients was 86.9%. No adverse events related to CCE2 were reported. Conclusion: Our study showed that CCE2 is safe and effective at detecting colorectal polyps. CCE2 has a sensitivity (85%) significantly higher than CCE1 (71%). CCE could be a novel modality for CRC screening as the procedure is minimally invasive, safe, does not require sedation or air insufflation and is well accepted by patients. Since CCE could be done in outpatient setting this would make it more cost effective than OC. CCE has 2 important limitations. First, it still requires same level of bowel preparation as OC and more importantly when polyps are identified by CCE, patients will need subsequent OC for polyp removal. More robust studies are needed to validate CCE as a screening tool, but for now CCE could be used as an alternative approach in patients whose OC is contraindicated or incomplete.Figure 1Figure 2