Stone formation after augmentation cystoplasty: the role of intestinal mucus

PURPOSE

We evaluated the role of mucus in urine after bladder augmentation and hypothesize that mucus acts as a possible etiological factor in stone formation.

MATERIALS AND METHODS

Mucus was collected via centrifugation from the 24-hour urine specimens of 8 stone forming and 10 nonstone forming patients who were randomly selected from our augmentation population. The mucus and stones were lyophilized, and then analyzed via scanning electron microscopy and energy dispersive x-ray spectrometry for calcium, phosphate, magnesium and sodium. The 24-hour urine collections were also analyzed to determine any metabolic differences between the 2 groups.

RESULTS

Scanning electron microscopy and energy dispersive x-ray spectrometry spectra showed increased calcium, phosphate, and magnesium, and significantly higher (p < 0.05) calcium-to-phosphate ratios in the mucus of stone versus nonstone forming patients. Of the 8 stones examined all had viscous fluid (mucus) centers rich in calcium, phosphate and magnesium. Calcium-to-phosphate ratios in the corresponding mucus recovered from stone centers were similarly high. Urinary citrate levels were low in both groups, and calcium, phosphate and magnesium were within normal ranges.

CONCLUSIONS

Mucus appears to have an important role in the genesis of bladder stones after augmentation, possibly acting as a nidus. Metabolic changes following augmentation were similar in stone and nonstone forming populations. Our data suggest that mucous calcium-to-phosphate ratios may be predictive of future stone formation. Furthermore, there may be a benefit in instituting more aggressive measures aimed at clearing mucus from the bladder.

Torsion of an indirect hernia sac: an unusual cause of acute scrotal swelling in children

OBJECTIVES

An indirect inguinal hernia is a common cause of inguinoscrotal swelling in young boys. We describe 3 cases of an extremely unusual entity that has a similar clinical presentation to more commonly diagnosed intrascrotal processes.

METHODS

Two patients presented with acute hemiscrotal enlargement and pain, and a third patient presented with scrotal enlargement only. All patients underwent a scrotal ultrasound evaluation and subsequent inguinoscrotal exploration.

RESULTS

All patients had a multiseptated peritesticular fluid-filled mass on ultrasound evaluation. Subsequent inguinoscrotal exploration revealed a torsion of the indirect hernia sac in each case. A high ligation and excision of the sac was curative.

CONCLUSIONS

Torsion of a hernia sac is an extremely rare entity, and current sonographic imaging fails to clearly diagnose this unusual phenomenon. Because pediatric urologists are commonly called to evaluate a child with an acutely swollen scrotum, awareness of this diagnosis is important.

An algorithm for the management of anterior urethral valves

PURPOSE

We present our management algorithm for patients with anterior urethral valves seen in the last 2 decades with and without the benefit of prenatal sonography.

MATERIALS AND METHODS

A case series design was used to study 17 cases of anterior urethral valves. Five patients presented with prenatal hydronephrosis from 1984 to 1993 and 12 presented with predominant voiding symptoms between 1975 and 1996 at a mean age of 6 years.

RESULTS

Treatment included supravesical diversion in 1 case, vesicostomy in 5, urethroplasty in 5 and transurethral fulguration in 6. Four of the 5 patients with a prenatal diagnosis of hydronephrosis had moderate to severe hydronephrosis compared to 3 of the 12 who did not undergo prenatal sonography. All 17 patients were continent and infection-free, and had little or no hydronephrosis at a mean followup of 5 years.

CONCLUSIONS

We recommend vesicostomy in infants with high grade bilateral vesicoureteral reflux and poor emptying of the urinary tract, transurethral fulguration if the urethra has sufficient caliber and support, and urethroplasty in other patients. Based on our management algorithm patients with anterior urethral valves do not have sequelae due to distal obstruction of the urinary tract.

The nonneurogenic neurogenic bladder of early infancy

PURPOSE

The nonneurogenic neurogenic bladder has traditionally been believed to represent a disorder of older children. We report on patients in whom congenital dysfunctional voiding may be the underlying cause of nonneurogenic neurogenic bladder in early infancy.

