The sensitivity of pressure specific bladder volume versus total bladder capacity as a measure of bladder storage dysfunction

Why are pediatric urologists unable to predict renal deterioration using urodynamics? A focused narrative review of the shortcomings of the literature

In this focused narrative review we set out to review the current literature addressing the utilization of UDS in patients with spina bifida (SB). We specifically analyzed 6 urodynamic parameters and their roles as predictors of upper tract deterioration in pediatric SB patients. The material available did not allow a systematic analysis or the usage of metanalysis methodology, due to the predominance of small retrospective cohorts, and high heterogeneity. We identified 10 retrospective chart reviews that met our study criteria. The results of each of these papers, as well as other studies deemed relevant to the discussion, are included in our narrative review of the literature. We summarize the current literature, offer explanations for divergences in opinion, and identify future research directions and emerging solutions with a focus on machine learning.

Translating pediatric urodynamics from clinic into collaborative research: Lessons and recommendations from the UMPIRE study group

Pediatric patients present unique challenges in the performance and interpretation of urodynamic studies. Interpretation of urodynamics to guide clinical management at an institutional level is accepted as reliable. Challenges arise however when multi-site collaborations incorporate urodynamics into study design to determine primary or secondary outcomes or to direct decision-making. Although standardized terminology has been established by ICCS, the application of this shared language to performance and interpretation of pediatric urodynamics to across multiple sites may not be intuitive or reliable. With a primary goal of defining the care necessary to protect future renal function, the UMPIRE protocol (Urologic Management to Preserve Initial REnal function) utilizes a urodynamics-based risk stratification to determine medical management for infants with myelomeningocele. Iterative changes in the protocol are based upon the clinical progress of the enrolled children. Despite a team experienced in subtleties of urodynamics and despite efforts to minimize variability across sites, the UMPIRE study group identified several areas in which the language of urodynamics required additional clarification or creation of more explicit definitions to standardize performance and interpretation across sites. This article reviews the foundations of current urodynamics practice, describes limitations and challenges unique to pediatric studies, and the shares the humble lessons learned by the UMPIRE study group on their journey toward standardized urodynamic language for management of infants and children with myelomeningocele.

Predictors of upper tract damage in pediatric neurogenic bladder

INTRODUCTION

Upper tract damage (UTD) is a life-threatening complication of neurogenic bladder (NB). Early identification of risk factors for UTD and institution of remedial measures may probably prevent UTD. The aim was to study the predictors of UTD in children 2 years or older with NB.

METHOD

This cross-sectional, observational study over 2 years included 30 children. UTD was defined as serum creatinine of >1 mg/dL or society of fetal urology grade III-IV hydronephrosis or hydroureteronephrosis on ultrasonography or renal scars on ^99mtechnetium dimercaptosuccinic scan or subnormal glomerular filtration rate (GFR) for age. The evaluated clinical variables were age at presentation, gender, palpable bladder lump, and recurrent urinary tract infection (UTI). Bladder wall thickness (BWT), grade and laterality of vesicoureteric reflux (VUR), status of the bladder neck, post-void residue (PVR), and level and type of intraspinal lesions were also noted. Urodynamic studies were performed for functional bladder assessment. A p-value <0.05 identified the risk factors.

RESULTS

UTD was detected in 15 (50%) with serum creatinine >1 mg% (2, 6%), SFU III-IV (11, 36%), renal scars (12, 40%), and subnormal GFR in (2, 6%) patients. Clinical risk factors for UTD were delayed presentation (p = 0.034), palpable bladder lump (p ≤ 0.001; OR 38.5; CI 5.6-262.5), and recurrent UTI (p = 0.033, OR 4.125, CI 0.913-18.630). The presence of significant PVR, trabeculated bladder, spin-top urethra, and bilateral VUR were identified as radiological risk factors for UTD. Mean BWT in patients with and without UTD was 4.69 ± 1.78 mm and 2.91 ± 1.08 mm respectively. BWT predictive of UTD was 3.05 mm (Figure). The mean detrusor leak point pressure (DLPP) did not vary significantly in those with and without UTD (36.82 ± 14.74 and 29.09 ± 10.44 cmH₂O, respectively), yet 75% patients with DLPP > 40 cmH₂O had UTD (p = 0.038, OR 5.4, CI 0.84-34.84). DLPP <40 cmH₂O was associated with UTD in 35% patients.

