Pelvic ileal reservoirs: experimental assessment of reservoir capacity in three reservoir designs.

In order to examine the possible effect of different pouch shape to the capacity of ileal reservoirs three different types of pelvic ileal reservoir (2-, 3- and 4-loop) were compared in piglets, with four animals in each group. The intraoperative volume of all of these reservoirs was 55 ml, measured with saline. A larger (110 ml) 2-loop reservoir was used in a control group of four animals. The animals were kept alive for 6 weeks after which time the capacity and emptying of the reservoirs were studied. The resulting volume increases (ml/kg) were 15.4, 9.2, 8.9 and 8.1 in J-, S-, large-J- and W-shaped reservoirs, respectively. The emptying of the reservoirs was incomplete in all designs. No statistical difference (P greater than 0.5) was found between groups for either of these parameters. If resistance to outflow from the pouch can be avoided, the capacity of the reservoir seems to depend more on its initial size at the time of construction than on the pouch design.