A Comparative Study of Histotripsy Parameters for the Treatment of Fibrotic ex-vivo Human Benign Prostatic Hyperplasia Tissue.

Histotripsy is a noninvasive focused ultrasound therapy that mechanically fractionates tissue to create well-defined lesions. In a previous clinical pilot trial to treat benign prostatic hyperplasia (BPH), histotripsy did not result in consistent objective improvements in symptoms, potentially because of the fibrotic and mechanically tough nature of this tissue. In this study, we aimed to identify the dosage required to homogenize BPH tissue by different histotripsy modalities, including boiling histotripsy (BH) and cavitation histotripsy (CH). A method for histotripsy lesion quantification via entropy (HLQE) analysis was developed and utilized to quantify lesion area of the respective treatments. These data were correlated to changes in mechanical stiffness measured by ultrasound shear-wave elastography before and after treatment with each parameter set and dose. Time points corresponding to histologically observed complete lesions were qualitatively evaluated and quantitatively measured. For the BH treatment, complete lesions occurred with >=30s treatment time, with a corresponding maximum reduction in stiffness of -90.9±7.2(s.d.)%. High pulse repetition frequency (PRF) CH achieved a similar reduction to that of BH at 288s (-91.6±6.0(s.d.)%), and low-PRF CH achieved a (-82.1±5.1(s.d.)%) reduction in stiffness at dose >=144s. Receiver operating characteristic curve analysis showed that a >~75% reduction in stiffness positively correlated with complete lesions observed histologically, and can provide an alternative metric to track treatment progression.

Validation of Urostomy Parastomal Herniation Incisional Prevention Strategies.

OBJECTIVE: To evaluate simulated parastomal herniation forces in in vitro abdominal fascial models. Our group previously illustrated how incision type may play a consequential role in bowel herniation force generated across an incision using several abdominal fascia models. We sought to (1) Confirm findings in fresh human tissue, (2) Assess correlation between herniation force and incision size, and (3) Determine whether incision type impacts drainage in a simulated ex vivo ileal conduit. MATERIALS AND METHODS: Axial tension force (N) of herniation was measured using our previously published protocol, pulling a Foley catheter balloon 3.8 cm diameter affixed to a dynamometer through silicone/fascial incisions ranging 3-5.8 cm. We simulated ileal conduits using bovine small intestine with stoma matured through human fascia using 3.0 cm linear or cruciate incisions. The conduit's caudal end was catheterized and filled at 20 mL/min. Drainage was measured by pad weight change. Two-sided α < 0.05 was used to reject the null hypothesis. RESULTS: Mean (±SD) herniation forces in fresh human fascia varied significantly across linear longitudinal, linear transverse, and cruciate incisions (20.9 ± 3.7, 23.3 ± 8.8, and 8.9 ± 3.8 N, respectively [P = .011]). Fresh human fascial linear incisions 3 cm in diameter had a herniation force of 22.1 ± 6.3 vs 3.5 ± 0.7 N for 5.8 cm incisions when herniating a 3.8 cm balloon (P = .002). All observations were similar in silicone. In simulated ileal conduit, mean drainage: 70.8 ± 3.6 vs 82.1 ± 9.7 mL (linear vs cruciate) after 100 mL instilled, respectively (P = .05). CONCLUSION: This ex vivo study further suggests incision type has predictable influence on herniation force. These data support standardization of urostomy construction techniques and evaluating the clinical impact of stomal maturation techniques on parastomal hernia rates.

Increase in robot assisted operating room efficiency: A quality improvement study.