DISCUSSION

The incidence of UTD in this series is in accordance with that reported with expectant management (40%) and is much higher than the 17% stated with proactive management. A limitation of this study is the small number of patients and heterogeneous clinical diagnosis.

CONCLUSION

Delayed presentation with palpable bladder lump, recurrent UTI, increased BWT, bilateral VUR, increased PVR, and DLPP > 40 cm H₂O were identified as potential risk factors for UTD. This study highlights the significance of BWT as a predictor of UTD in NB.

Initial urological evaluation and management of children with neurogenic bladder due to myelomeningocele

INTRODUCTION

The proactive management of children with myelomeningocele (MMC) has contributed to decreasing their progression to end-stage renal disease, thanks to early urological evaluation and timing implementation of treatments.

OBJECTIVE

To demonstrate that early urological evaluation of the urinary tract in MMC shows functional alterations in most cases, and that it requires medical intervention, even when in some cases the complementary imaging studies do not show any abnormalities.

MATERIAL AND METHODS

A retrospective study including 60 patients aged <1 year with MMC who were followed by a multidisciplinary team. All of them underwent renal/bladder ultrasound, videourodynamic studies, renal scintigraphy/dimercaptosuccinic acid (DMSA), and laboratory tests for kidney function. The studied variables were: bladder capacity and pressure, presence of overactivity, vesicoureteral reflux (VUR), urinary dilations and abnormalities on renal scintigraphy/DMSA. All the patients received clean intermittent catheterization (CIC).

RESULTS

See Summary Table all the patients showed alterations in at least some of the assessed urodynamic variables: reduced cystometric capacity, 21.6%; detrusor overactivity, 55%; end filling detrusor pressure >20 cm H₂O, 43.3%; inefficient bladder voiding, 98.3%; indirect dyssynergic patterns, 28.8%. The high-risk videourodynamic findings were observed in 28 cases (46.6%). DMSA was abnormal in 30%. Renal impairment was detected in 6.6% of cases. A total of 66% of cases received oxybutynin.

DISCUSSION

Almost all the children in this sample population showed urinary dysfunction, and approximately half of them had high-risk videourodynamic findings. Although many cases showed reflex urinary contractions, almost the entire sample had inefficient bladder voiding. An important limitation of this work was the lack of simultaneity in obtaining each of the requested studies.

CONCLUSIONS

In the initial urological evaluation of patients with myelomeningocele, almost all the urodynamic studies showed abnormalities and one-third showed abnormal DMSA, which led to therapeutic actions being initiated, although imaging studies were normal in a great number of patients. CIC alone, starting immediately after birth, is not sufficient. To eliminate or decrease upper tract damage, oxybutynin should be started in addition.

Outcomes of living donor renal transplantation in children with lower urinary tract dysfunction: a comparative retrospective study

OBJECTIVES

To compare outcomes of renal transplantation (RTx) in children with end-stage renal disease (ESRD) resulting from lower urinary tract dysfunction (LUTD) vs other causes.

PATIENTS AND METHODS

A database of children (<18 years old) who underwent RTx between May 2008 and April 2012 was reviewed. Patients were divided into those with LUTD (group A, n = 29) and those with other causes of ESRD (group B, n = 74). RTx was performed after achieving low intravesical pressure (<30 cmH2 O) with adequate bladder capacity and drainage. The groups were compared using Student's t-test, Mann-Whitney, chi-squared or exact tests. Graft survival rates (GSRs) were evaluated using Kaplan-Meier curves and the log-rank test.

