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Long-term outcome analysis of low pressure rectal reservoirs in 33 children with bladder exstrophy
A T Hafez1, M T Elsherbiny, M S Dawaba
1Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
Insights
Ureterosigmoidostomy modifications, augmented valved rectum and double folded rectosigmoid bladder, offer excellent continence and upper urinary tract preservation. However, long-term metabolic issues like acidosis, reduced growth, and bone demineralization are common in patients.
Area of Science:
- Urology
- Pediatric Surgery
- Reconstructive Surgery
Background:
- Ureterosigmoidostomy is a urinary diversion technique.
- Modifications aim to improve continence and protect the upper urinary tract.
- Bladder exstrophy requires complex reconstructive surgery.
Purpose of the Study:
- To evaluate outcomes of two ureterosigmoidostomy modifications: augmented valved rectum and double folded rectosigmoid bladder.
- Assess impact on upper urinary tract, continence, metabolic profile, linear growth, and bone density.
- Compare the efficacy of the two surgical techniques.
Main Methods:
- 22 boys and 11 girls with bladder exstrophy underwent urinary diversion.
- Procedures included augmented valved rectum (18 cases) and double folded rectosigmoid bladder (15 cases).
- Evaluations included serial ultrasounds, voiding proctography, height measurements, serum electrolytes, blood gases, and bone density (DXA).
Main Results:
- Excellent daytime and nighttime continence achieved in all patients.
- Upper urinary tract improved or stabilized in 64/66 renal units; no reflux.
- Over 50% experienced subclinical metabolic acidosis and decreased linear growth; all showed significant bone demineralization.
Conclusions:
- Augmented valved rectum and double folded rectosigmoid bladder offer good continence and upper urinary tract preservation.
- Prophylactic alkalization does not prevent long-term metabolic complications.
- Anticipate subclinical acidosis, growth deficits, and significant bone demineralization in most patients.
Purpose:
The augmented valved rectum and double folded rectosigmoid bladder represent 2 modifications of ureterosigmoidostomy. Both procedures improve continence by lowering the reservoir pressure. We present the outcome of these techniques on the upper urinary tract, continence, metabolic profile, linear growth and bone density.
Materials And Methods:
Between March 1987 and May 1997, 22 boys and 11 girls with bladder exstrophy underwent urinary diversion to a low pressure rectal reservoir. Patient age at surgery ranged from 2 to 13 years (mean 5.4). The augmented valved rectum technique was used in 18 cases and the double folded rectosigmoid bladder method was used in 15. Serial followup ultrasounds were obtained and voiding proctography was performed 1 year postoperatively in all patients. Supine height was measured at last followup in all cases. Serum electrolytes, arterial blood gases, the results of which were plotted on an acid base nomogram, and bone density using dual energy x-ray absorptiometry were measured in all patients. Prophylactic alkalization was administered to all patients.
Results:
Mean followup is 66 months (range 24 to 148). All patients are continent during the daytime with an emptying frequency of 3 to 5 times, and all are continent at night. No patient experienced pyelonephritis or clinical acidosis. The upper urinary tract was either improved or stabilized in 64 of 66 renal units. No patient had reflux to the upper urinary tract. All patients had normal serum creatinine, sodium, potassium, calcium and phosphorus. Hyperchloremia was noted in 19 of the 33 patients (57%), and arterial blood gases showed subclinical metabolic acidosis in 18 (55%). Supine height measurements at last followup revealed that 19 of the 33 patients (57%) had decreased linear growth (below 3rd percentile). All patients had significant reduction in bone density, and mean for age corrected bone density was 70% (standard deviation 10.9%). Both groups (augmented valved rectum and double folded rectosigmoid bladder) were comparable in regard to age, sex and followup duration. There was no statistically significant difference between the groups in any parameter measured.
Conclusions:
The augmented valved rectum and double folded rectosigmoid bladder provide preservation of the upper urinary tract with excellent continence rates. However, prophylactic alkalization and functional isolation of the reservoir do not prevent the long-term metabolic consequences. Subclinical metabolic acidosis and decreased linear growth are to be anticipated in more than 50% of patients. Moreover, significant bone demineralization is to be expected in all of these patients.
