Determinants of optimal bowel function in ileal pouch-anal anastomosis - physiological differences contributing to pouch function.

BACKGROUND: Variability in functional outcome after ileal-pouch anal anastomosis (IPAA) is to a large extent unexplained. The aim of this study was to perform multiple physiological and biochemical tests including an endoscopic examination with histology on IPAA patients with well and poorly functioning pouches to determine factors, or combinations thereof, contributing to functional outcome. METHODS: All patients with ulcerative colitis undergoing restorative proctocolectomy between 2000 and 2013 (N = 108) were interviewed using a pouch functioning score. The best and worst functioning quartiles were invited to undergo examination with a barostat measuring pouch volume at preset variable distension pressures, and a pouch endoscopy. RESULTS: Forty five of 58 eligible patients agreed to participate. The most significant physiological parameter differing between the well and poorly functioning pouches was pouch volume at first sensation, urge and discomfort (p value <.001). Urge volumes were 213 (CI 171-256) ml for poorly and 352 (CI 305-401) ml for well functioning pouches. Pouchitis episodes were negatively correlated to function. The poorly functioning patients had a higher prevalence of histological signs of inflammation and hand-sewn anastomosis, and a longer remaining rectal cuff, however, nonsignificant. The pouch pressure at sensation thresholds did not differ between the groups. CONCLUSIONS: Pouch volume is the most dominant predictor of pouch function in this study. The present comprehensive study of a multitude of different factors that possibly could be contributing to functional outcome, failed to shed much further light on the functional variability among pouch patients. The pouch physiology remains to a large extent unexplained.

Surgery in the age of biological treatment.

Surgery for IBD is in constant evolution; it does not appear that the introduction of biologicals has had a major effect on the chance of a patient being operated on or not. Pouch surgery had its heydays in the 80s and 90s and has since then become less frequent, but the number of patients undergoing surgery still seem about the same from one year to the other. Likewise, there is no substantial evidence that surgery for Crohn's disease is diminishing. There have been fears that patients on biological treatment have an increased risk of postoperative complications. The issue is not completely settled but it is likely that patients on biological treatment who come to surgery are those who do not benefit from biologicals. Thus, they are compromised in that they have an ongoing inflammation, are in bad nutritional state, and might have several other known risk factors for a complicated postoperative course. These factors and perhaps not the biologicals per se is what surgeons should consider. During the recent years, we have seen several new developments in IBD surgery; the ileorectal anastomosis is being used for ulcerative colitis and laparoscopic surgery usually resulting in a shorter hospital stay, less pain, and better cosmetics. We have also seen the introduction of robotic surgery, single incision minimal invasive surgery, transanal minimal invasive surgery, and other approaches to minimize surgical trauma. Time will show which of these innovations patients will benefit from.