RESULTS

The mean ± sd (range) age of the study cohort was 5.05 ± 12.4 (2.2-18) years. Causes of LUTD were posterior urethral valve (PUV; 41.4%), vesico-ureteric reflux (VUR; 37.9%), neurogenic bladder (10.3%), prune belly syndrome (3.4%), obstructive megaureter (3.4%) and urethral stricture disease (3.4%). There was no significant difference in age, dialysis duration or donor type. In group A, 25 of the 29 patients (86.2%) underwent ≥1 surgery to optimize the urinary tract for allograft. Pretransplant nephrectomy was performed in 15 of the 29 patients (51.7%), PUV ablation in nine patients (31%) and ileocystoplasty in four patients (13.7%). The mean ± sd follow-up was 4.52 ± 1.55 and 4.07 ± 1.27 years in groups A and B, respectively. There was no significant difference in creatinine and eGFR between the groups at different points of follow-up. The GSRs at the end of the study were 93.1 and 91.1% in groups A and B, respectively (P = 1.00). According to Kaplan-Meier survival curves, there was no significant difference in the GSR between the groups using the log-rank test (P = 0.503). No graft was lost as a result of urological complications. In group B, one child died from septicaemia. The rate of urinary tract infections was 24 and 12% in groups A and B, respectively, but was not significant. No significant difference was found between the groups with regard to the incidence of post-transplantation hydronephrosis. Of the 22 patients who had hydronephrosis after transplantation, three were complicated by UTI. Injection of bulking agents was required in two patients for treatment of grade 3 VUR. In the third patient, augmentation cystoplasty was needed.

CONCLUSION

Acceptable graft function, survival and UTI rates can be achieved in children with ESRD attributable to LUTD. Thorough assessment and optimization of LUT, together with close follow-up, are key for successful RTx.

Alternatives to conventional enterocystoplasty in children: a critical review of urodynamic outcomes

Alternatives to conventional enterocystoplasty have been developed in order to avoid the most common complications derived from contact of the urine with intestinal mucosa. In this article critically we review the literature on the topics: ureterocystoplasty, detrusorectomy, detrusorotomy, seromuscular gastroenterocystoplasty, use of off the shelf biomaterials, and bladder augmentation by bioengineering. Recognizing the difficulty of deciding when a child with a history of posterior urethral valves requires and augmentation and that the development of a large megaureter in cases of neurogenic dysfunction represents a failure of initial treatment, we conclude that ureterocystoplasty can be useful in selected cases when a large dilated ureter is available. Seromuscular colocystoplasty lined with urothelium (SCLU) has been urodynamically effective in several series when the outlet resistance is high and no additional intravesical procedures are necessary. Seromuscular gastrocystoplasty lined with urothelium seems to offer no distinct advantages and involves a much more involved operation. The use of seromuscular segments without urothelial preservation, with or without the use of an intravesical balloon has been reported as successful in two centers but strict urodynamic evidence of its effectiveness is lacking. The published evidence argues strongly against the use of detrusorectomy or detrusorotomy alone because of the lack of significant urodynamic benefits. Two recent reports discourage the use of small intestinal submucosa patches because of a high failure rate. Finally, research into the development of a bioengineered bladder constructed with cell harvested from the same patient continues but is fraught with technical and conceptual problems. In conclusion of the methods reviewed, only ureterocystoplasty and SCLU have been proven urodynamically effective and reproducible.

Strategies to treat children with end-stage renal dysfunction and severe lower urinary tract anomalies for receiving a kidney transplant

Dealing with children with bladder dysfunction and kidney transplant is certainly not a new issue. Nevertheless, it is still a matter of discussion and dilemma, based on few, not standardized, institutional center experiences. The authors perform a review of the techniques employed to restore the bladder condition in terms of storage and drainage of urine to receive a kidney transplant in a safer condition. Aspects of the etiology and the way of evaluation of such a group of patients are discussed. The strategies and individualized therapeutic options are presented and compared with the author's experience based upon 25 children with urinary anomalies who received 28 kidney transplants. Nevertheless, the number of complications, mainly UTI, graft and patient survival rates are equivalent to the group of children with non-urological causes of ESRD. Patients with severe lower urinary tract abnormalities and ESRD may receive a kidney transplant with comparable success.

Bladder augmentation and artificial sphincter implantation: urodynamic behavior and effects on continence

OBJECTIVE

To quantify changes in bladder capacity, pressure and compliance after isolated bladder augmentation or augmentation associated with implantation of an artificial sphincter, and to compare the various types of augmentation.

PATIENTS AND METHODS

Preoperative and postoperative urodynamic studies were performed in a group of 38 patients (18 males and 20 females; age range 2-19 years), who underwent a type of bladder augmentation.

