MAGNETIC RESONANCE IMAGING OF PELVIC MUSCULOSKELETAL AND GENITOURINARY ANATOMY IN PATIENTS BEFORE AND AFTER COMPLETE PRIMARY REPAIR OF BLADDER EXSTROPHY

PURPOSE

We characterize pelvic soft tissue and bony anatomy of patients before and after complete primary repair of exstrophy (CPRE).

MATERIALS AND METHODS

We evaluated 15 measurements on pelvic magnetic resonance imaging (MRI) in patients who underwent CPRE without osteotomy at our institution from 1996 to 2004. MRI protocols included axial, sagittal and coronal fast spin echo proton density sequences. Measurements were compared before and after CPRE using a paired t test, and between patients after CPRE, and age and gender matched controls using linear regression adjusting for the matched case-control groups. Patients older than 3 years with continent intervals longer than 3 hours after CPRE were compared to age and gender matched controls using linear regression.

RESULTS

A total of 29 MRIs in 18 patients with exstrophy were available for analysis. Median patient age at postoperative MRI was 25 months (range 4 to 36). The configuration of the post-CPRE pelvis was significantly different from that of controls in all parameters measured including wider symphyseal diastasis (34.5 mm vs less than 1 mm) and more obtuse iliac wing (121 degrees vs 98 degrees), puborectalis (94 degrees vs 49 degrees) and ileococcygeus angles (111 degrees vs 98 degrees ). The anatomy of continent patients after CPRE was not significantly different from that of controls in most parameters measured.

CONCLUSIONS

Comparison of the pelvic anatomy in patients before and after CPRE suggests that after CPRE patients have parameters that more closely approximate, but are still significantly different, from those of control patients. Patients with greater than 3-hour continent intervals after CPRE have anatomic parameters most similar to those of age matched controls.

INTERMITTENT TESTICULAR TORSION: DIAGNOSTIC FEATURES AND MANAGEMENT OUTCOMES

PURPOSE

Intermittent testicular torsion (ITT) is a poorly characterized condition but harbors potentially serious implications with regard to testicular viability. We report better characterization of the diagnostic features of ITT.

MATERIALS AND METHODS

We performed a retrospective review of all patients 1 to 18 years old seen from 1997 to 2003 at our institution diagnosed with ITT. Patients with acute scrotal pain and spontaneous resolution who underwent bilateral testicular fixation were included in the study.

RESULTS

A total of 50 patients meeting the inclusion criteria were identified with mean age at presentation of 12.2 years (range 4 to 17). The mean number of painful episodes before surgery was 4.3 (range 1 to 30). The most common presenting features were severe pain of rapid onset and resolution. Nausea and/or vomiting was reported in a quarter of the patients. Finding of a horizontal lie of the testes on examination was significantly associated (p <0.05) with the existence of the bell-clapper deformity. All patients underwent surgical fixation of the testes. There were no postoperative complications. Of 38 patients (97%) for whom followup was available 37 had complete resolution of symptoms (mean followup 7.9 months).

CONCLUSIONS

ITT should be a diagnostic consideration in patients who present with recurrent acute scrotal pain with rapid spontaneous resolution. Recurrent severe pain with rapid onset and resolution seems to be highly characteristic. Horizontal lie on examination is highly correlated with the bell-clapper deformity at surgical exploration. Surgery may be recommended in these patients as it appears to result in pain relief in the majority, is likely to prevent future testicular infarction and is associated with low morbidity.

Pediatric retroperitoneal laparoscopic partial nephrectomy: comparison with an age matched cohort of open surgery

PURPOSE

We assessed the clinical usefulness of laparoscopic retroperitoneal partial nephrectomy (LRPN) in children by comparing an age matched cohort of pediatric patients undergoing open partial nephrectomy (OPN) to those undergoing LRPN for safety, efficacy, operative time, blood loss, inpatient narcotic use and length of hospitalization.

MATERIALS AND METHODS

A retrospective case-control study was performed of 1 group undergoing LRPN (treatment arm) and 1 undergoing OPN (controls) between 1997 and 2003. The 14 patients in each group were matched by age (mean 1.9 years in LRPN group vs 2.2 years in OPN group, p = 0.98) and gender.

RESULTS

All patients had duplication anomalies. Mean operative time was 194 minutes in the LRPN group and 193 minutes in the OPN group (p = 0.83). The single complication in the LRPN group was a urinoma that did not require intervention. There were no complications in OPN group. LRPN patients had a mean hospitalization of 1.7 days compared to 4.7 days in OPN patients (p = 0.001). Intraoperative narcotic requirements were higher in the LRPN group (0.59 vs 0.22 mg/kg, p = 0.04). Postoperative narcotic requirements were significantly less in the LRPN group (0.44 vs 1.53 mg/kg, p = 0.04). Similar findings were noted in a subanalysis of patients younger than 2 years. All patients had documented postoperative ipsilateral renal growth. Mean followups in the treatment and control groups were 26 and 25 months, respectively.

