Uroepithelial thickening improves detection of vesicoureteral reflux in infants with prenatal hydronephrosis.

INTRODUCTION: Postnatal evaluation of prenatal hydronephrosis (PNH) often includes a voiding cystourethrogram (VCUG) for VUR assessment. Despite limited supporting data, VCUG is currently recommended if postnatal renal and bladder ultrasound (RBUS) reveals moderate/severe hydronephrosis (HN) or hydroureter (HU). Recent studies have shown VUR is more accurately diagnosed by using certain sonographic findings as criteria for obtaining VCUG. Uroepithelial thickening (UET) of the renal pelvis is a finding associated with high-grade vesicoureteral reflux (HGVUR); however, the clinical significance of UET with PNH has not been studied. OBJECTIVE: We sought to determine if the presence of UET implies increased risk for VUR, and to investigate whether UET can improve the test characteristics of RBUS for VUR. STUDY DESIGN: We retrospectively analyzed postnatal RBUS and VCUG findings in infants ≤30 days undergoing evaluation for "prenatal hydronephrosis" over an 11-year period. We used logistic regression to identify factors associated with VUR. Test characteristics of RBUS for HGVUR were compared based on the presence of UET and two criteria sets to define abnormal RBUS. Criteria set 1 consisted of HN SFU grade 3-4 and/or HU; criteria set 2 was defined by the presence of two of following: UET, HU, duplication, and/or renal dysmorphia. RESULTS: Of 135 patients, 39 (29%) had VUR, of whom 16 (41%) had HGVUR. UET was significantly associated with VUR (p < 0.001), and the sensitivity for HGVUR based on UET alone was 94%. On multivariable analysis, UET, HU, duplication, and renal dysmorphia remained significant independent predictors of HGVUR. Compared to criteria 1, using criteria 2 resulted in 43 fewer VCUGs, and significant improvement in sensitivity and specificity for HGVUR (Table). DISCUSSION: Consistent with previous studies, HN alone on postnatal RBUS has little value in predicting the presence or severity of VUR. This study is the largest known series to evaluate UET in the setting of PNH, and our results demonstrate that UET, as well as HU, duplication and renal dysmorphia, are independent sonographic findings predicting HGVUR. Using our proposed criteria, the probability of HGVUR is fourfold more than the prevalence described in the literature, and importantly, when compared to the criteria recommended by the SFU and AUA, would have resulted in 53% fewer VCUGs while missing zero cases of HGVUR. CONCLUSION: In infants with PNH, the sonographic findings of UET, HU, duplication and renal dysmorphia independently indicate greater risk of HGVUR, and the sensitivity and specificity of RBUS for HGVUR is markedly improved when at least two of the four are present.

Epidural pressure changes following caudal blockade: a prospective, observational study.

PURPOSE: Recent case reports raise the question as to whether anesthetic agents injected into the epidural space could lead to a 'compartment syndrome' and neurovascular sequelae. Single-shot caudal epidural anesthesia has been established as a safe technique, but changes in pressure in the caudal epidural space have not been described. Our aim was to study pressure changes to provide preliminary information for future studies design. METHODS: We prospectively measured the pressure changes in the caudal epidural space in 31 pediatric patients. The pressures were measured at loss of resistance, immediately after the bolus dose of local anesthetic (1 ml/kg), and at 15-s intervals up to 3 min. RESULTS: The pressure at loss of resistance was 35.6 ± 27.8 mmHg. A pulsatile waveform was observed once the epidural space was accessed. The pressure after administration of the local anesthetic bolus (1 ml/kg 0.2 % ropivacaine/bupivacaine with 1:200,000 epinephrine) was 192.5 ± 93.3 mmHg. The pressure decreased to 51.5 ± 39.0 mmHg at 15 s, 26.9 ± 9.9 mmHg after 2 min, and 24.7 ± 11.7 after 3 min. The return to baseline occurred at approximately 45-60 s. CONCLUSIONS: Following the administration of the local anesthetic into the caudal epidural space, there was a marked, but transient, increase in the pressure within the epidural space. It appears unlikely that a slow epidural catheter infusion could lead to a sustained increase in epidural pressure.

Successful transcloacal ureteral stent removal.

We report a percutaneous transcloacal approach for removal of a ureteral stent in a 15-year-old girl with a cloacal anomaly, spinal dysraphism, and complex pelvic anatomy, including a bicornuate uterus, reconstructed hindgut neobladder, and duplicated left pelvic kidney. The patient had undergone 3 previous unsuccessful attempts at stent removal, 2 endoscopic attempts by way of her neobladder, and 1 percutaneous transcloacal attempt before successful removal.

Computer enhanced visual learning method to train urology residents in pediatric orchiopexy provided a consistent learning experience in a multi-institutional trial.

