There is a clear division in the literature regarding the outcomes of IPAA in CD in terms of the time of diagnosis of the primary disease. Studies divide the timing of the CD diagnosis as preoperative (resulting in an ‘intentional’ IPAA formation), perioperative (IPAA formation with ‘incidental’ or ‘accidental’ CD diagnosis on analysis of the surgical specimen) or at a later date following IPAA creation (so called ‘delayed’ diagnosis). A comparison of the data for these three distinct groups has been reported in prior studies. However, the ensuing recommendations and debate are based solely on those studies pertaining to patients with a documented diagnosis or high clinical suspicion of CD prior to undergoing IPAA, the aforementioned ‘intentional’ IPAA cohort.

The first published paper of ‘intentional’ IPAA formation in CD (patients in whom there was a high clinical suspicion based on the findings described below) was from Hyman and colleagues from the Cleveland Clinic in 1991 [1]. They reported on 25 patients with a postoperative pathologic diagnosis of CD out of 362 consecutive patients undergoing IPAA for a preoperative diagnosis of ulcerative colitis (UC). Of these 25 patients, 9 had preoperative features suggestive of CD: 5 with perianal disease (fistula, fissure or stricture), 2 with abnormal distribution of colonic disease, 1 with a cecal stricture and possible terminal ileal disease and 1 with a rectovaginal fistula. Although none of these 9 patients had a definitive preoperative diagnosis of CD, the above pathology would frequently be cited as a reason not to perform IPAA in cases with indeterminate pathology. At a mean follow-up of 34.8 months, only 1 of the 9 patients had a functioning pouch. Of the remainder, 1 died, 1 remained diverted and 6 had their pouch excised at a mean of 17.6 months postoperatively. The authors concluded that patients who manifest clinically as CD and have confirmatory pathology do very poorly following IPAA with short disease-free intervals and a high pouch failure rate.

Following this, Panis and colleagues published their initial results [2]. From 1985 onwards, they considered IPAA in selected CD patients in whom a proctectomy was required for either proctitis or rectal stenosis. Strict inclusion criteria were employed to ensure the disease was confined solely to the colorectum: all patients underwent an examination under anesthesia prior to IPAA to exclude anoperineal disease and also had a small bowel contrast study to exclude concurrent enteric disease. Eighteen patients were recruited over an initial 7-year period. These 18 patients were combined with a further 13 patients with a pre-IPAA diagnosis of indeterminate colitis (IC) which was subsequently shown to be CD in the postoperative specimen. This group then totaled 31 patients and reported outcomes were for the group as a whole (i.e., n = 31) and were not subdivided into the specific diagnostic timeframes of pre-operative (n = 18) or post-operative (n = 13) CD diagnosis. The results were encouraging: 6 patients had a CD-related complication with 2 of these ultimately requiring pouch excision and the remaining 4 patients reporting acceptable pouch function. Overall, 90 % of the cohort had a functional pouch at 5-year follow up. When compared with a corresponding ulcerative colitis (UC) cohort (n = 71) over the same time period, there was no demonstrable difference in terms of stool frequency, continence, gas/stool discrimination, leak or need for protective pads and sexual activity.

The same group subsequently reported on their experience with 41 patients, 26 of whom had a preoperative CD diagnosis [3]. Once again, the results in terms of CD-related complications are reported for the whole group and not reported in subgroup analysis for the intentional IPAA patients and incidentally diagnosed CD patients following IPAA. Twenty patients were followed for 10 years or more with a CD-related complication rate of 35 % and an impressive pouch excision rate of only 10 %.

The Cleveland Clinic adopted the intentional IPAA in CD patients in the late 1990’s and subsequently reported its initial experience [4]. The analysis included 20 patients who underwent an intentional IPAA out of the study cohort of 204 patients (additional 97 patients with incidental diagnosis and 87 patients with delayed diagnosis). These 20 patients had a median time of 6.6 years from CD diagnosis to IPAA with a median follow up of 5 years and were more likely to be female. The 10- year pouch retention rate in the 20 patient strong intentional group was 85 % and thus closely mirrored the long-term follow up reported by Regimbeau and colleagues of 90 % pouch retention at 10 years as described above. For those patients with retained IPAA, 72 % reported near-perfect or perfect continence, 68 % reported rare or no fecal urgency and the median number of daily bowel movements was 7 (range 2 – 20). Interestingly, these patients also reported their quality of life and quality of health as 9/10 and 9/10 respectively and happiness with the IPAA procedure as 10/10.

The Mount Sinai Medical Center, New York, reported their experience with 13 patients who received an IPAA, 4 of whom were definitively diagnosed preoperatively with CD [5]. None of these patients had perianal disease and all had disease solely limited to the colon. Two of these 4 patients (50 %) subsequently developed perianal disease, 2 (50 %) developed postoperative complications and 1 patient (25 %) required a pouch excision. Of note, the outcomes for all 13 CD patients were compared with a matched cohort of patients undergoing IPAA for chronic UC; the CD patients had fewer bowel movements per 24 h, a lower incidence of incontinence and a lower incidence of pouchitis.

The most recent series on the intentional use of IPAA in CD patients reported on 17 patients [6]. Seven of 17 patients (41 %) developed recurrent CD following IPAA and this compared with a corresponding postoperative incidence of 11 % in a UC cohort undergoing IPAA during the same time period. The pouch excision rate over an average follow up of 60 months in the 17 preoperatively diagnosed CD patients was an impressive 6 %. This study is also notable in that 9 of the 17 patients had a preoperative diagnosis of CD outside of the colorectum: 5 patients had previously undergone small bowel resections with no evidence of active small bowel disease and 4 patients had perianal disease (3 perianal fistulae, 1 anal stenosis), where the fistulae were managed by insertion of draining setons with subsequent evaluation demonstrating no evidence of active perianal sepsis.

The most current study on this topic is a United States multi-institutional study examining the cost-effectiveness of two surgical options in patients with Crohn’s colitis [7]. They compared what is referred to as ‘colectomy with permanent ileostomy’ with IPAA. It should be noted that some of the evidence for the former group involves patients described in a prior study who underwent either total abdominal colectomy with end ileostomy or panproctocolectomy with end ileostomy [8] and the reader cannot determine whether it was only the panproctocolectomy patients who were included in the cost analysis by Taleban and colleagues. Additionally, Taleban and colleagues assumed that patients undergoing J-pouch formation would have ‘complete mucosectomy’, yet this is clearly not the operative approach employed by all. Nonetheless, colectomy with permanent end ileostomy was shown to be more cost-effective unless the associated surgical cost exceeded $20,167 at which point IPAA was the more effective option. They also reported that IPAA was the more effective strategy with an incremental cost-effectiveness ratio of $70,715 per QALY gained.