Functional results and visceral perception after ileo neo-rectal anastomosis in patients: a pilot study

Abstract

Introduction: To reduce pouch related complications after restorative proctocolectomy, an alternative procedure was developed, the ileo neo-rectal anastomosis (INRA). This technique consists of rectal mucosa replacement by ileal mucosa and straight ileorectal anastomosis. Our study provides a detailed description of the functional results after INRA.

Patients and methods: Eleven patients underwent an INRA procedure with a temporary ileostomy. Anorectal function tests were performed two months prior to and six and 12 months after closure of the ileostomy and comprised: anal manometry, ultrasound examination, rectal balloon distension, and transmucosal electrical nerve stimulation (TENS). Function was subsequently related to the histopathology of rectal biopsy samples.

Results: Median stool frequency decreased from 15/24 hours (10-25) to 6/24 hours (4-11) at one year. All patients reported full continence. Anal sensibility, and resting and squeeze pressures did not change after INRA. Rectal compliance decreased (2.1 (0.7-2.8) v 1.5 (0.4-2.2) and 1.4 (0.8-3.7) ml/mm Hg (p=0.03)) but the maximum tolerated volume increased (70 (50-118) v 96 (39-176) (NS) and 122 (56-185) ml (p=0.03)). Decreasing rectal sensitivity was found: the maximum tolerated pressure increased (14 (8-24) v 22 (8-34) (NS) and 26 (14-40) (p=0.02)) and the rectal threshold for TENS displayed a similar tendency. All patients displayed a low grade chronic inflammatory infiltrate in neorectal biopsy samples before closure of the ileostomy, with no change during follow up.

Conclusions: The technique of INRA provides a safe alternative for restorative surgery. Stool frequency after INRA improves with time and seems to be related to decreasing sensitivity and not to histopathological changes in the neorectum. Furthermore, after the INRA procedure, all patients reported full continence.

Figure 1

(A) The mucosal sling is created from the distal end of the terminal ileum by removing the seromuscular layer. In order to adapt the sling to the diameter of the rectum and to enable slough to be evacuated from between the rectal cuff and the mucosal sling, multiple longitudinal incisions of 5-10 mm are made in the mucosa. Note that the mucosal vascularisation is preserved because the mesentery is left intact. (B) The ileo neo-rectal anastomosis: anastomosis (3) between the ileum and proximal rectal muscular wall with the ileal mucosal sling (2) plugged on the denuded rectal muscle. The distal end is sutured to the dentate line (1). The central vascular pedicle is shown, as well as the mucosal fenestrations for drainage and increased luminal diameter.

Figure 2

(A) Total stool frequency over 24 hours for each patient. The number of stools per 24 hours decreased significantly during follow up (Friedman test, p<0.0001). (B) Stool frequency at night for each patient. Nocturnal stool frequency decreased significantly during follow up (Friedman test, p<0.0001).

Figure 3

(A) Anal electrosensitivity thresholds for each patient before and after ileo neo-rectal anastomosis (INRA). Bars indicate median levels. (B) Rectal electrosensitivity thresholds of each patient before and after INRA. Bars indicate median levels.