Combining Oxygenated Cold Perfusion With Normothermic Ex Vivo Perfusion Improves the Outcome of Donation After Circulatory Death Porcine Kidney Transplantation

BACKGROUND

Ex vivo machine perfusion is a novel preservation technique for storing and assessing marginal kidney grafts. All ex vivo perfusion techniques have advantages and shortcomings. The current study analyzed whether a combination of oxygenated hypothermic machine perfusion (oxHMP) followed by a short period of normothermic ex vivo kidney perfusion (NEVKP) could combine the advantages of both techniques.

METHODS

Porcine kidneys were exposed to 30 min of warm ischemia followed by perfusion. Kidneys underwent either 16-h NEVKP or 16-h oxHMP. The third group was exposed to 16-h oxHMP followed by 3-h NEVKP (oxHMP + NEVKP group). After contralateral nephrectomy, grafts were autotransplanted and animals were followed up for 8 d.

RESULTS

All animals survived the follow-up period. Grafts preserved by continuous NEVKP showed improved function with lower peak serum creatinine and more rapid recovery compared with the other 2 groups. Urine neutrophil gelatinase-associated lipocalin, a marker of kidney injury, was found to be significantly lowered on postoperative day 3 in the oxHMP + NEVKP group compared with the other 2 groups.

CONCLUSIONS

A short period of NEVKP after oxHMP provides comparable short-term outcomes to prolonged NEVKP and is superior to oxHMP alone. A combination of oxHMP with end-ischemic NEVKP could be an attractive, practical strategy to combine the advantages of both preservation techniques.

Perinatal testicular torsion: The clear cut, the controversial, and the "quiet" scenarios

BACKGROUND

Perinatal testicular torsion (PTT) is a catastrophic event that occurs in utero or up to 30 days postnatally, with testicular loss being the most common outcome.

OBJECTIVE

To assess clinical evaluation, surgical management and clinical outcomes in patients with PTT in a quaternary referral pediatric center, to determine testicular salvageability and propose future management options.

METHODS

We retrospectively reviewed a cohort of males born outside the quaternary center with a diagnosis of PTT, from May 2000 to July 2020. Data collection included mode of delivery, gestational age, birth weight, testicular examination at birth, clinical presentation, ultrasound results at diagnosis, surgical management and findings, perioperative complications, and follow-up.

RESULTS

62 patients, including 2 patients with bilateral asynchronous PTT, were identified. Median (IQR) gestational age and birth weight were 39 (38-39.4) weeks and 3.4 (3.1-3.72) kg, respectively. Abnormal testicular examination at birth was found in 69% (Table 1). Doppler ultrasound was performed in all but 1 patient. 59 patients underwent surgery, 21 within 4 h, with bilateral exploration in 44 cases. Affected and non-affected testicles were explored in 76% and 98% of cases, respectively. 3 "nubbins" were found, of which 2 were excised. 3 nonsurgical complications were identified. During a median (IQR) follow-up of 3 (3-3) months, 63 testicles were removed or found to be non-functional, with compensatory hypertrophy in 38% of patients.

CONCLUSION

Given that 3% of our patients presented with asynchronous bilateral PTT, as well as the safety of general anesthesia in a referral pediatric hospital, early bilateral scrotal exploration of PTT is recommended.

LEVEL OF EVIDENCE

IV.

A systematic review of paediatric neurogenic lower urinary tract dysfunction guidelines using the Appraisal of Guidelines and Research Evaluation (AGREE) II instrument

OBJECTIVE

To examine and critique current international clinical practice guidelines (CPGs) on management of paediatric neurogenic lower urinary tract dysfunction (NLUTD) and assess the applicability of these guidelines to clinical practice.

MATERIALS AND METHODS

We conducted a systematic review of all CPGs on NLUTD published in English from the year 2010 to 2022. Six reviewers independently used the Appraisal of Guidelines and Research Evaluation (AGREE) II instrument to appraise all eligible CPGs. This instrument is comprised of 23 items organised into six quality domains. The scores for each item and domain were tabulated for each reviewer and interrater reliability was assessed for each domain using the intraclass correlation coefficient (ICC).

RESULTS

Six CPGs were appraised and these included: National Institute for Health and Care Excellence (NICE), European Society for Paediatric Urology, International Children's Continence Society, Irish, Spina Bifida Association (SBA), and International Brazilian Journal of Urology guidelines. They had high mean standardised scores in the domain on 'scope and purpose' and 'clarity of presentation' but had low scores in the domain of 'applicability'. The top three CPGs based on overall score were the NICE, Irish and SBA guidelines and the reviewers had high degree of interrater reliability (ICC 0.912, P < 0.001). The mean scores in various domains for the top three guidelines were 95.8 (scope and purpose), 87.5 (stakeholder involvement), 69.1 (rigour of development), 94.0 (clarity of presentation), 68.4 (applicability), and 59.7 (editorial independence). The diagnostic and treatment recommendations of the top three guidelines were presented.

