Inter-disciplinary provider development of an online, interactive adolescent varicocele decision aid prototype

BACKGROUND

Decision-making regarding varicocele management can be a complex process for patients and families. However, to date, no studies have presented ways to mitigate the decisional conflict surrounding varicoceles.

OBJECTIVE

To facilitate a discussion among physicians in order to develop a framework of the decision-making process regarding adolescent varicocele management, which will inform the development of the first online, interactive decision aid.

MATERIALS AND METHODS

Semi-structured interviews with pediatric urologists and interventional radiologists were conducted to discuss their rationale for varicocele decision-making. Interviews were audio recorded, transcribed, and coded. Key themes were identified, grouped, and then qualitatively analyzed using thematic analysis. Utilizing the common themes identified and the Ottawa Decision Support Framework, a decision aid prototype was developed and transformed into a user-friendly website: varicoceledecisionaid.com.

RESULTS

Pediatric urologists (n = 10) and interventional radiologists (n = 2) were interviewed. Key themes identified included: (1) definition/epidemiology; (2) observation as an appropriate management choice; (3) reasons to recommend repair; (4) types of repair; (5) reasons to recommend one repair over another; (6) shared decision-making; and (7) appropriate counseling. With this insight, a varicocele decision aid prototype was developed that engages patients and parents in the decision-making process.

DISCUSSION AND CONCLUSIONS

This is the first interactive and easily accessible varicocele decision aid prototype developed by inter-disciplinary physicians for patients. This tool aids in decision-making surrounding varicocele surgery. It can be used before or after consultation to help families understand more about varicoceles and their repair, and why intervention may or may not be offered. It also considers a patient and family's personal values. Future studies will incorporate the patient and family perspective into the decision-making aid as well as implement and test the usability of this decision aid prototype in practice and in the wider urologic community.

Internal hernia with volvulus after major abdominal reconstructions in pediatric urology - An infrequently reported and potentially devastating complication

INTRODUCTION

Enterocystoplasty (EC), appendico- or ileovesicostomy (APV), and appendicocecostomy (APC) can facilitate continence and prevent renal damage for patients with congenital urologic or bowel disease. Bowel obstruction is a well-documented complication of these procedures, and the etiology of obstruction is variable. The aim of this study is to determine the incidence and describe the presentation, surgical findings, and outcomes of bowel obstruction from internal herniation due to these reconstructions.

METHODS

In this single institution retrospective cohort study patients who underwent EC, APV, and/or an APC between 1/2011 and 4/2022 were identified via CPT codes within the institutional billing database. Records for any subsequent exploratory laparotomy during this same timeframe were reviewed. The primary outcome was an internal hernia of bowel into the potential space between the reconstruction and the posterior or anterior abdominal wall.

RESULTS

Two hundred fifty seven index procedures were performed in 139 patients. These patients were followed for a median of 60 months (IQR 35-104 months). Nineteen patients underwent a subsequent exploratory laparotomy. The primary outcome occurred in 4 patients (including one patient who received their index procedure elsewhere) for a complication rate of 1% (3/257). The complications occurred between 19 months and 9 years after their index procedure (median 5 years). Patients presented with bowel obstruction; two patients also had sudden pain following an ACE flush. One complication was caused by small bowel and cecum passing around the APC and subsequently volvulizing. A second was caused by bowel herniating behind the EC's mesentery and the posterior abdominal wall. A third was caused by bowel herniating behind the APV mesentery and subsequently volvulizing. The exact etiology of fourth internal herniation is unknown. Of the three surviving patients, all required resection of ischemic bowel and 2 required resection of the involved reconstruction. One patient died intraoperatively from cardiac arrest. Only 1 patient required a subsequent procedure to regain lost function.

CONCLUSION

Internal herniation caused by small or large bowel passing through a defect between the mesentery and abdominal wall or twisting around a channel occurred in 1% of 257 reconstructions performed over 11 years. This complication can arise many years after abdominal reconstruction, resulting in bowel resection and possibly takedown of the reconstruction. When anatomically possible and technically feasible, the surgeon should close any potential spaces created during the initial abdominal reconstruction.

