Ipsilateral ureteroureterostomy for ureteral duplication anomalies: predictors of adverse outcomes

INTRODUCTION AND OBJECTIVE

Ipsilateral ureteroureterostomy (UU) has gained popularity for treating ureteral duplication (UD) associated with obstruction or vesicoureteral reflux (VUR). Several studies have demonstrated its high success rate and low morbidity. This study aimed to identify the predictors of adverse outcomes associated with UU.

STUDY DESIGN

A retrospective chart review was conducted for patients with UD treated with UU at the study institution. Patients with less than 6 months of follow-up were excluded. Charts were reviewed for demographics, pre-operative imaging, surgical indications, operative notes, and follow-up data. Pre-operative and intra-operative variables were tested for association with adverse outcomes including unplanned surgery, worsening hydronephrosis, and febrile UTI recurrence.

RESULTS

A total of 35 patients underwent UU for UD between 2009 and 2017 at the study institution. The majority (33/35) had a distal anastomosis. A concomitant re-implantation of the recipient ureter was performed in 9 (25.7%) patients. After a median follow-up of 36.7 months, adverse outcomes developed in 9 patients (25.7%). No further surgery was required in 88.6% of the subjects. Adverse outcomes were associated with female gender (p = 0.048) and hydronephrosis of both upper and lower moieties (p = 0.015) and were more likely associated with ectopic ureteroceles (50%, p = 0.074) and having a concomitant re-implant performed (44.4%, p = 0.19) (table).

DISCUSSION

In this study, the low re-operation rates of UU for treating UD in patients with ectopic ureters or intravesical ureteroceles was demonstrated. The majority of patients with ectopic ureteroceles treated with UU and concomitant ureteral re-implantation had worsening hydronephrosis of both moieties and recurrent febrile UTI in the absence of mechanical obstruction. Interestingly, some of them had progression of hydronephrosis after excision of the upper pole. While worsening of hydronephrosis of the recipient moiety after UU was historically attributed to yo-yo reflux, most of the study patients did not have worsening hydronephrosis despite having distal anastomosis. Therefore, mechanical obstruction should be ruled out, and any underlying bladder dysfunction should be aggressively managed in patients with worsening hydronephrosis or recurrent UTI after UU before considering additional surgery.

CONCLUSION

Ureteroureterostomy is a successful option for UD with a low risk of adverse events in patients with ectopic ureters or intravesical ureteroceles. However, it should be cautiously considered in patients with hydronephrosis of both moieties, with ectopic ureteroceles, or if a concomitant re-implant is needed.

Effect of donor pneumoperitoneum on early allograft perfusion following renal transplantation in pediatric patients: an intraoperative Doppler ultrasound study

Decreased perfusion and trauma during laparoscopic harvesting are proposed causative factors for DGF and rejection in children following renal transplantation with laparoscopic donor nephrectomy (LDN) allograft. We performed a retrospective review of 11 children who underwent LDN transplant and 11 preceding patients who underwent ODN transplant. Intraoperative DUS findings, creatinine values and clearance, time to nadir creatinine and AR episodes were compared. There were no significant differences in the BMI, vascular anatomy, side of nephrectomy, or warm ischemia time in the two groups. Mean follow-up duration was 11.4 and 30.4 months in LDN and ODN groups. DUS showed initial turbulent flow in five of the LDN and four of the ODN group with an average RI of 0.59 and 0.66 in the ODN and LDN groups, respectively (NS). Three patients in the ODN group had an abnormal RI compared to none in the LDN group (p = 0.034). The creatinine values, creatinine clearances (at 24 h, one, four wk and last follow-up) and AR episodes were similar in both groups. Pneumoperitoneum during LDN does not appear to have an adverse impact on early graft reperfusion.

Should the presence of congenital para-ureteral diverticulum affect the management of vesicoureteral reflux?

PURPOSE

The presence of congenital para-ureteral diverticulum (PUD) has been presumed to lower the resolution rate of vesicoureteral reflux (VUR). PUD is considered an important cause of distortion of the vesicoureteral junction and persistence of VUR. Early surgery has been recommended based on this assumption. However, the scientific evidence supporting this approach is weak. We have been managing this group of patients more conservatively in the last 7 to 8 years on the premise that the presence of PUD is not per se an indication for surgery. To test this hypothesis, we performed a retrospective cohort study to compare the outcome of VUR in children with and without PUD.

MATERIALS AND METHODS

We identified 141 consecutive patients with VUR associated with PUD between 1990 and 2004. Of the patients 57 with duplication, ureterocele, neurogenic bladder or outlet obstruction were excluded from study. Median age of the remaining 84 patients at diagnosis was 2.9 years and 56 (69%) were males. Reflux was bilateral in 4 patients, and low (I to II), intermediate (III) and high (IV to V) grade in 39%, 35% and 26%, respectively. Followup was 3 to 168 months (median 47). The outcome was compared to a control group of 95 patients (150 units) with primary VUR and no PUD. The baseline parameters and followup were comparable in both groups.

RESULTS

Overall, VUR resolved in 43%, persisted in 27% and was surgically corrected in 30% of the units with PUD. In the 25 patients (26 units) who underwent surgical intervention breakthrough urinary tract infection or new renal scars were the indication in only 5. The remainder were operated on because of persistent VUR and the presence of PUD, mainly before 1997. The incidence of breakthrough urinary tract infection or new renal scar was similar in the controls (6% in PUD group vs 10% in controls, p = 0.7). The resolution rate was 60% for low grade, 39% for intermediate grade and 22% for high grade VUR. These figures were not significantly different from those of the control group in which the resolution rates were 52%, 28% and 33% for comparable grades (p = 0.9). Kaplan-Meier analysis and log rank test did not show any difference in resolution of VUR in the 2 groups (p = 0.84). Multivariate analysis identified grade as the only variable affecting resolution (p = 0.028). The size of PUD did not affect the likelihood of resolution.

CONCLUSIONS

The outcome of VUR is similar in children with or without PUD. Therefore, treatment of these patients should not differ. Surgery should be reserved for patients with breakthrough infection or renal scar progression.

The predictive value of diagnostic imaging for histological lesions of the upper poles in duplex systems with ureteroceles

OBJECTIVE

To compare the diagnostic imaging findings with the histological lesions in upper pole nephrectomy (UPN) specimens of duplex system ureteroceles, using renal ultrasonography (US) and nuclear renal scintigraphy.

