Walid A. Farhat

THE DYSFUNCTIONAL VOIDING SCORING SYSTEM: QUANTITATIVE STANDARDIZATION OF DYSFUNCTIONAL VOIDING SYMPTOMS IN CHILDREN

PURPOSE Academic research on pediatric nonneurogenic voiding dysfunction has long been hampered by the lack of a standardized reporting system for voiding symptoms. We evaluated the performance of a newly devised, objective instrument to quantify or grade the severity of abnormal voiding behaviors of children. MATERIALS AND METHODS There were 10 voiding dysfunction parameters that were assigned scores of 0 to 3 according to prevalence, and possible total scores ranged from 0 to 30. The Dysfunctional Voiding Symptom Score was completed by 2 groups of patients. Group 1 consisted of patients 3 to 10 years old presenting to the pediatric urology clinic with a history of diurnal urinary incontinence, urinary tract infections or abnormal voiding habits. Group 2 consisted of an age matched cohort with no history of urological complaints presenting to hospital clinics outside of urology. Patients diagnosed with organic or anatomical disease, such as posterior urethral valves or meningomyelocele, were excluded from our analysis. RESULTS Group 1 consisted of 104 patients (female-to-male ratio 4:1) with a median symptom score of 14 and group 2 consisted of 54 patients (female-to-male ratio 1.3:1) with a median score of 4. The dysfunctional voiding odds ratio was 2.93 for females compared to that of males. Using receiver operating characteristics the optimum cutoff score was 6.026 (sensitivity 92.77% and specificity 87.09%) for females and 9.02 (sensitivity of 80.95% and specificity of 91. 30%) for males. In addition, we found certain questions to be more reflective than others of dysfunctional voiding symptoms in our population. CONCLUSIONS The Dysfunctional Voiding Symptom Score appears to provide accurate and objective, that is, numerical, grading of voiding behaviors of children. Comparative research studies of dysfunctional voiding diagnosis and response to therapy as well as objective measurements of treatment efficacy and outcomes analysis should be aided greatly by this system.

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 post...

OUTCOME ANALYSIS OF VESICOAMNIOTIC SHUNTING IN A COMPREHENSIVE POPULATION

PURPOSE Prenatal detection of obstructive uropathy is used widely and vesicoamniotic shunting is the accepted procedure in well-defined cases. We present outcomes of vesicoamniotic shunting in a consecutive series from a coordinated prenatal-postnatal treatment program. MATERIALS AND METHODS From 1989 to 1998 bladder obstruction was identified in 89 fetuses at a multidisciplinary prenatal high risk clinic. Prenatal intervention was considered in cases of bilateral hydronephrosis associated with evidence of bladder outlet obstruction and oligohydramnios. RESULTS Indications for prenatal shunting were present in 12 patients (13%), and 9 underwent vesicoamniotic shunt insertion between weeks 20 and 28 of gestation. None of the prenatal procedures was associated with preterm labor, chorioamnionitis or urine chemistry values greater than cutoff threshold on bladder tap. Shunts were extruded from 2 fetuses, which required sequential insertion. After prenatal intervention 1 patient elected pregnancy termination and the others proceeded to term. Two neonates died at birth, and 6 survived. The underlying urological diagnosis was posterior urethral valves in 4 newborns, urethral atresia in 1, and prune belly variant and urethral atresia in 1. Of the patients 3 had relatively normal renal function, 2 had severe renal insufficiency and 1 had mild renal impairment. Five newborns are voiding freely and 1 underwent bladder reconstruction and is on intermittent catheterization. None of the patients had pulmonary problems at last followup. CONCLUSIONS Although vesicoamniotic shunting is effective in reversing oligohydramnios, its ability to achieve sustainable good renal function in infancy is variable. No specific prenatal parameters were effective in predicting eventual good renal function. Pulmonary function cannot be assured with restoration of amniotic fluid.