CONCLUSION

The existing CPGs on paediatric NLUTD provide high-quality evidence based recommendations. The NICE, Irish and SBA guidelines were the top three CPGs identified. They scored high on most domains except applicability and editorial independence. These domains need to be considered for future updates to improve the utility.

Scoping review of neurogenic bladder patient-reported readiness and experience following care in a transitional urology clinic

OBJECTIVE

To generate a scoping review that summarizes thematically on all reported patient perceptions on readiness and experiences during transitional urologic care for patients with neurogenic bladder and or congenital genitourinary conditions that require continuity of care into adulthood.

METHODS

A systematic literature search was performed in October 2021. Records were screened and identified for studies relevant to reported readiness and experience in urologic transitional care among patients needing life-long urologic care. The methodological quality of the cross-sectional studies was assessed using AXIS. The included studies were clustered according to patient readiness in transition and patient experience-satisfaction in the urologic transition process. This scoping review was part of a systematic review registered on PROSPERO CRD42022306229 and was conducted in compliance with the PRISMA extension for scoping reviews.

RESULTS

A total of 12 articles were included that assessed patients with neurogenic bladder that reported either readiness or patient experience following the transitional care process. The patient readiness was assessed in six studies, determined using the TRAQ score with a range of 3-4/5. Older age, high health literacy, and parental or families' transition process awareness were associated with readiness. Generally, patients experience better satisfaction with pediatric care than with adult care facilities. Most patients felt that sexuality and fertility were not adequately tackled during the transition. The reported barriers to successful transition were patient, provider, and system factors, including lack of insurance coverage/financial management, patient preference, long-term bond with the pediatric providers, and communication by the adult provider. Based on AXIS, all of the studies identified for this scoping review did not determine the sample size, and most of the studies did not categorize the responders, which could introduce bias to the interpretation of their results.

CONCLUSION

This scoping review summarizes the readiness and experience of neurogenic bladder patients who underwent the urologic transitional process. Overall, understanding the patient, provider, and system factors associated with better readiness and enhancing the patient experience will ensure a better transition process.

The utilization of hyperbaric oxygenation therapy in hypospadias repair: a systematic review and meta-analysis

INTRODUCTION

This study aimed to evaluate the efficacy and safety of Hyperbaric Oxygen Therapy (HBOT) use in hypospadias repair through systematic review and meta-analysis of comparative studies.

METHODS

A systematic literature search was performed in May 2021. Comparative studies assessing the surgical outcome of hypospadias repair between control versus HBOT utilization were identified and evaluated according to Cochrane collaboration recommendations. The assessed outcome includes hypospadias repair failures and graft failure for staged repair using a buccal graft. Relative risk with corresponding 95% confidence intervals (CI) were extrapolated. A random-effect model was used to generate pooled effect estimates. Heterogeneity and inter-study variability were assessed using Chi-square and I-square. Subgroup analysis was performed according to primary repair versus redo-hypospadias with buccal graft. PROSPERO registration (CRD42021251423).

RESULTS

Five comparative studies with 576 cases (301 HBOT versus 275 controls) were included. Overall pooled effect estimates showed that the HBOT group has significantly lesser hypospadias repair failure (RR 0.52, 95%CI 0.37, 0.72). Subgroup analysis on the use of HBOT for graft take showed lesser graft failure compared to the control group (RR 0.20, 95% CI 0.05, 0.75), while the use of HBOT for primary and redo single staged hypospadias repair showed lesser complication rate (RR 0.56, 95%CI 0.40, 0.78). Based on ROBINS-I assessment, all included comparative studies are determined to be of serious risk of bias mainly due to presence of confounding.

CONCLUSION

The currently available low-quality of evidence suggests that compared to control groups, HBOT as an adjunctive intervention to complicated hypospadias repair was able to reduce surgical outcome failure and graft failure rates.

Do post-operative phone calls enhance family satisfaction and outcomes after outpatient pediatric urological surgeries? A prospective study

INTRODUCTION

This study assesses whether post-operative check-in phone calls (POPC) performed within 48 h of outpatient pediatric urological surgeries by a non-medical professional (NMP) would increase patient/family satisfaction and minimize extraneous resource use by increasing email/telephone communication, while reducing emergency department (ED) visits within 30 days of that procedure.

METHODS

Families of patients undergoing ambulatory pediatric urology surgeries were enrolled over 8 weeks. Group 1 did not receive POPC. Group 2 received a POPC within 48 h of their operation by a NMP. Both groups received a phone-call survey 2 weeks after surgery to assess families' perioperative satisfaction.