RESULTS

The bladder improved in capacity in all patients (mean values: initial 137 ml, final 336 ml, individual increase 229 ml; 434%) except two, in which the augmentation was done with ureter. The mean pressure improved (initial 32 cm of H(2)O, final 14, decrease per patient 18 cm of H2O; 49%). The curve of compliance, progressively increasing typical of hyperreflexia and poor compliance, present in 70% of the cases preoperatively, improved in 78% cases postoperatively, although there were several different patterns. Urodynamic behavior was analyzed with regard to the tissue used for augmentation (ileum, ureter or sigmoid colon). In the sigmoid colon group, there were no significant differences in the urodynamic behavior of the bladder neo-reservoir in relation to the configuration used.

CONCLUSION

With bladder augmentation comes an increase in bladder capacity, a reduction in pressure, and an improvement in compliance and continence. The level of change in capacity, pressure and compliance varies with the tissue used and the length and caliber of the insert. When the procedure is carried out using sigmoid colon tissue, there are no noteworthy differences among the various possible configurations.

Urologischer Erkrankungen bei Patienten mit Meningomyelozele

Since the 1980s the management of children and adolescents with meningomyelocele has undergone major changes. The introduction of pharmacotherapy with antimuscarinic agents, clean intermittent catheterization (CIC) and antibacterial prophylaxis has revolutionized the management of children with neurogenic bladder. The co-operation between neonatologists, neurosurgeons, paediatric neurologists, paediatricians, paediatric urologists, paediatric nephrologists, paediatric orthopaedists and paediatric surgeons is necessary to achieve an optimized therapy in each individual patient. In this interdisciplinary consensus paper we provide definitions and classifications as well as a timetable for the appropriate investigations. The conservative and surgical options are explained in detail. A short review is given concerning orthopaedic management, incidence of latex allergy, options for bowel management, diagnosis and treatment of urinary tract infections, problems with sexuality and fertility as well as the long-term compliance of these patients and their relatives.

Upper and lower urinary tract evaluation of 104 patients with myelomeningocele without adequate urological management

To evaluate the upper and lower urinary tract and revise the urodynamic parameters on myelomeningocele patients without adequate urological management. 104 myelomeningocele patients without previous adequate urological management were assessed by clinical, urodynamic and imaging evaluation. The urodynamic.data were correlated with the status of the upper urinary tract (UUT). Thirty patients presented with vesico-ureteral reflux. Six patients presented signs of UUT damage without reflux. The cystometry showed detrusor overactivity (DO), poor compliance, increased bladder capacity and normal cystometry in 48, 49, 2 and 1% of the patients, respectively. Detrusor leak point pressure (DLPP) over 40 cm H(2)O was associated with UUT damage. Patients with decrease on functional bladder capacity (FBC) <or= 33% had more renal scars than their counterparts (P = 0.01). Overall, urological untreated myelomeningocele patients have 26% of kidney damage. DLPP >or= 40 cm H(2)O and decrease in FBC <or= 33% are associated with greater UUT damage. DO and poor compliance are predominant and pose similar risk of UUT damage.

Dysfunction of the lower urinary and distal gastrointestinal tracts in pediatric patients with known spinal cord problems

Destruction of the urinary tract in children with elimination, storage, and holding dysfunction of the lower urinary and the distal GI tracts is caused primarily by high intravesical pressure. UTI accelerates this process. The LPP and the status of the urethral control mechanism and its relationship to the detrusor are the primary determinants of intravesical pressure. Intravesical pressures of more than 40 cm H2O are dangerous because they cause a pressure gradient that is transmitted proximally to the renal papillae, which results in the cessation of renal blood flow and a loss of renal function over time. Hydroureteronephrosis, VUR, UTI, urinary incontinence, and calculi formation also may occur. If these dangerously high intravesical pressures remain untreated, renal failure is likely to occur over time. These children then require dialysis or renal transplantation to survive, which is tragic and represents an enormous economic cost to society. Renal failure and upper urinary tract damage is nearly 100% preventable with early and appropriate evaluation and treatment. CIC is a crucial part of the management of these children and has been shown to be safe and effective, even in newborn boys. The use of the Credé maneuver (i.e., manual compression) to empty the bladder is obsolete and should be abandoned. The distal GI tract is inseparable from the lower urinary tract and must be treated simultaneously. Failure to treat the distal GI tract yields poor clinical results and much patient dissatisfaction and makes it difficult or impossible to treat the child's urinary tract problem successfully. Bowel-management programs must include daily high water and fiber intake, together with digital perianal stimulation or fecal extraction. Neuropathic bladder and bowel problems that are intractable to conservative medical and mechanical (i.e., CIC and digital perianal stimulation or fecal extraction, respectively) management almost always can be corrected surgically with high success rates in cooperative patients. Finally, neuropathic bladder and bowel problems can be extremely isolating and debilitating problems. Psychologic counseling and emotional support must be provided as needed. The care that these patients receive must be organized, comprehensive, and correlated with these patients' lifestyles. If these children are evaluated and treated early, they have the potential to live long, healthy, and productive lives.

