Predictors of Incomplete Optical Colonoscopy Using Computed Tomographic Colonography

BACKGROUND/AIMS: Optical colonoscopy (OC) is the primary modality for investigation of colonic pathology. Although there is data on demographic factors for incomplete OC, paucity of data exists for anatomic variables that are associated with an incomplete OC. These anatomic variables can be visualized using computed tomographic colonography (CTC). We aim to retrospectively identify variables associated with incomplete OC using CTC and develop a scoring method to predict the outcome of OC. PATIENTS AND METHODS: In this case–control study, 70 cases (with incomplete OC) and 70 controls (with complete OC) were identified. CTC images of cases and controls were independently reviewed by a single CTC radiologist. Demographic and anatomical parameters were recorded. Data was examined using descriptive linear statistics and multivariate logistic regression model. RESULTS: On analysis, female gender (80% vs 58.6% P = 0.007), prior abdominal/pelvic surgeries (51.4% vs 14.3% P < 0.001), colonic length (187.6 ± 30.0 cm vs 163.8 ± 27.2 cm P < 0.001), and number of flexures (11.4 ± 3.1 vs 8.4 ± 2.9 P < 0.001) increased the risk for incomplete OC. No significant association was observed for increasing age (P = 0.881) and history of severe diverticulosis (P = 0.867) with incomplete OC. A scoring system to predict the outcome of OC is proposed based on CTC findings. CONCLUSION: Female gender, prior surgery, and increasing colonic length and tortuosity were associated with incomplete OC, whereas increasing age and history of severe diverticulosis were not. These factors may be used in the future to predict those patients who are at risk of incomplete OC.