National Trends and Outcomes in the Use of Intravesical Botulinum Toxin and Enterocystoplasty Among Patients With Myelomeningocele

OBJECTIVE

To compare trends in the treatment of patients with myelomeningocele receiving intravesical Botulinum (IVB) toxin and enterocystoplasty.

METHODS

We identified patients with myelomeningocele in a commercial insurance database from 2008-2017 and stratified them into adult and pediatric samples. Index procedure was identified as either IVB toxin injection or enterocystoplasty. The annual rate of treatments was measured and a change in treatment rate was identified. Time to enterocysplasty was calculated using survival analysis and factors associated with clinical outcomes up to 10 years after index procedure were determined using multivariate Poisson regression.

RESULTS

We identified 60,983 patients with myelomeningocele. Nearly twice as many pediatric patients had an enterocystoplasty (n = 317) compared to IVB (n = 138). Very few adult patients underwent enterocystoplasty (n = 25) compared to IVB (n = 116). We identified a significant increase in the annual rate of IVB use around mid-2010 among pediatric patients and around mid-2009 among adults. Twelve pediatric patients (8.6%) and 5 adults (4.3%) went on to receive an enterocystoplasty. Patients who received IVB as the index procedure experienced significantly lower rates of hospitalization days (RR 0.64; 95% CI 0.53-0.78), emergency department visits (RR 0.72; 95% CI 0.63-0.82), and an increased rate of urologic procedures (RR 1.44; 95% CI 1.28-1.62).

CONCLUSION

The annual rate of IVB use has increased among patients with myelomeningocele. Nearly 1 in 10 pediatric patients and 1 in 20 adults go on to receive enterocystoplasty. Patients who receive IVB experience lower rates of hospitalization and emergency department visits compared to patients who receive enterocystoplasty.

Urodynamic characteristics of neurogenic bladder in newborns with myelomeningocele and refinement of the definition of bladder hostility: Findings from the UMPIRE multi-center study

INTRODUCTION

Infants with myelomeningocele are at risk for chronic kidney disease caused by neurogenic bladder dysfunction. Urodynamic evaluation plays a key role to risk stratify individuals for renal deterioration.

OBJECTIVE

To present baseline urodynamic findings from the Urologic Management to Preserve Initial Renal function for young children with spina bifida (UMPIRE) protocol, to present the process that showed inadequacies of our original classification scheme, and to propose a refined definition of bladder hostility and categorization.

STUDY DESIGN

The UMPIRE protocol follows a cohort of newborns with myelomeningocele at nine children's hospitals in the United States. Infants are started on clean intermittent catheterization shortly after birth. If residual volumes are low and there is no or mild hydronephrosis, catheterization is discontinued. Baseline urodynamics are obtained at or before 3 months of age to determine further management. Based on protocol-specific definitions, urodynamic studies were reviewed by the clinical site in addition to a central review team; and if necessary, by all site urologists to achieve 100% concurrence.

RESULTS

We reviewed 157 newborn urodynamic studies performed between May 2015 and September 2017. Of these 157 infants, 54.8% were boys (86/157). Myelomeningocele closure was performed in-utero in 18.4% (29/157) and postnatally in 81.5% (128/157) of newborns. After primary review, reviewers agreed on overall bladder categorization in 50% (79/157) of studies. Concurrence ultimately reached 100% with further standardization of interpretation. We found that it was not possible to reliably differentiate a bladder contraction due to detrusor overactivity from a volitional voiding contraction in an infant. We revised our categorization system to group the "normal" and "safe" categories together as "low risk". Additionally, diagnosis of detrusor sphincter dyssynergia (DSD) with surface patch electrodes could not be supported by other elements of the urodynamics study. We excluded DSD from our revised high risk category. The final categorizations were high risk in 15% (23/157); intermediate risk in 61% (96/157); and low risk in 24% (38/157).

CONCLUSION

We found pitfalls with our original categorization for bladder hostility. Notably, DSD could not be reliably measured with surface patch of electrodes. The effect of this change on future renal outcomes remains to be defined.

Continence outcomes following a modification of the Mitchell bladder neck reconstruction in myelomeningocele: A single institution experience

BACKGROUND

Many surgical procedures have been developed to improve continence in myelomeningocele patients. Our modification of the Mitchell bladder neck reconstruction involves removal of a diamond-shaped wedge of the anterior bladder neck, tubularization of the bladder neck and urethra to increase outlet resistance, and addition of a bladder neck autologous fascial sling.