PATIENTS AND METHODS

Between 1992 and 2000, 86 patients with a ureterocele in a duplex system underwent surgery. The results from US were reviewed in 84 patients by a radiologist, for echogenicity, parenchymal thinning and hydronephrosis; 77 nuclear renal scans describing the differential function of the upper poles were also reviewed. Fifty-five patients underwent UPN (25 antenatal, 30 postnatal; 18 intravesical, 37 extravesical) and the specimens were available for independent review by a pathologist, describing five histological categories, i.e. chronic interstitial inflammation, fibrosis, tubular atrophy, glomerulosclerosis and dysplasia. Histological lesions were categorized as severe (> 25%) or minimal (<or= 25%). Radiological features and the histology of UPN were then analysed, and correlated using Fisher's exact test and multivariate analysis.

RESULTS

Severe histological lesions were reported in 38 specimens (69%) and minimal lesions in 17 UPN specimens (31%). Severe parenchymal thinning was associated with a severe pathological lesion (P < 0.02). There was no correlation with the echogenicity or degree of hydronephrosis. Dysplasia, found in 64% of specimens, did not correlate with increased echogenicity. Minimally functioning upper poles on nuclear renal scan (<or= 4% overall function) were significantly associated with severe histological lesions (P = 0.01). There was no correlation between diagnostic imaging features and the mode of presentation or type of ureterocele.

CONCLUSIONS

Multivariate analysis, severe parenchymal thinning on renal US and minimal function on nuclear renal scan can be used to predict the severity of histological lesions of the upper pole. These results may be helpful in the making therapeutic decisions for patients with ureteroceles in duplex systems.

The use of tolterodine in children after oxybutynin failure

OBJECTIVE

To assess the safety and efficacy of tolterodine tartrate prescribed to children who previously failed to tolerate oxybutynin chloride.

PATIENTS AND METHODS

We reviewed 34 children, followed for>1 year, who were prospectively crossed-over from oxybutynin to tolterodine because of side-effects. The initial diagnosis was dysfunctional voiding in 31 patients. All patients were placed on a behavioural modification protocol. When their symptoms did not improve after 6 months, treatment with an anticholinergic agent was considered. Urodynamic studies were conducted in 20 patients, confirming uninhibited contractions in 19. The remaining 14 patients were empirically started on antimuscarinic or anticholinergic agents. The 34 patients were treated with oxybutynin for a median (range) of 6 (2-84) months. When significant side-effects were reported, they were crossed over to tolterodine. The efficacy of tolterodine was assessed as defined by the International Children's Continence Society, with tolerability assessed and side-effects documented using a questionnaire.

RESULTS

The mean age at the first dose of tolterodine was 8.9 years; the dose was 1 mg twice daily for 12 patients and 2 mg twice daily for 22. The median treatment with tolterodine was 11.5 months, with 20 (59%) patients reporting no side-effects; six described the same but tolerable side-effects as with oxybutynin. Eight patients discontinued tolterodine because of side-effects after a median (range) of 5 (1-11) months. The efficacy of tolterodine was comparable with that of oxybutynin, as reported by the questionnaire and voiding diaries. The reduction in wetting episodes at 1 year was> 90% in 23 (68%), more than half in five and less than half (or failure) in six patients.

CONCLUSION

Tolterodine is tolerated well in children. In this subgroup of patients who could not tolerate oxybutynin, 77% were able to continue tolterodine treatment with no significant side-effects.

Renal pseudoaneurysm after blunt renal trauma in a pediatric patient: management by angiographic embolization

Renal pseudoaneurysm is a rare complication after blunt renal trauma. Only 18 cases have been reported in English-language published reports. We present a case of blunt renal trauma in an 11-year-old boy, complicated by delayed bleeding from a renal artery pseudoaneurysm. The patient was initially treated with conservative measures and was later treated with selective embolization of the pseudoaneurysm. The clinical presentation, management options, and clinical decisions are discussed.

Healing of unstented tubularized incised plate urethroplasty: an experimental study in a rabbit model

OBJECTIVE

To develop a rabbit model to study the temporal healing taking place after an unstented tubularized incised plate urethroplasty (TIPU).

MATERIALS AND METHODS

The study comprised 13 New Zealand white rabbits (3-4 kg); the ventral wall of the penile urethra was excised to create a hypospadias-like defect. A vertical incision was made in the dorsal urethral plate and the incised urethra tubularized. Two animals were killed at 2 days and two at 5 days after surgery, and the remainder killed at 2, 6 and 12 weeks (three each). A retrograde urethrogram was taken at autopsy. Serial sections of the penis were stained with haematoxylin and eosin, and Masson trichrome for microscopy.

RESULTS

There were no deaths related to the procedure and all animals voided spontaneously. Retrograde urethrograms showed no fistulae or stricture. Microscopic examination at 2 and 5 days showed partial coverage of the incision with regenerating urothelium. At 2 weeks there was full-thickness urothelium with a mild inflammatory reaction. At 6 and 12 weeks, remodelling of the peri-urethral connective tissue with minimal fibrosis completed the healing.

CONCLUSION

The mechanism of healing of the incised urethral plate involves normal urothelial regeneration into the depth of the incised defect, which explains the gain in urethral diameter after TIPU. Urine flow, during normal voiding, might be responsible for keeping the incised plate open during urothelial regeneration. A urethral stent was not necessary for normal healing in this model.

22 week assessment of bladder acellular matrix as a bladder augmentation material in a porcine model

Previous studies on the reconstruction of porcine bladder using bladder acellular matrix allograft (BAMA) have indicated positive preliminary results with respect to graft shrinkage and cellular repopulation. The current study was conducted to investigate the feasibility of using BAMA in a similar model of bladder reconstruction out to longer time frames (22 weeks). At predetermined time points, the macroscopic, histological and mechanical properties of explanted native and BAMA tissues were evaluated and compared. Macroscopically, contracture of the BAMA was observed. The peripheral regions of the grafts experienced extensive cellular repopulation. Towards the centre however, all grafts were consistently devoid of organized smooth muscle bundles and a well-developed urothelium. An alteration in both the amount and organization of collagen was also observed within this region. Significant differences (p < 0.05) in the rupture strain and the elastic modulus of the BAMA compared to native bladder tissue appear to correlate with macroscopic graft contracture as well as the fibroproliferative tissue response of the matrix.

High resolution ultrasound characterization of early allograft hemodynamics in pediatric living related renal transplantation

PURPOSE

Allograft vascular thrombosis occurs in 5% to 10% of pediatric renal transplants. The hemodynamics of renal allograft immediately after implantation is unclear. High resolution Doppler ultrasound of the renal allograft performed in the operating room after incision closure is an effective and objective method to advance our understanding of baseline renal allograft hemodynamics, and identify unsuspected vascular complications early enough to ensure prompt surgical repair.

MATERIALS AND METHODS

Between September 1998 and July 2000 high resolution, color power Doppler ultrasound was prospectively performed on 21 living related renal transplants in the operating room immediately after incision closure. Each ultrasound described allograft anastomotic blood flow, direction of diastolic flow, parenchymal perfusion and resistive indexes.