RESULTS

In total, 74 families were enrolled (Group 1 = 44, Group 2 = 31). The response rates to phone surveys for Groups 1 and 2 were 59.1% and 77.4%, respectively. POPC did not improve perioperative satisfaction, nor did it significantly promote the use of nursing email/telephone communication (19.2% vs. 4.2%, p = 0.128) or reduce ED visits (15.4% vs. 0.0%, p = 0.111). However, all families in Group 2 thought POPC was timed appropriately and 79.1% perceived it to be helpful in reducing post-operative anxiety.

CONCLUSION

POPC by a NMP within 48 h of surgery may not affect perioperative satisfaction of families of patients undergoing same-day pediatric urology surgery but may have an impact in reducing post-operative anxiety.

Accuracy of point-of-care ultrasound by pediatric emergency physicians for testicular torsion

INTRODUCTION

Acute scrotum is a common presentation to the pediatric emergency department, and ultrasound is frequently used to narrow the differential diagnosis. Point-of-care ultrasound (POCUS) is increasingly used by urologists and emergency physicians and could potentially be used to detect pediatric testicular torsion.

OBJECTIVES

This study aimed to determine the accuracy of POCUS by pediatric emergency physicians in diagnosing testicular torsion and the agreement between point-of-care ultrasound and final diagnosis for other causes of acute scrotum.

STUDY DESIGN

A chart review of patients presenting to the study emergency department who received POCUS by a pediatric emergency physician, as well as radiology department ultrasound and/or surgery, was performed. Charts were reviewed for POCUS diagnoses, final diagnoses, and imaging time metrics.

RESULTS

A total of 120 patients met study criteria, with 12 cases of testicular torsion. The diagnostic accuracy of POCUS for testicular torsion is described in the summary table. For all causes of acute scrotum, point-of-care ultrasound agreed with final diagnosis in 70% (95% confidence interval [CI] 62-78%) of cases, and more experienced point-of-care ultrasound users displayed higher agreement with final diagnosis. Point-of-care ultrasound results were generated a median of 73 min (Q1 = 51, Q3 = 112) before radiology department ultrasound results.

DISCUSSION

Scrotal POCUS performed by pediatric emergency physicians appears to be an accurate tool to detect testicular torsion in children with acute scrotum and saves time compared with radiology ultrasound. The study results may not be generalizable to hospitals without a multidisciplinary POCUS system for quality assurance and image sharing. Future work on POCUS for acute scrotum should investigate its impact on patient outcomes, cost-effectiveness, and family satisfaction.

CONCLUSION

Point-of-care ultrasound by pediatric emergency physicians is accurate for detecting testicular torsion in children with acute scrotum and could expedite diagnosis of this time-sensitive condition.

Modified staged repair of bladder exstrophy: a strategy to prevent penile ischemia while maintaining advantage of the complete primary repair of bladder exstrophy

INTRODUCTION

Penile ischemic injury is a reported catastrophic complication after complete primary repair of exstrophy (CPRE). Aiming to improve the bladder exstrophy-epispadias repair outcomes, the study institution adopted a modified staged exstrophy repair to incorporate the advantages of CPRE by avoiding concurrent epispadias repair and adding bilateral ureteral re-implantation and bladder neck tailoring (staged repair of bladder exstrophy with bilateral ureteral re-implantation [SRBE-BUR]) at the initial repair. It was hypothesized that such modifications minimize penile complications and prevent upper tract deterioration while enhancing bladder resistance and consequent capacity. Here, a comparative series of outcomes between CPRE and SRBE-BUR is reported.

METHODS

A retrospective cohort study including all exstrophy-epispadias male neonates managed in the study institution from January 2000 to December 2014 was performed. Patients were divided into those who underwent CPRE-BUR (group 1) and SRBE-BUR (group 2) (Figure). Baseline characteristics, peri-operative data, and long-term surgical outcomes were collected and analyzed for between-group comparison. Fisher exact and Mann-Whitney U tests were performed for statistical analysis.

RESULTS

A total of 21 eligible patients were included: 10 in group 1 and 11 in group 2. Baseline characteristics were comparable. Two patients in group 1 had intra-operative penile ischemic injury (one with subsequent penile tissue loss), whereas none of the group 2 patients had intra-operative complications. No significant difference between the groups was noted for operative time; however, significantly lesser blood loss was noted in group 2. Comparable long-term surgical outcomes such as additional surgical intervention, urinary continence, bladder capacity, vesicoureteral reflux, hydronephrosis and recurrent urinary tract infections (UTIs) were noted. In addition, although subjective, better penile length and cosmesis were achieved by staging the repair (Figure).

