Is early colonoscopy beneficial in patients with CT-diagnosed diverticulitis?

OBJECTIVE

The purpose of this study was to establish CT criteria as an indication for colonoscopy in patients with acute diverticulitis.

MATERIALS AND METHODS

The study was composed of patients diagnosed with acute diverticulitis on contrast-enhanced CT (CECT) from January 2000 to December 2004. Patients without subsequent colonoscopy were excluded. Findings on CT were correlated with patient outcomes over follow-up. Sensitivity, specificity, and predictive values of the imaging parameters for prediction of colon cancer were calculated. Outcomes were also compared between men and women.

RESULTS

Of 1034 patients with a CT diagnosis of diverticulitis, 402 (235 women and 167 men; mean age, 63.3 years) had available endoscopic colonic evaluation after CECT. The mean follow-up was 5.3 years. Seventy-eight patients had polyps (71% adenomatous) and nine patients (2.2%) were diagnosed with colon cancer (seven women, two men). The odds ratio for diagnosis of colon cancer was 23.35 in patients with mesenteric or retroperitoneal lymphnodes, 4.67 for abscess, and 24.43 in patients with obstruction and localized mass reported on CT. A significant correlation was found between the location of diverticulitis and cancer (p < 0.001). The diagnosis of cancer was made within 6 months from the date of CECT in eight patients. The odds of cancer were 2.5 times higher in women.

CONCLUSION

On the basis of the significant correlation of complicated diverticulitis or presence of lymph nodes with new diagnoses of colon cancer, we recommend early colonoscopy in patients with wall thickness more than 6 mm, abscess, obstruction, or lymph nodes seen on CECT.