[Applications of robotic surgery in pediatric urology. Description of the technical principles]. / Aplicaciones de la cirugía robótica en urología pediátrica. Descripción de los principios técnicos.

The incorporation of the robotic surgery to the pediatric urology permits less invasive and more precise therapeutic alternatives for the patient. It corrects some limitations of laparoscopic surgery, with its 3 dimensional vision, accurate movements without tremor, and more degrees of freedom, allows an ergonomic position to the surgeon and has a shorter learning curve. Different procedures were performed with da Vinci surgical system, in a secure and effective way, as pyeloplasty, total or partial nephrectomy, orchidopexy, intra or extravesical ureteral reimplant, enterocystoplasty, Mitrofanoff and others. These techniques and their outcomes will be reviewed, as well as some of the challenges still posed by this methodology.

The effectiveness of aerosolized intraperitoneal bupivacaine in reducing postoperative pain in children undergoing robotic-assisted laparoscopic pyeloplasty.

OBJECTIVE: To assess the effectiveness of aerosolized intraperitoneal bupivacaine in reducing postoperative pain in children. Laparoscopic surgery has decreased the severity of postoperative pain in children. However, children often experience abdominal and shoulder pain requiring significant amounts of opioids, potentially prolonging their hospitalization. METHODS: Forty-one consecutive patients undergoing unilateral robotic-assisted pyeloplasty between December 2005 and December 2007 were retrospectively reviewed to assess perioperative opioid requirements and length of hospitalization. RESULTS: In addition to standard-of-care perioperative analgesia, five patients received intraperitoneal aerosolized bupivacaine just prior to trocar removal, 17 patients received aerosolized bupivacaine just prior to incising the perirenal fascia, and 19 patients received no intervention. There was a significant reduction in postoperative opioid utilization when bupivacaine was administered at the beginning of the surgery (0.1mg/kg vs 0.4mg/kg, P=0.04), but not at the end (0.3mg/kg, P=0.25), as compared to controls. All patients receiving aerosolized bupivacaine had a significantly shorter time in hospital (2.4 vs 1.4 days, P=<0.01). CONCLUSIONS: The administration of intraperitoneal aerosolized bupivacaine just prior to incising the perirenal fascia appears to be a simple, effective and low-cost method to reduce postoperative pain in children undergoing laparoscopic pyeloplasty.

The outcome of voiding dysfunction managed with clean intermittent catheterization in neurologically and anatomically normal children.

OBJECTIVE: To describe the tolerability and efficacy of clean intermittent catheterization (CIC) in the management of dysfunctional voiding in patients who are neurologically and anatomically normal. PATIENTS AND METHODS: The medical records were reviewed in 23 patients (16 girls, mean age 9 years, range 6-14.5, and seven males, mean age 8 years, range 5-20.5) with urinary incontinence and/or urinary tract infection (UTI) who were offered CIC because they had a large postvoid residual urine volume (PVR). All had extensive instruction before starting CIC. All patients underwent urodynamic studies, and urinary and fecal elimination habits were recorded. Detrusor hyperactivity, when present, was treated with anticholinergic medication. The follow-up evaluation included tolerance of CIC, continence status and the incidence of UTI. Behavioural modification or biofeedback training was not used in any patient. RESULTS: Of the 23 patients, 13 presented with both UTI and urinary incontinence, five with incontinence only, four with UTI only, one with frequency and no incontinence, and one with haematuria. Associated symptoms included frequency/urgency, constipation or soiling, and straining to void or incomplete emptying (in nine each), and infrequent voiding in six. CIC was performed within 2 days by 15 patients, while four others required up to 2 weeks to master CIC. However, three of the four patients (all older girls) who needed 2 weeks to learn the technique did not tolerate CIC and discontinued it within 3 weeks. Four other adolescents (three girls and one boy) refused to learn CIC. Of the 16 patients remaining on CIC only three had cystitis; no patient had a febrile UTI. Once successfully instituted, all patients became continent while on CIC. Six boys (mean follow-up 4 months) had a marked decrease in their PVR. CIC was discontinued in three girls who voided normally to emptiness within 6 months of starting CIC; they remained dry and infection-free 16 months (two) and 6 years later. CONCLUSION: CIC is a viable therapeutic option for the treatment of dysfunctional voiding, associated with a large PVR, in the absence of any neurological abnormality. CIC is well tolerated in the sensate patient and provides a means for expeditiously achieving continence and improving bladder emptying cost-effectively.