RESULTS

There were 20 (95%) allografts with good power Doppler perfusion that had satisfactory immediate function with no vascular complications at 9 to 26-month followup. Initially, anastomotic turbulence was described in 15 (71%) allografts, and resistive indexes were abnormal in 8 (38%). Turbulence and abnormal resistive index normalized in all allografts by 1-month followup. Ultrasound of 1 allograft identified unsuspected poor perfusion and reversal of diastolic flow in the operating room after incision closure. In another allograft in which a 4-hour post-transplant ultrasound was compared with the baseline study in the operating room an unsuspected thrombosis of the right common iliac vein was confirmed.

CONCLUSIONS

Good parenchymal perfusion and forward diastolic flow after renal reperfusion correlated well with immediate graft function. Initial turbulence and abnormal resistive index in the presence of favorable perfusion are misleading and not independent predictors of graft function. Ultrasound performed in the operating room identified 2 unsuspected major vascular complications facilitating prompt surgical correction.

Tunica vaginalis for correcting penile chordee in a rabbit model: is there a difference in flap versus graft?

PURPOSE

We compared tunica vaginalis applied as a flap versus a graft for covering defects in the ventral tunica albuginea in a rabbit model.

MATERIALS AND METHODS

We used 18 New Zealand White rabbits in the study. The urethra was mobilized off of the corpus cavernosum. A defect was created in the ventral aspect of the tunica albuginea by excising a 1 x 0.5 cm. rectangular area. The defect was covered by the testicular surface of tunica vaginalis as a vascularized flap in 9 animals and as a graft in 9. At 2, 6 and 12-week intervals 3 animals per group were sacrificed. Transverse sections of the penis at the repair site were stained with hematoxylin and eosin, and Masson's trichrome for microscopy.

RESULTS

Autopsy revealed no contracture in any of the tunica vaginalis flaps. In contrast, the tunica vaginalis grafts had contracted by a mean of 22% (range 20% to 25%) at 2, 38% (range 30% to 44%) at 6 and 42% (range 38% to 48%) at 12 weeks. Microscopic examination of the tunica vaginalis flaps showed evidence of an intact blood supply and viable cremasteric muscle layer but no evidence of necrosis. Collagen remodeling and maturation was noted at 12 weeks. In tunica vaginalis grafts there was evidence of necrosis of all tunica vaginalis layers at 2 weeks with granulation tissue and active fibrosis at the periphery. At 6 and 12 weeks most necrotic tissue was replaced by fibrosis. Osseous metaplasia was identified in 1 graft at 12 weeks.

CONCLUSIONS

The optimal use of tunica vaginalis for correction of chordee is as a flap rather than as a free graft. Grafts were associated with significant necrosis and contracture, of which neither was associated with flaps.

A population based analysis of continence outcomes and bladder exstrophy

PURPOSE

Whereas the literature on bladder exstrophy is replete with outcomes of specific continence surgical procedures in highly select patients, there are no data on the outcomes related to continence for a complete exstrophy population, which is more comprehensive with respect to a variety of surgical procedures performed to achieve continence. To provide urologists and patients with an overview of potential continence outcomes devoid of any selection bias, we report on a comprehensive exstrophy population, focusing on the various procedures required for urinary continence.

MATERIALS AND METHODS

We reviewed the charts of all patients with bladder and cloacal exstrophy who underwent a staged repair to achieve urinary continence at a single institution between 1988 and 1998. Urinary continence was then correlated to the types of surgical procedures, and subgroup analysis for predictors of urinary continence was performed. The type of bladder neck reconstruction allowed subgrouping cases into group 1-bladder neck reconstruction only, group 2-bladder neck reconstruction with augmentation and/or appendicovesicostomy and group 3-bladder neck closure.

RESULTS

Of the 43 patients identified 26 were male, 4 had cloacal exstrophy and 3 had complex exstrophy variants with ectopic hindgut and spina bifida. Groups 1 to 3 comprised 9, 15 and 19 patients with urinary continence rates of 56%, 67% and 100%, respectively. The age at which patients became continent was delayed in groups 2 and 3 (8.2 and 8.7 years, respectively) compared to group 1 (4.8). Of all the potential variants measured gender was the strongest predictor of continence with 94% of females versus 69% of males achieving it. Of the males those with (57%) compared to those without (83%) a history of bladder neck stenosis or paraexstrophy flaps had worse continence. Repeat bladder neck reconstruction was only successful in 23% of patients.

CONCLUSIONS

All patients can be rendered continent but many may achieve this successful outcome by other procedures following initial bladder neck reconstruction. When managing failed bladder neck reconstruction, the type of surgical repair chosen may need to address the need for enhanced bladder storage and the issue of potential bladder augmentation. The advances made in the treatment of the epispadiac urethra may now facilitate clean intermittent catheterization. Earlier recognition of the need for adjunctive storage procedures in addition to bladder neck reconstruction may facilitate the timing of providing enhanced continence, independence and self-esteem, and do so with fewer operative procedures. We speculate that the current complete urethral and bladder repair in newborns will add further to the storage functions of the native bladder tissues and improve the potential of achieving more effective bladder outlet control.

A population based analysis of continence outcomes and bladder exstrophy

PURPOSE

Whereas the literature on bladder exstrophy is replete with outcomes of specific continence surgical procedures in highly select patients, there are no data on the outcomes related to continence for a complete exstrophy population, which is more comprehensive with respect to a variety of surgical procedures performed to achieve continence. To provide urologists and patients with an overview of potential continence outcomes devoid of any selection bias, we report on a comprehensive exstrophy population, focusing on the various procedures required for urinary continence.

MATERIALS AND METHODS

We reviewed the charts of all patients with bladder and cloacal exstrophy who underwent a staged repair to achieve urinary continence at a single institution between 1988 and 1998. Urinary continence was then correlated to the types of surgical procedures, and subgroup analysis for predictors of urinary continence was performed. The type of bladder neck reconstruction allowed subgrouping cases into group 1-bladder neck reconstruction only, group 2-bladder neck reconstruction with augmentation and/or appendicovesicostomy and group 3-bladder neck closure.

RESULTS

Of the 43 patients identified 26 were male, 4 had cloacal exstrophy and 3 had complex exstrophy variants with ectopic hindgut and spina bifida. Groups 1 to 3 comprised 9, 15 and 19 patients with urinary continence rates of 56%, 67% and 100%, respectively. The age at which patients became continent was delayed in groups 2 and 3 (8.2 and 8.7 years, respectively) compared to group 1 (4.8). Of all the potential variants measured gender was the strongest predictor of continence with 94% of females versus 69% of males achieving it. Of the males those with (57%) compared to those without (83%) a history of bladder neck stenosis or paraexstrophy flaps had worse continence. Repeat bladder neck reconstruction was only successful in 23% of patients.