Prototype system for enhancing cystometric analysis with special emphasis on the pediatric population

BACKGROUND AND PURPOSE

A urodynamic test system of improved accuracy and reliability was developed and implemented for enhancing cystometry. This system integrates known medical information, including the specialized problems of pediatric urodynamics, with the cystometric and imaging data.

METHODS

After the requirements for the ideal cystometrogram test unit were established, a system was constructed, calibrated, and implemented in clinical practice. The patient's age, size, and sex are used to produce a patient-specific pressure-volume template for the cystometrogram test.

RESULTS

This template showed the minimal and normal bladder capacities and the physiologically safe, equivocal, and dangerous pressure fields coded with symbolic colors. Different time averages of the pressure data were used to show bladder factors such as compliance and instability. The templates with data were presented automatically (therefore objectively) without operator intervention on monitors during testing and as printed copies on completion.

CONCLUSIONS

The presentation of data in an easily understood format facilitates effective communication between the urologist, referring physician, and patient. Some of the physiological and statistical problems in pediatric urodynamic testing are efficiently and accurately resolved by this system, resulting in better analysis and diagnostic capabilities.

Bladder function before and after selective dorsal rhizotomy in children with cerebral palsy

PURPOSE

Approximately a third of children with cerebral palsy are expected to present with dysfunctional voiding symptoms. Selective dorsal rhizotomy, which is indicated for managing lower extremity spasticity in children with cerebral palsy, also has the potential of affecting bladder function. We evaluate the impact of selective dorsal rhizotomy on bladder function by comparing preoperative and postoperative symptoms, and urodynamic parameters in children undergoing selective dorsal rhizotomy for spasticity.

MATERIALS AND METHODS

We reviewed urodynamic studies in 25 boys and 15 girls with a mean age plus or minus standard deviation of 5.43+/-2.1 years who underwent selective dorsal rhizotomy for spasticity at our institution between January 1992 and September 1995. Urodynamics were performed preoperatively only in 22 patients, preoperative and postoperatively in 13, and postoperatively only in 5. Preoperative urodynamic studies were done within 2 weeks of surgery and postoperative studies were done at least 6 months after surgery (mean 1.32+/-0.65 years).

RESULTS

Of the 35 patients with preoperative urodynamic studies total bladder capacity, pressure specific volumes and full resting pressure were abnormal for age in 23 (65.7%). In addition, 17 of the 23 children (74%) were completely asymptomatic. In the group that underwent preoperative and postoperative urodynamic studies there was significant improvement in total bladder capacity (p <0.005) and pressure specific volumes (p <0.005) using the paired Student t test. All children had neurological improvement postoperatively, 5 of 7 (71%) who were incontinent preoperatively became continent and none had deterioration on urodynamics.

CONCLUSIONS

At least half of the children with spastic cerebral palsy have clinically silent bladder dysfunction. Selective dorsal rhizotomy improves spasticity and significantly improves bladder storage characteristics. We propose that urodynamic studies be included in the evaluation of children with spastic cerebral palsy who are possible candidates for selective dorsal rhizotomy to treat lower limb spasticity.

Neurogenic bladder

Management of neurogenic bladder in children is challenging for the practising clinician. This involves consideration of multiple and diverse factors which must be balanced in an ever changing environment. Also the dynamics of a child's growth must always be considered because it contributes to the ongoing instability of the neurologic lesion. Prevention and proactive approaches have become the mainstay of the therapy. It is not appropriate to wait for problems to occur before treating these children, because changes that take place may not be reversible, even if they are detected early. The clinician should be aware of the various clinical presentations of neurogenic bladder dysfunction in children and familiarize themselves with the modes of treatment available. Long term follow-up is mandatory. Finally, the value of streamlining these children into society at an early age must always be considered.