MATERIALS AND METHODS

We evaluated 5 male and 2 female patients newborn to 30 months old with dysfunctional neurogenic bladder and no evidence of neurological pathology or anatomical outflow obstruction. Presentation included prenatal hydronephrosis in 3 cases, urosepsis in 2 and failure to thrive in 2. Radiological and urodynamic investigations revealed thick walled, poorly compliant bladders in 5 patients and incomplete bladder emptying bordering on urinary retention in 2. There was significant upper tract pathology in all cases, including azotemia in 4, reflux in 4 and hydroureteronephrosis in 6. Due to poor bladder function, manifested by incomplete emptying or high storage pressures, all patients were initially treated with cutaneous vesicostomy.

RESULTS

Bladder appearance and function subsequently improved in 3 patients and vesicostomy was reversed. Three patients with persistently thickened bladders, including 2 with renal failure, underwent bladder augmentation. The remaining patient had improved bladder storage function but requires intermittent catheterization.

CONCLUSIONS

The nonneurogenic neurogenic bladder represents a rare, severe form of dysfunctional voiding that may be present even in the neonatal period.

Basic fibroblast growth factor in the urine of children with voiding pathology

PURPOSE

Basic fibroblast growth factor is a mediator of tissue response to injury. Voiding pathology often results in bladder abnormalities. We prospectively determined whether basic fibroblast growth factor is elevated in the urine of children with bladder dysfunction compared to that of normal controls.

MATERIALS AND METHODS

A total of 97 consecutive children with myelomeningocele and 32 with voiding pathology due to other etiologies underwent urodynamic testing, and 11 children with no bladder symptoms and sterile urine served as controls. Urinary basic fibroblast growth factor levels were assayed by enzyme-linked immunosorbent assay and normalized to urinary creatinine.

RESULTS

Mean urinary basic fibroblast growth factor was higher in bladder dysfunction from myelomeningocele (6,673 pg./gm. creatinine, p = 0.0015) and other etiologies (5,665 pg./gm. creatinine, p = 0.0025) compared with urine from normal bladders (2,995 pg./gm. creatinine). In the myelomeningocele group urinary tract infection was associated with higher urinary basic fibroblast growth factor than in sterile urine (9,214 versus 5,642 pg./gm. creatinine, p = 0.018). Patient age, gender, remote bladder surgery, clean intermittent catheterization, detrusor hyperreflexia, detrusor compliance, age adjusted pressure specific bladder volume, low grade reflux and degree of trabeculation did not correlate with levels of basic fibroblast growth factor (p > 0.05).

CONCLUSIONS

Urinary elevation of basic fibroblast growth factor, a critical mediator of wound repair, in children with voiding pathology and clinically abnormal bladders supports the paradigm that bladder dysfunction may result from generalized response-to-injury mechanisms. The role of fibrogenic cytokines, such as basic fibroblast growth factor, merits further directed investigation in bladder pathology.

Urodynamic correlates of resolution of reflux in meningomyelocele patients

PURPOSE

Resolution of reflux in meningomyelocele patients is a reflection of improved bladder storage. We correlated resolution of reflux with changes observed in sequential urodynamic studies.

MATERIALS AND METHODS

The study included 27 children with meningomyelocele born between 1975 and 1985 who presented with or developed vesicoureteral reflux. Resolution of reflux was observed during the 10-year followup period as they were treated with a regimen of clean intermittent catheterization and pharmaco-therapy. Urodynamic studies were performed when vesicoureteral reflux was present and subsequent to its resolution. The urodynamic parameters compared in the 2 studies included bladder capacity, pressure specific bladder volume, bladder compliance and leak point pressure.

RESULTS

Significant increases in bladder capacity, pressure specific bladder volume and bladder compliance were noted. Leak point pressure appeared to be decreased subsequent to resolution of reflux.

CONCLUSIONS

Resolution of reflux in meningomyelocele patients correlates with changes in parameters of bladder storage observed on sequential urodynamic studies.

Urethral lengthening with anterior bladder wall flap (Pippi Salle procedure): modifications and extended indications of the technique

PURPOSE

We report a clinical case series of an innovative method of urethral reconstruction for the treatment of urinary incontinence. Modifications of our original technique are presented.