CONCLUSIONS

All patients can be rendered continent but many may achieve this successful outcome by other procedures following initial bladder neck reconstruction. When managing failed bladder neck reconstruction, the type of surgical repair chosen may need to address the need for enhanced bladder storage and the issue of potential bladder augmentation. The advances made in the treatment of the epispadiac urethra may now facilitate clean intermittent catheterization. Earlier recognition of the need for adjunctive storage procedures in addition to bladder neck reconstruction may facilitate the timing of providing enhanced continence, independence and self-esteem, and do so with fewer operative procedures. We speculate that the current complete urethral and bladder repair in newborns will add further to the storage functions of the native bladder tissues and improve the potential of achieving more effective bladder outlet control.

Serotonergic function in major depression and effect of sertraline and paroxetine treatment

We investigated platelet [14C]serotonin (5-HT) uptake and lysergic acid diethylamide [N-methyl-3H] ([3H]LSD)- and phenyl-6'-paroxetine ([3H]paroxetine) binding in 30 patients with major depression at baseline and after 6 months of treatment with either paroxetine or sertraline. The study was of a double-blind design. Baseline data was compared with an age- and gender-matched group of healthy volunteers. Baseline Vmax was significantly lower in patients than in controls. Bmax for [3H]paroxetine binding were similar in patients and controls, but patients who suffered their first depression had significantly lower Bmax for [3H]paroxetine binding than patients who had suffered multiple depressions. Twenty-three patients (76%) (13 in the paroxetine group and 10 in the sertraline group) responded to treatment as judged by a 50% or more reduction in Montgomery-Asberg Depression Rating Scale (MADRS) scores after 6 months of treatment. There were no significant differences between the paroxetine and sertraline treated groups. Both paroxetine and sertraline caused a significant reduction in Vmax and a significant increase in Km. There was a strong correlation between Km and plasma drug concentration in patients who experienced their first depression but not in patients who had suffered multiple episodes. Bmax for [3H]paroxetine binding increased after paroxetine treatment while the opposite occurred after sertraline treatment. There was a significant interaction between the impact of drug and earlier depressions. All patients included in the study had been drug free for at least 2 months. Earlier antidepressant treatment may have long withstanding effects on the serotonin uptake machinery but it cannot be excluded that the sensitivity of the uptake mechanism may become more resistant to change in patients with recurrent depressive episodes.

Are postoperative studies justified after extravescial ureteral reimplantation?

PURPOSE

We evaluated the usefulness of postoperative imaging studies after extravesical ureteroneocystostomy and identified patient subsets in which these studies are necessary.

MATERIALS AND METHODS

Records of 438 patients who had undergone extravesical ureteroneocystostomy from 1991 to 1997 were reviewed retrospectively. Study inclusion criterion was primary reflux with at least 1 year of postoperative followup. Grades I to III reflux were defined as low, and grades IV and V were defined as high. All patients were on prophylactic antibiotics. Evaluation included ultrasound and a voiding cystourethrogram 3 months postoperatively, and if reflux persisted the studies were repeated at 12 months.

RESULTS

A total of 438 patients (723 renal units) underwent extravesical ureteral reimplantation. At 3 months the procedure was successful in 93.2% of ureters (91.3% patients), and at 12 months the success rate increased to 97.9% of ureters (95.4% patients). There were 49 renal units in 38 cases that were refluxing at 3 months, 11 of which were contralateral. At 12 months reflux resolved spontaneously in 20 of 38 ipsilateral and 8 of 11 contralateral ureters. Of the remaining 18 ipsilateral units reflux was high grade preoperatively in 12 and persisted postoperatively in 4. There was a statistically significant difference in the success rate at 1 year between high (94%) versus low (99%) grade reflux (p = 0.007). Age and preoperative bladder function did not significantly affect the success rates but males had a lower success rate. Hydronephrosis was noted in 7.2% of ureters at 6 weeks and in only 0.005% at 12 months.

CONCLUSIONS

Extravesical reimplantation is successful in treating vesicoureteral reflux. Postoperative voiding cystourethrogram should be reserved for high grade reflux. Limiting these studies will help reduce patient discomfort and the cost of treatment.

Regeneration of functional bladder substitutes using large segment acellular matrix allografts in a porcine model

PURPOSE

We previously reported on the short-term (4 weeks) morphometric analysis of a large bladder acellular matrix allograft used as a bladder bioprosthesis (average size 24 cm.2). We demonstrated cellular repopulation through the entire thickness of the graft. We now present the long-term (12 weeks) morphometric results of graft regenerated porcine bladders using segments measuring an average of 40 cm.2.

MATERIALS AND METHODS

Bladders harvested from pigs were subjected to detergent and enzymatic extractions to render them acellular. Partial cystectomy was performed in 21 pigs and the defect was repaired with a bladder acellular matrix allograft (average size 40.52 cm.2). Of the animals 8 were sacrificed at 1, 2 and 4 weeks and 13 were sacrificed at 8 and 12 weeks. To evaluate cellular repopulation and matrix reorganization the native bladder and graft were analyzed using standard histological and immunofluorescent techniques. To evaluate for calcium deposits in the grafts a radiological evaluation of the graft was performed after explantation.

RESULTS

All animals survived the surgical procedure and there were no significant urinary leaks. No stones were noted in any of the bladders. At 1 week there was a diffuse infiltration with acute inflammatory cells. At 2 weeks the luminal surface of the graft was lined with a single layer of urothelium, and there was stromal infiltration with unorganized smooth muscle cells and angiogenesis. At 4 weeks the urothelium was multilayered with organizing groups of smooth muscle cells and angiogenesis. At 8 and 12 weeks there was repopulation throughout the bladder acellular matrix allograft implant with all native cellular components participating.

CONCLUSIONS

We present evidence that large patch bladder acellular matrix allograft implantation is technically feasible and may prove to be a viable surgical alternative to bladder augmentation with intestinal segments. Its advantages may include the potential for complete and functional regeneration of a bladder substitute.

Lessons learned from laser tissue soldering and fibrin glue pyeloplasty in an in vivo porcine model

PURPOSE

We compared sutured pyeloplasty to 2 newer techniques of tissue anastomosis, including laser soldered pyeloplasty using a diode laser with 50% albumin solder mixed with indocyanine green and fibrin glue.

MATERIALS AND METHODS

We performed 53 pyeloplasties in 50 pigs using suture, laser or fibrin glue. In the immediate group anastomotic leak pressure was measured immediately postoperatively, and then animals were euthanized. At 1, 3 and 4 weeks postoperatively a pressure flow study at 10 cc per minute in cm. H2O was performed, and tissue was sent for histological and collagen content analysis.