OBJECTIVE

We aimed to evaluate rates of continence and re-operation in children with myelomeningocele undergoing this Modified Mitchell bladder neck reconstruction.

STUDY DESIGN

We retrospectively identified children with myelomeningocele having undergone bladder neck reconstruction at our tertiary care referral center from 2012 to 2016.

RESULTS

We identified twelve patients with myelomeningocele undergoing this modified bladder neck reconstruction with sling, four female and eight male, median age at the time of surgery was 7 years old. After initial bladder neck reconstruction with sling only 33% were dry. All patients with bothersome leakage after reconstruction underwent bladder neck bulking. Two patients of twelve (17%) ultimately underwent bladder neck closure and achieved dryness. 58% of patients ultimately achieved continence (Summary Figure).

DISCUSSION

Our modification of the bladder neck reconstruction with autologous fascial sling showed midterm rates of incontinence near 60%, with initial post-operative continence at 33%. Our patients, however, required higher rates of reoperation (43%) than previous results would suggest (27%). The first line of re-treatment was bladder neck bulking, but this showed low success. While this procedure is minimally invasive and safe, reasonable expectations of efficacy should be established with families when offering this option. Two patients (17%) required bladder neck closure to achieve dryness. While bladder neck closure is often considered a procedure of last resort, both of these patients were immediately dry. Perhaps bladder neck closure should be considered earlier in our algorithm of surgical continence.

CONCLUSION

Our rates of continence with the Modified Mitchell bladder neck reconstruction with a fascial sling were similar to prior bladder neck reconstructions. We did find higher rates of reoperation, and further modifications are warranted to continue to improve continence after surgical procedures in the myelomeningocele population. Select cases may warrant early consideration of bladder neck closure.

Unilateral open extravesical ureteral reimplanation with contralateral dextronomer/hyaluronic acid injection performed as an outpatient therapy

INTRODUCTION

Historically, patients with unilateral high-grade vesicoureteral reflux (VUR) and contralateral low-grade or resolved VUR have been treated with bilateral intravesical ureteral reimplantation, which requires postoperative admission. If the high-grade VUR side is treated alone, then the contralateral side is at risk of developing recurrent or worsening VUR. Bilateral subureteric injection of dextronomer/hyaluronic acid (DHA) is another option that can be performed as an outpatient therapy, but a single injection is less effective for high-grade VUR.

OBJECTIVE

The safety and efficacy of an outpatient combination of open extravesical ureteral reimplantation (EVUR) and contralateral DHA injection were investigated.

STUDY DESIGN

A retrospective review of children who had concomitant EVUR and subureteric injection of DHA between January 2005 and December 2015 was performed. Exclusion criteria were diagnosis other than VUR, repeat procedures, and patients with no follow-up. Patient characteristics, postsurgical complications, and follow-up imaging were evaluated. Febrile urinary tract infection (fUTI) was defined as ≥50,000 Colony Forming Units (CFU) of an organism from clean-catch or catheterized urine and temperature ≥ 101.5 F. Clinical success is defined as no fUTI for 1 year after the initial operation. Univariate analyses were used to identify risk factors for treatment failure.

RESULTS

A total of 117 patients met inclusion criteria. Mean age at surgery was 6.0 years, and 85% were female. The mean pre-operative grade of VUR was 3.3 on the EVUR side and 0.6 on the contralateral side (42% resolved before treatment). Median follow-up was 12.2 months (interquartile range, 3.1-25.4). Sixteen patients (14%) had documented fUTI within 1 year, with a clinical success rate of 86%. Of these, five had a postoperative imaging showing resolution of VUR, increasing overall success to 91%. Postoperative fUTI was more common in patients with pre-operative bowel and bladder dysfunction (BBD) (P = 0.003), but this was not associated with a higher reoperation rate (P = 0.168). There were 11 total complications, with three grade 3 complications.

DISCUSSION

This study is the first to report safety and outcomes of EVUR and contralateral DHA injection for patients with high-grade VUR with contralateral low-grade or resolved VUR. It was shown that it is an effective and safe treatment that can be performed as an outpatient therapy. Limitations to this study include the retrospective design and the clinical definition of success that is used in a cohort of patients from across the mountain west region without routine postoperative voiding cystourethrogram.