Rectus fascial sling for the treatment of neurogenic sphincteric incontinence in boys: is it safe and effective?

PURPOSE: While a fascial sling for treating children with intractable urinary incontinence is often successful in girls, its effectiveness in boys remains unclear. We determined the long-term efficacy of a rectus fascial sling in boys with neurogenic sphincteric incontinence and defined its urodynamic characteristics for achieving continence. METHODS AND METHODS: We reviewed the charts of all boys who underwent a rectus fascial sling procedure for neurogenic incontinence to determine urinary continence status at the most recent office visit or by telephone interview, the type and dose of anticholinergic and sympathomimetic medications, the frequency of intermittent clean intermittent catheterization, status of the upper urinary tract and comparative urodynamic findings preoperatively and postoperatively. RESULTS: We evaluated 7 boys 7 to 19 years old, of whom 4 were postpubertal, who fulfilled study criteria and had a followup of 1 to 9 years. In 4 patients a continent stoma was created concurrently at surgery. Postoperatively all patients were dry during the first 3 months after surgery. At the last followup 1 patient was completely dry, 3 had occasional nighttime wetting, 2 had occasional stress incontinence, and 1 had frequent daytime and nighttime wetting requiring subsequent bladder neck closure. Prepubertal and postpubertal males performed catheterization without difficulty and all required less frequent clean intermittent catheterization and medication postoperatively compared to preoperative status. None had hydronephrosis. Postoperatively urodynamic evaluation revealed normal bladder compliance, improved urethral resistance that did not decay with bladder filling and no uninhibited contractions. CONCLUSIONS: The rectus fascial sling is effective for increasing bladder outlet resistance and decreasing the degree of incontinence in prepubertal and postpubertal males with neurogenic sphincteric incontinence. It has no long-term deleterious effects on bladder function and does not impair the ability to catheterize postoperatively. A fascial sling is an effective alternative to bladder neck closure when creating a continent stoma.

Tubularized incised plate urethroplasty: expanded use in primary and repeat surgery for hypospadias.

PURPOSE: We evaluated the impact of tubularized incised plate urethroplasty on primary and repeat hypospadias repair. MATERIALS AND METHODS: We retrospectively reviewed the medical records of all boys who underwent hypospadias repair at our institution during a recent 3-year period. The level of the hypospadias defect, technique of repair, primary repair versus reoperation, age at surgery and complications were recorded. RESULTS: A total of 520 hypospadias repairs were done from May 1996 through June 1999. We began to perform tubularized incised plate urethroplasty in November 1996. During the ensuing consecutive 32 months 181 primary and 25 repeat hypospadias repairs were done using this technique. Mean patient age at surgery was 22 months (range 3 months to 30 years). During the 6 months immediately before we began to use this method the Mathieu flip-flap procedure was the most commonly performed technique, accounting for 38% of all hypospadias repairs. In contrast, during the last 6 months reviewed tubularized incised plate urethroplasty accounted for 63% of all repairs, including 41 of 65 primary operations (63%) and 4 of 6 reoperations (67%), while no Mathieu procedures were performed. Postoperative followup was 6 to 38 months for tubularized incised plate repair. Overall meatal stenosis and a urethrocutaneous fistula developed in 1 and 14 boys, respectively (7% complication rate). CONCLUSIONS: Tubularized incised plate urethroplasty has become the preferred technique of primary and repeat hypospadias repair at our institution. The technique has few complications as well as proved success and versatility that continues to expand its applicability and popularity.

99m Technetium dimercapto-succinic acid renal scintigraphy abnormalities in infants with sterile high grade vesicoureteral reflux.

