Pre-operative factors associated with the development of distal ureteral stump syndrome after upper pole heminephrectomy.

INTRODUCTION: For children with duplex systems and severe hydroureteronephrosis of the upper pole, heminephrectomy is one of many suitable treatments, particularly if there is no associated lower pole reflux. Distal ureteral stump syndrome (DSS) is a very difficult complication and manifests as stump empyema, urinary tract infection and/or vulvar discharge and can occur months to years later in 10-20 percent of patients. Secondary distal ureterectomy is an extremely difficult surgery due to inflammation and adhesions. To avoid DSS, distal ureterectomy at the time of heminephrectomy can be performed concurrently but carries a risk of lower pole ureter devascularization and injury. Current literature on DSS has shown associations with subtotal ureterectomy or long ureteral stumps. We hypothesized that there may be preoperative variables prior to heminephrectomy that are associated with the development of DSS. OBJECTIVE: Identify pre-operative risk factors for the development of DSS in pediatric patients who underwent upper pole heminephrectomy for duplex kidneys. STUDY METHODS: Retrospective analysis of pediatric patients who underwent upper pole heminephrectomy at single, academic institution from 1999 to 2021. Pre-operative patient age, gender, history, imaging, and lab results were extracted from patient charts to assess for factors that may predict the development of DSS. Patient groups with and without DSS were compared using Fischer's Exact Test. RESULTS: Five (14%) of 36 patients developed DSS and required secondary distal ureterectomy at a median time of 22 months (IQR 6-27) after heminephrectomy. The presence of ureteral debris (80% of DSS) on preoperative ultrasound (p < 0.001), reflux into the upper pole (p = 0.005), and mucus discharge (100% of DSS) (p < 0.001) prior to surgery were found to be significantly associated with those who developed DSS, compared to those who did not. These three pre-operative factors had high specificity (97-100%) and negative predictive value (94-97%). DISCUSSION: Substantial experience has shown that less than 20% of patients benefit from distal ureterectomy during upper heminephrectomy. Whether using an open or laparoscopic approach, selection of at-risk patients should lower operative time and avoid injury and devascularization of the lower pole ureter for most patients. CONCLUSION: The presence or absence of ureteral debris, mucus discharge and/or upper pole reflux prior to heminephrectomy may be useful guides in selecting which patients would benefit from concurrent distal ureterectomy and conversely which patients may safely avoid the additional dissection.

Prenatal Rupture of Hydrocolpos in a Cloacal Malformation.

INTRODUCTION: Cloacal dysgenesis occurs from failure of embryological division of urogenital sinus and hindgut, leading to a single common perineal opening for genitourinary and gastrointestinal tracts. The prenatal diagnosis of cloacal malformation is imprecise, but the clinical correlation of postnatal findings to prenatal history can help reveal explanations for unusual pathological findings in patients with urogenital abnormalities. CASE PRESENTATION: A 21-year-old woman was referred after her 20-week ultrasound demonstrated anhydramnios and concern for dilated fetal bowel. Fetal MRI confirmed anhydramnios and a dilated fetal colon, in addition to hydronephrosis and a pelvic cyst. Repeat ultrasound at 27 weeks showed unexpected complete resolution of her anhydramnios but new fetal ascites. The newborn girl was postnatally diagnosed with a cloacal malformation and an unusual near-complete fusion of her labia. She underwent proximal sigmoid colostomy and a tube vaginostomy at birth followed by cloacal reconstruction at 1.5 years old. CONCLUSION: In female fetus with a pelvic cyst, one should have a high index of suspicion for cloacal anomaly and consider the possibility of urinary obstruction leading to alteration in amniotic fluid.

Using uniaxial tensile testing to evaluate the biomechanical properties of bladder tissue after spinal cord injury in rat model.