PURPOSE: Computer enhanced visual learning is a new method to train residents to perform surgery using components and provide them with access to a personalized surgical feedback archive using the Internet. At the parent institution in Chicago we have already noted that this method is effective to train residents to perform orchiopexy. To assess whether this new methodology to enhance resident surgical instruction is generalizable we performed a prospective, multi-institutional clinical trial. MATERIALS AND METHODS: We prospectively compared ratings of resident skills in performing pediatric orchiopexy at 4 institutions as novices to computer enhanced visual learning curriculum (study group) vs those at the single institution accustomed to that curriculum (control group). All urology residents and attending physicians accessed the computer enhanced visual learning curriculum. After each case was completed the attending urologist rated resident performance of each step and provided feedback on weaknesses for the resident to remediate at the next case. The learning score was calculated for each case as the sum of the ratings × case difficulty. Scores on the first case and the best case were compared between the study and control groups by resident and institution. RESULTS: The study group included 6 attending physicians and 36 residents (99 orchiopexies). The control group included 8 attending physicians and 21 residents (108 orchiopexies). Between the study and control groups we noted no significant differences in average resident postgraduate year (2.9 vs 2.7), number of procedures per resident (3.9 vs 4.9), frequency with which residents viewed computer enhanced visual learning preoperatively (63% vs 74%) or attending physician provision of feedback (63% vs 88%) (each p not significant). Similarly of residents who completed more than 1 surgery there was no significant difference in the percent who showed an improved learning score in the study vs the control group (86% vs 79%) or in the magnitude of average improvement (10.5 vs 13.4) (each p not significant). CONCLUSIONS: The institutional groups did not differ in training resident skills using computer enhanced visual learning for pediatric orchiopexy. Thus, the program provides a consistent learning experience and is generalizable across institutions. We believe that this tool will change the practice of how training programs educate residents by enhancing learning by a checklist approach and a computer platform to archive feedback and remediation.

Urinary tract infections in children: recommendations for antibiotic prophylaxis and evaluation. An evidence-based approach.

Urinary tract infections (UTIs) are common in children, but the routine work-up and treatment recommendations are still controversial. Long-term complications, including renal scarring, hypertension, and renal failure, have been the main concern and the reason for use of antibiotic prophylaxis and invasive imaging techniques. In the past several years, numerous studies have been published comparing different imaging protocols and questioning the use of antibiotic prophylaxis. The latest guidelines from the United Kingdom, published in 2007, recommend more selective approach based on evidence. In this review, we critically appraise the literature published in the past 5 years. The risk of developing long-term complications after a UTI is extremely low, and the evidence suggests selective imaging to a select group of children at risk. Finding those at risk for long-term complications is yet to be determined.

Intermittent torsion of the spermatic cord portends an increased risk of acute testicular infarction.

PURPOSE: Intermittent torsion of the spermatic cord is an episode of acute torsion of the spermatic cord that resolves spontaneously. We compared the outcomes in boys with intermittent spermatic cord torsion treated electively with testicular fixation with those in boys with a history of recurrent scrotal pain who required emergent operation for acute spermatic cord torsion without spontaneous resolution. MATERIALS AND METHODS: A retrospective review revealed 17 boys who required emergency operation for acute spermatic cord torsion and 30 who underwent elective surgery for intermittent spermatic cord torsion. The clinical presentation, number of recurrent painful episodes, lead time to operation, prior alternate diagnoses, intraoperative findings and clinical outcomes were recorded. RESULTS: There was a mean of 2 recurrent painful episodes in the elective group and 3 in the emergency group (p <0.005). In the elective group all boys were cured of pain after bilateral testicular fixation with 100% testicular preservation at a mean of 4 months of followup. In the emergency group at a mean of 10 months of followup the testicular preservation rate was 47% (p <0.01). Intraoperatively an ipsilateral bell clapper malformation was found in 100% of boys in each group. A contralateral bell clapper malformation was noted in 90% and 88% of boys in the elective and emergency groups, respectively. CONCLUSIONS: When diagnosed accurately, intermittent spermatic cord torsion can be treated with elective testicular fixation with an excellent outcome. Misdiagnosis may create a cohort of boys with intermittent spermatic cord torsion who are at risk for acute unresolved torsion and potential testicular loss. Urologists should be proactive in recommending elective scrotal exploration when intermittent spermatic cord torsion is a likely diagnosis.

Collagen directly stimulates bladder smooth muscle cell growth in vitro: regulation by extracellular regulated mitogen activated protein kinase.