CONCLUSION

The SRBE with bilateral ureteral re-implantation is a safe alternative for the repair of the exstrophy-epispadias repair as it prevents the catastrophic complication of penile tissue loss, while having comparable long-term outcomes with the CPRE. Delaying epispadias repair avoids penile injury besides possible improvement of its overall cosmesis.

Non-invasive voiding assessment in conscious mice

OBJECTIVE

To review available options of assessing murine bladder function and to evaluate a non-invasive technique suitable for long-term recording.

METHODS

We reviewed previously described methods to record rodent bladder function. We used modified metabolic cages to capture novel recording tracings of mouse micturition. We evaluated our method in a pilot study with female mice undergoing partial bladder outlet obstruction or sham operation, respectively; half of the partial obstruction and sham group received treatment with an S6K-inhibitor, targeting the mTOR pathway, which is known to be implicated in bladder response to obstruction.

RESULTS

Our non-invasive method using continuous urine weight recording reliably detected changes in murine bladder function resulting from partial bladder outlet obstruction or treatment with S6K-inhibitor. We found obstruction as well as treatment with S6K-inhibitor to correlate with a hyperactive voiding pattern.

CONCLUSIONS

While invasive methods to assess murine bladder function largely disturb bladder histology and intrinsically render post-cystometry gene expression analysis of questionable value, continuous urine weight recording is a reliable, inexpensive, and critically non-invasive method to assess murine bladder function, suitable for a long-term application.

Activated Hedgehog-GLI Signaling Causes Congenital Ureteropelvic Junction Obstruction

Intrinsic ureteropelvic junction obstruction is the most common cause of congenital hydronephrosis, yet the underlying pathogenesis is undefined. Hedgehog proteins control morphogenesis by promoting GLI-dependent transcriptional activation and inhibiting the formation of the GLI3 transcriptional repressor. Hedgehog regulates differentiation and proliferation of ureteric smooth muscle progenitor cells during murine kidney-ureter development. Histopathologic findings of smooth muscle cell hypertrophy and stroma-like cells, consistently observed in obstructing tissue at the time of surgical correction, suggest that Hedgehog signaling is abnormally regulated during the genesis of congenital intrinsic ureteropelvic junction obstruction. Here, we demonstrate that constitutively active Hedgehog signaling in murine intermediate mesoderm-derived renal progenitors results in hydronephrosis and failure to develop a patent pelvic-ureteric junction. Tissue obstructing the ureteropelvic junction was marked as early as E13.5 by an ectopic population of cells expressing Ptch2, a Hedgehog signaling target. Constitutive expression of GLI3 repressor in Ptch1-deficient mice rescued ectopic Ptch2 expression and obstructive hydronephrosis. Whole transcriptome analysis of isolated Ptch2⁺ cells revealed coexpression of genes characteristic of stromal progenitor cells. Genetic lineage tracing indicated that stromal cells blocking the ureteropelvic junction were derived from intermediate mesoderm-derived renal progenitors and were distinct from the smooth muscle or epithelial lineages. Analysis of obstructive ureteric tissue resected from children with congenital intrinsic ureteropelvic junction obstruction revealed a molecular signature similar to that observed in Ptch1-deficient mice. Together, these results demonstrate a Hedgehog-dependent mechanism underlying mammalian intrinsic ureteropelvic junction obstruction.

Utilization of Postpenile Surgery Illustrated Healing Atlas: A Comparative Study

OBJECTIVE

To determine the effect of the postpenile surgery illustrated healing atlas on caregivers' anxiety levels pre- and postoperatively, the frequency of family's postoperative communication with the urology care team, and the number of unplanned emergency room (ER) return for wound checks.

METHODS

A prospective cohort enrolled children who underwent penile surgeries (distal hypospadias repair and phalloplasty) with no concomitant procedures from December 2016 to June 2017. A 6-item short-form Spielberger State-Trait Anxiety Inventory (STAI) was used to determine baseline and postoperative anxiety levels of the caregivers. Two groups were created: caregivers who did not view the illustrated atlas vs caregivers who were shown the atlas. Baseline characteristics and demographics were compared, along with caregiver's pre- to postoperative anxiety level difference, frequency of postoperative communication, and number of unplanned ER return for wound checks.

RESULTS

Fifty-four patients were enrolled with 27 families in each group. Baseline characteristics and demographics were comparable with no significant differences. The assessment of the pre- to postoperative anxiety levels in both groups showed no significant differences (median difference -5 [interquartile range -8 to -5] vs -5 [interquartile range -8 to -4], P = .94). Although no differences were noted for ER-return rates between the groups (18% vs 11.1%, P = .704), significantly less postoperative calls and e-mails were noted among families who received or viewed the postpenile surgery illustrated healing atlas (51.9% vs 11.1%, P = .003).