PURPOSE: Although vesicoureteral reflux associated with bacteriuria may cause renal scarring, sterile reflux is thought not to cause renal injury. We determined the incidence and associated characteristics of renal abnormalities using 99mtechnetium(Tc) dimercapto-succinic acid (DMSA) renal scintigraphy in infants with high grade vesicoureteral reflux but no history of urinary tract infection. MATERIALS AND METHODS: We retrospectively reviewed the results of 99mTc-DMSA renal scintigraphy and renal ultrasonography performed during the first 6 months of life in infants with vesicoureteral reflux detected during the postnatal evaluation of prenatal hydronephrosis or sibling reflux screening. Those with a history of urinary tract infection, or evidence of ureteropelvic junction or bladder outlet obstruction were excluded from study. RESULTS: Of the 28 male and 6 female infants who met study criteria vesicoureteral reflux was bilateral in 25 and unilateral in 9. Reflux grade was IV or V, II or III and I in 38, 18 and 3 of the 59 refluxing renal units, respectively. 99mTc-DMSA renal scintigraphy revealed parenchymal abnormalities in 24 refluxing renal units (41%) in 22 patients (65%), of whom 19 (86%) were male and 15 (68%) had bilateral reflux. We noted differential uptake less than 40% with and without cortical defects in 10 and 7 refluxing units, respectively, and cortical defects only in 7. Of the 24 refluxing units with abnormalities 21 were associated with grade IV or V and 3 with grade II or III reflux. Ultrasound showed evidence of renal injury in only 7 of the 17 patients (41%) in whom 99mTc-DMSA scintigraphy was abnormal. CONCLUSIONS: In our study the majority of infants with high grade reflux had decreased differential function and/or cortical defects. Parenchymal defects detected by 99mTc-DMSA renal scintigraphy were often not identified by renal ultrasound. Therefore, 99mTc-DMSA renal scintigraphy is especially useful for initially evaluating infants with high grade, sterile vesicoureteral reflux.

Initial experience with the transurethral self-detachable balloon system for urinary incontinence in pediatric patients.

PURPOSE: A new endoscopic technique to treat urinary incontinence in children using a self-detachable balloon device was studied. MATERIALS AND METHODS: The study includes 11 patients with a mean age of 14.6 years and all of whom had intrinsic sphincter deficiency due to myelomeningocele in 9, spinal artery bleed in 1 and cloacal exstrophy in 1. All patients were on clean intermittent catheterization preoperatively and postoperatively. Endoscopic balloon treatment was performed on an outpatient basis. A mean of 5 balloons (range 2 to 8) were placed per patient. All patients underwent formal urodynamic study preoperatively and at 6 weeks and 6 months following balloon placement. RESULTS: Of the 9 patients without prior bladder neck surgery 7 had improvement in urodynamic parameters, including urethral pressure profile in all 7 and functional bladder capacity in 6, 4 were markedly improved clinically and 2 were dry. Two patients with prior bladder neck surgery were clinically unchanged following balloon placement, although 1 had urodynamic improvement. CONCLUSIONS: Our initial experience with the transurethral self-detachable balloon system as a minimally invasive outpatient procedure to treat urinary incontinence in children has been encouraging. To date this procedure appears most applicable to the patient who has not undergone surgery and has a neurogenic etiology for urinary incontinence.

Comparative assessment of pediatric testicular volume: orchidometer versus ultrasound.

PURPOSE: Testicular volume measurements obtained with the Prader and Rochester orchidometers were compared to those obtained using scrotal ultrasound. The ability of each orchidometer versus ultrasound in detecting volume differential between 2 testes and the accuracy of orchidometer measurement by a less experienced examiner to that of a urologist were compared. MATERIALS AND METHODS: A total of 65 males were examined by the attending urologist and urology nurse using the Prader and Rochester orchidometers, and scrotal ultrasound was subsequently performed by an attending radiologist. Statistical analysis of the results was performed to determine the correlation of orchidometer measurements between examiners, as well as with ultrasound, and sensitivity and specificity of orchidometer and ultrasound in detecting defined volume differentials between testes of 10%, 15%, 20% and 25%. RESULTS: There was a strong linear relationship between testicular volume measurements using either orchidometer and ultrasound. To detect a defined volume differential as determined by ultrasound orchidometer sensitivity was weak, whereas orchidometer specificity was better. There was a strong correlation between orchidometer measurements of the urology nurse and attending urologist. CONCLUSIONS: Although the orchidometer remains valuable in assessing size of the individual testis, it is too insensitive to volume differentials relative to ultrasound to be used routinely to determine growth impairment. For this reason observation of an adolescent with varicocele should include an annual ultrasound assessment of testicular volume.