PURPOSE: Bladders clinically subjected to excessive pressure or distention demonstrate an altered extracellular matrix (ECM) composition. We determined how an altered collagen substratum might affect bladder smooth muscle cell (bSMC) growth in vitro and probed the mechanism of this response. MATERIALS AND METHODS: Primary culture rat bSMCs were seeded onto culture plates pre-coated with normal type I collagen (NC) or heat denatured type I collagen (DNC) under standard culture conditions. In separate experiments bSMCs from the 2 substrates were enzymatically released and changed to growth on normal collagen (NC-->NC or DNC-->NC) or denatured collagen (DNC-->DNC or NC-->DNC). At 24 hours proliferation was assessed by 3H-thymidine incorporation. Statistical significance in triplicate wells was determined by ANOVA. RESULTS: The proliferation of bSMCs on DNC was 5-fold greater than on NC (p <0.0001). Passage onto damaged collagen (DNC-->DNC) showed 2-fold further augmentation in proliferation (p <0.0001) but only a 50% decrease when NC was reintroduced (DNC-->NC) (p <0.001). Conversely replating on NC (NC-->NC) generated a 33% decrease in the already low proliferation rate (p <0.001) but 9-fold stimulation of proliferation when changed to damaged ECM (NC-->DNC) (p <0.0001). The mitogenic effect of damaged ECM on bSMC growth was abolished by specific inhibition of extracellular regulated kinase mitogen activated protein kinase signaling using PD98059. CONCLUSIONS: Damaged type I collagen (ECM) is mitogenic to bSMCs. The response is amplified by re-exposure to DNC. However, mitogenicity is only partially reversible by re-introducing NC. These results demonstrate striking bSMC responsiveness to ECM conformation. Signaling through the extracellular regulated kinase mitogen activated protein kinase pathway supports bSMC-ECM interaction. We speculate that remodeling the ECM in vivo may regulate bSMC growth.

Single layered small intestinal submucosa in the repair of severe chordee and complicated hypospadias.

PURPOSE: Severe ventral chordee often accompanies proximal hypospadias. We describe our experience with single layered small intestinal submucosa (SIS), a commercially available, acellular, collagen based biomaterial, in the repair of severe chordee as part of a multistage approach to the repair of proximal hypospadias. MATERIALS AND METHODS: Between 2001 and 2002, 9 boys with proximal hypospadias (penoscrotal to perineal) and severe ventral chordee (greater than 40 degrees) underwent SIS grafting to correct the curvature. In each case the urethral plate was transected at the point of maximal curvature, the defect in the corporal bodies was measured, and the SIS graft was cut 2 mm wider around the perimeter of the defect and sutured into place. Skin resurfacing of the ventral penis was performed in standard fashion using Byars flaps. Recurrence of chordee was assessed by an artificial penile erection test at the time of stage 2 reconstruction. RESULTS: Of the 9 boys 8 underwent a planned 2-stage repair with subsequent urethroplasty 6 to 12 months after the initial stage 1 chordee repair. Median age at stage 1 repair of the 8 boys was 9 months. Native meatus location was penoscrotal in 6 boys, mid scrotal in 1 and perineal in 1. A 14 month-old boy underwent 1-stage chordee correction with SIS and a transverse preputial island tube graft urethroplasty for penoscrotal hypospadias. There were no perioperative medical or surgical complications related to use of SIS for chordee repair. Median age of the 8 boys at stage 2 repair was 18 months. At stage 2 the graft site was supple and smooth without significant scarring. All chordee correction has remained durable with followup ranging from 16 to 21 months. Postoperative complications occurred in 3 cases, including meatal stenosis requiring meatoplasty, subcoronal fistula requiring repair and complete breakdown of the neourethra in the single stage repair case. CONCLUSIONS: Although this study includes a small population of patients and has limited followup, our favorable experience with single layer SIS suggests that it is a safe and effective, commercially available material for corporal body grafting to correct severe chordee as part of a multistage surgical approach to repair complex hypospadias. A larger series of patients with longer followup is necessary to determine if the chordee correction remains durable. Our experience is insufficient to judge its efficacy in single stage repairs.

Long-term results of pediatric renal transplantation into a dysfunctional lower urinary tract.

BACKGROUND: The authors reviewed their long-term experience with pediatric renal transplantation into a dysfunctional lower urinary tract to evaluate the results of contemporary lower urinary tract evaluation and management on graft survival and function. METHODS: Between 1990 and 1996, 21 renal transplants were performed in 20 children with dysfunctional lower urinary tracts and 61 transplants were performed in 61 patients with normal lower urinary tracts. The minimum follow-up was 36 months (mean, 62.0 +/- 19.6 months). The cause of lower urinary tract dysfunction included posterior urethral valves (n=13), prune belly syndrome (n=4), meningomyelocele (n=2), and urogenital sinus abnormality (n=1). Urodynamics were performed on all children with dysfunctional lower urinary tracts. Using these perioperative assessments, lower tract management strategies were devised, including timed voiding alone (n=6), clean intermittent catheterization (n=8), bladder augmentation (n=4), and supravesical urinary diversion (n=2). RESULTS: Overall 5-year actuarial patient and graft survival rates were 100% versus 95% (P=not significant [NS]) and 83% versus 69% in the dysfunctional and normal urinary tract groups (P=NS), respectively. Mean serum creatinine levels in dysfunctional and normal urinary tract patients with functioning grafts at 3 years were 1.3 +/- 0.5 and 1.3 +/- 0.7 mg/dL, respectively (P=NS). However, 35% of patients with a dysfunctional lower urinary tract experienced urologic complications. CONCLUSIONS: Pediatric renal transplantation into a dysfunctional lower urinary tract yields outcomes comparable to transplantation into the normal lower urinary tract. Because of the high urologic complication rates, careful surveillance of lower urinary tract function by urodynamic evaluation is essential to optimize these outcomes.