CT colonography followed by elective surgery in patients with acute diverticulitis: a radiological-pathological correlation study

Abstract

Purpose: To perform a radiologic-pathologic correlation analysis of sigmoid colon in patients undergoing pre-operative CT Colonography (CTC) after an episode of acute diverticulitis (AD).

Methods: Fifty-nine consecutive patients (31/28 M/F; 58 ± 13 years) underwent CTC 55 ± 18 days after AD, 8 ± 4 weeks before surgery. Thirty-seven patients (63%) underwent conventional abdominal CT at time of AD. An experienced blinded radiologist retrospectively analyzed all images: disease severity was graded according to the Ambrosetti classification on conventional CT and according to the diverticular disease severity score (DDSS) on CTC. A GI pathologist performed a dedicated analysis, evaluating the presence of acute and chronic inflammation, and fibrosis, using 0-3 point scale for each variable.

Results: Of 59 patients, 41 (69%) had at least one previous AD episode; twenty-six patients (44%) had a complicated AD. DDSS was mild-moderate in 34/59 (58%), and severe in 25/59 (42%). All patients had chronic inflammation, while 90% had low-to-severe fibrosis. Patients with moderate/severe fibrosis were older than those with no/mild fibrosis (61 ± 13 versus 54 ± 13). We found a significant correlation between DDSS and chronic inflammation (p = 0.004), as well as DDSS and fibrosis (p = 0.005). Furthermore, fibrosis was correlated with complicated acute diverticulitis (p = 0.0.27), and with age (p = 0.067). At multivariate analysis, complicated diverticulitis was the best predictor of fibrosis (odds ratio 4.4). Patient age and DDSS were other independent predictors.

Conclusion: DDSS-based assessment on preoperative CTC was a good predictor of chronic colonic inflammation and fibrosis. In addition, the presence of complicated diverticulitis on CT during the acute episode was most predictive of fibrosis.

Keywords: Abdominal CT; Acute diverticulitis; CT colonography; Colon; Diverticular disease; Surgery.

Fig. 1

Images in a 59-year-old-man who underwent elective surgery after recovery from acute diverticulitis. Axial two-dimensional (2D) supine conventional computed tomography (CT) a shows acute diverticulitis in the presence of sigmoid colon wall thickening, mesenteric fascial thickening and small abscess (complicated AD). Axial 2D supine computed tomography colonography (CTC) image b and DCBE CTC like-view c images showing sigmoid colon diverticula without wall thickening or significant lumen stenosis (diverticular disease severity score [DDSS] 1). In this whole-thickness section of the colonic wall (d), only scarce fibrosis and focal chronic inflammation (arrows) is appreciable

Fig. 2

Images in a 49-year-old-man who underwent elective surgery after recovering from acute diverticulitis. Axial two-dimensional (2D) supine conventional computed tomography (CT) a shows acute diverticulitis in the presence of sigmoid colon wall thickening, inflamed diverticula, mesenteric fat stranding and mesenteric fascial thickening (uncomplicated AD). Axial 2D supine computed tomography colonography (CTC) image (b) and DCBE CTC like-view c images showing sigmoid colon diverticula in the presence of severe diffuse wall thickening and severe lumen stenosis (diverticular disease severity score [DDSS] 4). Heavy, dense fibrosis intermingled with inflammatory cells is appreciable at histology (d). Note fibrotic bands in perivisceral fat tissue around large bowel walls