Ketorolac suppresses postoperative bladder spasms after pediatric ureteral reimplantation.

UNLABELLED: We evaluated the efficacy of ketorolac in suppressing postoperative bladder spasms after ureteroneocystostomy (ureteral reimplantation). Twenty-four pediatric patients undergoing intravesical ureteroneocystostomy were enrolled prospectively to receive either ketorolac or placebo via double-blinded randomization. Twelve patients in each group shared similar preoperative characteristics. All were maintained on an epidural infusion of bupivacaine (0.1%) with fentanyl (2 microg/mL) throughout the study. Patients were given either ketorolac (0.5 mg. kg(-1). dose(-1)) or placebo (equivalent volume saline) IV after surgery and every 6 h thereafter for 48 h. Parents were instructed to record bladder spasm episodes prospectively by using a standardized time-flow diary. Three patients (25%) in the ketorolac group experienced bladder spasms, compared with 10 patients (83%) in the placebo group (two-sided P < 0.05). The median severity score for the ketorolac group was 1.2 (mild = 1.0, severe = 3.0), compared with 2.6 for the placebo group (P = 0.003). We conclude that IV ketorolac reduces the frequency and severity of postoperative bladder spasms after intravesical ureteroneocystostomy. IMPLICATIONS: We studied the efficacy of ketorolac, a prostaglandin synthesis inhibitor, in the treatment of bladder spasm after ureteroneocystostomy (antireflux operation). Patients were randomized in a double-blinded manner to receive either ketorolac or placebo after the surgery. We demonstrate that ketorolac reduces the frequency and severity of postoperative bladder spasm.

The effects of sustained hydrostatic pressure on select bladder smooth muscle cell functions.

PURPOSE: Normal bladder development is believed to depend on the active work of the bladder for storing and expelling urine. When high urinary diversion is performed in infants and the bladder no longer undergoes normal filling, bladder development may be altered, ultimately resulting in bladder dysfunction. To help better understand this relationship of bladder function with growth at the cellular level we developed a novel laboratory method for applying hydrostatic pressure to cell cultures, and we characterized the response of neonatal bladder smooth muscle cells to physiological levels of sustained hydrostatic pressure. MATERIALS AND METHODS: Neonatal ovine smooth muscle cells staining positive for desmin and alpha-smooth muscle actin were exposed to pressures of 0.3 (controls), 2, 4, 6 and 8.5 cm. water for 1, 3, 5 and 7 days. At the end of the experiments the cells were fixed, stained and counted. Mitogenic activity of the supernatant media from bladder smooth muscle cells exposed to 8.5 cm. water for 5 days (conditioned media) was tested before and after treatments of heating, freezing, passing through a heparin-sepharose affinity chromatography column or after the addition of suramin, a nonspecific growth factor inhibitor. Statistical analysis was performed using Student's t test with p <0.05 considered statistically significant. RESULTS: Exposure of bladder smooth muscle cells to sustained hydrostatic pressures of 4, 6 and 8.5 cm. water resulted in increased cell proliferation. Differences became statistically significant (p <0.05) by day 5. Also, conditioned media contained mitogenic activity that was ablated by heating, freezing, passage through a heparin-sepharose affinity chromatography column or with the addition of suramin. CONCLUSIONS: We have demonstrated a proliferative response of neonatal bladder smooth muscle after exposure to physiological levels of sustained hydrostatic pressure. This response is partially due to 1 or more transferable mitogenic factors. These data support the hypothesis that pressure associated with bladder filling is an important stimulus for detrusor development.