Long-Term Followup and Time to Event Outcome Analysis of Continent Catheterizable Channels

PURPOSE Creation of a continent catheterizable channel has facilitated the treatment of patients undergoing lower urinary tract reconstruction. We present outcomes and complications of a single center series of continent catheterizable channels followed out to 15 years. MATERIALS AND METHODS We retrospectively reviewed medical records of all children who underwent continent catheterizable channel (Mitrofanoff and Monti) between 1992 and 2007. Collected data included age, underlying diagnosis, associated procedures, stoma site, conduit type (appendix or reconfigured bowel), time to complications and need for subsequent surgical revisions. RESULTS We identified 71 girls and 98 boys who underwent surgery at a mean age of 7.5 years (range 6 months to 22 years) and were subsequently followed for a mean of 5.8 years (8 months to 15 years). Underlying diagnoses included neurogenic bladder (36% of patients), bladder exstrophy (25%), epispadias (6%) and posterior urethral valves (6%). Concurrent procedures were conducted in 71% of cases, including augmentation (35%) and bladder neck plasty (22%) or closure (8%). Surgical revision was performed in 39% of patients, including stomal revision (18%), redo operation (8%), bulking agent injection (8%) and prolapse correction (4%). Although an initial peak was followed by a relatively stable complication-free period, delayed problems were detected on long-term followup. No statistically significant differences in complication rates were noted when comparing use of appendix and reconfigured bowel or different stoma locations. CONCLUSIONS Despite an initial decrease in complications soon after continent catheterizable channel creation, late problems appeared on long-term evaluation. In our experience no specific factor predicted the likelihood of complications. Nevertheless, despite the need for surgical revision, good functional outcomes were evidenced in this series.

Bladder tissue engineering: Tissue regeneration and neovascularization of HA-VEGF-incorporated bladder acellular constructs in mouse and porcine animal models

Successful tissue engineering requires appropriate recellularization and vascularization. Herein, we assessed the regenerative and angiogenic effects of porcine bladder acellular matrix (ACM) incorporated with hyaluronic acid (HA) and vascular endothelial growth factor (VEGF) in mouse and porcine models. Prepared HA-ACMs were rehydrated in different concentrations of VEGF (1, 2, 3, 10, and 50 ng/g ACM). Grafts were implanted in mice peritoneum in situ for 1 week. Angiogenesis was quantified with CD31 and Factor VIII immunostaining using Simple PCI. Selected optimal VEGF concentration that induced maximum vascularization was then used in porcine bladder augmentation model. Implants were left in for 4 and 10 weeks. Three groups of six pigs each were implanted with ACM alone, HA-ACM, and HA-VEGF-ACM. Histological, immunohistochemical (Uroplakin III, alpha-SMA, Factor VIII), and immunofluorescence (CD31) analysis were performed to assess graft regenerative capacity and angiogenesis. In mouse model, statistically significant increase in microvascular density was demonstrated in the 2 ng/g ACM group. When this concentration was used in porcine model, recellularization increased significantly from weeks 4 to 10 in HA-VEGF-ACM, with progressive decrease in fibrosis. Significantly increased vascularization, coupled with increased urothelium and smooth muscle cell (SMC) regeneration, was observed in HA-VEGF grafts at week 10 in the center and periphery, compared with week 4. HA-VEGF grafts displayed highest in vivo epithelialization, neovascularization, and SMCs regeneration. A total of 2 ng/g tissue VEGF when incorporated with HA proved effective in stimulating robust graft recellularization and vascularization, coordinated with increased urothelial bladder development and SMC augmentation into bundles by week 10.

Does mechanical stimulation have any role in urinary bladder tissue engineering

IntroductionTissue engineering of the urinary bladder currently relies on biocompatible scaffolds that deliver biological and physical functionality with negligible risks of immunogenic or tumorigenic potential. Recent research suggests that autologous cells that are propagated in culture and seeded on scaffolds prior to implantation improve clinical outcomes. For example, normal urinary bladder development in utero requires regular filling and emptying, and current research suggests that bladders constructed in vitro may also benefit from regular mechanical stimulation. Such stimulation appears to induce favorable cellular changes, proliferation, and production of structurally suitable extracellular matrix (ECM) components essential for the normal function of hollow dynamic organs.Materials and methodsTo mimic in vivo urinary bladder dynamics, tissue bioreactors that imitate the filling and emptying of a normal bladder have been devised. A “urinary bladder tissue bioreactor” that is able to recapitulate these dynamics while providing a cellular environment that facilitates cell–cell and cell–matrix interactions normally seen in-vivo may be necessary to successfully engineer bladder tissue.ConclusionsThe validation of a urinary bladder tissue bioreactor that permits careful control of physiological conditions will generate a broad interest from researchers interested in urinary bladder physiology and tissue engineering.