INTRODUCTION: Pyeloplasties are time-sensitive, and the most common robot assisted intervention performed in pediatric urology. Early intervention is intended to avoid permanent loss of renal function with negative long-term effects if surgery is delayed when indicated. A need to increase capacity has become a premium value in patient care. OBJECTIVE: Our aim was to reduce operative time, providing value by reducing total robotic console time in robot assisted pyeloplasty (RP) cases. We hypothesized that process improvement and supply management during RP leads to a significant reduction in operative time. METHODS: Intraoperative surgical workflow was reviewed and routine tasks performed during the various sections were selected with the goal of reducing Operating room inactivity. We focused on robotic arm activity, and total operative time to assess our outcomes. Our intervention was to standardize an OR staff task list, a priori supply inventory procurement for each anticipated major step in the case, confirmed prior to each major step. Baseline RP duration data for a single Pediatric Urologist were identified and recorded before any interventions. A clinical standard work (CSW) was developed based on optimization of equipment/supplies for the RP procedure, compartmentalized into the 8 key steps for RP. These major steps included: patient positioning, docking, retroperitoneal and ureteral dissection, hitch stitch, pyelotomy, stent placement, and anastomosis. Balancing measures included percentage trainee console use, preparatory time, and OR block start/end time. Baseline data for RP cases performed between 11/2020 and 2/2022 were automatically extracted from charts and analyzed using AdaptX (Seattle, WA). Post-intervention was between 3/2022 to 3/2023. Mann-WhitneyU was used for continuous variables for non-parametric distribution. RESULTS: 37 patients underwent RP during the study period. 15 cases were performed prior to intervention and 22 post intervention Total console time prior to intervention was 152 vs 109 min after intervention (p = 0.0002). Dual instrument inactivity was reduced from 13.1 % to 7.1 % (p < 0.0001). Dual consoles were used in 40 % vs ∼69 % pre-vs post-intervention, respectively (p = 0.5000). No difference in patient age distribution between groups was seen (p = 0.1498). Trainee operative time did not differ statistically pre- and post-intervention (63.0 vs 48.6 %, p = 0.0871). CONCLUSIONS: Decreasing surgical lapses and standardizing intraoperative tasks can result in more efficient case completion, potentially increasing OR capacity.

Assessment of Urostomy Parastomal Herniation Forces Using Incisional Prevention Strategies with an Abdominal Fascia Model.

Background: Approximately 10 000 patients undergo cystectomy/ileal conduit annually in the USA, of whom over 70% subsequently develop a parastomal hernia (PSH). Still, no well-established "best" practice for stoma creation to prevent a PSH exists. Objective: To measure the relationship between incision size/type/material and axial tension force (ATF) as a surrogate for herniation force, using several models to mimic abdominal fascia. Design setting and participants: Abdominal fascia models included silicone membrane, ex vivo porcine, and embalmed human cadaveric fascia. A dynamometer pulled a Foley catheter (20 mm/min) with the balloon inflated to 125% incision (linear, cruciate, and circular) diameter using a motorized positioning system. The maximum ATF before herniation was recorded. The study was repeated in unused silicone/tissue for suture reinforcement. We evaluated silicone, ex vivo porcine, and human abdominal fascia. Intervention: Incision sizes (1-3 cm) in 0.5-cm increments were evaluated in silicone. A 3-cm incision was used in porcine/human tissue. Outcome measurements and statistical analysis: ATF for herniation was recorded/compared across incision types/sizes using Mann-Whitney U and Kruskal-Wallis tests as appropriate, with α = 0.05. Results and limitations: Linear incision ATF was significantly greater than cruciate and circular incisions. A cruciate incision had significantly greater ATF than a circular incision. In cadaveric tissue, incisions were significantly greater for linear (34.5 ± 12.8 N) versus cruciate (15.3 ± 2.9 N, p = 0.004) and for cruciate versus circular (p = 0.023) incisions. Results were similar in ex vivo porcine fascia and silicone. Reinforcement with a suture significantly increased ATF in all materials/incision sizes/types. The ex vivo nature is this study's main limitation. Conclusions: This study suggests that urostomy fascial incision type may influence ATF required for herniation. Linear incisions may be preferable. Urostomy reinforcement may significantly increase ATF required for a PSH. These data may help establish best practices for PSH risk reduction. Patient summary: The results of this study illustrate that urostomy fascia incision type may influence the force required to create a parastomal hernia. Linear incisions may be preferable.