MATERIALS AND METHODS

Bladder neck repair was done in 17 patients, mean age 9.3, with neurogenic incontinence (13) or exstrophy (4). Average followup is 25.6 months. Of the patients 9 with neurogenic bladder underwent the original procedure using a midline anterior bladder wall flap. In the 4 patients with exstrophy a modified procedure was done using an anterolateral bladder wall flap. In another 4 patients an extended flap of distal mucosa was used to avoid ureteral reimplantation. Augmentation was performed in 13 of the 17 cases (10 detubularized ileum and 3 detubularized colon).

RESULTS

Continence (greater than 4 hours) was obtained in 12 of the 17 patients (70%), 2 are dry for 1 to 2 hours and 3 are incontinent. A urethrovesical fistula developed in 2 patients (1 closed successfully), and 3 patients have problems with catheterization.

CONCLUSIONS

Urethral lengthening with anterior bladder wall flap is a versatile alternative in the surgical treatment of urinary incontinence. Variations of the original technique resulted in an improved vascular supply and decreased the formation of fistula at the base of the flap. The modified technique was successful in patients with exstrophy, including those who had failed bladder neck surgery.

Renal transplantation in children following augmentation ureterocystoplasty

OBJECTIVES

To assess the impact of augmentation ureterocystoplasty on the success of cadaveric renal transplantation in children with dysfunctional bladders.

METHODS

Two patients with end-stage renal failure secondary to dysfunctional bladders (one myelodysplasia and one posterior urethral valves) underwent augmentation ureterocystoplasty prior to renal transplantation in order to increase bladder capacity and improve compliance.

RESULTS

Significant improvement of bladder storage function was achieved in both patients. By the use of megaureter for augmentation, untoward sequelae of enteric or gastric augmentation were obviated. Renal transplantation was successful in both patients. Both have normal renal function 4 and 3 years after transplantation.

CONCLUSIONS

Renal transplantation into bladders previously augmented with megaureters is successful. The use of urothelial-lined biomaterial for augmentation avoids the potential complications of gastro- or enterocystoplasty, which are especially dangerous in transplant patients.

Outcome analysis of vesicoureteral reflux in children with myelodysplasia

PURPOSE

Vesicoureteral reflux in children with myelodysplasia is usually secondary to abnormal bladder storage. The purpose of this study was to assess the outcome of vesicoureteral reflux in children with myelodysplasia.

MATERIALS AND METHODS

We retrospectively analyzed the records of 319 children with myelodysplasia who presented to our institution between 1978 and 1985. Of these children 95 presented with or had reflux during followup and they were treated with prophylactic antibiotics. Clean intermittent catheterization and anticholinergic medication were added to the regimen when indicated.

RESULTS

Reflux resolved in 63% of these patients with nonsurgical management. Temporary cutaneous vesicostomy was performed in 23 children (24%) with persistent high grade reflux or evidence of upper tract deterioration. Ureteral reimplantation and augmentation cystoplasty were performed in 18 (20%) and 8 (8%) patients, respectively. No patient had progression to chronic renal failure and scars developed in only 14 kidneys (10%).

CONCLUSIONS

In the majority of cases (63%) reflux resolved with nonsurgical management. Reflux in these patients should not be treated in isolation. The management of reflux is primarily aimed at improving bladder storage. The combination of aggressive nonsurgical therapy and close observation is recommended. This regimen leads to the satisfactory resolution of reflux with minimal renal morbidity.

Ischiopagus twins: an outcome analysis of urological aspects of repair in 3 sets of twins

PURPOSE

We assessed the urological components of ischiopagus twins and outcomes of surgical correction.

MATERIALS AND METHODS

We performed a longitudinal study of 3 pairs of twins who presented to a single institution for repair and analyzed the outcomes of certain aspects of repair.

RESULTS

Three pairs of twins joined from diaphragm to pelvis and facing each other in an embracing posture were separated in the last 10 years at a single institution. Each pair of twins had a similar constellation of shared organs, including abdominal wall, bony pelvis, liver, bowel, crossed ureters, bladder and genitalia. Followup ranges from 18 months to 10 years. All children are independent and ambulatory with fully healed wounds. Of the 6 kidneys 5 are functioning well. Of the 4 children old enough to undergo continence evaluation all are fully continent and void spontaneously.