Heparin-binding EGF-like growth factor expression increases selectively in bladder smooth muscle in response to lower urinary tract obstruction.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF), an activating ligand for the epidermal growth factor receptor (ErbB1) tyrosine kinase and at least one isoform of the ErbB4 receptor tyrosine kinase, is synthesized by the smooth muscle of the human bladder wall. In this study we tested the hypothesis that HB-EGF plays a role in the bladder-wall thickening that occurs in response to obstructive syndromes affecting the lower urinary tract, possibly by acting as an autocrine smooth muscle cell (SMC) growth factor. HB-EGF was mitogenic for primary culture human bladder SMC, and cell growth in serum-containing medium was inhibited more than 70% by [Glu52]-diphtheria toxin/CRM197, a specific HB-EGF inhibitor, consistent with a physiologic role for HB-EGF as an autocrine bladder SMC mitogen. Human and mouse bladder SMC in vivo and cultured human bladder SMC expressed the primary HB-EGF receptor, ErbB1, but not mRNA for the secondary HB-EGF receptor, ErbB4, thereby identifying ErbB1 as the cognate HB-EGF receptor in the bladder wall. Reverse transcription-polymerase chain reaction analysis also demonstrated ErbB2 and ErbB3 expression in human bladder muscle tissue, suggesting the possibility of receptor cross-talk after ErbB1 activation. Urethral ligation in mice resulted in an increase in steady-state HB-EGF mRNA expression up to 24 hours in whole bladder tissue in comparison with ErbB1 and glyceraldehyde 3-phosphate dehydrogenase mRNA levels, which did not change in a demonstrable pattern. HB-EGF protein increased coordinately with HB-EGF mRNA levels. Dissection of bladder tissue into muscle and mucosal layers demonstrated that the increase in HB-EGF mRNA occurred predominantly in the muscle layer, with peak levels (13-fold higher than sham controls) occurring 12 hours after obstruction. These data support a physiologic role for HB-EGF as a mediator of hypertrophic bladder tissue growth.

Pediatric retroperitoneoscopic nephrectomy using 2 mm. instrumentation.

PURPOSE: We describe several modifications of the retroperitoneoscopic approach to nephrectomy for benign renal disease, including the use of 2 mm. instrumentation and prone patient positioning. MATERIALS AND METHODS: A total of 14 children underwent retroperitoneoscopic nephrectomy in the prone position. An inflatable dissecting device was inserted into the retroperitoneum after a small muscle splitting incision was made at the lateral border of the sacrospinalis muscle approximately 1 cm. below the costovertebral angle. After inflation the dissecting device was replaced with a 5 mm. cannula and pneumoretroperitoneum was maintained with carbon dioxide insufflation. Two 2 mm. trocars were then placed under endoscopic guidance. Dissection was performed using 2 mm. instrumentation and the specimen was retrieved through the largest port site. RESULTS: Nephrectomy was performed in 9 girls and 5 boys 3 months to 9.8 years old. The preoperative diagnosis included chronic pyelonephritis with minimal renal function, reflux with a nonfunctioning kidney, multicystic dysplastic kidney, an upper pole dysplastic moiety with an associated ureterocele and a dysplastic kidney with a vaginal ectopic ureter. Mean operative time for retroperitoneoscopic nephrectomy was 142 minutes with an estimated blood loss of less than 15 ml. Contralateral ureteral reimplantation was performed after retroperitoneoscopic dissection in 5 patients. Overall average hospital stay was 2 days and there were no complications. CONCLUSIONS: Several modifications of the retroperitoneal approach, including the use of prone patient positioning and 2 mm. instrumentation for visualization and dissection, may improve the safety and efficacy of this technique in children.

Normal urodynamics in patients with bladder exstrophy: are they achievable?

PURPOSE: Urodynamic study was performed in patients with exstrophy to determine the effect of bladder neck reconstruction and the ability to achieve normal urodynamics following surgery. MATERIALS AND METHODS: A total of 30 exstrophy cases at different stages of reconstruction were retrospectively reviewed in terms of bladder capacity, compliance, stability and presence of detrusor contractions following urodynamic study. RESULTS: Bladder capacity increased from a third predicted volume for age to half after reconstruction. Approximately 80% of patients had compliant and stable bladders before bladder neck reconstruction. Following bladder neck reconstruction approximately half of the patients maintained normal compliance with a smaller number maintaining normal stability. A quarter of patients maintained normal filling dynamics following bladder neck reconstruction, and 19% maintained normal filling and voiding dynamics after reconstruction. CONCLUSIONS: The majority of closed exstrophy bladders have normal filling dynamics before bladder neck reconstruction. Compliance and stability are impaired following bladder neck reconstruction. Approximately 25% of patients with exstrophy may maintain normal detrusor function following reconstruction. However, less invasive alternatives to the Young-Dees-Leadbetter bladder neck reconstruction should be sought.

The incidence of intersexuality in children with cryptorchidism and hypospadias: stratification based on gonadal palpability and meatal position.