CONCLUSIONS

Retroperitoneal laparoscopic partial nephrectomy in small children was shown to be safe and effective. It had equivalent operative times, and decreased postoperative narcotics and hospitalization relative to the open approach, and, therefore, is a potentially advantageous technique.

IS ADOLESCENT VARICOCELE A PROGRESSIVE DISEASE PROCESS?

PURPOSE

We determined whether there was evidence of progression in either varicocele grade or testicular volume differentials over time in our adolescent varicocele population.

MATERIALS AND METHODS

A total of 41 boys 7.3 to 19 years old (mean age 13.7, SD 2.5) were seen at sequential visits. At each visit varicocele grade was determined by the attending urologist and ultrasound calculated testicular volume differential was determined by an attending ultrasonographer. A senior staff statistician performed statistical analysis of the sequential data.

RESULTS

The varicocele grade data were analyzed using the nonparametric Wilcoxon test and no significant evidence of progression on sequential visits was demonstrated. Similarly, the serial volume differential data were assessed using the paired t test and no significant evidence for progression of testicular volume differentials was demonstrated.

CONCLUSIONS

In our study population neither varicocele grade nor change in testicular volume differentials increased over time in a statistically significant manner. These results argue against the concept that adolescent varicocele is a progressive disease process.

Current management of bladder exstrophy

Bladder exstrophy is a complex anomaly involving the urinary, genital, and intestinal tracts and the musculoskeletal system. The diagnosis is made typically at the newborn examination or on fetal ultrasonography that is performed by an experienced observer. Management of bladder exstrophy presents several challenges, beginning with initial repair using the more conventional staged approach or the recently re-popularized complete primary repair technique. Major goals in the management of bladder exstrophy are preservation of normal kidney function, close observation for development of adequate bladder function including urinary continence, and provision of acceptable cosmesis and function of the external genitalia. This article provides a brief overview of bladder exstrophy and a detailed description of modern management.

Neonatal scrotal haematoma: mimicker of neonatal testicular torsion

OBJECTIVE

To describe the clinical features of neonatal scrotal haematoma and distinguish them from those of neonatal testicular torsion.

PATIENTS AND METHODS

Five neonates presenting with an acute scrotum and initial diagnosis of neonatal testicular torsion were found to have neonatal scrotal haematoma. In one case the diagnosis was surgical and in four subsequent cases the diagnosis was by colour Doppler ultrasonography, and surgery was avoided. Four of the five children had risk factors associated with neonatal scrotal haematoma, including bleeding diathesis, birth trauma and high birth weight.

CONCLUSIONS

The importance of including haematoma in the differential diagnosis of the acute neonatal scrotum is emphasized, as is the value of contemporary Doppler ultrasonography in making this diagnosis.

Fibroepithelial polyps causing ureteropelvic junction obstruction in children

PURPOSE

Fibroepithelial polyps are benign mucosal projections that can be found throughout the urinary system. We review our experience with fibroepithelial polyps of the ureteropelvic junction in children to define more clearly this entity and its outcome following treatment.

METHODS

We reviewed the records of all children with fibroepithelial polyps causing ureteropelvic junction obstruction treated at our institution between December 1967 and February 2002.

RESULTS

Nine patients 6 weeks to 9 years old had 11 ureteropelvic junction obstructions secondary to fibroepithelial polyps, representing a 0.5% incidence of all ureteropelvic junction obstructions seen during that period. The majority of the patients were male (89%) and had obstruction on the left side (78%). Only 22% of the patients had a diagnosis of obstructing polyps suggested preoperatively. All patients underwent dismembered pyeloplasty but 1 required subsequent nephrectomy due to progressive loss of renal function. All lesions were characterized microscopically by polypoid projections of fibrous tissue covered by epithelium and demonstrating varying degrees of inflammation. No recurrences were seen during a mean followup of 44 months.

CONCLUSIONS

Fibroepithelial polyps are rare lesions that cause ureteropelvic junction obstruction in children, primarily in males and on the left side. Filling defects were diagnosed preoperatively in 22% of the patients in this series. Excision and dismembered pyeloplasty were curative, and recurrences were not observed. The etiology of this disease remains obscure.