CONCLUSION

The utilization of a postpenile surgery illustrated healing atlas as part of the postoperative support provided to families was able to decrease postoperative calls and e-mails.

Assessment of local structural disorders of the bladder wall in partial bladder outlet obstruction using polarized light imaging

Partial bladder outlet obstruction causes prominent morphological changes in the bladder wall, which leads to bladder dysfunction. In this paper, we demonstrate that polarized light imaging can be used to identify the location of obstruction induced structural changes that other imaging modalities fail to detect. We induced 2-week and 6-week partial outlet obstruction in rats, harvested obstructed bladders, then measured their retardances while distended to high pressures and compared them to controls. Our results show that the retardance of the central part of the ventral side (above the ureters) closer to the urethra can be used as a potential metric of the distending bladder obstruction.

Reduced flow after tubularized incised plate urethroplasty--increased fibrogenesis, elastin fiber loss or neither?

PURPOSE

Low urinary flow rates are common after tubularized incised plate urethroplasty but the etiology remains unclear and may be related to low urethral compliance due to abnormal collagen concentrations and/or fewer elastic fibers in the healed urethral plate. We hypothesized that inserting a preputial mucosal graft over the dorsal raw area after the midline incision may avoid scarring and improve urethral compliance.

MATERIALS AND METHODS

Adult rabbits were submitted to tubularized incised plate urethroplasty with or without inlay preputial graft according to a previously described protocol. Tissular concentrations of collagens I, III, IV, VI, VIII and XIII were measured. Histomorphometric analysis was used to quantify elastic fibers in the urethra. Tubularized incised plate urethroplasty with and without inlay preputial graft was compared to normal rabbit urethras (controls).

RESULTS

mRNA concentrations for collagens I, II and XIII were similar between controls and operated rabbits. The proportions between collagens I and III were 1.05, 0.87 and 1.21, respectively, in controls and animals undergoing tubularized incised plate urethroplasty with and without inlay preputial graft. mRNA concentrations for collagen IV and collagens VI/VIII tended to be higher and lower, respectively, in the operated urethras, despite showing statistical significance only for collagen VIII in animals undergoing tubularized incised plate urethroplasty with inlay preputial graft vs controls (p=0.02). The operated animals did not demonstrate a reduced number of elastic fibers in the urethral tissues compared to controls.

CONCLUSIONS

Elastic fiber number and distribution were similar between tubularized incised plate urethroplasty cases and controls, suggesting that decreased concentrations of elastic fibers do not explain the reduced urethral compliance after tubularized incised plate urethroplasty. The raw area determined by the dorsal urethral incision regenerated after standard tubularized incised plate urethroplasty, while cicatrization with fibrosis occurred in correspondence to the grafted areas after tubularized incised plate urethroplasty with inlay preputial graft.

Failed pyeloplasty in children: revisiting the unknown

OBJECTIVE

To perform a critical analysis of the management of the pediatric failed pyeloplasty in a large tertiary center. The ideal approach to this rare entity is not well established.

METHODS

Retrospective record review of children undergoing pyeloplasty from 2000 to 2010. All cases that required any type of reintervention, excluding stent removal, were analyzed. Data collected included: demographics, indication for and modality of the initial surgery, presence of crossing vessels, mode of diagnosis of failure, and type(s) of reintervention with the correspondent success rate(s).

RESULTS

Overall, pyeloplasty failure rate was 27 per 455 patients (5.9%). Age, initial indication for pyeloplasty, and modality of surgery (open vs laparoscopic) yielded similar failure rates. Indications for reintervention were as follows: worsening asymptomatic hydronephrosis 16 of 27 (59%), pain 7 of 27 (26%), urosepsis 2 of 27 (7.5%), and others 2 of 27 (7.5%). Eight of 27 (30%) improved with 1, 14 of 27 (52%) had 2, and 5 of 27 (18%) required 3 reinterventions, respectively. Mean interval between the first operation and subsequent interventions was 19.3, 24.9, and 27 months for the first, second, and third reinterventions, respectively. Modalities of reintervention with respective success rates were as follows: double J stent insertion 16% (6%), endopyelotomy 18% (50%), redo pyeloplasty 12% (92%), and ureterocalicostomy 4% (100%). Only 1 patient (7%) was documented to have a missed crossing vessel. All patients were stable and doing well after a mean follow-up of 56 months after the first operation.

CONCLUSION

According to this series, more invasive and definitive techniques, such as redo pyeloplasty and ureterocalicostomy, are more successful than minimally invasive ones to treat failed pyeloplasty and should probably be offered sooner rather than later.