PURPOSE: The combined findings of cryptorchidism and hypospadias often indicate the existence of an intersex state. Testicular maldescent and incomplete tubularization of the urethral plate occur in a spectrum with the severity of the 2 processes likely dependent on the degree of pathophysiology in the androgenic hormonal axis. The incidence of intersexuality in children with undescended testes, hypospadias and otherwise nonambiguous male genitalia has been reported to be 27%. Although the likelihood of genotypic or gonadal ambiguity has previously been associated with meatal position in this population, to our knowledge our study is the first to evaluate the incidence of intersexuality relative to whether the undescended testis is palpable or nonpalpable. MATERIALS AND METHODS: The database at our hospital was searched for all cases of undescended testes (2,105) and hypospadias (1,057) between 1982 and 1996. Radiographic, histological and karyotypic data were compiled for all patients presenting with both diagnoses. Gonadal palpability (palpable versus nonpalpable) and meatal position (anterior versus mid versus posterior) were recorded and correlated with the likelihood of identifying an intersex condition. Ten boys with a diagnosis of undescended testes subsequent to inguinal hernial repair were excluded from study. Patients with congenital adrenal hyperplasia or complete testicular feminization were also excluded from study due to the clearly female appearance of the external genitalia. Statistical significance was assessed using Fisher's exact test. RESULTS: We identified 79 patients presenting with undescended testes, hypospadias and a phallus that was believed to be a possible penis. Intersex conditions were identified with nearly equal frequency in the 44 cases of unilateral (30%) and 35 of bilateral (32%) cryptorchidism. In the unilateral undescended testes group patients with a nonpalpable testis were at least 3-fold more likely to have an intersex condition than those with a palpable undescended testis (50 versus 15%, p = 0.02). In the bilateral group patients with 1 or more nonpalpable testes were also nearly 3-fold as likely to have an intersex condition than those with bilateral palpable undescended gonads (47 versus 16%, p = 0.07). Meatal position was graded as anterior in 33% of cases, mid in 25% and posterior in 41% with the more posterior location conferring a significantly greater likelihood of an intersex condition (anterior 2 of 26, mid 1 of 20 and posterior 21 of 33). CONCLUSIONS: Gonadal palpability is an important predictor of an intersex state in unilateral and bilateral cases of cryptorchidism with hypospadias. Patients with an undescended testis that cannot be palpated are significantly more likely to have an intersex condition than those in whom the undescended testis may be palpated on physical examination. The severity of hypospadias likewise has a strong positive correlation with an intersex state.

Experimental fetal vesicoureteral reflux induces renal tubular and glomerular damage, and is associated with persistent bladder instability.

PURPOSE: We assessed renal function and urodynamic status in animals with experimental congenital vesicoureteral reflux. MATERIALS AND METHODS: Vesicoureteral reflux was surgically induced in male sheep fetuses at 95 days of gestation. After birth the animals were maintained on antibiotic prophylaxis. At ages 1 week and 6 months reflux was assessed by fluoroscopic voiding cystography. Cystometrography was performed with the animals awake. Serum creatinine, inulin clearance and the excretion of urinary N-acetyl-beta-D-glucosaminidase were measured at ages 1 week, 1 month and 6 months by surveillance urine cultures. Urinary concentrating capacity was assessed by desmopressin testing at ages 1 and 6 months. RESULTS: Nine animals (18 renal units) were born after the induction of reflux. There was no reflux in 2 renal units, while reflux was mild in 2, moderate in 5 and severe in 9. In the 6 animals available for followup at age 6 months only severe reflux persisted. Reflux resolution was associated with normalization of bladder urodynamics. Surveillance urine cultures were negative until age 6 months, when infection developed in 3 of the 6 lambs. In all animals serum creatinine was normal during followup. Glomerular filtration rate in the lambs with reflux was no different from normal at age 1 week but it was significantly less than normal independent of infection at age 6 months (2.7 versus 3.9 ml./kg. per minute, p = 0.002). As an indicator of renal tubular injury the ratio of N-acetyl-beta-D-glucosaminidase-to-creatinine remained significantly higher in animals with reflux than in normal animals from ages 1 week to 6 months (51.0 versus 10.2 IU/mg., p = 0.03). Maximal concentrating ability after desmopressin testing was already less than normal by age 1 month with a maximal increase of 98 versus 435 mOsm./l. in lambs with reflux versus normal lambs (p <0.0001). It was further impaired by age 6 months. Urodynamic evaluation of the animals with reflux revealed decreased bladder compliance at age 1 week with normal voiding pressure. In addition, in those with reflux there was a more pronounced immature voiding pattern with multiple phasic contractions due to sphincteric activity as well as a post-void bladder contraction. CONCLUSIONS: Our model of fetal vesicoureteral reflux induces alterations in renal function that are consistent with clinical observations and marked by altered tubular function but a relatively mild decrease in glomerular filtration. Bladder dynamics are altered, consistent with observations in human neonates with high grade reflux and bladder instability. Whether this represents cause or effect remains unclear. Our model permits focused study of the interaction of these factors in neonatal reflux and may allow the application of more specific therapies, particularly those directed toward mechanisms of renal and bladder dysfunction.