CONCLUSIONS

Conjoined twins can be successfully separated with an effective outcome.

The dartos flap as an adjunct in preventing urethrocutaneous fistulas in repeat hypospadias surgery

PURPOSE

Vascularized flaps for repeat hypospadias repair are often limited. We report our experience with the dartos flap in children undergoing secondary hypospadias and complex urethral repair.

MATERIALS AND METHODS

The dartos flap is fibroadipose tissue between the scrotal skin and tunica vaginalis layers with its vascular pedicle based at the penoscrotal angle. The flap reaches the distal penile shaft without tension. Eight patients 1 to 17 years old (mean age 6) underwent urethral surgery and an interposed dartos flap procedure in 1994 to 1995.

RESULTS

Of 6 patients cosmesis was excellent in 84%, erections were straight in 100%, and urinary streams were of good quality and without fistula in 100% after repeat hypospadias surgery. Following staged repair for anterior urethral valves a urethrocutaneous fistula developed in 1 patient and following urethral duplication repair results were excellent in 1. Mean followup was 1 year.

CONCLUSIONS

The dartos flap is easy to mobilize and it provides excellent coverage for repeat proximal hypospadias surgery, since the dartos remains undisturbed. We endorse its use for complex urethral surgery and believe that the extra layer of closure helps to prevent urethrocutaneous fistulas.

Outcome analysis of Mitrofanoff principle applications using appendix and ureter to umbilical and lower quadrant stomal sites

PURPOSE

We compared the indications for and results of application of the Mitrofanoff principle using appendix and ureter to umbilical and lower quadrant stomal sites.

MATERIAL AND METHODS

We created continent catheterizable conduits in 60 patients 3 days to 20 years old (mean age 8.8 years). The primary indication was refractory urinary incontinence associated with bladder or cloacal exstrophy, or anomalies in 31 cases. We constructed 38 umbilical (all appendix) and 22 lower quadrant (10 appendix and 12 ureter) stomas. Mean followup was 3 years.

RESULTS

We preferred the umbilicus as a stomal site for its cosmetic value. The most common indication for a lower quadrant stomal site was preservation of the retroperitoneal course of the ureter. The stomal stenosis rate was 13 and 4% in patients with umbilical and lower quadrant stomas, respectively. We preferred the appendix as a conduit due to availability. Indications for the ureter as a catheterizable conduit were absence of an adequate appendix or presence of a healthy ureter after nephrectomy. The appendiceal and ureteral conduits were catheterizable in 94 and 84% of patients, respectively, and continence was achieved in 97%.

CONCLUSIONS

In a complex group of patients with incontinence application of the Mitrofanoff principle yielded good results for either combination of stomal site or catheterizable conduit. Appendicovesicostomy to the umbilicus remains our preferred procedure.

Percutaneous vacuum vesicolithotomy under direct vision: a new technique

PURPOSE

The number of vesical calculi is increasing as the number of patients with intestinocystoplasty increases. We describe our technique for easily removing vesical calculi in children via an atraumatic percutaneous endoscopic approach.

MATERIALS AND METHODS

The procedure involves percutaneous suprapubic puncture and direct visualization of the calculi via cystoscopy through the urethra or via a second suprapubic puncture when the bladder neck is closed. The stones are vacuumed up 1 at a time with suction tubing through the suprapubic working sheath in a controlled manner with no urethral trauma. Ten patients 3 to 16 years old (mean age 8) with vesicolithiasis underwent percutaneous vacuum vesicolithotomy under direct vision in 1993 to 1995.

RESULTS

Two to 12 bladder calculi were extracted (mean 7). All calculi less than 1 cm. were removed by this procedure. All bladder calculi between 1 and 1.5 cm. were also removed but they required simultaneous electrohydraulic lithotripsy. There were no complications at a mean 1-year followup. Mean hospitalization was less than 24 hours (range 0 to 3 days).

CONCLUSIONS

Percutaneous vacuum vesicolithotomy is highly successful, easy to perform and safe for extracting vesical calculi. Since the procedure is done through a percutaneous sheath, it is particularly suited to the individual with an absent, small caliber, sensitive or surgically reconstructed urethra.