A nuclear form of the heparin-binding epidermal growth factor-like growth factor precursor is a feature of aggressive transitional cell carcinoma

Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the ErbB receptor ligand family, exists in distinct molecular forms with disparate biological activities. Previous studies have shown that the HB-EGF precursor, proHB-EGF, localizes to the cytoplasm of transitional cells of the human bladder urothelium and that the soluble form of the growth factor is an autocrine urothelial cell mitogen. In this study, we identify a potential role for proHB-EGF in transitional cell carcinoma (TCC) of the bladder. In an analysis of 33 TCC specimens and 8 normal controls, proHB-EGF, identified using an antibody directed against the cytoplasmic tail domain, localized to cell nuclei in a manner that correlated positively with tumor stage and grade (P < 0.001). The ability of proHB-EGF to localize to the nucleus was independently confirmed in a TCC cell line (TCCSUP), in which approximately 40% of transfected proHB-EGF was found to reside in the nuclear compartment. In Kaplan-Meier survival analysis, TCC patients with >20% proHB-EGF-positive cell nuclei demonstrated markedly reduced survival compared with patients with <20% proHB-EGF-positive nuclei (P < 0.005, log-rank test). In multivariate analysis, nuclear localization of proHB-EGF of >20% was an independent prognostic indicator of disease-specific mortality. This is the first report in any cell type that HB-EGF is capable of translocating to the cell nucleus. In addition, our findings suggest that nuclear proHB-EGF may play a role in disease progression in bladder cancer and possibly other cancers.

Rate and predictors of spontaneous resolution of prenatally diagnosed primary nonrefluxing megaureter

PURPOSE

We assessed clinical and ultrasound predictors of the spontaneous resolution of prenatally diagnosed, primary nonrefluxing megaureter.

MATERIALS AND METHODS

Primary nonrefluxing megaureter was prenatally diagnosed in 54 neonates from 1993 to 1998, including 15 in whom it was bilateral (69 megaureters). Median followup period from birth to the last radiology examination was 25.8 months (range 2.3 to 72).

RESULTS

Of the patients 10 underwent surgical repair for severe hydroureteronephrosis, including decreasing renal function on diuretic renography in 1, and an episode of bilateral obstruction and acute renal failure in 1. Hydroureteronephrosis resolved in 39 cases (72%) and persisted in 5 at 30 to 72 months of followup. Laterality, gender and retrovesical ureteral diameter had no significant effect on the resolution rate (p >0.05). Mean initial ureteral diameter in patients with resolution was less than in those without resolution and in those who underwent surgery (0.8 versus 1.15 and 1.32 cm., respectively). Presenting hydronephrosis grade was a significant predictor of the resolution rate (p = 0.03). Grades 1 to 3 hydronephrosis resolved at a median age of 12.9, 23.9 and 34.6 months, respectively (range 4.1 to 66). In patients in whom grades 4 and 5 hydronephrosis resolved the median age at resolution was 48.5 months.

CONCLUSIONS

Most cases of prenatally diagnosed, primary nonrefluxing megaureter resolve spontaneously. Grades 1 to 3 hydronephrosis tend to resolve between ages 12 and 36 months. For these grades followup intervals may be progressively elongated after a pattern of improving hydronephrosis has been established. In children with grade 4 or 5 hydronephrosis, or a retrovesical ureteral diameter of greater than 1 cm. the condition may resolve slowly and require surgery.

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.

Testicular volume: comparison of orchidometer and US measurements in dogs

PURPOSE

To compare the accuracy and precision of orchidometer and ultrasonographic (US) measurements of testicular volume in a canine model.

MATERIALS AND METHODS

Volume measurements of 18 canine testes were obtained by using Prader and Rochester orchidometers. Testes were scanned with two linear-array US transducers with imaging frequencies of 6-13 MHz and 5-10 MHz. For each transducer, testicular volumes were calculated by using three formulas: length (L) x width (W) x height (H) x 0.52, L x W(2) x 0.52, and L x W x H x 0.71. Testes were weighed following bilateral orchiectomies. True testicular volume was determined by using the formula volume = weight/density. Paired t tests were used to assess whether mean measurement biases differed significantly from zero. The relationship between true and measured volume was evaluated with a linear regression model.

RESULTS

US volume measurements demonstrated lower variability and better linear fit compared with orchidometry (R(2) = 0.75-0.90 vs R(2) = 0.14-0.38). The formula L x W x H x 0.71 had the smallest mean bias relative to true volume with use of either transducer over the entire volume range.

CONCLUSION

US methods of testicular volume measurement are more accurate and precise than orchidometry. The formula L x W x H x 0.71 provides a superior estimate of testicular volume and should be used in clinical practice.

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.