A RHAMM mimetic peptide blocks hyaluronan signaling and reduces inflammation and fibrogenesis in excisional skin wounds

Hyaluronan is activated by fragmentation and controls inflammation and fibroplasia during wound repair and diseases (eg, cancer). Hyaluronan-binding peptides were identified that modify fibrogenesis during skin wound repair. Peptides were selected from 7- to 15mer phage display libraries by panning with hyaluronan-Sepharose beads and assayed for their ability to block fibroblast migration in response to hyaluronan oligosaccharides (10 kDa). A 15mer peptide (P15-1), with homology to receptor for hyaluronan mediated motility (RHAMM) hyaluronan binding sequences, was the most effective inhibitor. P15-1 bound to 10-kDa hyaluronan with an affinity of K(d) = 10(-7) and appeared to specifically mimic RHAMM since it significantly reduced binding of hyaluronan oligosaccharides to recombinant RHAMM but not to recombinant CD44 or TLR2,4, and altered wound repair in wild-type but not RHAMM(-/-) mice. One topical application of P15-1 to full-thickness excisional rat wounds significantly reduced wound macrophage number, fibroblast number, and blood vessel density compared to scrambled, negative control peptides. Wound collagen 1, transforming growth factor β-1, and α-smooth muscle actin were reduced, whereas tenascin C was increased, suggesting that P15-1 promoted a form of scarless healing. Signaling/microarray analyses showed that P15-1 blocks RHAMM-regulated focal adhesion kinase pathways in fibroblasts. These results identify a new class of reagents that attenuate proinflammatory, fibrotic repair by blocking hyaluronan oligosaccharide signaling.

Optical assessment of tissue anisotropy in ex vivo distended rat bladders

Microstructural remodelling in epithelial layers of various hollow organs, including changes in tissue anisotropy, are known to occur under mechanical distension and during disease processes. In this paper, we analyze how bladder distension alters wall anisotropy using polarized light imaging (followed by Mueller matrix decomposition). Optical retardance values of different regions of normal rat bladders under different distension pressures are derived. Then optical coherence tomography is used to measure local bladder wall thicknesses, enabling the calculation of the tissue birefringence maps as a measure of the tissue anisotropy. Selected two-photon microscopy is also performed to better understand the compositional origins of the obtained anisotropy results. The dome region of the bladder shows maximum birefringence when the bladder is distended to high pressures, whereas the ventral remains roughly isotropic during distension. In addition, the average anisotropy direction is longitudinal, along the urethra to dome. The derived wall anisotropy trends are based on birefringence as an intrinsic property of the tissue organization independent of its thickness, to aid in understanding the structure-functions relation in healthy bladders. These new insights into the wall microstructure of ex vivo distending bladders may help improve the functionality of the artificially engineered bladder tissues.

Hypertension in children with poorly functioning unilateral kidneys: predictors of resolution after nephrectomy

OBJECTIVE

To identify the outcome of nephrectomy and predictors of hypertension (HTN) resolution in children with poorly functioning unilateral kidneys (differential renal function, DRF of < 15%), as concurrent HTN is often an indication for nephrectomy.

PATIENTS AND METHODS

Over a 7.5-year period, a single centre retrospective analysis of 89 children with unilateral nonfunctioning/poorly functioning kidney who underwent nephrectomy was conducted. Preoperative HTN was present in 18 children (20.2%). The childrens' characteristics (age, sex, body mass index, pathology, side), cause of nonfunction, diagnostics including preoperative proteinuria (dipstick) and DRF (nuclear scan), pathological features of specimen and follow-up were recorded.

RESULTS

The mean (median; range) age at nephrectomy was 6.8 (5; 0.333-14) years with a mean (median; range) follow-up of 2.4 (3; 0.083-5.5) years. The mean (median; range) DRF was 6.5 (1; 0-15)%. Twelve of 18 children (67%) resolved their HTN. Age at nephrectomy, sex, side of nonfunctioning kidney and surgical approach (78% laparoscopic nephrectomy) did not correlate with HTN resolution. Persistence of HTN seemed to correlate with residual function of more than a DRF threshold of 5% (P = 0.05), the presence of preoperative qualitative proteinuria by dipstick (P = 0.03) and inflammation on pathology.

CONCLUSIONS

HTN resolved after nephrectomy for poorly functioning unilateral kidney in most of the children. Persistence of HTN is probably multifactorial. Ipsilateral residual function before nephrectomy, preoperative proteinuria and pathological features of nephrectomy specimen may serve as clinically useful markers for outcome prediction.

Effects of doxycycline on voiding behaviour of rats with bladder outlet obstruction

OBJECTIVE

To examine the voiding behaviour changes in rats with bladder outlet obstruction (BOO) while inhibiting matrix metalloproteinase (MMP) activity with doxycycline, as increased MMP activity may be involved in obstruction-induced bladder hypertrophy.