Impact of urodynamic studies on the surgical management of spinal cord tethering

To determine the usefulness of urodynamic studies in the management of children with a suspected tethered spinal cord, the authors retrospectively reviewed case records of 25 patients evaluated both pre- and postoperatively using this diagnostic adjunct. All patients were also evaluated with magnetic resonance imaging or computerized tomography myelography. Seven patients who presented initially with orthopedic deformity, skin stigmata, and neurological problems underwent primary cord untethering (Group 1). All seven patients were urologically asymptomatic; all but one had normal findings on urodynamic study. Eighteen patients with prior myelomeningocele closure underwent secondary untethering (Group 2). They presented with urological (11 cases), neurological (three cases), or both urological and neurological (four cases) deterioration. All patients underwent surgery via a microsurgical technique. At a mean follow-up time of 2 years, the only Group 1 patient with preoperative abnormal urodynamic findings normalized following untethering, whereas another asymptomatic patient showed worsened results on his postoperative study. In Group 2, all seven patients with preoperative neurological deterioration improved. Ten of the 15 patients who had isolated or associated preoperative clinical urological deterioration improved or stabilized, whereas five displayed continued deterioration in their bladder function. With respect to urodynamic studies, there was a significant increase in total and pressure-specific bladder capacities following untethering. We conclude that urodynamic studies are useful both diagnostically and in follow-up examinations of patients with tethered cord, that disturbances identified by these studies often precede clinical manifestations of deterioration, and that spinal cord untethering favorably influences the urological status in most patients.

Pediatric neurourology

Children with voiding disturbances or neurologic dysfunction of the lower urinary tract present challenges to the practicing clinician. With careful clinical and radiologic evaluation, many of these disturbances can be managed. Complex situations, however, generally require expert urodynamic evaluation to delineate the cause of the bladder dysfunction and to guide management. These investigations combined with long-term follow up should provide new insights for further improvement in the management of neurogenic bladders in children. Urodynamic studies also have given us insights into the pathophysiology of abnormal voiding states secondary to dysfunctional bladders in children with posterior urethral valves, the prune belly syndrome, and the Hinman syndrome.

Ten-year experience with the artificial urinary sphincter in children

PURPOSE

To assess the efficacy of the artificial urinary sphincter survival and continence were first evaluated 5 years ago. We now evaluated the effects of the artificial urinary sphincter more than a decade after implantation.

MATERIALS AND METHODS

Before 1985 an artificial urinary sphincter was implanted in 22 male and 14 female consecutive patients 4 to 30 years old (median age 12). In addition, between 1985 and 1990, 18 other children underwent artificial urinary sphincter implantation. Results of both series were compared.

RESULTS

Of the 25 sphincters in the original series that were functioning after 5 years 1 was removed and 2 patients were lost to followup, resulting in 22 functioning implants (61% of the patients). Mean survival time of the prostheses was 12.1 years and average followup for functioning sphincters was 13.7 years. There was no statistically significant difference in artificial urinary sphincter survival between the original group at 5 years and the second group treated after 1985. Of the patients in both groups with sphincters in place 32 of 39 (82%) were dry. Augmentation cystoplasty was performed in 9 of 18 patients (50%) in the second series (5 preoperatively and 4 postoperatively) compared to 10 of 36 (28%) in the original series at 5 years (3 preoperatively and 7 postoperatively). Renal failure developed in 6 patients from both series.

CONCLUSIONS

The artificial urinary sphincter is a durable long-term solution for children with intractable incontinence. Long-term surveillance of the urinary tract is mandatory because of the potential for renal failure in patients who have bladder hypertonicity after placement of the device.

Cystometry

Cystometry provides crucial information on which therapy for voiding dysfunction is predicated. The technique of cystometry can be altered to address specific clinical questions; however, the goal of the study is to reproduce the clinical situation being investigated. Specific areas remain to be clarified, including the estimation and interpretation of compliance and the utility of standard versus natural filling methods.