A novel inert collagen matrix for hypospadias repair.

PURPOSE: In select patients with hypospadias in whom genital skin is insufficient alternative tissues are needed for urethral reconstruction. Although skin and mucosal grafts may be used, they may increase hospitalization and morbidity. We explored the feasibility of using a bladder submucosal, collagen based inert matrix as a free graft substitute for urethral repair. MATERIALS AND METHODS: Four patients with a history of hypospadias underwent repeat hypospadias repair using a collagen based inert matrix for urethral reconstruction. The inert collagen matrix was trimmed to size as needed for each patient. The neourethra was created by anastomosing the matrix in an onlay fashion to the urethral plate with continuous 6-zero polyglactin sutures. The created neourethra size ranged from 5 to 15 cm. RESULTS: After a 22-month followup 3 of the 4 patients had a successful outcome in regard to cosmesis and function. One patient in whom a 15 cm. neourethra was created had a subglanular fistula. CONCLUSIONS: The use of a collagen inert matrix appears to be beneficial in patients who have undergone previous hypospadias repair and who may lack sufficient genital skin for reconstruction.

Urodynamic findings in children with isolated epispadias.

PURPOSE: The exstrophy-epispadias complex represents a spectrum of anomalies with variable implications for upper and lower urinary tract function. Successful treatment of incontinence in this population is challenging and often elusive. To date few studies have focused on urodynamic findings specific to primary epispadias. MATERIALS AND METHODS: We retrospectively reviewed the records of patients presenting with primary epispadias in the absence of bladder exstrophy. We identified 18 boys and 12 girls, of whom 16 underwent formal urodynamic evaluation before (5), after (6) or before and after (5) surgical narrowing of the bladder neck. Bladder capacity was recorded as percent of expected capacity for age. Bladders were considered hypertonic when end filling pressure was greater than 20 cm. water. End filling pressure was defined as the pressure at which urinary leakage was noted or the patient had discomfort. Uninhibited contractions were considered significant when the amplitude was greater than 15 cm water. The ability of the detrusor to generate a voiding contraction at the end of the filling phase was also recorded. Urodynamic studies were performed with a balloon catheter occluding the incompetent bladder neck or with a standard urodynamic catheter after formal bladder neck repair. RESULTS: Before bladder neck repair average bladder capacity was 157 ml (range 55 to 450), corresponding to 52% (range 22 to 100) of expected capacity. Significant uninhibited contractions were noted in 2 patients. In 7 of the 9 evaluable patients (78%) a voiding contraction was generated. In children in whom urodynamic studies were done after surgery mean bladder capacity was 260 ml (range 77 to 660), corresponding to 76% (range 36 to 147) of expected capacity. Hypertonicity and hyperreflexia were noted in 3 and 2 patients, respectively. In 5 of the 11 cases (46%) a voiding bladder contraction was generated. Of the 5 patients who underwent urodynamic evaluation before and after bladder neck repair the percent increase in bladder capacity was significantly greater in the 2 boys (67 and 110%, respectively) than in the 3 girls (-20, 10 and 20, respectively). CONCLUSIONS: The most frequently noted urodynamic pattern before surgical correction of the bladder neck in patients with isolated epispadias is a low capacity, highly compliant bladder with minimal detrusor dysfunction. Postoperatively capacity increases, albeit to a greater extent in boys than in girls, and the incidence of detrusor dysfunction increases as well. In some patients classic bladder neck repair may result in detrimental bladder dynamics due to as yet poorly elucidated mechanisms.

