The Optimal Ileal Pouch: Physiologic Parameters Significantly Correlate with Overall Pouch Function.

Background: Ileal pouch function is affected by several patient factors and pouch physiology. The significance of pouch physiology on optimal pouch function has not been well characterized. The purpose of this study was to examine specific post-ileal pouch anal anastomosis (IPAA) physiologic parameters to determine impact on pouch function and quality of life.

Methods: Patients undergoing proctocolectomy with IPAA for ulcerative colitis were examined. Post-IPAA compliance, pouch anal pressure gradient (PAPG), and function were assessed 6-8 months postoperatively. Compliance was calculated as change in volume divided by change in pressure. PAPG was calculated as the difference between anal pressure and intra-pouch pressure at a fixed volume. Pouch function evaluation included stool frequency and episodes of incontinence. Quality of life was evaluated using the Rockwood Fecal Incontinence Quality of Life Scale.

Results: A total of 125 patients were investigated. Post-IPAA resting anal pressure averaged 58.1 ± 15 mmHg. Mean volume and intra-pouch pressure at evacuation were 245 mL and 33.9 mmHg, respectively. Compliance averaged 11.2 mmHg/mL with a mean PAPG of - 29.3 mmHg. Compliance and PAPG correlated with 24-h (p = 0.003, p = 0.004) and nighttime stool frequency (p = 0.04, p = 0.03). Daytime continence was impacted by compliance (p = 0.04), PAPG (p = 0.02), and resting anal pressure (p = 0.02).

Conclusion: This unique evaluation reveals a significant correlation between IPAA physiologic properties and function. Optimal function and quality of life depend in part on maintaining optimal pouch compliance and pressure differentials between the pouch and anal canal, defined by the pouch anal pressure gradient.