Biocompatibility of silver-coated peritoneal dialysis catheter in a porcine model

OBJECTIVE

Previous studies have shown that silver formulations coated onto implantable materials retard bacterial colonization and reduce the incidence of catheter-related infections. The objective of this study was to assess the histologic effects of sputter-coated silver/ silicone implants on host tissue.

DESIGN

Sputter silver-coated silicone peritoneal dialysis catheter segments with and without Dacron cuffs were implanted in the subcutaneous fat and muscle in 4 pigs. Noncoated implants served as controls. The specimens were retrieved at 1, 2, 3, 4, 7, 8, 9, 10, 12, and 27 weeks.

EXPERIMENTAL ANIMALS

Four 6-week-old male Yorkshire-Landrace pigs (5-6 kg) were used.

MAIN OUTCOME MEASURES

Histologic parameters evaluated included the degree of inflammation, the number of giant cells, the extent of silver particulate inclusions, and the thickness of the capsules. All specimens were evaluated by a single blinded pathologist. Microbiologic analyses were also performed.

RESULTS

The silver-coated catheters were associated with less inflammation than were the noncoated catheters, both in fat and muscle (p = 0.04). The number of giant cells was also lower around the silver-coated than the non-coated catheters, which were implanted in subcutaneous fat (p < 0.05). Particulate inclusions compatible with silver or silver oxide were observed only in tissue around silver-coated implants (p < 0.0001). The thickness of the capsules and the extent of the inflammatory zones were not significantly different. There was no evidence of infection-related changes.

CONCLUSIONS

These data suggest that the sputter silver coating does not act as a significant tissue irritant.

Minimizing stomal stenosis in appendicovesicostomy using the modified umbilical stoma

PURPOSE

We describe creation of a modified umbilical stoma as part of continent urinary diversion using appendicovesicostomy.

MATERIALS AND METHODS

Umbilical stomas were created using the eversion-inversion principle in 25 patients undergoing appendicovesicostomy.

RESULTS

Mean followup was 3 years. Cosmesis of the umbilical stoma was good in all cases. Stomal stenosis required surgical revision in 8% of cases.

CONCLUSIONS

We recommend our modified umbilical stomal technique for appendicovesicostomy because it allows good cosmesis without compromising stomal function.

Pressure decay half-life: a method for characterizing upper urinary tract urine transport

PURPOSE

We examined the pressure dynamics of hydronephrotic kidneys after elevated renal pelvic pressure developed.

MATERIALS AND METHODS

A total of 40 patients (44 renal units) 0.2 to 12 years old was evaluated. Transiently elevated renal pelvic pressure was induced with a percutaneous nephrostomy infusion. After renal pelvic pressure increased the infusion was stopped and the subsequent decrease in pressure with time was plotted as a pressure decay curve. The rapidity of the decrease in renal pelvic pressure was then quantitated as a half-life for each pressure decay curve. Pressure decay half-lives were compared to corresponding pressure flow study results and diuretic nuclear renography half-lives.

RESULTS

Renal units without elevated renal pelvic pressure during infusion at a high physiological flow rate were associated with relatively rapid pressure decay, whereas those with elevated renal pelvic pressure during infusion were associated with much slower pressure decay (p < 0.0001). Diuretic nuclear renography half-lives had no correlation with collecting system pressure dynamics.

CONCLUSIONS

Pressure decay half-life provides an objective quantitative measure of the relative tendency for elevated renal pelvic pressure to persist. When used in conjunction with other diagnostic modalities, it may be a useful parameter for a comprehensive assessment of the risk of pressure induced injury in hydronephrotic kidneys.

Pediatric renal transplantation into the abnormal urinary tract

Many children with end-stage renal disease have significant urinary tract problems other than irreversible loss of native kidney function. These significant other urinary tract problems, if not corrected prior to transplantation, may significantly increase recipient mortality, graft loss, and patient morbidity. These other urinary tract problems may cause hydroureteronephrosis in the transplanted kidney, lead to an increased incidence of graft rejection, be the source of sepsis after subsequent immunosuppression, and cause hypertension. In addition, pre-existing urinary diversion, large interabdominal masses, or previous cancer require specific pre-transplant management plans. Potential pediatric transplant recipients with other significant urinary tract problems can be classified according to three parameters; anatomical extent, pathology, and pathophysiology of the significant other problems. Particular attention must be paid to pre-existing lower tract problems. Strategy must be worked out pre transplant as to how the lower urinary tract is going to store, hold, and empty urine. The means for assessing the potential recipients and strategies and techniques for correcting pre-existing problems have been summarized in this article.