Use of 3-Dimensional Printing Technology and Silicone Modeling in Surgical Simulation: Development and Face Validation in Pediatric Laparoscopic Pyeloplasty

OBJECTIVES Pediatric laparoscopy poses unique training challenges owing to smaller workspaces, finer sutures used, and potentially more delicate tissues that require increased surgical dexterity when compared with adult analogs. We describe the development and face validation of a pediatric pyeloplasty simulator using a low-cost laparoscopic dry-laboratory model developed with 3-dimensional (3D) printing and silicone modeling. DESIGN AND SETTING The organs (the kidney, renal pelvis, and ureter) were created in a 3-step process where molds were created with 3D modeling software, printed with a Spectrum Z510 3D printer, and cast with Dragon Skin 30 silicone rubber. The model was secured in a laparoscopy box trainer. A pilot study was conducted at a Canadian Urological Association meeting. A total of 24 pediatric urology fellows and 3 experienced faculty members then assessed our skills module during a minimally invasive surgery training course. Participants had 60 minutes to perform a right-side pyeloplasty using laparoscopic tools and 5-0 VICRYL suture. Face validity was demonstrated on a 5-point Likert scale. PARTICIPANTS AND RESULTS The dry-laboratory model consists of a kidney, a replaceable dilated renal pelvis and ureter with an obstructed ureteropelvic junction, and an overlying peritoneum with an inscribed fundamentals of laparoscopic surgery pattern-cutting exercise. During initial validation at the Canadian Urological Association, participants rated (out of 5) 4.75 ± 0.29 for overall impression, 4.50 ± 0.41 for realism, and 4.38 ± 0.48 for handling. During the minimally invasive surgery course, 22 of 24 fellows and all the faculty members completed the scoring. Usability was rated 4 or 5 by 14 participants (overall, 3.6 ± 1.22 by novices and 3.7 ± 0.58 by experts), indicating that they would use the model in their own training and teaching. Esthetically, the model was rated 3.5 ± 0.74 (novices) and 3.3 ± 0.58 (experts). CONCLUSIONS We developed a pediatric pyeloplasty simulator by applying a low-cost reusable model for laparoscopic training and skills acquisition. The models usability, realism, and feel are good, it can be imaged under common modalities, and it shows promise as an educational tool.

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.

Outcome Analysis and Cost Comparison Between Externalized Pyeloureteral and Standard Stents in 470 Consecutive Open Pyeloplasties

PURPOSE Despite the widespread use of ureteral stents for pyeloplasty by pediatric urologists there is ongoing controversy regarding the most advantageous type of transanastomotic drainage. We compared patients who underwent placement of an externalized pyeloureteral Salle intraoperative pyeloplasty stent (Cook Urological, Spencer, Indiana) to those who had a standard Double-J ureteral stent placed to assess the benefits, drawbacks and costs of each modality during open pyeloplasty. MATERIALS AND METHODS Our study sample comprised 470 age matched children who underwent primary open pyeloplasty in an 11-year period. A total of 242 patients (51.5%) underwent Double-J ureteral stent insertion and 228 (48.5%) underwent placement of a Salle intraoperative pyeloplasty stent at surgery. Operative time, hospital stay, overall complication and success rates, type of complications and hospital costs were compared between the 2 groups. RESULTS Median age was 18 months and median followup was 39 months. Mean hospital stay was 3.0 and 3.1 days in children with a Double-J ureteral and a Salle intraoperative pyeloplasty stent, respectively (p = 0.7). The overall complication rate was 9.9% (24 of 242 patients) for the Double-J ureteral stent vs 8.3% (19 of 228) for the Salle intraoperative pyeloplasty stent (p = 0.6). Complications in patients with a Double-J ureteral stent consisted of urinoma in 3, return visits due to bladder spasms in 7 or catheter obstruction in 6 and readmission due to pyelonephritis in 5. Complications in children with a Salle intraoperative pyeloplasty stent involved urinoma in 1, prolonged drainage through the Penrose drain in 5 and readmission due to pyelonephritis in 1. Recurrent ureteropelvic junction obstruction developed in 12 cases per group. The success rate was 95.0% (230 of 242 cases) and 94.7% (216 of 228) for the Double-J ureteral and the Salle intraoperative pyeloplasty stent, respectively (p = 0.2). Hospital charges, including the surgical procedure, postoperative hospitalization and cystoscopy or a clinical visit for catheter removal, in patients with a Double-J ureteral and a Salle intraoperative pyeloplasty stent were

Learning From the Learning Curve: Factors Associated With Successful Endoscopic Correction of Vesicoureteral Reflux Using Dextranomer/Hyaluronic Acid Copolymer

9,825 and