Prospective Radionuclide Renal Function Evaluation and its Correlation with Radiological Findings in Patients with Kock Pouch Urinary Diversion

Abstract

In an attempt to understand better the status of renal function after Kock pouch urinary diversion we conducted a prospective evaluation of renal function in 25 patients using the radionuclide 131iodine-hippurate. Studies were done before, and at 1 month and every 6 months for 30 months postoperatively. The radionuclide results were then compared to excretory urography and contrast study of the reservoir. Our renal function study included the determination of individual and total effective renal plasma flow (ml. per minute), the time to maximal radioactivity over the kidney (peak time in minutes) and a renogram. The mean total (both kidneys) effective renal plasma flow rates before (25 patients) and at month 1 (19), month 6 (14), month 12 (12), month 18 (6), month 24 (6) and month 30 (7) after operation were 385.5 +/- 112.2, 310.5 +/- 109.9, 362.7 +/- 69.2, 442.0 +/- 97.5, 468.2 +/- 82.5, 405.7 +/- 70.6 and 414.0 +/- 65.1, respectively. A comparison of individual and total effective renal plasma flow before and after operation revealed that only the change of the flow at each or both sides of the kidney before and at 1 month after the operation reached statistically significant differences, respectively (p less than 0.05, paired t test). Postoperatively 5 of 6 patients with hydronephrosis had abnormal peak time and a third segment on the renogram was performed on the corresponding side of the kidney. No reflux was noted on contrast study of the reservoir of any patient followed for up to 30 months. In conclusion, the radionuclide renal function evaluation showed a significant decrease of renal function 1 month after Kock pouch diversion, then it resumed and remained stable (neither improved nor deteriorated) for 30 months. Also the abnormal peak time and third segment on the renogram usually implicated a dilated upper urinary tract.

Caveats when interpreting intravenous urograms following ileal orthotopic bladder substitution

“…Firstly, because IVU studies in the early postoperative phase show dilatation of the upper urinary tract in the vast majority of cases; this is clinically irrelevant because it resolves spontaneously with further follow-up. Similar observations have been made with other forms of urinary diversions [10][11][12]. Secondly, IVUs in the early phase are not necessary to exclude upper urinary tract recurrences because these develop later (28-64 months after surgery in our series).…”

Kock Urinary Reservoir Maturation in Children and Adolescents: Consequences for Kidney and Upper Urinary Tract

“…Chen et al [17]reported a decrease in renal function 1 month after Kock surgery and attributed it to the swelling at the ureteroileal anastomotic site resulting in hydroureteronephrosis in some cases. In our patients, there was a significant urinary tract dilatation during the first 3 months after surgery, then it started to subside in most cases.…”

Early and late metabolic alterations in children and adolescents with a Kock urinary reservoir

“…Renal function was significantly impaired one month after Kock pouch diversion but then resumed and remained stable (neither improved nor deteriorated) [19]. Permanent deterioration of the upper urinary tract occurs only as a consequence of high reservoir pressure, mechanical obstruction or reflux [19–21]. Patients who had symptomatic UTIs and infrequent reservoir emptying (<5 times/day) showed significant deterioration of renal function.…”