Ventriculoperitoneal shunt infection after augmentation cystoplasty

PURPOSE

We characterized the occurrence of ventriculoperitoneal shunt infections after augmentation cystoplasty.

MATERIALS AND METHODS

We reviewed the records of 20 myelodysplastic children with ventriculoperitoneal shunts followed for a minimum of 12 months after augmentation.

RESULTS

In 4 children (20%) a ventriculoperitoneal shunt infection developed. The single gram-positive infection occurred early (less than 30 days). The 3 gram-negative infections were delayed presentations (greater than 30 days). Organisms in 2 of the 3 gram-negative infections had been noted in a preoperative urine culture.

CONCLUSIONS

Ventriculoperitoneal shunt infection after bladder augmentation is common. Delayed presentation of shunt infections may indicate gram-negative infection. Sterilization of the urinary tract is indicated before augmentation.

Donor aortic cuff reduces the rate of anastomotic arterial stenosis in pediatric renal transplantation

A total of 333 pediatric renal transplantations performed at our institution between January 1977 and July 1994 was retrospectively reviewed to provide guidelines for minimizing the incidence of transplant renal artery stenosis. The patients who had renal artery stenosis were 3 months to 17.5 years old (median age 9.3 years) at the time of transplantation and the condition was diagnosed 2.2 months to 2.5 years (median 4.2 months) after transplantation. Renal artery stenosis was diagnosed in 19 transplants (19 of 333, 5.7%) as a result of severe hypertension or renal function deterioration. Stenosis occurred at the anastomosis in 7 cases (37%) and distal to the anastomosis in 12 (63%). Transplantations performed with a donor aortic cuff resulted in a lower rate of renal artery stenosis at the anastomosis (0 of 193, 0%) compared to those performed without a cuff (7 of 140, 5.0%, p = 0.0021). The rate of renal artery stenosis distal to the anastomosis was not different regardless of whether a cuff was used (5 of 193 cases, 2.6%) or not (7 of 140, 5.0%, p = 0.37). End-to-end anastomoses to internal iliac arteries, which were always performed without cuffs, had a particularly high rate of renal artery stenosis (3 of 10, 30%) compared to end-to-side anastomoses performed without cuffs (4 of 130, 3.1%, p = 0.0080). Bench surgery or multiple renal arteries did not adversely influence the rate of renal artery stenosis. With prompt diagnosis and treatment the actuarial graft survival of the transplants with renal artery stenosis was similar to that of the transplants without renal artery stenosis (p > 0.05).

Evaluation of pediatric hydronephrosis using individualized pressure flow criteria

In pursuit of a diagnostic modality better able to assess collecting system urine transport characteristics while operating within physiological ranges, a new set of guidelines for the pressure flow study was proposed. An infusion rate individualized for each patient was chosen based on a calculated estimate of the maximum physiological urine output, adjusted for patient size and age. The upper limit of normal renal pelvic pressure used was 14 cm. water. We evaluated 37 renal units with grade 3 or 4 hydronephrosis with the individualized pressure flow study. Patient age ranged from 0.2 to 12 years (median 1.1). Calculated individualized infusion rates ranged from 1.3 to 12.5 ml. per minute and resulting renal pelvic pressures ranged from 7 to greater than 40 cm. water. In each patient the corresponding renal pelvic pressure resulting from a fixed 10 ml. per minute infusion rate was uniformly equal to or higher than the corresponding individualized study pressures (p < 0.0001). Disagreement between the individualized and fixed rate pressure flow studies was highest in the younger patients. The correlation coefficient between diuretic nuclear renography half-times and individualized pressure flow results was 0.09, indicative of a random association between the 2 variables. By using individualized infusion rates based on the calculated estimate of the maximum physiological urine output, much of the falsely high pressures induced by nonphysiologically high fixed infusion rates in pediatric patients can be avoided.