RESULTS

In the immediate studies laser soldering achieved a significantly higher mean anastomotic leak pressure (50.5 +/- 15.1 cm. H2O) than sutured (17.3 +/- 5.4) or fibrin glued (3.5 +/- 1.5) repairs. In the 1, 2 and 4-week studies animals in the sutured pyeloplasty group had no complications, and all pressure flow studies except 1 were normal. However, in the laser soldered groups we observed 8 urinomas in 19 animals, and most occurred during the first part of our study. This complication was prevented by stopping urine flow at the anastomotic site at laser irradiation and by improving application of the solder. Of the 11 animals in which pressure flow studies were performed only 2 were obstructed. Of the 7 chronic fibrin glue group 4 animals had urinomas and 2 had unobstructed pressure flow studies. Histological studies and immunohistochemical staining for collagen showed no differences in collagen distribution among the 3 procedures.

CONCLUSIONS

Laser soldering and fibrin glue pyeloplasties are not superior in the long-term compared to sutured pyeloplasty. Fibrin glue in our animal model had the highest failure rate. Further improvements in the technical aspect of laser tissue welding need to be made to benefit from its theoretical advantages in minimally invasive surgery.

Localized drug delivery using crosslinked gelatin gels containing liposomes: factors influencing liposome stability and drug release

We describe a drug-delivery vehicle that combines the sustained release properties of liposomes with the structural advantages of crosslinked gelatin gels that can be implanted directly or coated onto medical devices. Liposome inclusion in gelatin gels does not compromise thermal stability nor does it interfere with the resiliency of gels to tensile force. However, electron spin resonance analysis of sequestered DPPC liposomes revealed a slight depression (ca. 1.0 degrees C) of the gel-to-fluid phase transition relative to liposomes in suspension. The level of liposome release from gels was determined by liposome concentration, liposome size, and the presence of poly(ethylene oxide) chains in the gel matrix or in the liposome membrane. Both neutral and charged liposomes displayed relatively high affinities for poly(ethylene glycol)gelatin gels, with only 10-15% release of initially sequestered liposomes while liposomes in which poly(ethylene glycol) was included within the membrane were not as well retained (approximately 65% release). The in vitro efflux of ciprofloxacin from liposomal gels immersed in serum was nearly complete after 24 h compared to 38% release of liposomal chlorhexidine after 6 days. The serum-induced destabilization of liposomal ciprofloxacin depended on the accessibility of serum components to gels as partly immersed gels retained approximately 50% of their load of drug after 24 h. In vivo experiments using a catheterized rabbit model of urinary tract infection revealed the absence of viable Escherichia coli on coated catheter surfaces in seven out of nine cases while all untreated catheter surfaces examined (n = 7) were contaminated.

The use of magnetic resonance imaging in the diagnosis and followup of pediatric pelvic rhabdomyosarcoma

PURPOSE

Previous radiological descriptions of pelvic rhabdomyosarcoma emphasized ultrasonography and computerized tomography (CT). Few reports are available on the use of magnetic resonance imaging (MRI) for diagnosing and following pelvic rhabdomyosarcoma. We retrospectively compared MRI to CT for diagnosing and following children with pelvic rhabdomyosarcoma.

MATERIALS AND METHODS

We treated 4 boys and 3 girls for pelvic rhabdomyosarcoma. Initial and followup evaluations included pelvic CT and MRI at intervals determined by treatment and disease status. We retrospectively reviewed the clinical charts and imaging studies of these patients. The initial radiological report was evaluated and then 1 radiologist reviewed all studies. Attention was directed toward identifying lesions revealed by CT or MRI but not by the other modality.

RESULTS

MRI detected all lesions shown by CT. On the other hand, MRI detected residual disease in 1 case that was not demonstrated by CT. In 2 other patients MRI was superior to CT for delineating the local extent of disease, especially urethral involvement.

CONCLUSIONS

Compared with CT, MRI improves the detection of residual pelvic rhabdomyosarcoma. Tissue planes are well delineated, allowing more accurate assessment of tumor invasion into adjacent structures. MRI is the imaging modality of choice for following pediatric patients with pelvic rhabdomyosarcoma.

Acellular bladder matrix allografts in the regeneration of functional bladders: evaluation of large-segment (> 24 cm) substitution in a porcine model

OBJECTIVES

To evaluate the use of a large-segment (> 24 cm2) bladder substitution with porcine bladder acellular matrix allograft (BAMA) in a large animal model. Materials and methods Bladders were harvested from pigs at the time of necropsy and subjected to detergent and enzymatic extractions to render them acellular. The BAMA produced had the surgical handling and suture-retaining properties of normal bladder tissue. Six pigs had BAMA segments implanted under general anaesthesia, through a low midline abdominal incision and after partial cystectomy. The defect was repaired with a BAMA patch (mean size 43.88 cm2, range 12-72), with no urinary diversion. Two animals each were then killed at 9, 16 and 30 days and the bladders explanted. The native bladder and BAMA patch were analysed morphometrically to evaluate cellular re-population and matrix re-organization.

RESULTS

All animals survived surgery; there were no urinary leaks and no stones detected in any of the bladders. At 9 days there was a diffuse infiltration with acute inflammatory cells, but no areas of necrosis. There were isolated areas of smooth muscle cell (SMC) infiltration of the BAMA. At 16 days the luminal surface was lined with a single layer of urothelium, there was stromal infiltration with disorganized SMC and angiogenesis, with mature vessels in the BAMA patch. At 30 days the urothelium was multilayered with organizing groups of SMCs and angiogenesis. The highest cell density was at the periphery of the repopulated BAMA patch, decreasing towards the centre.

CONCLUSIONS

The implantation of large patches of BAMA is technically feasible and may prove to be a viable surgical alternative to bladder augmentation with intestinal segments. The advantages of BAMA include the potential for complete and functional regeneration of a bladder substitute. This model provides a tool with which to obtain a better understanding of the cellular and molecular aspects of matrix re-population.

Issues surrounding the prevention and management of device-related infections

The use of biomaterial devices in all aspects of modern medicine has increased exponentially in the past three decades. Device-related infections constitute one of the main impediments to their long-term use. We discuss the pathogenesis, prevention, and management of catheter-associated urinary tract infection (CAUTI). The recent innovations in biomaterial design and surface coatings intended to prevent colonization of the device surface are presented. Despite these significant advances, the ability to protect these surfaces beyond the short term presents a continued challenge to investigators.

Concomitant modified bladder neck closure and Mitrofanoff urinary diversion

PURPOSE

We describe a modification of bladder neck closure for managing urinary incontinence in children.

MATERIALS AND METHODS

In 11 patients with intractable urinary incontinence that persisted after multiple failed surgical procedures we performed modified bladder neck closure with construction of a catheterizable continent conduit.

