A COMPARISON OF J AND W POUCHES USING AN ISOLATED ILEAL RESERVOIR IN PIGS

A new model for studying ileal reservoirs was used to compare J and W pouches. Sixteen female piglets were operated on between 62 and 67 day s of age (median = 65). An approximately 50 cm vascularized segment of terminal ileum was isolated from the faecal stream and intestinal con tinuity restored. The distal 40 cm of the isolated loop was opened alo ng its antimesenteric border and the pouch constructed (J = 8, W = 8). The remaining proximal length of ileum was brought out through the ab dominal wall as a mucous fistula. One piglet in the W pouch group died post-operatively and in another, spontaneous closure of the mucous fi stula prevented access to the W pouch for testing leaving six W and ei ght J pouches for comparison. Compliance was tested at 4 weeks by meas uring intrapouch pressure during continuous distension by water. The v olumes instilled at pressures of 20, 40, 60 and 80 cm of water were co mpared using the Mann-Whitney U-Test. Volumes varied widely at all pre ssures within both study groups although W pouches tended to be of lar ger volume for any given pouch pressure (P = NS). The failure of this study to demonstrate more clearly a difference between J and W pouches may be due to the small numbers involved but the wide range of volume s seen raises doubts about the usefulness of this pouch model.