MATERIALS AND METHODS

Female Sprague-Dawley were divided into eight groups (three rats in each group): normal control (NC) +/- doxycycline, 3 weeks partial BOO (3WPBOO) +/- doxycycline, 6 weeks PBOO +/- doxycycline, and 3 weeks PBOO followed by 3 weeks de-obstruction (3WOD) +/- doxycycline. All rats received the same food and water and were on the same 12 h dark/light cycle housed in metabolic cages. Treatment groups were given doxycycline 15 mg/kg/day subcutaneously twice daily. The voiding variables measured were average voided volume (AV V) and voiding frequency (VF) in 24 h. After completion of the voiding behaviour studies, the rats were killed and their bladders were excised and weighed.

RESULTS

The AV Vs were significantly increased (P < 0.05) in all study groups compared with the NC group except for the 3WPBOO-doxycycline and 3WOD-doxycycline groups. The VF was significantly increased (P < 0.05) only in the 3WOD-doxycycline group. The bladder weights were significantly increased after PBOO in all the study groups (P < 0.05), except for the 3WOD group.

CONCLUSION

These data show that MMP inhibition may affect voiding behaviour during the response to BOO or its relief. This is the first clinical demonstration that interfering with a principal target of bladder muscle wall remodelling may have a direct effect on bladder function.

Comparative Analysis of Tubularized Incised Plate Versus Onlay Island Flap Urethroplasty for Penoscrotal Hypospadias

PURPOSE

Despite being the dominant technique for repair of distal hypospadias, application of the tubularized incised plate approach for penoscrotal hypospadias remains controversial. We report our experience with severe hypospadias, comparing tubularized incised plate to transverse island flap onlay urethroplasty.

MATERIALS AND METHODS

We retrospectively reviewed consecutive patients with penoscrotal hypospadias presenting between 1998 and 2006. Based on surgeon preference 35 children underwent tubularized incised plate and 40 underwent onlay urethroplasty. Penoscrotal transposition and degree of ventral curvature, type of ventral curvature repair, complication rate, postoperative uroflowmetry pattern in toilet trained patients and number of reoperations were compared between the 2 groups.

RESULTS

Mean patient age at surgery was 17 months (range 9 to 91) for tubularized incised plate urethroplasty and 17.8 months (10 to 58) for the onlay procedure. Urethroplasty was performed over an 8Fr catheter in all patients. With mean followups of 30 months (range 6 to 74) and 38.8 months (16 to 80) the overall complication rates were 60% and 45% for the tubularized incised plate and onlay procedures, respectively. Fistula occurred in 15 patients and repair breakdown in 3 patients (total 51.4%) treated with tubularized incised plate repair, compared to 8 and 2 patients, respectively (25%), treated with onlay repair (p = 0.01). Fistula location also differed significantly between the 2 groups, with proximal fistulas occurring in 11 of 15 tubularized incised plate repairs (73.3%) vs 2 of 8 onlay repairs (25%, p = 0.02). Recurrent ventral curvature was more frequent after onlay urethroplasty (5.7% vs 12.5%, not significant). At a mean age of 5.1 years a plateau uroflow curve (vs normal bell curve) was observed in 16 of 24 children (66.7%) who underwent tubularized incised plate repair and in 7 of 21 (33.3%) who underwent onlay repair (p <0.01).

CONCLUSIONS

In this series the overall complication rate was similar for tubularized incised plate and onlay urethroplasty. Despite similar urethroplasty calibers, the uroflow curves and fistula positions in patients undergoing tubularized incised plate repair suggest that the neourethra distal to the fistula may be relatively narrow, creating flow resistance and leading to proximal fistula. Longer followup and close monitoring are needed before embracing one approach over the other.

Outcome Analysis of Severe Chordee Correction Using Tunica Vaginalis as a Flap in Boys With Proximal Hypospadias

PURPOSE

There is ongoing controversy regarding optimal treatment for severe ventral curvature. It has been suggested that ventral corporeal lengthening may be associated with recurrent curvature and erectile dysfunction. To further assess these issues we reviewed our experience with ventral penile lengthening for correcting the severe ventral curvature associated with proximal hypospadias.

MATERIALS AND METHODS

We reviewed the records of 38 boys with severe hypospadias and congenital ventral curvature greater than 45 degrees who were treated at our institution from 1995 to 2004 with placement of a flap or graft in the corporeal bodies to straighten the phallus. Of the patients 21 had perineal and 17 had penoscrotal hypospadias, including 22 with associated penoscrotal transposition and/or bifid scrotum and 6 with ambiguous genitalia. Testosterone stimulation before surgery was given in 11 children at surgeon discretion.