The spectrum of Sertoli cell tumors in children

The spectrum of Sertoli cell tumors in children covers a wide range of testis and ovarian tumors classified as sex cord-stromal tumors. Sertoli cell tumor of the testis is extremely rare in the pediatric population. The American Academy of Pediatrics Section on Urology Prepubertal Testicular Tumor Registry has reported a total of six cases of Sertoli cell tumor of the testis, accounting for 1.3% of the 430 cases reported to the registry as of October 1996. Despite their rarity, Sertoli cell variants of sex cord-stromal tumors have generated keen interest because of their variable histologic appearance and biologic behavior, including endocrine activity. Because sex cord-stromal tumors occur in the ovary and testis, a primitive cellular origin to these tumors is likely in males and females.

Ketorolac suppresses postoperative bladder spasms after pediatric ureteral reimplantation

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.

Pediatric retroperitoneoscopic nephrectomy

The endoscopic retroperitoneal (retroperitoneoscopic) approach to extirpative intervention for benign renal disease is increasingly popular. We describe several modifications of this approach, including the use of prone positioning and 2-mm instruments, that may improve the safety and efficacy of the technique in children. These modifications provide unobstructed views of the kidney and renal hilum and facilitate dissection in a small working space.

Amphiregulin is coordinately expressed with heparin-binding epidermal growth factor-like growth factor in the interstitial smooth muscle of the human prostate

Peptide growth factors have been proposed as mediators of smooth muscle-epithelial cell interactions in the human prostate; however, the identity of these molecules has not been established. In this study, we compared expression levels of messenger RNAs (mRNAs) encoding the epidermal growth factor (EGF) receptor-related receptor tyrosine kinases (ErbB1 through 4), the six EGF receptor ligands, EGF, transforming growth factor (TGF)-alpha, amphiregulin (ARG), HB-EGF, betacellulin, and epiregulin, and the related molecule heregulin-alpha, in a series of 10 prostate tissue specimens. Only EGF showed a disease-specific association, with increased mRNA levels in four of five PCa specimens in comparison to matched normal tissue from the same subject. In contrast, ARG and HB-EGF mRNAs showed a coordinate pattern of expression in 7/10 specimens that was distinct from all other growth factor or receptor genes examined and from mRNAs for prostate specific antigen, the androgen receptor and GAPDH, a house-keeping enzyme. Analysis of an additional series of benign prostatic hyperplasia and prostate cancer specimens from 60 individuals confirmed that ARG and HB-EGF mRNA levels varied in a highly coordinate manner (r = 0.93; P < 0.0001) but showed no association with disease. ARG was immunolocalized largely to interstitial smooth muscle cells (SMC), previously identified as the site of synthesis of HB-EGF in the prostate, while the cognate ARG and HB-EGF receptor, ErbB1, was localized exclusively to ductal epithelial cells and carcinoma cells. Although ARG was a relatively poor mitogen for Balb/c3T3 cells in comparison to HB-EGF, it was similar in potency to HB-EGF in stimulating human prostate epithelial cell growth, suggesting that prostate epithelia may be a physiologic target for ARG in vivo. Expression of both ARG and HB-EGF mRNAs was induced in cultured prostate SMC by fibroblast growth factor-2, a human prostate SMC mitogen linked to prostate disease. These findings indicate that ARG and HB-EGF are likely to be key mediators of directional signaling between SMC and epithelial cells in the human prostate and appear to be coordinately regulated.

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.

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.

Stretch activates heparin-binding EGF-like growth factor expression in bladder smooth muscle cells

Cultured rat bladder smooth muscle cells (SMC) were grown on collagen-coated silicone membranes and subjected to continuous cycles of stretch-relaxation. Semiquantitative RT-PCR analysis revealed a time-dependent increase in heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) mRNA levels after stretch, with maximal levels appearing after 4 h. Immunostaining for proHB-EGF revealed higher levels of HB-EGF protein in the stretched than in the nonstretched SMC. The ANG II receptor type 1 antagonist losartan markedly suppressed stretch-activated HB-EGF expression. ANG II levels were 3.3-fold higher in the stretch- than in the non-stretch-conditioned media. Stretch stimulation of bladder SMC that had been transiently transfected with an HB-EGF promoter-luciferase expression construct resulted in an 11-fold increase in reporter activity. Mechanical stretch induced a 4.7-fold increase in tritiated thymidine incorporation rate, and this was reduced by 25% in the presence of losartan. We conclude that mechanical stretch activates HB-EGF gene expression in bladder SMC and that this is mediated in part by autocrine ANG II secretion.

Large-cell calcifying Sertoli cell tumor of the testis: case report and review of the literature

Large-cell calcifying Sertoli cell tumor (LCCSCT) is a rare sex cord-stromal tumor found predominantly in the pediatric population. This tumor has distinctive histopathologic features and clinical associations. LCCSCT has also been noted in association with the Carney complex, and in patients with Peutz-Jeghers syndrome. The propensity to metastasize is low, and radical orchiectomy has traditionally been the treatment of choice.