CONCLUSION

Extravesical ureteral reimplantation and contralateral DHA injection can safely be performed as an outpatient therapy and are effective in the treatment of higher grade VUR with contralateral low-grade or resolved VUR. Treatment failure is more likely in patients with BBD.

Variation in surgical management of neurogenic bowel among centers participating in National Spina Bifida Patient Registry

PURPOSE

Optimal management of neurogenic bowel in patients with spina bifida (SB) remains controversial. Surgical interventions may be utilized to treat constipation and provide fecal continence, but their use may vary among SB treatment centers.

METHODS

We queried the National Spina Bifida Patient Registry (NSBPR) to identify patients who underwent surgical interventions for neurogenic bowel. We abstracted demographic characteristics, SB type, functional level, concurrent bladder surgery, mobility, and NSBPR clinics to determine whether any of these factors were associated with interventions for management of neurogenic bowel. Multivariable logistic regression with adjustment for selection bias was performed.

RESULTS

We identified 5,528 patients with SB enrolled in the 2009-14 NSBPR. Of these, 1,088 (19.7%) underwent procedures for neurogenic bowel, including 957 (17.3%) ACE/cecostomy tube and 155 (2.8%) ileostomy/colostomy patients. Procedures were more likely in patients who were older, white, non-ambulatory, with higher-level lesion, with myelomeningocele lesion, with private health insurance (all p< 0.001), and female (p= 0.006). On multivariable analysis, NSBPR clinic, older age (both p< 0.001), race (p= 0.002), mobility status (p= 0.011), higher lesion level (p< 0.001), private insurance (p= 0.002) and female sex (p= 0.015) were associated with increased odds of surgery.

CONCLUSIONS

There is significant variation in rates of procedures to manage neurogenic bowel among NSBPR clinics. In addition to SB-related factors such as mobility status and lesion type/level, non-SB-related factors such as patient age, sex, race and treating center are also associated with the likelihood of undergoing neurogenic bowel intervention.

Bladder Reconstruction Rates Differ among Centers Participating in National Spina Bifida Patient Registry

PURPOSE

We performed an exploratory analysis of data from the NSBPR (National Spina Bifida Patient Registry) to assess variation in the frequency of bladder reconstruction surgeries among NSBPR centers.

MATERIALS AND METHODS

We queried the 2009-2014 NSBPR to identify patients who had ever undergone bladder reconstruction surgeries. We evaluated demographic characteristics, spina bifida type, functional level, mobility and NSBPR center to determine whether any of these factors were associated with reconstructive surgery rates. Multivariable logistic regression was used to simultaneously adjust for the impact of these factors.

RESULTS

We identified 5,528 patients with spina bifida enrolled in the NSBPR. Of these patients 1,129 (20.4%) underwent bladder reconstruction (703 augmentation, 382 continent catheterizable channel, 189 bladder outlet procedure). Surgical patients were more likely older, female, nonHispanic white, with a higher lesion level, myelomeningocele diagnosis, nonambulators (all p <0.001) and nonprivately insured (p=0.018). Bladder reconstruction surgery rates varied among NSBPR centers (range 12.1% to 37.9%, p <0.001). After correcting for known confounders NSBPR center, spina bifida type, mobility, gender and age (all p <0.001) were significant predictors of surgical intervention. Race (p=0.19) and insurance status (p=0.11) were not associated with surgical intervention.

CONCLUSIONS

There is significant variation in rates of bladder reconstruction surgery among NSBPR centers. In addition to clinical factors such as mobility status, lesion type and lesion level, nonclinical factors such as patient age, gender and treating center are also associated with the likelihood of an individual undergoing bladder reconstruction.

Design and Methodological Considerations of the Centers for Disease Control and Prevention Urologic and Renal Protocol for the Newborn and Young Child with Spina Bifida

PURPOSE

Care of children with spina bifida has significantly advanced in the last half century, resulting in gains in longevity and quality of life for affected children and caregivers. Bladder dysfunction is the norm in patients with spina bifida and may result in infection, renal scarring and chronic kidney disease. However, the optimal urological management for spina bifida related bladder dysfunction is unknown.

