Jejunal pouch-distal rectal anastomosis (JP) after proctocolectomy in dogs results in slower gastrointestinal transit and fewer bowel movements per day than does ileal pouch-distal rectal anastomosis (IP)(J Gastrointest Surg, 4:307, 2000). Our present aim was to determine whether the mucosa of a jejunal pouch so used retains its morphologic features better than the mucosa of an ileal pouch does.
METHODS: Among ten dogs who underwent proctocolectomy, five had a jejunal pouch-distal rectal anastomosis and five an ileal pouch-distal rectal anastomosis. After 6 months, the animals were sacrificed. The intestinal pouches and portions of unaltered ileum 5 cm proximal to the pouches were removed, fixed and stained for blinded histological analysis.
RESULTS: The mucosa of the jejunal pouches had a villous height, crypt depth and overall thickness greater than that of the ileal pouches (Table). Moreover, the mucosa of the ileal pouches (mean ± SD= 920 ± 70 m) was thinner than that of the ileum 5 cm above the pouch (1163 ± 88 m; p<0.05), whereas, the mucosa of the jejunal pouches was not (1300 ± 140 m vs 1200 ± 200 m, p>0.05).
CONCLUSION: The jejunal mucosa maintains its morphologic features when the jejunum is used as a rectal substitute after proctocolectomy. In contrast, the ileal mucosa atrophies when the ileum is so used.
Mean Microns ± SD
Morphologic parameter Jejunal pouch (n = 5 dogs) Ileal pouch (n = 5 dogs)
Villous height 286 ± 46 208 ± 7
Crypt depth 790 ± 77 530 ± 30
Mucosal thickness 1300 ± 140 920 ± 170
Differs from jejunal pouch, p<0.05