Effect of increased intrareservoir pressure on upper urinary tract function in continent urinary diversion patients assessed by radioisotope renography.

To assess upper urinary tract function and determine an ideal continent reservoir capacity, we investigated the relationship between intrareservoir pressure and functional parameters using radioisotope renography. Forty-three patients for whom ileal reservoir construction was performed by Kock pouch (n = 33) or Hautmann's ileal neobladder (n = 14) approaches between November 1984 and September 1996 were studied. After the reservoir contents were catheterized, (99m)Tc-MAG 3 renoscintigraphy was carried out and time activity curves in the kidney (renogram) and reservoir (reservoirgram) were recorded, while saline solution was poured into the reservoir for monitoring of intrareservoir pressure. Three basic abnormal curves were noted in the excretory phase on renograms: a normal downward curve followed by an upward curve, a continuous upward curve associated with or without a sharp decline after the catheterization of the reservoir contents, and episodes of spike waves. Based on these curves, renograms were classified into five types: normal, high pressure, retention, obstruction, and reflux. Abnormal types were noted with 51 of 65 renal units (78.5%) in the Kock pouch group and 15 of 25 renal units (60.0%) in the neobladder group. This examination method may be useful for evaluating urodynamics in the upper urinary tract of patients with a continent ileal reservoir and provide data on adequate voiding volumes for the individual patient.