MATERIALS AND METHODS

In 2012 the Centers for Disease Control and Prevention convened a working group composed of pediatric urologists, nephrologists, epidemiologists, methodologists, community advocates and Centers for Disease Control and Prevention personnel to develop a protocol to optimize urological care of children with spina bifida from the newborn period through age 5 years.

RESULTS

An iterative quality improvement protocol was selected. In this model participating institutions agree to prospectively treat all newborns with spina bifida using a single consensus based protocol. During the 5-year study period outcomes will be routinely assessed and the protocol adjusted as needed to optimize patient and process outcomes. Primary study outcomes include urinary tract infections, renal scarring, renal function and bladder characteristics. The protocol specifies the timing and use of testing (eg ultrasonography, urodynamics) and interventions (eg intermittent catheterization, prophylactic antibiotics, antimuscarinic medications). Starting in 2014 the Centers for Disease Control and Prevention began funding 9 study sites to implement and evaluate the protocol.

CONCLUSIONS

The Centers for Disease Control and Prevention Urologic and Renal Protocol for the Newborn and Young Child with Spina Bifida began accruing patients in 2015. Assessment in the first 5 years will focus on urinary tract infections, renal function, renal scarring and clinical process improvements.

Enterocystoplasty 30-day outcomes from National Surgical Quality Improvement Program Pediatric 2012

INTRODUCTION

Enterocystoplasty is an important procedure in the management of children with difficult neurogenic bladder. We report on short-term complications as captured by National Surgical Quality Improvement Program (NSQIP) Pediatric.

METHODS

We analyzed NSQIP Pediatric 30-day perioperative data on 114 patients who underwent enterocystoplasty in 2012 and compared those with and without complications.

RESULTS

Neurogenic bladder was the most common diagnosis. The proportion of the children who underwent two or more procedures was 71.9%, in addition to enterocystoplasty, most commonly appendicovesicostomy. Median length of hospital stay was 8 days (mean 9.7 days, range 2 to 46 days). Thirty-day complication rate was 33.3%, and the most common complications were urinary tract infections (9.6%), wound complications (8.7%), blood transfusions (6.1%), and sepsis (3.5%). Reoperation rate and readmission rate were 9.6% and 13.2%, respectively. No statistically significant differences in perioperative characteristics were found between children with and without postoperative complications. Addition of appendicovesicostomy or bladder neck continence procedures was not associated with significantly increased complications.

CONCLUSION

Enterocystoplasty is associated with significant perioperative morbidity, and reasonable expectations should be set during preoperative counseling.

How Pediatric Urology Fellowships in the United States are Funded

BACKGROUND

We desired to discover how pediatric urology fellowship positions in the United States were funded.

METHODS

Approved pediatric urology fellowship directors (25) were contacted by e-mail and asked how the 2 years of fellowship were funded at their institutions.

RESULTS

The response rate of the e-mail questions was 100%. The clinical year of the fellowship was 100% hospital-funded in 88% of the 25 fellowships. The second, American board of urology (ABU)-required year was 100% hospital-funded in only 44% of the fellowships. Clinical funds generated by pediatric urology faculty provided funding for 24% of the fellows and institutes and grants funded 20% of the fellowship positions for the second year. Thirty-two percent of the fellowship positions have supplemental funding through charges generated from the fellow's clinical activities in patient care.

CONCLUSION

All but three hospitals fund 100% of the clinical year of pediatric urology fellowship. Sources of funding for the second, ABU-required year vary widely among fellowship programs in the United States.

Reliability of voiding cystourethrogram for the grading of vesicoureteral reflux

OBJECTIVE

The voiding cystourethrogram (VCUG) is a commonly employed radiographic test used in the management of vesicoureteral reflux (VUR). Recently, the reliability of VCUG to accurately grade VUR has been questioned. The purpose of this study is to examine reliability of the VCUG for the grading of VUR in a setting mimicking daily practice in a busy pediatric hospital.

MATERIALS AND METHODS

Two-hundred consecutive VCUGs were independently graded by two pediatric urologists and two pediatric radiologists according to the International Classification of Vesicoureteral Reflux. A weighted kappa coefficient was calculated to determine inter-rater agreement and a modified McNemar test was performed to assess rater bias. Further assessment for impact on clinical and research decision-making was made for disagreement between grades II and III.