To investigate the biomechanical properties of rat bladder tissue after spinal cord injury (SCI) using uniaxial tensile testing. Evidence suggests the bladder wall undergoes remodeling following SCI. There is limited data describing the biomechanical properties of bladder wall after SCI. This study describes the changes in elastic and viscoelastic mechanical properties of bladder tissue using a rat model after SCI. Seventeen adult rats received mid-thoracic SCI. Basso, Beattie, and Bresnahan (BBB) locomotor testing was performed on the rats 7-14 days after injury quantifying the degree of SCI. Bladder tissue samples were collected from controls and spinal injured rats at 2- and 9-weeks post-injury. Tissue samples underwent uniaxial stress relaxation to determine instantaneous and relaxation modulus as well as monotonic load-to failure to determine Young's modulus, yield stress and strain, and ultimate stress. SCI resulted in abnormal BBB locomotor scores. Nine weeks post-injury, instantaneous modulus decreased by 71.0% (p = 0.03) compared to controls. Yield strain showed no difference at 2 weeks post-injury but increased 78% (p = 0.003) in SCI rats at 9 weeks post-injury. Compared to controls, ultimate stress decreased 46.5% (p = 0.05) at 2 weeks post-injury in SCI rats but demonstrated no difference at 9 weeks post-injury. The biomechanical properties of rat bladder wall 2 weeks after SCI showed minimal difference compared to controls. By week 9, SCI bladders had a reduction in instantaneous modulus and increased yield strain. The findings indicate biomechanical differences can be identified between control and experimental groups at 2- and 9-week intervals using uniaxial testing.

Identifying variability in surgical practices and instrumentation for hypospadias repair across the Western Pediatric Urology Consortium (WPUC) network.

BACKGROUND: Although hypospadias outcomes studies typically report a level or type of repair performed, these studies often lack applicability to each surgical practice due to technical variability that is not fully delineated. An example is the tubularized incised plate (TIP) urethroplasty procedure, for which modifications have been associated with significantly decreased complication rates in single center series. However, many studies fail to report specificity in techniques utilized, thereby limiting comparison between series. OBJECTIVE: With the goal of developing a surgical atlas of hypospadias repair techniques, this study examined 1) current techniques used by surgeons in our network for recording operative notes and 2) operative technical details by surgeon for two common procedures, tubularized incised plate (TIP) distal and proximal hypospadias repairs across a multi-institutional surgical network. STUDY DESIGN: A two-part study was completed. First, a survey was distributed to the network to assess surgeon volume and methods of recording hypospadias repair operative notes. Subsequently, an operative template or a representative de-identified operative note describing a TIP and/or proximal repair with urethroplasty was obtained from participating surgeons. Each was analyzed by at least two individuals for natural language that signified specified portions of the procedure. Procedural details from each note were tabulated and confirmed with each surgeon, clarifying that the recorded findings reflected their current practice techniques and instrumentation. RESULTS: Twenty-five surgeons from 12 institutions completed the survey. The number of primary distal hypospadias repairs performed per surgeon in the past year ranged from 1-10 to >50, with 40% performing 1-20. Primary proximal hypospadias repairs performed in the past year ranged from 1-30, with 60% performing 1-10. 96% of surgeons maintain operative notes within an electronic health record. Of these, 66.7% edited a template as their primary method of note entry; 76.5% of these surgeons reported that the template captures their operative techniques very or moderately well. Operative notes or templates from 16 surgeons at 10 institutions were analyzed. In 7 proximal and 14 distal repairs, parameters for chordee correction, urethroplasty suture selection and technique, tissue utilized, and catheter selection varied widely across surgeons. CONCLUSION: Wide variability in technical surgical details of categorically similar hypospadias repairs was demonstrated across a large surgical network. Surgeon-specific modifications of commonly described procedures are common, and further evaluation of short- and long-term outcomes accounting for these technical variations is needed to determine their relative influence.

Impact of caudal block on revision rates after hypospadias repair: Multi-institution review.