RESULTS

Mean followup is 3 years. All patients were continent after the procedure and none had a fistula or urinary leakage. One patient required stomal and conduit revision, and bladder stones in 3 necessitated endoscopic removal.

CONCLUSIONS

We recommend this modified technique of bladder neck closure as an option for managing urinary incontinence in a complex group of children because it allows the achievement of continence with minimal morbidity.

Initial experience with endoscopic holmium laser lithotripsy for pediatric urolithiasis

PURPOSE

Due to the unavailability of suitable pediatric instruments children have not benefited from advances in endoscopic lithotripsy. This limitation may be overcome by the holmium: YAG laser. We evaluated the indications for, and efficacy and complications of holmium:YAG laser lithotripsy.

MATERIALS AND METHODS

We retrospectively reviewed all cases of laser lithotripsy. Access to the calculus was antegrade or retrograde. A solid state holmium:YAG laser was used.

RESULTS

Eight patients 4 to 14 years old underwent laser lithotripsy during the study period. Average calculous surface area was 357.13 mm.2 (range 14 to 1,645). Five patients required 1 procedure to render them stone-free, while the remaining 3 required multiple procedures. No complications were associated with laser lithotripsy.

CONCLUSIONS

The ability of the holmium:YAG laser to pulverize urinary calculi makes it an alternative choice for lithotripsy. In our series all patients are stone-free with stable renal function. The advantages of the holmium:YAG laser are that it may be precisely applied via small fibers, and it pulverizes calculi with minimal scattering of energy and retropulsion of the calculus, decreasing trauma to tissues at the perioperative site. There is also a lower risk of residual fragments, which is associated with a lower incidence of calculous regrowth. Holmium: YAG laser is safe and effective for treating pediatric urolithiasis.

Atypical germ cells in a child with splenic-gonadal fusion

Splenic-gonadal fusion is a rare congenital anomaly associated with other anomalies, particularly limb defects. This is the first reported case of splenic-gonadal fusion, tetraperomelia (congenital malformations involving all 4 extremities), and spinal abnormality with neurogenic bladder, in which focal atypia of germ cells was found following orchiectomy. Testicular biopsy with frozen section examination should be performed if the diagnosis of splenic-gonadal fusion is made, especially if associated with cryptorchidism and an orchiopexy is planned.

Urinary retention after bilateral extravesical ureteral reimplantation: does dissection distal to the ureteral orifice have a role?

PURPOSE

We evaluated the outcome and incidence of urinary retention after bilateral detrusorrhaphy using 2 modifications of the original Lich-Gregoir procedure.

MATERIALS AND METHODS

We evaluated the charts of 220 patients who underwent correction of bilateral vesicoureteral reflux using the extravesical approach from January 1991 to December 1997. Inverted Y detrusorrhaphy was performed in 154 patients and the advancing suture modification was done in 66.

RESULTS

The success rate using the advancing suture technique was 92.4 and 95.4% at 3 and 12 months, respectively. The Y detrusorrhaphy technique was successful in 91.6 and 97.4% of cases at 3 and 12 months, respectively. The difference in the techniques was not statistically significant. Urinary retention developed in 8.4% of the patients who underwent Y detrusorrhaphy compared to 15.2% of those who underwent the advancing suture technique (not statistically significant). However, patients with grades IV and V reflux, children younger than 3 years and boys had significantly (p <0.05) higher postoperative retention rates of 24.6, 35.6 and 20.3%, respectively, when all 220 patients were considered.

CONCLUSIONS

Each modification of the original Lich-Gregoir technique is highly effective for treating bilateral vesicoureteral reflux and each is associated with a low rate of temporary urinary retention. Although there seems to be a lower incidence of retention with the Y detrusorrhaphy technique, this was not statistically significant. Because of the higher incidence of urinary retention in young children, boys and/or patients with high grade reflux, we recommend that physicians consider a longer period of catheterization regardless of the technique chosen.

Antibiotic hydrogel coated Foley catheters for prevention of urinary tract infection in a rabbit model

PURPOSE

We developed an antibiotic liposome (ciprofloxacin liposome) containing hydrogel for external coating of silicone Foley catheters and evaluated its efficacy in a rabbit model. Our goal was to create a catheter that would hinder the development of catheter associated nosocomial urinary tract infections.

MATERIALS AND METHODS

We inserted either an untreated, liposomal hydrogel coated or a liposome hydrogel with ciprofloxacin coated 10F silicone Foley catheter into New Zealand White rabbits. We challenged the system with 5x10(6) virulent Escherichia coli at the urethral meatus twice daily for 3 days. Urine cultures were evaluated twice daily for 7 days. When urine cultures became positive, the rabbits were sacrificed and urine, urethral catheter and urethral tissue were cultured.

RESULTS

The time to bacteriuria detection in 50% of the specimens was double for hydrogel with ciprofloxacin coated catheters versus untreated and hydrogel coated catheters. A significant (p = 0.04) improvement in average time to positive urine culture from 3.5 to 5.3 days and a 30% decrease in the bacteriuria rate for hydrogel with ciprofloxacin coated catheters were noted compared to untreated catheters.

CONCLUSIONS

A significant benefit was realized by coating the extraluminal catheter surface with a ciprofloxacin liposome impregnated hydrogel. We believe this procedure will provide a significant clinical advantage, while reducing health care costs substantially.

Urinary retention after bilateral extravesical ureteral reimplantation: does dissection distal to the ureteral orifice have a role?

PURPOSE

We evaluated the outcome and incidence of urinary retention after bilateral detrusorrhaphy using 2 modifications of the original Lich-Gregoir procedure.

MATERIALS AND METHODS

We evaluated the charts of 220 patients who underwent correction of bilateral vesicoureteral reflux using the extravesical approach from January 1991 to December 1997. Inverted Y detrusorrhaphy was performed in 154 patients and the advancing suture modification was done in 66.

RESULTS

The success rate using the advancing suture technique was 92.4 and 95.4% at 3 and 12 months, respectively. The Y detrusorrhaphy technique was successful in 91.6 and 97.4% of cases at 3 and 12 months, respectively. The difference in the techniques was not statistically significant. Urinary retention developed in 8.4% of the patients who underwent Y detrusorrhaphy compared to 15.2% of those who underwent the advancing suture technique (not statistically significant). However, patients with grades IV and V reflux, children younger than 3 years and boys had significantly (p <0.05) higher postoperative retention rates of 24.6, 35.6 and 20.3%, respectively, when all 220 patients were considered.