Contradictory supranormal nuclear renographic differential renal function: fact or artifact?

We previously reported contradictory supranormal nuclear renographic differential renal function in cases of unilateral hydroureteronephrosis, in which the kidneys with hydroureteronephrosis paradoxically had a greater differential function than the contralateral normal mate, based on diethylenetriaminepentaacetic acid (DTPA) nuclear renography. To evaluate whether DTPA supranormal differential function represented true hyperfunction, patients with DTPA supranormal differential function were evaluated with dimercaptosuccinic acid (DMSA) nuclear renography and the results were compared. A total of 16 patients with unilateral hydronephrosis was identified to have DTPA differential function of 53% or more. They were younger than age 1 year and had never undergone any urological surgery. In all 16 patients the DMSA differential function (mean 51.1%, range 42 to 57%) was lower than their own corresponding DTPA differential function (mean 58.3%, range 53 to 66%, p < 0.0001). In addition, the DMSA differential function was not significantly different from the intuitively anticipated mean of 50% (p = 0.48). The DTPA supranormal differential function identified in our patients was not corroborated by the DMSA differential function. With recent evidence that DMSA differential function may be a better predictor of outcome following relief of unilateral ureteral obstruction consideration should be given to using DMSA as a potentially more relevant method for differential function measurement in the setting of unilateral hydronephrosis. Conversely, until the potential deficiencies of DTPA are fully understood caution should be exercised in the interpretation of DTPA differential function in the setting of hydronephrosis.

The effect of temporary cutaneous diversion on ultimate bladder function

We evaluated the effect of temporary cutaneous diversion on bladder function in cases of various congenital uropathies. The clinical courses of patients who underwent reversal of vesicostomy or pyelostomy/ureterostomy in a 7-year period were reviewed. Indications for diversion included azotemia, massive hydronephrosis, high grade reflux and/or incomplete bladder emptying. Mean age at diversion was 15 weeks. Overall 75 cases were evaluated (posterior urethral valves in 31, neurogenic bladder in 16, reflux in 14, the syndrome of vertebral defects, anal atresia, tracheoesophageal fistula with esophageal atresia, and radial and renal anomalies in 8 and other in 6). Of 55 patients who underwent undiversion by direct closure only 2 required later augmentation for bladder/renal deterioration. Excluding the myelomeningocele patients on clean intermittent catheterization 45 of 46 who underwent direct closure were able to void spontaneously with acceptable post-void residuals. Urodynamics in 22 cases revealed normal bladder capacity at pressures below 30 cm. water in 19 (86%) after direct closure. We conclude that after a period of defunctionalization approximately 75% of children will have essentially normal bladder function. The frequency of bladder augmentation varied from 54% in patients with myelomeningocele to 14% in those with vesicoureteral reflux. This observation suggests that the need for bladder augmentation in the remaining patients is more related to the effect of the primary pathological condition on the detrusor rather than the diversion itself.

Concomitant bladder neck closure and Mitrofanoff diversion for the management of intractable urinary incontinence

In a 7-year period 28 patients 1 to 20 years old have undergone bladder neck closure in conjunction with Mitrofanoff diversion for the management of severe incontinence. Surgery was performed as a salvage procedure in 19 patients and as a primary anti-incontinence procedure in 9. At a mean followup of 29 months 27 of 28 patients (96%) were totally continent, requiring no pads. Bladder neck closure was primarily successful in 24 of 28 patients (86%) and 25 (89%) had stable upper tracts. Five patients had bladder calculi and 5 required stomal revisions. One child had a bladder perforation associated with blunt trauma. Bladder neck closure and Mitrofanoff diversion were done without bladder augmentation in 11 cases and augmentation was performed previously or concurrently in the remainder. Four patients who did not initially undergo augmentation required later augmentation (2 for hydronephrosis and 2 for persistent incontinence). We conclude that bladder neck closure in conjunction with Mitrofanoff diversion is highly efficacious in achieving continence in a highly complex subgroup of patients with intractable urinary leakage. With careful patient selection and diligent followup total continence can be achieved in this most difficult patient population.