INTRODUCTION: There is controversy surrounding the association between caudal block and complication rates after hypospadias repair. Conflicting results have been reported mostly from single-center, low volume studies and those that did not include relevant variables. OBJECTIVES: We hypothesized that caudal block is not associated with increased rates of reoperation after primary repair and is associated with more complex hypospadias surgery. STUDY DESIGN: The Clinical Practice Solutions Center database was queried to identify patients who received a primary hypospadias repair between 2009 and 2010. Primary hypospadias repair was further categorized as meatal advancement and glanduloplasty, distal, one-stage proximal, or one-stage perineal repair. Anesthesia coding was evaluated to identify those who received a caudal block. Any revision surgery was captured between 2009 and 2019 and the types of revision surgeries were identified. Variables such as caudal block, age, insurance type, surgeon volume, and surgeon years in practice were analyzed with mixed effects multiple logistic regression models. RESULTS: The dataset query identified 3343 pediatric males who had primary hypospadias repair. The procedures were performed by 50 surgeons at 27 hospitals. Primary surgeries included meatal advancement and glanduloplasty (23%), distal (69%), proximal (6.9%), and perineal repairs (1%). Caudal block was administered to 42% of patients. Utilization of caudal block was not associated with type of primary surgery (p = 0.21). Adjusting for all other variables, increased patient age was associated with decreased usage of caudal block (p < 0.001). Analysis did not demonstrate a statistically significant association between utilization of caudal block with rates of revision surgery. CONCLUSIONS: This large, multi-institution study demonstrates that the use of caudal block was not associated with more complex hypospadias surgery nor statistically significantly associated with increased rates of revision surgery after primary hypospadias repair.

Reoperation rates for stress urinary incontinence and pelvic organ prolapse in women after undergoing Mid-Urethral sling with or without concomitant colporrhaphy in academic centers within the United States.

In this study, the rates of reoperation for stress urinary incontinence (SUI) and pelvic organ prolapse (POP) in women who underwent a mid-urethral sling (MUS) with or without concurrent colporrhaphy were evaluated. An academic faculty practice consortium database was used to identify a cohort of patients treated surgically for SUI with or without concurrent POP repair (apical, anterior, posterior, or a combination of the three) with or without hysterectomy between 2009 and 2011. A total of 20,484 patients matched the criteria. Of patients who underwent a MUS, 7.2% underwent secondary surgery, with a higher rate of 8.6% associated with those who underwent concurrent prolapse repair (Apical repair HR 1.84, p < .01; Anterior compartment repair HR 1.47, p < .01). Concurrent hysterectomy was associated with a lower hazard of secondary prolapse surgery (HR 0.48; p < .01) if the initial surgery involved a complete POP repair. Prolapse mesh repair resulted in a higher hazard of additional surgery (HR 1.43, p < .01). Medicaid insurance was also associated with an increased hazard ratio compared to commercial insurance for secondary surgery (HR 1.32, p < .01). For women undergoing MUS with complete prolapse repair, concurrent hysterectomy is associated with lower secondary surgery rates. Concurrent prolapse repair with mesh is associated with higher secondary surgery rates.Synopsis: For women undergoing MUS (mid-urethral sling) with complete prolapse repair, concurrent hysterectomy is associated with lower secondary surgery rates. Concurrent prolapse repair with mesh is associated with higher secondary surgery rates.Impact StatementWhat is already known on this subject? Stress urinary incontinence (SUI) and pelvic organ prolapse (POP) can present at the same time and negatively impact patients' quality of life. There is little data regarding reoperation rates for patients who undergo both MUS and colporrhaphy in one setting.What do the results of this study add? This study found that patients who undergo concurrent MUS (mid-urethral sling) and complete POP repair with the addition of hysterectomy had a lower risk of secondary surgery.What are the implications of these findings for clinical practice and/or further research? Our data can be used by surgeons to counsel patients on the risks of re-operation for SUI for those who would like to undergo concurrent POP repair with or without hysterectomy.

Autologous regeneration of blood vessels in urinary bladder matrices provides early perfusion after transplant to the bladder.