RESULTS

Weighted kappa values reflect strong reliability of VCUG for grading VUR between and among urologists and radiologists ranging from 0.95 to 0.97. There was statistically significant bias with radiologists reporting higher grades. Despite high kappa values, disagreement between raters was not infrequent and most common for grades II-IV.

CONCLUSIONS

VCUG is reliable for grading VUR, but small differences in grading between raters were detected and may play an important role in clinical decision-making and research outcomes.

Padded self-adhesive strap immobilization following newborn bladder exstrophy closure: the Utah straps

PURPOSE

Several methods have been described for immobilization of the pelvis following bladder exstrophy closure, which can be challenging to manage. We hypothesized that immobilization can be significantly simplified using a modified mermaid wrap with padded Velcro® straps around the thigh and lower leg.

MATERIALS AND METHODS

We retrospectively reviewed all patients who underwent bladder exstrophy closure in the newborn period at our institution from 1990 through 2010. Patients with cloacal exstrophy and those who underwent delayed closure due to other medical conditions were excluded. We collected data on closure technique, length of stay and complications of the primary closure as outcomes.

RESULTS

A total of 20 boys and 7 girls underwent closure of classic bladder exstrophy. Followup ranged from 2 to 22 years. Seven boys underwent complete primary repair and 13 underwent staged repair. All patients had the legs stabilized with a modified wrap technique using 2 lengths of Velcro straps lined with self-adhering open cell foam pads for 3 weeks. Complications of exstrophy closure included bladder dehiscence in 1 patient (4%) and incisional hernia in 2 (7%). Following complete primary repair urethrocutaneous fistula developed in 2 patients and urethral stricture in 2. Average length of stay for patients without significant prematurity was 15 days.

CONCLUSIONS

Padded Velcro strap immobilization simplifies postoperative care, provides secure fixation, decreases length of stay, and enables parents to hold and bond with the child shortly after repair. We advocate this simplified technique, which can be applied with a rate of complications that is comparable to other procedures.

The role of flaps and grafts in modern hypospadiology

The modern hypospadiologist must be proficient in the use of both vascularized flaps and free grafts. When choosing a repair for any given patient with hypospadias, one must consider the length of the urethroplasty, the presence and degree of ventral curvature and perhaps most importantly, the surgeon's own experience. Not all repairs are created equally and different complication rates and cosmetic outcomes can be seen among different surgeons utilizing the same technique. Each surgeon tends to infuse their own modifications to any given technique and many of these modifications go unreported. It is incumbent upon each surgeon to be familiar with a wide variety of techniques, which invariably includes the use of flaps and grafts. We present a spectrum of the uses of flaps and grafts in modern hypospadiology.

Is there a learning curve for subureteric injection of dextranomer/hyaluronic acid in the treatment of vesicoureteral reflux?

OBJECTIVE

To answer the question: 'Is there a learning curve associated with a subureteric injection of Deflux(®)?'

MATERIALS AND METHODS

We retrospectively reviewed charts of patients who received subureteric injection of dextranomer/hyaluronic acid (Deflux(®){AQ2}) (225 procedures) for treatment of vesicoureteral reflux (VUR) by four surgeons. The study included 55 patients, 82 ureters, who had postoperative follow-up with a voiding cystogram or nuclear medicine cystogram. Exclusion criteria were prior anti-refluxing procedures, duplicated collecting systems, and non-achievement of a negative intraoperative cystogram. Patients were divided into two groups based on whether or not they received an intraoperative cystogram after the injection. The two groups were compared for VUR resolution rates on follow-up imaging.

RESULTS

Twenty patients underwent an intraoperative cystogram (Group 1, 33 ureters) and 35 did not (Group 2, 49 ureters). The two groups were similar in age, preoperative reflux grade, amount of Deflux injected into each ureter, and time to postoperative studies. In Group 1, 11 ureters (33.3%) and also, in Group 2, 11 ureters (22.4%) had reflux on follow-up imaging.