RESULTS

Median age at surgery was 15 months. The urethral plate was divided in 94.7% of patients. A tunica vaginalis flap was used alone in 23 cases and associated with dura, pericardium or small intestinal submucosa in 8, 2 and 1, respectively. The remaining 4 patients underwent ventral grafting alone, including lyophilized dura in 1, pericardium in 1 and dermis in 1. Urethral reconstruction was achieved by the transverse island flap technique or 1 of its modifications in 34 children. Four boys underwent a 2-stage procedure. Followup available on 35 of 38 patients was 1 to 11 years (median 5.3). Recurrent ventral curvature in 5 of 35 patients was mild in 1 and clinically significant, requiring re-intervention, in 4. Four of 9 patients (44.4%) who underwent corporeal grafting with lyophilized dura had recurrent ventral curvature vs 1 of 23 (4.3%) who had a tunica vaginalis flap (chi-square 5.14, p = 0.02). At last followup straight erections were documented by patients and/or parents in 30 of 35 children (85.7%).

CONCLUSIONS

The short-term outcome of ventral penile lengthening using tunica vaginalis flap alone for correcting severe chordee is favorable with a 95% success rate. Dural grafts were associated with a higher risk of recurrent ventral curvature compared to tunica vaginalis flaps. Although most of our patients were not yet adults, when chordee and erectile dysfunction may become apparent, we believe that tunica vaginalis flap repair is a good option for correcting severe ventral curvature.

Role of signal transducer and activator of transcription 3 (STAT3) in stretch injury to bladder smooth muscle cells

Excessive stretch of the bladder can lead to wall thickening including the growth of bladder smooth muscle cells (BSMC). Only three phospho-proteins (JNK, p38, and PI3K) have been previously shown to participate in stretch-induced BSMC growth. CD1 mouse bladders were hyper- or non-distended by our ex vivo bladder distention model and screened, by a commercial screening method, for phosphorylated signaling proteins. This uncovered a factor previously unexamined for its role in bladder stretch injury: signal transducer and activator of transcription 3 (STAT3). STAT3 was assessed for its role in mitogen- and stretch-induced BSMC proliferation. Proliferation was assessed by 3H-thymidine incorporation/cell counting in response to mitogenic stimulation or to stretch on silastic collagen or carboxyl-coated membranes. JAK2, upstream of STAT3, was inhibited by AG490 (2 microM). Ex vivo distention of bladders activated a discrete number of kinases, including two MAPK pathways (JNK and ERK2) and STAT3. STAT3 signaling was activated during hyperdistention of intact bladder and by stretch and mitogenic treatments of BSMC in vitro. JAK2/STAT3 inhibition by AG490 blocked mitogen- and stretch-induced BSMC proliferation. Thus, BSMC stretch responses may involve the recruitment of both growth factor and mechanically induced BSMC growth responses integrated by a common signaling pathway, STAT3.

Effects of hyaluronan and SPARC on fibroproliferative events assessed in an in vitro bladder acellular matrix model

Bladder acellular matrix (BAM) is a promising candidate for urinary biomaterials development. In the current work we have modified the BAM construct to include two biologically active components; hyaluronan (HA) and a peptide (SP4.2) derived from secreted protein, acidic, rich in cysteine (SPARC), a matricellular glycoprotein. In order to assess the potential of an HA/SP4.2 modified BAM to influence cellular functions associated with bladder healing, experiments were conducted to evaluate the individual and combined effects of these molecules on in vitro fibroproliferative endpoints within a co-culture model. Thiol-modified HA (246 kDa, 15 mg/ml)+/-SP4.2 (200 microm) was incorporated and cross-linked into BAM disks through disulfide bond formation. The following scaffolds compositions were then evaluated in a bladder smooth muscle cell (SMC)-urothelial (UEC) cell co-culture model: BAM unmodified; BAM+HA, BAM+SP4.2 (media addition); BAM+HA+SP4.2 (media addition); BAM+HA+SP4.2 (matrix incorporated). At 3, 7 and 14 days post-seeding, SMC-mediated matrix contraction and gelatinolytic activity were evaluated. HA-modified BAM exhibited a significantly higher degree of contraction and gelatinase activity compared to unmodified BAM. In contrast, addition of SP4.2 to BAM produced a negligible effect on contraction, while significantly reducing gelatinase activity. Matrices containing both molecules displayed significant increases in contraction, while gelatinase activity was dependent upon the method of peptide delivery. These results demonstrate that both HA and SP4.2 have significant, yet distinct effects on the contractile and proteolytic activity of bladder SMCs and suggest that a modified BAM may be capable of modulating processes associated with post-surgical graft contracture and scar formation.