A METHOD FOR PREDICTING THE VOLUME OF AN ILEOANAL POUCH

Functional outcome following restorative proctocolectomy depends, in p art, on the volume of the pouch. This study investigates the relations hip between the length of ileum and volume of saline required to diste nd the ileum to a set pressure, and the possibility of predicting the volume of an ileoanal pouch using these measurements. Measurements wer e made on the ileum of 8 mongrel dogs. There was a linear relationship between the length of ileum and volume of saline infused to produce a n intraluminal pressure of 20 mmHg (r = 0.94-0.99). However, the capac ity of ileum varied widely from animal to animal (100 cc of saline fil led 15.5 cm to 43 cm of ileum). Twenty-four pouches (15J, 9S) were con structed from segments of ileum of known capacity. The capacity of a J pouch was 1.71 +/- 0.11 times greater than the capacity of the origin al length of bowel and an S pouch had a capacity 2.14 +/- 0.25 times g reater. These changes in capacity are similar to a theoretical calcula tion of change in volume of ileum after pouch construction. This techn ique is a simple, quick method of predicting the volume of an ileo-ana l pouch which will be useful in a clinical trial to compare function o f pouches of different volumes.