CONCLUSIONS

There was no improvement in VUR resolution rate following subureteric injection of Deflux(®) when an intraoperative cystogram demonstrated no reflux to be present immediately after injection. Of ureters that did not reflux on intraoperative cystograms, one-third displayed return of reflux on follow-up imaging, which suggests no learning curve and that failures are not likely to be caused by poor surgical technique.

Feasibility study of a novel urinary bladder bioreactor

We have devised a bioreactor to simulate normal urinary bladder dynamics. The design permits a cell-seeded scaffold made from a modified porcine acellular matrix to be placed between 2 closed chambers filled with culture medium and be mechanically stimulated in a physiologically relevant manner. Specifically designed software increased hydrostatic pressure from 0 to 10 cm of water in a linear fashion in 1 chamber, resulting in mechanical stretch and strain on the scaffold. Pressure was increased over 55 min (filling) and then decreased to 0 over 10 s (voiding). Commercially available small intestinal submucosa scaffolds were used to test the mechanical capabilities of the bioreactor, and pressure waveforms were generated for up to 18 h. Scaffolds were seeded with bladder smooth muscle or urothelial cells and incubated in the bioreactor, which generated pressure waveforms for 6 h. Scaffold integrity was preserved as seen through Masson's trichrome staining. No obvious contamination of the system was noted. Hematoxylin and eosin staining showed presence of cells after incubation in the bioreactor, and immunohistochemistry and real-time reverse transcriptase polymerase chain reaction suggested continued cellular activity. Cellular orientation tended to be perpendicular to the applied pressure. Preliminary results suggest that our bioreactor is a suitable model for simulating normal physiological conditions of bladder cycling in an ex vivo system.

Sex determination in platypus and echidna: autosomal location of SOX3 confirms the absence of SRY from monotremes

In eutherian ('placental') mammals, sex is determined by the presence or absence of the Y chromosome-borne gene SRY, which triggers testis determination. Marsupials also have a Y-borne SRY gene, implying that this mechanism is ancestral to therians, the SRY gene having diverged from its X-borne homologue SOX3 at least 180 million years ago. The rare exceptions have clearly lost and replaced the SRY mechanism recently. Other vertebrate classes have a variety of sex-determining mechanisms, but none shares the therian SRY-driven XX female:XY male system. In monotreme mammals (platypus and echidna), which branched from the therian lineage 210 million years ago, no orthologue of SRY has been found. In this study we show that its partner SOX3 is autosomal in platypus and echidna, mapping among human X chromosome orthologues to platypus chromosome 6, and to the homologous chromosome 16 in echidna. The autosomal localization of SOX3 in monotreme mammals, as well as non-mammal vertebrates, implies that SRY is absent in Prototheria and evolved later in the therian lineage 210-180 million years ago. Sex determination in platypus and echidna must therefore depend on another male-determining gene(s) on the Y chromosomes, or on the different dosage of a gene(s) on the X chromosomes.

Minimally invasive approach for treatment of urinary and fecal incontinence in selected patients with spina bifida

OBJECTIVES

At our institution, the use of cecostomy tubes has provided a successful method for managing severe constipation in patients with spina bifida, with good patient and caretaker satisfaction and minimal morbidity. We have developed a modified technique to allow placement of the cecostomy tube under direct vision during laparoscopic appendicovesicostomy. We present our initial experience and technique.

METHODS

Patients with a normal bladder capacity and compliance who were scheduled for creation of an appendicovesicostomy and who also had refractory constipation were offered concurrent cecostomy tube placement. At the laparoscopic procedure, we performed percutaneous placement of the cecostomy tube through the abdominal wall under direct visualization. Subsequently, dissection of the appendix with its mesentery was performed. The detrusor muscle was dissected and a trough for the appendix created. Laparoscopic anastomosis of the appendix to the bladder mucosa and approximation of the detrusor over the appendix created a nonrefluxing channel.

RESULTS

Three patients have undergone concurrent cecostomy tube placement at appendicovesicostomy. No complications have been encountered thus far. On follow-up, the cecostomy tube scar has been well concealed and appears no different from the ones placed under radiologic guidance. The patients have been using the catheterizable channel to access the bladder and dry performing intermittent catheterization without difficulties.

CONCLUSIONS

In patients with a neurogenic bladder who do not qualify for major bladder reconstructive procedures, such as augmentation cystoplasty or bladder neck repair, social continence and independence can be achieved with minimally invasive surgery. Concomitant laparoscopic appendicovesicostomy and cecostomy tube placement may be a suitable surgical option.