Large animal testing and clinical trials using bioengineered bladder for augmentation have revealed that large grafts fail due to insufficient blood supply. To address this critical issue, an in vivo staged implant strategy was developed and evaluated to create autologous, vascularized bioengineered bladder tissue with potential for clinical translation. Pig bladders were used to create acellular urinary bladder matrices (UBMs), which were implanted on the rectus abdominus muscles of rats and pigs to generate cellular and vascular grafts. Rectus-regenerated bladder grafts (rrBGs) were highly cellularized and contained an abundance of CD31-positive blood vessels, which were shown to be functional by perfusion studies. Muscle patterns within grafts showed increased smooth muscle formation over time and specifically within the detrusor compartment, with no evidence of striated muscle. Large, autologous rrBGs were transplanted to the pig bladder after partial cystectomy and compared to transplantation of control UBMs at 2 weeks and 3 months post-transplant. Functional, ink-perfused blood vessels were found in the central portion of all rrBGs at 2 weeks, while UBM grafts were significantly deteriorated, contracted and lacked central cellularization and vascularization. By 3 months, rrBGs had mature smooth muscle bundles and were morphologically similar to native bladder. This staged implantation technique allows for regeneration and harvest of large bladder grafts that are morphologically similar to native tissue with functional vessels capable of inosculating with host bladder vessels to provide quick perfusion to the central area of the large graft, thereby preventing early ischemia and contraction.

Combination product of dermal matrix, preconditioned human mesenchymal stem cells and timolol promotes wound healing in the porcine wound model.

A combination product of human mesenchymal stem/stromal cells (MSCs) embedded in an extracellular matrix scaffold and preconditioned with hypoxia and the beta-adrenergic receptor antagonist, timolol, combined with sustained timolol application post implantation, has shown promising results for improving wound healing in a diabetic mouse model. In the present study, we extend those findings to the more translatable large animal porcine wound model and show that the combined treatment promotes wound reepithelialization in these excisional wounds by 40.2% and increases the CD31 immunostaining marker of angiogenesis compared with the matrix control, while maintaining an accumulated timolol plasma concentration below the clinically safe level of 0.3 ng/mL after the 15-day course of topical application. Human GAPDH was not elevated in the day 15 wounds treated with MSC-containing device relative to wounds treated with matrix alone, indicating that the xenografted human MSCs in the treatment do not persist in these immune-competent animals after 15 days. The work demonstrates the efficacy and safety of the combined treatment for improving healing in the clinically relevant porcine wound model.

Reoperation after Hypospadias Repair: Long-Term Analysis.

PURPOSE: While the true incidence of secondary hypospadias repair is unknown, the current literature cites a 3.3% to 6.7% reoperation rate after distal hypospadias repair and an association with age. We hypothesized that secondary surgery rates are associated with patient factors and have been underreported due to limited followup. MATERIALS AND METHODS: We used an academic practice plan consortium database to identify a population that underwent primary hypospadias repair in 2009 and 2010. Secondary surgeries between 2009 and 2019 were captured. The association of variables such as age, insurance type, region, surgeon volume and surgeon years in practice with all-inclusive and specific secondary surgery procedures were analyzed using mixed effects multiple logistic regression models. RESULTS: We identified 5,178 boys who had primary hypospadias repair performed by 84 pediatric urologists at 46 hospitals in 2009 and 2010. During the ensuing 9 to 10 years, distal, proximal and perineal hypospadias repair had a 12.6%, 37.9% and 46.6% rate of secondary surgery, respectively. After adjusting for all other variables in the model, patients with noncommercial insurance had a 26% (OR 1.26, p=0.04) increased odds of secondary surgery. Patient age and surgeon years in practice were not associated with all-inclusive secondary surgery except for endoscopic treatment. Surgeon volume was not associated with secondary surgery. CONCLUSIONS: This study demonstrated that secondary surgery rates are underreported if followup is limited to less than 6 years. Patient age, surgeon volume and experience did not associate with all-inclusive reoperation rates whereas insurance status was a major predictor of reoperation.