Prophylactic Mesh Placement With Ileal Conduit: A Cost-effectiveness Analysis.

OBJECTIVE: To determine the cost-effectiveness of mesh placement in patients undergoing ileal conduit urinary diversion for bladder cancer. Long-term studies have shown that parastomal hernias (PSH) occur in more than half of all stomas. Mesh prophylaxis has been shown to reduce PSH after end-colostomy and ileal conduits. However, no cost-effectiveness studies on mesh prophylaxis have been performed for this population. METHODS: We created a Markov model incorporating the costs and effectiveness of mesh prophylaxis for patients undergoing radical cystectomy and ileal conduit construction. Costs were obtained from the literature and adjusted to 2022 US dollars. Effectiveness was measured in quality-adjusted life years (QALY). 1- and 2-way sensitivity analyses were performed to test the robustness of our model. RESULTS: In stage I-IV bladder cancer, prophylactic mesh placement was costlier, but more effective in providing quality of life compared with no mesh placement at index surgery. Average incremental cost between the 2 strategies across all stages was an additional $897 when mesh was utilized. Incremental effectiveness averaged 0.49 additional QALY across all stages. This resulted in an incremental cost-effectiveness ratio of $2114.71/QALY. Sensitivity analyses indicated that benefit of mesh placement was sensitive to the probability of mesh infection. CONCLUSION: In patients undergoing ileal conduit urinary diversion for bladder cancer, mesh prophylaxis at the time of radical cystectomy is an overall cost-effective strategy in preventing PSH for patients presenting with all stages of bladder cancer.

Long term renal outcome and risk of elevated blood pressure in children undergoing complete primary repair of bladder exstrophy (CPRE).

INTRODUCTION: Since the initiation of staged reconstruction for bladder exstrophy (BE), hypertension has been a known complication of the procedure. Hypertension is a well-established risk factor for chronic kidney disease (CKD) progression and associated with cardiovascular/cerebrovascular morbidity and mortality. Few studies exist evaluating the risk of developing hypertension among patients with bladder exstrophy who underwent CPRE. We hypothesized that long-term blood pressure levels may be elevated in males vs females, and may be correlated with presence of hydronephrosis, bladder neck reconstruction, or continence status. OBJECTIVE: We sought to revisit our long-term experience with CPRE and determine factors associated with incidence of elevated blood pressures. METHODS: We reviewed all BE patients undergoing CPRE at our institution from 1999 to 2019. Patients were considered eligible for inclusion if last renal ultrasound was obtained at least 5 years after repair. Upper tract outcomes based on imaging, history of pyelonephritis and renal function tests measured by serum creatinine and estimated glomerular filtration rate (eGFR, Schwartz formula) were reviewed. Systolic/diastolic blood pressures (SBP/DBP) from all encounters were captured. All blood pressure values were age adjusted by percentile. RESULTS: A total of 36 patients were considered eligible for review. Median follow-up of this cohort was 10.01 (5.16-21.47) years. The mean creatinine for the patients available was 0.58 mg/dL (SD = 0.20), at mean age of 8.90 years Neither SBP or DBP were significantly elevated in males vs females, but had lower odds of elevation >90th percentile for those with higher eGFR, lower renal length, and reimplantation. Pyelonephritis incidence was 38% (n = 14) with first episode at mean age of 8.8 years, and mean of 3.7 episodes per patient. DISCUSSION: At long term follow up, blood pressures following CPRE were not significantly elevated, despite the relatively frequent occurrence of CKD, and hydronephrosis. Male gender does appear to suggest higher risk for long-term deterioration in this regard. Higher eGFR, higher renal length, and presence of ureteral reimplantation were associated with lower likelihood of systolic/diastolic blood pressure elevation. Continence status and bladder neck reconstruction were not associated with likelihood of blood pressure elevation. CONCLUSIONS: Blood pressure and upper-tract outcomes for patients undergoing CPRE at birth are positive for the majority of patients. To avoid complications from hypertension, patients should be closely evaluated as the risks associated with elevated blood pressure are significant. Ultimately, larger-scale prospective and multi-institutional studies are further needed to characterize risks of hypertension in this complex patient population.