CONCLUSIONS

Each modification of the original Lich-Gregoir technique is highly effective for treating bilateral vesicoureteral reflux and each is associated with a low rate of temporary urinary retention. Although there seems to be a lower incidence of retention with the Y detrusorrhaphy technique, this was not statistically significant. Because of the higher incidence of urinary retention in young children, boys and/or patients with high grade reflux, we recommend that physicians consider a longer period of catheterization regardless of the technique chosen.

Utility of SPECT DMSA renal scanning in the evaluation of children with primary vesicoureteral reflux

OBJECTIVES

DMSA renal scanning is more sensitive than ultrasound in detecting renal parenchymal scars. We proposed to determine the utility of single-photon emission computed tomography (SPECT) dimercaptosuccinic acid (DMSA) renal scanning in children with primary vesicoureteral reflux (VUR).

METHODS

During a 24-month period, we evaluated the charts of 368 patients who had undergone SPECT DMSA renal scanning for primary VUR. Patients were divided into three age groups: (a) less than 1 year, (b) between 1 and 5 years, and (c) older than 6 years. Renal scars were deemed severe or focal. The data were analyzed to evaluate the utility of SPECT DMSA scanning in children with primary VUR and to determine the indications for performing SPECT DMSA. We also evaluated the sensitivity of recent renal ultrasound technology in detecting focal and diffuse scars.

RESULTS

One hundred twenty-eight patients were younger than 1 year at presentation. These included 24 cases that were detected prenatally. One hundred eighty-five were between the ages of 1 and 5 years, and 55 were 6 years or older. Reflux nephropathy at presentation was found in 99 (26.9%) of 368 patients. DMSA scanning changed the treatment in only 13 patients (3.5%). When scarring was diffuse, ultrasound examination correlated 100% with DMSA scanning; when focal scarring was present, the correlation was poor.

CONCLUSIONS

Our results suggest that DMSA scans should be tailored to children who have ultrasound abnormalities, high-grade reflux, or recurrent breakthrough urinary tract infections. These guidelines will result in a substantial cost savings and a significant decrease in radiation exposure.

Modifications of and extended indications for the Pippi Salle procedure

Total urinary incontinence is a difficult problem faced by the urologist. Several techniques to increase ureteral resistance have been described. The majority of them rely on intermittent catheterization for bladder emptying, especially in neurogenic incontinence. We have developed a new procedure in which a bladder flap is used to create a neourethra. This urethral extension acts as a flap valve to provide continence. Bladder emptying is accomplished by clean intermittent catheterization. Urethral lengthening with an anterior bladder-wall flap was performed in 18 patients aged a mean of 8.9 years who had neurogenic incontinence (14) or exstrophy (4). Patients with previous bladder interventions received a lateralized anterior flap. Bladder augmentation was performed in 14 of the 18 patients [detubularized ileum (11), detubularized colon (3)]. The average follow-up period is currently 29.3 months. Continence was achieved in 13 of the 18 patients (72%). Complications included urethrovesical fistulae, which developed in two patients. Two patients could not perform catheterization due to pain but had no obstruction to passage of catheter (exstrophy). Ureteral lengthening with an anterior bladder-wall flap is a useful alternative for the surgical treatment of urinary incontinence. This technique achieves a good continence rate and presents few problems with catheterization.

A liposomal hydrogel for the prevention of bacterial adhesion to catheters

The adhesion of bacteria to medical implants and the subsequent development of a biofilm frequently results in the infection of surrounding tissue and may require removal of the device. We have developed a liposomal hydrogel system that significantly reduces bacterial adhesion to silicone catheter material. The system consists of a poly (ethylene glycol)-gelatin hydrogel in which liposomes containing the antibiotic ciprofloxacin are sequestered. A poly (ethylene glycol)-gelatin-liposome mixture was applied to a silicone surface that had been pre-treated with phenylazido-modified gelatin. Hydrogel cross-linking and attachment to surface-immobilized gelatin was accomplished through the formation of urethane bonds between gelatin and nitrophenyl carbonate-activated poly (ethylene glycol). Liposomal hydrogel-coated catheters were shown to have an initial ciprofloxacin content of 185+/-16 microg cm(-2). Ciprofloxacin was released over seven days with an average release rate of 1.9+/-0.2 microg cm(-2) h(-1) for the first 94 h. In vitro assays using a clinical isolate of Pseudomonas aeruginosa established the antimicrobial efficacy of the liposomal hydrogel. A modified Kirby-Bauer assay produced growth-inhibition zone diameters of 39+/-1 mm, while bacterial adhesion was completely inhibited on catheter surfaces throughout a seven-day in vitro adhesion assay. This new antimicrobial coating shows promise as a prophylactic and/or treatment for catheter-related infection.

Artificial neural networks in pediatric urology: prediction of sonographic outcome following pyeloplasty

PURPOSE

Computerized artificial neural networks are analogous to biological neuronal systems. Since they may be trained to recognize the relevance of complex patterns in data, neural networks may be useful for decision making in the multifactorial management of ureteropelvic junction obstruction. We determine the ability of a customized neural network to predict sonographic outcome after pyeloplasty in children with ureteropelvic junction obstruction.

MATERIALS AND METHODS

A data set was constructed with 242 demographic, clinical, radiological and surgical elements. We analyzed the available retrospective data in 100 consecutive children who underwent unilateral pyeloplasty for ureteropelvic junction obstruction chosen from all 144 surgically treated for ureteropelvic junction obstruction between 1993 and 1995. One radiologist reviewed all film data and provided a final sonographic outcome designation in each case. We wrote a set of computer programs to construct a neural network. A composite 4-layer network was built with output nodes representing 4 possible sonographic outcomes. The 100 patient data set was randomly divided into 84 training and 16 testing examples.

RESULTS

The neural network correctly predicted all 5 of 5 significantly improved, 7 of 7 improved, 2 of 2 same and 2 of 2 worse sonogram results after pyeloplasty. Therefore, sensitivity and specificity were 100% for all 4 outcomes. Linear regression analysis of the data yielded inferior sensitivity and specificity values (52 to 94%), confirming that ureteropelvic junction obstruction is a nonlinear data analysis problem.

CONCLUSIONS

The 100% accuracy, sensitivity and specificity of our neural network in this pilot study provide evidence of the value of the neural computational approach for the modern exploration and modeling of the clinical problem of pediatric ureteropelvic junction obstruction.

Outcome analysis of rhabdomyosarcoma of the lower urinary tract

PURPOSE

Multimodal therapy has resulted in a high cure rate for genitourinary rhabdomyosarcoma. We propose that the strategy of induction chemotherapy followed by excision and reconstruction without radiotherapy may provide a high cure rate without the late sequelae of pelvic radiotherapy.

