Drainage of the upper urinary tract as recorded with renography in patients with a continent urostomy (Kock pouch). An experimental study with various degrees of reservoir filling.

The drainage from the upper urinary tract was studied by the use of renography in thirteen patients with well functioning continent ileal reservoirs for urinary diversion (Kock-pouch). Renography was performed with empty reservoir and with submaximal or maximal filling of the reservoir. The reservoir pressure was continuously recorded when renography was performed with a full reservoir. When the reservoir was empty renography showed normal drainage in all patients. When the reservoir was full the renography was normal in eight patients, these having a mean reservoir volume of 715 ml but showed a delay in five patients, these having a mean reservoir volume of 930 ml. When the renography was repeated in the latter group of patients with submaximal filling (mean reservoir volume 544 ml) there was no delay of the drainage phases on the renograms. In these five patients the considerable "over-filling" of the reservoir had resulted in volumes greatly exceeding the previously recorded maximal reservoir capacity and also in pressures exceeding considerably those usually recorded in ileal reservoirs. These results show that the pressure in the bladder substitute is of great significance for the drainage from the upper urinary tract and that the low pressure ileal reservoir under ordinary circumstances does not obstruct the flow from the upper urinary tract.