Inflammation of ileal reservoir mucosa, or pouchitis as it is commonly known, is a frequent occurrence in ulcerative colitis (UC) patients who have had a colectomy with ileal pouch anal-anastomosis (IPAA).
Dr Rhonda K Yantiss and colleagues write that while several clinical, genetic and laboratory parameters have been evaluated, there are no reliable pathologic predictors for the development of pouchitis.
For this reason, they conducted a case-controlled study to determine whether there are any pathologic features in UC colectomy specimens that may help predict the subsequent development of pouchitis after an IPAA procedure.
The researchers investigated 39 UC patients, 21 male and 18 female, mean age 35 years, who had at least 1 episode of pouchitis after and IPAA procedure during the follow-up period (mean: 57 months, range: 12 to 121 months).
|Appendiceal ulceration is highly associated with pouchitis|
|American Journal of Surgical Pathology|
As a control group, 26 patients (male/female ratio: 11/15, mean age: 37 years), all of whom also underwent a total colectomy and IPAA procedure for UC, but did not develop pouchitis during the follow-up period (mean: 78 months, range: 14-223 months) were also studied.
Routinely processed tissues from each colectomy specimen were evaluated for a variety of histologic features. These included extent of colitis, severity of colitis and the extent of severe colitis.
The type and extent of ulceration, presence and severity of appendiceal inflammation, and the presence of active ileitis were also evaluated and then and compared between the study and control patients.
The researchers found that pathologic features associated with the subsequent development of pouchitis included the presence of severe colitis that extended into the cecum (severe pan-colitis), which was present in 7 of the 39 (18%) pouchitis patients, but in none (0%) of the control patients.
Early fissuring ulcers were another indicator, being present in 9 (23%) of the pouchitis patients but only 1 (4%) of the control group.
Active inflammation of the appendix and appendiceal ulceration (20 out of 32 (63%) versus 7 out of 19 (31%), and 13 out of 32 (42%) versus 0 (0%), respectively for pouchitis and control patients) were also found to be predictors of subsequent development of pouchitis.
There were no significant differences however, in patient gender or age, depth or extent of ulceration, or the presence or absence of "backwash ileitis" between the 2 groups.
Commenting on their findings, Dr Yantiss said, "There are several histologic features in colectomy specimens from UC patients who have undergone an IPAA procedure that may help predict the subsequent development of pouchitis. Of these features, appendiceal ulceration is highly associated with pouchitis."