Right colonic diverticulitis in Caucasians: presentation and outcomes versus left-sided disease.

PURPOSE: To compare clinical features, computed tomography (CT) findings, and outcomes of right vs. left colonic diverticulitis (CD) in Caucasians. METHODS: This single-center retrospective case-control study of patients seen between July 2005 and February 2013 included 30 consecutive cases of right CD and 70 controls taken at random from a consecutive cohort of patients with left CD. The final diagnosis was established by consensus between a gastrointestinal surgeon and a gastrointestinal radiologist. Clinical features, treatment, and follow-up data were collected. Two radiologists blinded to patient data reached a consensus about multiple CT criteria. Cases and controls were compared using appropriate statistical tests, and odds ratios (ORs) associated with clinically meaningful variables were computed using univariate logistic regression. RESULTS: Median age was significantly lower in cases than in controls (48.5 years [IQR, 31-61] vs. 63.5 years [54-75], P < 0.0001). A body mass index <20 kg/m2 compared to >30 kg/m2 was associated with a higher risk of right than of left CD (OR 22.7, 95% confidence interval [95% CI], 2.6-200, P = 0.005). Compared to controls, cases more often had CT evidence of focal diverticular inflammation (86.7% [26/30] vs. 50% [35/70], P = 0.0006) and noncircumferential (≤180°) colonic wall thickening (66.7% [20/30] vs. 20% [14/70], P < 0.001). Complications were less common in the cases (6.7% [2/30] vs. 25.7% [18/70] than in controls, P = 0.03). CONCLUSION: In Caucasians, right CD occurs in younger and thinner patients and carries a lower risk of complications compared to left CD. Focal diverticular inflammation by CT is more common in right than in left CD.