Risk for Crohn’s Disease Diagnosis After Proctocolectomy

Julian Hercun, MD

More than 10% of patients that undergo proctocolectomy may experience a diagnosis of Crohn’s disease (CD) after 77 months postoperation, according to a paper published in the journal Diseases of the Colon & Rectum.

Investigators from Centre hospitalier de l’Université de Montréal in Canada conducted a retrospective cohort study at a tertiary care center in Montreal in order to determine the postoperative diagnosis of Crohn’s disease following proctocolectomy with ileal pouch-anal anastomosis (IPAA). They also wanted to identify potential preoperative predictive factors and to review the evolution of patients on treatments.

The investigators identified 301 patients that underwent an IPAA for ulcerative colitis between 1985-2014 and they underwent a median follow-up period of 68 months.

Crohn’s disease was diagnosed at a median time of 77 months in 38 patients, which translates to a cumulative incidence of Crohn’s disease at 7.5% at 5 years postoperatively. The cumulative incidence increased gradually to 17.7% and 33% at 10 and 20 years, respectively.

The investigators identified predictive factors for Crohn’s disease, including tobacco smoking at surgery, suspicion of indeterminate colitis, presence of mouth ulcers prior to surgery, and age at diagnosis of ulcerative colitis. Medical therapy was able to control postoperative inflammatory disease in most patients, but removing the pouch was necessary in 16 percent of patients with Crohn’s disease.

“Diagnosis of Crohn’s disease can occur at a distance from surgery with an increasing cumulative incidence over time,” the study authors concluded. “Preoperative predictive factors are few and should not determine candidacy for surgery. Therapeutic options are identical to those available for treatment of typical Crohn’s disease and allow a favorable evolution in most patients.”

In a related editorial, Amy L. Lightner, MD, from the Cleveland Clinic said that “CD of the pouch” is becoming an increasingly recognized and reported diagnosis. She added that as many as 13% of patients undergoing an IPAA for ulcerative colitis can get the diagnosis of Crohn’s disease of the pouch – even though the diagnostic criteria isn’t precisely clear.

“Making the distinction between Crohn’s disease of the pouch and post-IPAA morbidity can be exceedingly difficult but critically important to guide both medical treatment strategies and surgical options, such as pouch reconstruction,” Lightner wrote.

While the study authors found that 12.6% of their IPAA cohort developed Crohn’s disease at a median of 77 months, Lightner said that rate is higher than the rate reported by the Mayo Clinic, which was 6.5%.