P201 Crohn’s Disease of the terminal ileum associated with ileo-sigmoid fistula: risk factors for ileostomy formation and postoperative complications during the years of biologics

Belvedere, A.(1);Gerti, D.(1);Canavese, A.(1);Pulcina, G.(1);Romano, A.(1);Poggioli, G.(1);Rottoli, M.(1);

(1)Alma Mater Studiorum University of Bologna. IRCCS Azienda Ospedaliero-Universitaria di Bologna., Department of Medical and Surgical Sciences, Bologna, Italy;


Ileo-sigmoid fistula (ISF) is a complication of Crohn’s disease occurring in a significant proportion of patients. The aim of this study was to describe the perioperative outcomes of patients affected by ISF and to identify the risk factors for complications and ileostomy formation.


Consecutive patients operated for ISF between 2004 and 2021 in a single referral centre were included. Considering the presence of a large number of regressors the variables to include in the models were selected using the least absolute shrinkage and selection operator (LASSO) method. The multivariate analyses of the independent variables associated with the risk of ileostomy formation and post-operative complications were conducted using logistic regression.


Of the 208 patients who underwent ileocolic resection for ISF (Table 1), 161 (77.4%) also underwent sigmoid resection, while 47 (22.6%) underwent a conservative treatment of the target sigmoid colon.  ISF was detected preoperatively with CT scan in 121 (58%) patients and with colonoscopy in 63 (30%) patients.

Significant risk factors for ileostomy (performed in 63 patients - 30%, Table 2) were the preoperative diagnosis of ISF (Odds Ratio - OR - 2.22, 95% Confidence Interval - CI – 1.02-4.78), surgery for a recurrence (OR 6.71, 95%  CI 1.46-30.86), the presence of an intrabdominal abscess (OR 3.03, 95% CI 1.44-6.35), and additional small bowel surgery (OR 2.6, 95% CI 1.08-6.25).

Anastomotic leak occurred in 19 (9%) patients. Postoperative complications classified grade 2 or higher according to Clavien-Dindo (71 patients, 34.1%) were significantly associated with additional small bowel surgery (OR 2.42, 95% CI 1.11-5.3), the presence of an intrabdominal abscess (OR 2.45, 95%CI 1.44-6.35), and the localization of Crohn’s disease to the left colon (OR 1.98, 95%CI 1.03-3.8).


Although a diverting ileostomy was more likely to be performed in those patients identified perioperatively as high-risk subjects (more clinically relevant ISF, recurrent disease, addition bowel surgery or abdominal sepsis), this did not prevent the onset of postoperative complications, which seem to be associated with a more disseminated disease (either to the colon or to other locations of the small bowel) or with the presence of untreated intra-abdominal sepsis.