Introduction
Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the gold standard in the surgical treatment of ulcerative colitis [
1]. According to most guidelines, the procedure is typically performed in several stages in patients with long-term pharmacological immunosuppression, reduced general condition, and nutritional status [
2]. In the three-staged procedure, a colectomy with a rectal stump and terminal ileostomy is performed first. After a few months of recovery, the second step, namely proctectomy and the creation of the ileal pouch, is performed. Some patients develop or retain proctitis in the remaining rectal stump after colectomy [
3]. Little is known about the actual mid- and long-term consequences of proctitis on the outcome of IPAA. Proctitis can be treated conservatively with local anti-inflammatory therapy, but often does not heal by the time of IPAA [
2]. The exact causes of proctitis are unclear. There are data indicating a higher rate of anastomotic leakage after IPAA surgery in the case of proctitis [
4]. However, these results are based on a small study in pediatric surgery. There is also a suggestion that the presence of colitis or proctitis is associated with a higher rate of pouchitis [
3,
5] or a higher failure rate of the IPAA [
6]. A rate of up to 30% of chronic pouchitis has been reported [
5]. This study aimed to investigate the extent of inflammation in the anastomotic area during IPAA and to determine the impact of perioperative proctitis on postoperative complications and long-term outcomes. We hypothesized that a higher degree of inflammation in the rectal remnant during IPAA compromises the success of the procedure.
Discussion
Restorative proctocolectomy is the gold standard in the definitive treatment of refractory UC and UC associated colorectal cancer, including its preliminary states [
16]. Determined by the pathophysiology of UC, the disease activity is highest in the distal colon and rectum, the area where IPAA is performed [
2]. The integrity of IPAA is paramount for postoperative complications and long-term success including quality of life and continence [
17,
18]. The study aimed to investigate the prevalence of inflammation in the anastomotic area during IPAA and to determine the impact of proctitis on postoperative complications and long-term outcomes. We hypothesized that a higher degree of inflammation during IPAA compromises the future success of the procedure.
In this retrospective, single-center study, we showed that rectal stump inflammation or inflammation in the distal anastomotic area is common, with mild to medium degree of proctitis (MIP) in 40.4% and severe proctitis (SEP) in 42.8 of our cases. This high rate of proctitis is similar to the rate found in one other recent study [
3]. In that study, no differentiation was made into several degrees of inflammation. This is important because we could show that a higher degree of inflammation leads to more severe consequences. With an increasing degree of proctitis, the portion of three-staged IPAA was rising. This fits the recommendations of the guidelines [
9]. The choice for a three-staged concept in cases with a severe UC and high-dose immunosuppression results in fewer perioperative complications and better long-term outcomes [
18‐
20]. We interpreted the higher degree of proctitis in three-staged IPAA as an indicator of the overall higher activity of the disease in those patients, which led to the decision for a three-staged concept. We could show that proctitis is a risk factor for complications during follow-up after IPAA. The idea that local inflammation in the rectal stump may influence the fate of IPAA, even after complete resection of the diseased and inflammation-bearing rectal mucosa, is not yet well established, and the mechanism is not clear. In three-staged interventions, the inflammation of the rectal stump could trigger pelvic abscesses [
21]. In addition, it is known that residual rectal mucosa after IPAA triggers long-term complications [
22]. It may be speculated that this is the reason for complications related to pouchitis, but there may also be an effect of local inflammation on the surrounding tissues in the deep pelvis. This uncertainty may be one reason for the low rate of patients receiving topical anti-inflammatory medication. This rate was higher in severe proctitis compared to NOP (20.3% vs. 12.5%,
p = 0.023), but still, only every 5th of SEP patients had received this therapy, similar to the study of Wasmann et al. [
3]. There is evidence that 5-ASA enemas improve the activity of inflammation in UC [
23]. Topical treatment of UC shows good results with low side effects according to a recent review in non-surgical UC patients under conservative treatment [
24]. Furthermore, the endoscopic view may underestimate the histologic extent of inflammation [
25]. To our best knowledge, there is no study or guideline aiming to optimize the local inflammation in surgical patients prior to IPAA. This conflicts with the high rate of proctitis and the rate of complications associated with proctitis after IPAA.
Regarding postoperative complications, there is one study showing no influence of proctitis on the rate of anastomotic leakage [
4]. In our study, the 30-day morbidity was not different between the degrees of proctitis. During long-term follow-up, the rate of re-interventions, pouchitis, and pouch failure was significantly rising with the degree of inflammation at the time of IPAA. The time to pouch failure was shorter in severe proctitis. ASA 3, pouchitis, and pouch fistula were identified as independent predictors for pouch failure. In a recent retrospective study regarding pouch failure [
26], the overall failure rate was lower than in our study (15.5% vs. 16.5%), but their definition of failure included only pouch explantation. Pouchitis and pouch fistula were independent risk factors, too.
Pouch survival was shortest in severe proctitis; however, after 5 years, there was no difference to medium proctitis. After 10 years, there still was a difference in pouch survival between the groups with any degree of inflammation and with no proctitis, but the gap was closing over time. As in our study, the failure rate was highest during the first year in a large Cleveland Clinic study [
27]. From a clinical perspective, it may be reasonable to assume that the impact of proctitis at the time of IPAA on follow-up complications is highest in the first 5 years (“mid-term”). As other factors may become more important for pouch failure during the 10-year period, the influence of proctitis is declining over time. It seems plausible that a higher degree of inflammation causes more pouch-related complications in the first years. In the later course, the influence of proctitis diminishes.
One limitation of the study is the relatively low number of pouch failures (n = 5) in the group without proctitis, raising the question of model stability. Due to the retrospective design, it cannot be shown if there is a beneficial effect of topical anti-inflammatory treatment or just a correlation. A weakness of the study’s design is that in three-staged IPAA, the influence of diversion colitis could not be determined exactly. A strength of the study is the single-center design in a tertiary referral center for inflammatory bowel disease with a homogenous way of diagnosing and treating UC. A possible implication for future studies could be the re-evaluation of the degree of proctitis and prescription of local anti-inflammatory treatments some time before IPAA, in order to evaluate a benefit for IPAA results.
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