Postoperative hydronephrosis following ureteral reimplantation: Clinical significance and importance of surgical technique and experience.

BACKGROUND: Though common, postoperative hydronephrosis (POHN) following ureteroneocystostomy raises concern for an underlying obstruction. We aimed to determine the clinical significance of POHN following open (OUR) or robotic (RALUR) ureteral reimplantation. METHODS: We retrospectively reviewed pediatric patients who underwent ureteral reimplantation for vesicoureteral reflux (VUR) from 2008 to 2019 by a single surgeon. Baseline characteristics, operative outcomes, and trends in POHN were assessed. POHN was defined as new onset hydronephrosis or exacerbation of pre existing hydronephrosis. Renal ultrasounds were performed 1, 4, and 12 months postoperatively. Voiding cystourethrograms were performed 4 months postoperatively. Surgical experience for RALUR cases was defined as number of ureters operated over time. RESULTS: Altogether, 93 patients (127 ureters) underwent RALUR and 19 patients (26 ureters) underwent OUR. POHN was found in 27.6% and 30.8% of ureters after RALUR and OUR, respectively. Rate and time to POHN resolution for RALUR (91.4%, 112 days) and OUR (75%, 211 days) were statistically similar. Odds of POHN after RALUR were directly related with preoperative VUR grade (Range OR: 2.82[2.26-3.52]) and surgical experience (Range OR: 8.88[7.16-11.02]). Surgical experience was inversely related with odds of VUR recurrence (Range OR: 0.41[0.32-0.54]). Rates of VUR resolution were comparable for OUR and RALUR patients. No patient required additional intervention for POHN. CONCLUSIONS: Incidence and resolution rate of POHN after OUR and RALUR were similar. Higher VUR grades were associated with increased odds of POHN after RALUR. Increasing RALUR experience improved VUR resolution rate but increased odds of POHN. Surgical success rates were similar for RALUR and OUR. LEVEL OF EVIDENCE: II.

Vicarious excretion of intravenous contrast masquerading as a nephroenteric fistula in a patient with a grade IV renal injury.

We describe a case of a patient who suffered a grade IV renal injury who demonstrated vicarious excretion of intravenous contrast into the bowel masquerading as a nephroenteric fistula. Despite concerning imaging features, given the patient's lack of clinical symptoms of a nephroenteric fistula, negative oral activated charcoal test, and our understanding of the pharmacokinetics of intravenous contrast, our suspicion for nephroenteric fistula was low. This case highlights the importance of carefully considering the mechanism of injury when developing a differential diagnosis of potential sequela after trauma and understanding the pharmacokinetics of intravenous contrast in the trauma setting.

A Phenotypic Female Adolescent with Primary Amenorrhea and Dysmorphic Features.

We report on a case of a 14-year-old phenotypic female with a microdeletion at 13q31.1-q31.3, dysmorphic facial and limb features, and neurologic symptoms. She presented to her pediatrician with concerns for delayed puberty, and laboratory analysis revealed hypergonadotropic hypogonadism. She was found to have an XY karyotype and streak gonads. Further genetic studies did not reveal another cause for her gonadal dysgenesis and, to our knowledge, an association with her known 13q-microdeletion has not yet been reported. Given the risk of malignancy with XY gonadal dysgenesis, the patient had surgery to remove the gonads and had no postoperative complications after a 6-month follow-up visit. We also discuss the role of the pediatrician in cases of delayed puberty, from initial diagnosis to definitive management. [Pediatr Ann. 2019;48(12):e495-e500.].