Current trends in hypospadias repair.

There is no single, universally applicable technique for hypospadias repair. Command of a technically straightforward repair with few complications and proven success and versatility in a reasonable range of hypospadias defects are desired goals. Several well-established techniques exist for the repair of all hypospadias defects. The Snodgrass tubularized incised plate urethroplasty, a recent contribution with exemplary early results, has become a popular technique for primary and preoperative repair of middle and anterior hypospadias. Other innovative modifications, and technical advances, such as the use of laser and tissue solder, continue to emerge. With time, these may herald improvements to even the most basic of sound principles involved in all hypospadias repair.

Renal findings on radiological followup of patients with Beckwith-Wiedemann syndrome.

PURPOSE: The Beckwith-Wiedemann syndrome is most commonly characterized by macroglossia and abdominal wall defect(s), and it carries a predisposition to embryonal tumors, including Wilms tumor. We report our experience with the character and incidence of renal disease in patients with the Beckwith-Wiedemann syndrome, and discuss the role of radiological followup. MATERIALS AND METHODS: We reviewed the medical records of all patients diagnosed with the Beckwith-Wiedemann syndrome who were treated at our institution between March 1979 and February 1998. Radiological followup consisted of renal ultrasound at approximately 3 to 6-month intervals with the addition of computerized tomography or magnetic resonance imaging (MRI) in patients with an indeterminate lesion(s) or nephrogenic rest(s). RESULTS: A total of 29 patients were identified. Of these cases renal ultrasound showed normal kidneys bilaterally in 19 (70%), simple cysts in 5 (19%), indeterminate lesion(s) in 2 (7%) and nephrocalcinosis in 1 (4%). Nephrogenic rests were followed with MRI in 1 patient, and 1 in whom a 2 cm. mass was revealed by followup MRI underwent partial nephrectomy and chemotherapy for stage I Wilms tumor. CONCLUSIONS: The 3.7% incidence of Wilms tumor in our patients with the Beckwith-Wiedemann syndrome is similar to that in previously published reports. Aggressive follow-up by a sensitive radiological technique is warranted in cases of the Beckwith-Wiedemann syndrome, and associated hemihypertrophy and/or nephromegaly with or without evidence of a Wilms tumor precursor. The detection of suspected malignant disease at an early stage may permit curative nephron sparing surgery.

Reservoir calculi: a comparison of reservoirs constructed from stomach and other enteric segments.

PURPOSE: The intestinal augmented bladder has an increased propensity to form urinary calculi. Predisposing risk factors include chronic bacteriuria, urinary stasis and mucus production. Gastric reservoirs have negligible mucus production and the ability to acidify the urine. We determined whether they also have a decreased incidence of stones. MATERIALS AND METHODS: We retrospectively reviewed the records of all patients undergoing augmentation cyptoplasty (215) or creation of a freestanding reservoir (44) between May 1976 and March 1996. Of these cases 83 were augmented with stomach and 179 were constructed from other intestinal segments, (that is ileal, ileocecal, sigmoid and/or a combination of these). Presenting diagnosis, patient age, gender, additional surgical procedures, interval to stone formation and calculous composition were recorded. Patients were excluded from study when there was less than 1 year of followup, as were those with renal or pre-augmentation bladder calculi. RESULTS: Stones formed in 32 of 207 patients (15%) after an average interval of 3.6 years (range 0.5 to 8.6). The majority of stones were composed of struvite (magnesium ammonium phosphate). Reservoirs containing gastric segments were significantly less likely to form calculi than those augmented with other intestinal segments (2 of 70 versus 30 of 137, p <0.0001 Fisher's exact test). Seven additional patients with pre-augmentation bladder stones who subsequently underwent gastrocystoplasty remain stone-free at an average followup of 3.0 years. CONCLUSIONS: Calculous formation is rare in reservoirs that incorporate a gastric segment. In patients with gastric augmentation stones appear only to develop when the patient is on histamine blockade or has a propensity to form stones that only favor an acidic environment, such as uric acid.