Mapping platypus SOX genes; autosomal location of SOX9 excludes it from sex determining role

In the absence of an SRY orthologue the platypus sex determining gene is unknown, so genes in the human testis determining pathway are of particular interest as candidates. SOX9 is an attractive choice because SOX9 deletions cause male-to-female sex reversal in humans and mice, and SOX9 duplications cause female-to-male sex reversal. We have localized platypus SOX9, as well as the related SOX10, to platypus chromosomes 15 and 10, respectively, the first assignments to these platypus chromosomes, and the first comparative mapping markers from human chromosomes 17 and 22. The autosomal localization of platypus SOX9 in this study contradicts the hypothesis that SOX9 acts as the sex determining switch in platypus.

What are the most powerful determinants of endoscopic vesicoureteral reflux correction? Multivariate analysis of a single institution experience during 6 years

PURPOSE

As the indications for endoscopic correction of vesicoureteral reflux continue to expand, the emergence of potential predictive variables has been noted. We used univariate and multivariate statistical analyses to find the most significant predictors of correction to improve patient selection.

MATERIALS AND METHODS

A consecutive series of patients treated at a single institution was reviewed. Between August 1998 and August 2004, 232 children endoscopically injected with polydimethylsiloxane were identified, representing 351 refluxing units. A total of 23 variables were subjected to statistical analysis to detect predictors of reflux correction after injection. All identified patients with complete data and followup evaluations were included irrespective of anatomical variations, previous interventions or comorbidities.

RESULTS

The overall success rate by patient and renal unit was 65% and 72%, respectively. In patients with a single system low grade (1-3) vesicoureteral reflux who did not previously undergo injection this success rate increased to 80%. Univariate analysis demonstrated that higher physician experience, low preoperative vesicoureteral reflux grade, absent renal scars and no previous injections were statistically significant predictors of vesicoureteral reflux correction (p <0.05). A history of febrile urinary tract infections and a duplex system did not attain significance (p = 0.069 and 0.076, respectively). On multivariate statistical evaluation only physician experience, preoperative vesicoureteral reflux grade and the number of previous injections remained significant.

CONCLUSIONS

Multivariate analysis of our data showed the most important determinants of vesicoureteral reflux correction after endoscopic injection. Prospective validation will allow us to generate nomograms to better select and counsel patients who would benefit from vesicoureteral reflux treatment.

Outcome analysis of retroperitoneal laparoscopic heminephrectomy in children

PURPOSE

Retroperitoneal laparoscopic heminephrectomy is a relatively new, well tolerated, minimally invasive alternative to open surgery for children with a nonfunctioning moiety in a duplex kidney. We collected data to assess outcomes in our experience with this procedure.

MATERIALS AND METHODS

Data were retrospectively gathered on all patients operated on for retroperitoneal laparoscopic heminephrectomy at our institution between February 2001 and November 2004. Followup ultrasound was performed in all patients, and additional imaging was done only when clinically indicated.

RESULTS

Retroperitoneal laparoscopic heminephrectomy was performed in 18 girls and 4 boys (18 upper and 5 lower pole moieties). Indications included ureterocele (12 patients), ectopic ureter (9) and vesicoureteral reflux (5). Mean age at surgery was 5 years (range 4 months to 18 years). Four patients required conversion to an open procedure due to inadequate exposure and were excluded from further review. Urine leaks developed postoperatively in 3 patients and were treated with Foley catheter drainage and/or stent placement. Two patients were noted to have large (more than 5 cm) asymptomatic retroperitoneal fluid collections on followup ultrasound. Functional loss of the remaining ipsilateral moiety was confirmed by DMSA scan in 2 children (ages 6 and 7 months). Doppler studies confirmed normal hilar blood flow in both cases. Clinical presentation for this subgroup included fever on postoperative day 3 in 1 patient and hypertension at 32 months postoperatively in 1. Mean followup was 33 months (range 3 to 56).

CONCLUSIONS

Although retroperitoneal laparoscopic renal ablative surgery in children appears to be relatively safe and is associated with low morbidity, serious complications may occur with subtle or even late presentation.