MATERIALS AND METHODS

We reviewed the records of 13 patients with a mean age of 3.3 years diagnosed with rhabdomyosarcoma of the urinary tract from 1986 to 1996. The primary site was the bladder in 4 cases and prostate in 9. After biopsy confirmation of the diagnosis patients were treated with chemotherapy and subsequent surgery, while radiotherapy was reserved for those with residual disease.

RESULTS

After induction chemotherapy 8 patients underwent tumor excision via an organ sparing approach, which involved radical prostatectomy and partial cystectomy with or without bladder augmentation. In 5 patients the final pathological analysis showed positive margins. Repeat surgery in 6 patients included complete cystectomy and urinary diversion in 2 who had positive margins and recurrence after radiotherapy, urethrectomy and continent diversion for positive margins in 1, partial cystectomy and continent diversion in 1, and radical prostatectomy, partial cystectomy and continent diversion in 1 with stage IV disease who had local recurrence. In the latter case ileocystoplasty had been performed for a small noncompliant bladder. Six patients with microscopic residual or metastatic disease received radiotherapy. At a mean followup of 5.6 years 11 patients are disease-free. Continence was preserved in all reconstructed cases. Erections were reported in 8 patients, and renal function was maintained in 10.

CONCLUSIONS

Our results suggest that urinary tract reconstruction may be safely performed at primary excision surgery, radiotherapy induced morbidity may be minimized by limiting radiotherapy to residual and metastatic disease, frozen section results may be false-negative, potency may be achieved and radiological disappearance of the tumor should be confirmed histologically.

Urethral replacement with vascularized tunica vaginalis: defining the optimal form of use

PURPOSE

Residual urethral defects after failed hypospadias surgery present difficulties in reconstruction. In these situations, repair using vascularized tissue flaps remains ideal, yet challenging. In order to offer more surgical alternatives in these cases, the use of vascularized tunica vaginalis flaps as urethral replacements has recently been established in an animal model. We undertook the following studies to further define the role of tunica vaginalis in urethral reconstruction.

MATERIALS AND METHODS

A vascularized flap of tunica vaginalis was used to replace an experimentally created 25-30 mm. gap in the anterior urethra of 26 rabbits, either as an onlay or tube flap. A control group consisting of 7 animals underwent only a segmental anterior urethral resection and primary re-anastomosis.

RESULTS

Satisfactory urethral healing occurred in all control animals that survived the procedure. All 8 animals which had tunica vaginalis tube flap reconstruction underwent contracture of the neourethra probably secondary to the presence of striated cremasteric muscle elements brought with the tunica during mobilization. All 16 animals available for long term study in the onlay flap group had excellent flap viability and 100% urethral patency rates. The mesothelial lining of the tunica was seen to be replaced by a stratified epithelial lining similar to the urothelial lining of the native urethra.

CONCLUSION

The tunica vaginalis is a viable alternative to other tissues presently used for urethral replacement and can be used successfully as a vascularized onlay flap.

Ureteral opening pressure: a novel parameter for the evaluation of pediatric hydronephrosis

PURPOSE

The antegrade nephrostogram is an important tool in the evaluation of the upper urinary tract. However, the information currently provided by a nephrostogram is largely limited to anatomical details. To establish a meaningful pressure-flow parameter that may be incorporated into a routine nephrostogram, we evaluated the ureteral opening pressure (defined as the pressure at which contrast material is first seen beyond the suspected site of obstruction) and correlated these findings with the results of pressure-flow studies performed with an external infusion and/or furosemide induced diuresis.

MATERIALS AND METHODS

A total of 52 renal units were studied under a prospective pressure-flow study protocol. All patients had grade 3 or 4 hydronephrosis (Society of Fetal Urology classification) and patient age range was 0.2 to 12 years (median 1.1). The suspected sites of obstruction were the ureteropelvic and ureterovesical junctions in 42 and 10 renal units, respectively. With the patient under general anesthesia 22 gauge percutaneous nephrostomy needles were inserted. Pressure-flow studies with an external infusion and/or furosemide induced diuresis were then performed. As the renal pelvic pressure progressively increased during the course of the pressure-flow studies, the renal pelvic pressure at which contrast material was first seen to appear distal to the suspected site of obstruction was recorded as the ureteral opening pressure. Ureteral opening pressures were compared to the results of the pressure-flow studies.

RESULTS

With a positive test defined as renal pelvic pressure greater than 14 cm. water, positive ureteral opening pressures were associated with positive pressure-flow study results in 100% of the cases, regardless of which form of pressure-flow study was used or where the suspected site of obstruction was located. In contrast, negative ureteral opening pressures had specificities and negative predictive values of only 19 to 57%, depending on the form of the pressure-flow study and the suspected site of obstruction.

CONCLUSIONS

An elevated ureteral opening pressure was 100% predictive of obstruction and may obviate the need for more elaborate pressure-flow analyses. However, if the ureteral pelvic pressure remained low, the possibility of a potentially significant obstruction could not be definitively eliminated and further evaluation was required.

Sexuality and reproductive issues in children with myelomeningocele

Recent advancements in surgical and medical therapies have improved the life expectancy of children with myelomeningocele. Yet, there has been a contrasting lack of improvement with regards to sexual function and reproductive issues that continue to infantilize this population. This article identifies five major risk factors that contribute to these delays which invariably lead to irreversible emotional trauma if they are not addressed early in childhood. Adequate psychosexual education of myelomeningocele patients and their families is a tremendous societal challenge. But, only with education will there be trends away from policies of isolation to those that reinforce community integration of the physically disabled.

Bilateral single ureteral ectopia: difficulty attaining continence using standard bladder neck repair

PURPOSE

We reviewed the surgical results of the management of bilateral single ureteral ectopia, a rare congenital cause of severe urinary incontinence.

MATERIALS AND METHODS

We reviewed the records of 6 girls and 1 male infant who presented to 1 institution with this diagnosis in a 10-year period.

RESULTS

All patients were incontinent and 3 had undergone ureteral reimplantation as an initial procedure with persistent postoperative wetting. Of the 5 patients who underwent a total of 8 attempts at increasing bladder outlet resistance, including 3 Young-Dees-Leadbetter, 2 Kropp, 1 Stamey, 1 Burch and 1 pubovaginal sling procedure, 2 also underwent simultaneous bladder augmentation to increase bladder capacity. However, none of these children had satisfactory continence after the continence procedure. Three of these patients who subsequently underwent appendicovesicostomy with bladder neck closure are continent. The 2 remaining patients underwent initial appendicovesicostomy with bladder neck closure and augmentation, and they are also continent.

CONCLUSIONS

In our series total day and nighttime continence was only achieved by bladder neck closure, appendicovesicostomy and augmentation. Attempts at increasing bladder outlet resistance in patients with bilateral single ectopic ureters led to suboptimal rates of success even when adequate bladder capacity had been ensured by simultaneous augmentation.

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.