Effect of Cholecystectomy on Bubble Formation and Endoscopic Visualization: A Retrospective Cohort Study

Introduction: Colonoscopy, the gold standard screening test for colon cancer, requires proper bowel preparation for optimal results. The presence of colonic bubbles poses challenges in visualizing the mucosa, affecting the accuracy of diagnosis and treatment. The aim of our study is to assess the association between cholecystectomy and colonic bubble formation. Methods: This is a single center retrospective cohort study done at Staten Island University Hospital in New York. IRB approval was granted. Colonoscopy reports were reviewed. Primary endpoint was bubble formation as represented by a score from 0-3 as reported in previous studies (0 indicates no bubbles and clear mucosa, 3 indicates severe bubbles with < 50% of mucosa clear). Secondary endpoints were number of polyps detected, presence of adenoma, withdrawal and procedure time, quality of prep, and need to repeat procedure. Continuous parametric data were reported as a mean and standard deviation. Continuous nonparametric data were reported as a median and an interquartile range. Categorical variables were calculated as proportions. In our two groups, differences between continuous parametric and nonparametric data were explored using the student’s t-test and the Mann-Whitney U test, respectively. Similarly, Pearson's chi-squared test (χ) was utilized to assess differences in proportions and categorical variables. A P-value of less than 0.05 is considered statistically significant (Table 1). Results: In this study, 348 colonoscopy reports were reviewed, including 56 patients who had undergone cholecystectomy and 292 patients who had not. There was no significant difference between the two groups in terms of patient demographics, medical history, indication for the procedure, or quality of bowel preparation. Patients with cholecystectomy had a higher incidence of colonic bubble formation with a bubble score of 3 (28.6% vs 12%, P-value 0.001), longer withdrawal (18 ± 8 vs 15 ± 5 mins, P-value 0.024) and procedure times, and a higher rate of repeat procedures (10.7% vs. 2.1%, P-value 0.001). There was no difference between both groups regarding number of polyps detected, or number of adenomas. Conclusion: Cholecystectomy was associated with higher colonic bubble formation during colonoscopy, but it did not affect the detection of polyps or adenomas. Endoscopists should be aware that patients with cholecystectomy may require longer procedure time to ensure thorough cleaning of the mucosa from bubbles and minimize the risk of missing polyps. Table 1. - Variables and Demographics Variable Cholecystectomy (n=56) No- Cholecystectomy (n=292) P Value Demographics Age, y, mean ± SD 59 ± 12 57 ± 13 0.910 White, n (%) 36 (64.3) 143 (49.0) 0.036* Black, n (%) 3 (5.4) 49 (16.8) 0.028* Hispanic, n (%) 5 (8.9) 28 (9.6) 0.877 BMI, kg/m2, mean ± SD 30 ± 7 29 ± 6 0.090 History of Constipation 5 (8.9) 23 (7.9) 0.791 History of Abdominal Surgery 56 (100) 70 (24.0) < 0.001* Opioids 4 (7.1) 10 (3.4) 0.195 Screening 28 (50.0) 176 (60.3) 0.153 Golytly Containing Prep, n (%) 38 (67.9) 213 (72.9) 0.437 Miralax Containing Prep, n (%) 12 (21.4) 48 (16.4) 0.365 Other Prep, n (%) 6 (10.7) 31 (10.6) 0.983 Experience ≥ 20 y, n (%) 43 (76.8) 234 (80.1) 0.569 Experience ≥ 5 and ≤ 10 y, n (%) 1 (1.8) 14 (4.8) 0.310 Experience < 5 y, n (%) 12 (21.4) 44 (15.1) 0.235 Outpatient, n (%) 52 (92.9) 273 (93.8) 0.783