A comparison of the W-stapled ileal reservoir with hand-sewn reservoirs for orthotopic bladder replacement

OBJECTIVES

Confidence has increased in the use of an orthotopic reservoir to the urethra after a cystoprostatectomy for bladder cancer; however, many surgeons would welcome a method to simplify the operative procedure. The availability of absorbable staples on a GIA stapler allows study of the incorporation of stapling procedures into formation of a reservoir. Because of the success of hand-sewn W-configured ileal reservoirs, we initiated a Phase II study to evaluate absorbable staples in formation of a W-configured reservoir. We now present an expanded contemporary series comparing a W-stapled ileal neobladder with hand-sewn ileal (Studer) or hand-sewn ileocolic (Le Bag) reservoirs.

METHODS

Forty-five selected patients underwent orthotopic urinary diversion after cystoprostatectomy for bladder cancer (n = 42) or prostate cancer (n = 3) using one of the three methods of reservoir construction. There were 43 men and 2 women. The evaluation included a urodynamic evaluation and a questionnaire sent to patients inquiring about urinary function.

RESULTS

Most patients did well with the W-stapled ileal reservoir but 6 of 19 evaluable patients had unsatisfactory reservoir characteristics. Three patients needed an augmentation cystoplasty and 3 had higher pressure, smaller volume reservoirs. Reservoir function appeared to be consistently more favorable in patients with either of the hand-sewn reservoirs using an ileal or ileocolic segment.

CONCLUSIONS

Although the W-stapled ileal reservoir is safe and allows reservoir formation quickly, the inconsistencies of the results discourage its use in the particular configuration described. Failure of the reservoir to distend could be a function of reservoir design, areas of ischemia in the reservoir, or reaction to staple material. Absorbable staples on the GIA instrument may work satisfactorily for formation of an ileocolic reservoir for continent cutaneous diversion. However, the W-configured orthotopic reservoir as constructed using absorbable staples in this study is inferior to a hand-sewn ileal or ileocolic neobladder.

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.

Loss of elasticity in dysfunctional bladders: urodynamic and histochemical correlation

To store adequate volumes of urine at low safe pressures an elastic bladder wall is required. We developed 2 new techniques to measure this ability in our urodynamic laboratory: pressure specific bladder volume, which measures the bladder capacity at a given pressure, and dynamic analysis of bladder compliance. Recently, morphometric and histochemical techniques have been used to determine the relative volume of connective tissue in the bladder wall and to measure the 2 major types (I and III) of collagen within the bladder wall. These methods quantitate 3 parameters of bladder ultrastructure: 1) relative volume of per cent connective tissue, 2) ratio of connective tissue to smooth muscle and 3) ratio of type III to type I collagen. These parameters have been shown to be abnormally elevated in patients with dysfunctional bladders compared to normals. The purpose of the study was to describe the ultrastructural changes that occur in the wall of dysfunctional bladders and to determine the ability of these new urodynamic techniques to detect reliably the clinical effect of these histological changes. The study included 29 consecutive patients with dysfunctional bladders necessitating bladder augmentation. All patients had upper tract changes and/or were incontinent despite treatment with clean intermittent catheterization and pharmacotherapy. Preoperative urodynamic evaluation included measurement of the total bladder capacity, pressure specific bladder volume and dynamic analysis of bladder compliance. Full thickness bladder biopsies were obtained from the dome of the bladders during augmentation. The per cent connective tissue and the ratio of connective tissue to smooth muscle were determined for all patients, and 4 unselected patients from this group had the ratio of type III to type I collagen determined. These histological results were compared to previously established normal values. All 29 patients had a decreased pressure specific bladder volume and dynamic analysis of bladder compliance, whereas 9 had a normal total bladder capacity. The per cent connective tissue was 35.19 +/- 2.84 and ratio of connective tissue to smooth muscle was 0.60 +/- 0.08 compared to normal values of 10.6 +/- 0.020 and 0.131 +/- 0.021, respectively (p < 0.05). Ratio of type III to type I collagen was also significantly elevated in the 4 samples analyzed (30.53 +/- 1.37 versus 24.00 +/- 2.50, p < 0.05). We conclude that poor storage function of poorly compliant bladders is secondary to an alteration in the connective tissue content of the bladder wall. Furthermore, these pathological ultrastructural changes are universally reflected by an abnormally low pressure specific bladder volume and dynamic analysis of bladder compliance. This strong association validates the use of these parameters and suggests that they are urodynamic indicators of a loss of elasticity in bladder wall.