Cost comparison of intra-detrusor injection of botulinum toxin versus augmentation cystoplasty for refractory neurogenic detrusor overactivity in children.

INTRODUCTION: Treatment options for refractory neurogenic detrusor overactivity (NDO) in children include botulinum toxin type A (BTX-A) and augmentation cystoplasty (AC). Although BTX-A is accepted in contemporary pediatric urologic practice, cost and long-term outcomes data for BTX-A are limited relative to the gold standard, AC. The purpose of this study was to compare the projected 10-year costs of AC versus BTX-A. METHODS: We performed a cost analysis from the payer perspective by computationally modeling treatment sequences by a Markov model. In the model, we used probabilities derived from published sources, and costs obtained at a tertiary medical center. The base case was a pediatric patient with refractory NDO. In the model, we assumed biannual BTX-A treatments. Treatment costs over 10 years were compared between immediate AC versus bridging therapy with BTX-A. Using the computational model, we simulated 100,000 instances of 10-year treatment cost for each of the two treatment modalities. The costs for the two treatment approaches were then compared using t-test and Wilcoxon test. RESULTS: The projected median and mean 10-year cost of immediately AC were $51,798.72 (95% CI [$51,798.72, $327,483.80]) and $123,473.4 (SD: $98,085.23) respectfully, while the projected median and mean 10-year cost of bridging therapy with BTX-A prior to proceeding to AC as needed were $74,552.46 (95% CI [$53,188.56, $309,913.07]) and $124,858.80 (SD: $84,495.35) (p < 0.001). CONCLUSIONS: For a typical index pediatric patient with NDO, bridging therapy with intravesical BTX-A is associated with an increased cost compared to immediate AC over a ten-year period.

Design and validation of a low-cost, high-fidelity model for robotic pyeloplasty simulation training.

INTRODUCTION/BACKGROUND: Owing to restrictions in operative experiences, urology residents can no longer solely rely on 'hands-on' operative time to master their surgical skills by the end of residency. Simulation training could help residents master basic surgical skills and steps of a procedure to maximize time in the operative room. However, simulators can be expensive or tedious to set up, limiting the availability to residents and training programs. OBJECTIVE: The authors sought to develop and validate an inexpensive, high-fidelity training model for robotic pyeloplasty. STUDY DESIGN: Pyeloplasty models were created using Dragon Skin® FX-Pro tissue-mimicking silicone cast over 3-dimensional molds. Urology faculty and trainees completed a demographic questionnaire. The participants viewed a brief instructional video and then independently performed robotic dismembered pyeloplasty on the model. Acceptability and content validity were evaluated via post-task evaluation of the model. Construct validity was evaluated by comparing procedure completion time, the Global Evaluative Assessment of Robotic Skills (GEARS) score, blinded subjective physical evaluation of repair quality (1-10 scale), and flow rate between experts and novices. RESULTS: In total, 5 urology faculty, 6 fellows, and 14 residents participated. The median robotic console experience among faculty, fellows, and residents was 8 years (interquartile range [IQR] = 6-11), 3.5 years (IQR = 2-4 years), and 0 years (IQR = 0-0.5 years), respectively. The median procedure completion time was 29 min (IQR = 26-40 min), and the median flow rate was 1.11 mL/s (IQR = 0-1.34 mL/s). All faculty had flow rates >1.25 mL/s and procedure times <30 min compared with 2 of 6 fellows and none of the residents (P < 0.001). All faculty, half of the fellows, and none of the residents achieved a GEARS score ≥20, with a median resident score of 12.5 (IQR = 8-13) (P < 0.001). For repair quality, all faculty scored ≥9 (out of 10), all fellows scored ≥8, and the median score among residents was 6 (IQR = 2-6) (P < 0.001). The material cost was $1.32/model, and the average production time was 0.12 person-hours/model. DISCUSSION AND CONCLUSION: This low-cost pyeloplasty model exhibits acceptability and content validity. Construct validity is supported by significant correlation between participant expertise and simulator performance across multiple assessment domains. The model has excellent potential to be used as a training tool in urology and allows for repetitive practice of pyeloplasty skills before live cases.

Simple visual review of pre- to post-operative renal ultrasound images predicts pyeloplasty success equally as well as geometric measurements: A blinded comparison with a gold standard.

BACKGROUND: MAG3 diuretic renal scan remains the gold standard for determination of improvement in renal drainage following pyeloplasty for ureteropelvic junction obstruction. We hypothesized that (i) a change in geometric measurements between pre-operative and post-operative renal ultrasound (RUS) images and (ii) blinded simple visual review of images both would predict pyeloplasty success. OBJECTIVE: To determine if simple visual review and/or novel geometric measurement of renal ultrasounds can detect pyeloplasty failure. STUDY DESIGN: This study was a retrospective, blinded comparison with a gold standard. Included were children aged ≤18 years undergoing pyeloplasty at our institution from 2009 to 2015. For each kidney, representative pre-operative and post-operative RUS images were chosen. Our standard for pyeloplasty success was improved drainage curve on MAG3 and lack of additional surgery. Measurements for collecting system circularity, roundness, and renal parenchymal to collecting system area ratio (RPCSR) were obtained by three raters (Figure), who were blinded to the outcome of the pyeloplasty. Changes in geometric measurements were analyzed as a diagnostic test for MAG3-defined pyeloplasty success using ROC curve analysis. In addition, six reviewers blinded to pyeloplasty success reviewed pre-operative and post-operative images visually for improved hydronephrosis and categorized pyeloplasty as success or failure based on simple visual review of RUS. RESULTS: Fifty-three repaired renal units were identified (50 children). There were five pyeloplasty failures, four of which underwent revision or nephrectomy. While all geometric measurements could discriminate pyeloplasty failure and success, the geometric measurements that discriminated best between pyeloplasty failure and success were change in collecting system roundness and change in RPCSR. Consensus opinion among six blinded reviewers using simple visual review had a sensitivity of 94% and PPV of 100% with respect to identifying pyeloplasty success (AUC 0.97 (95% CI 0.93-1.0)). This was not significantly different from AUC for change in roundness (p = 0.09) or change in RPCSR (p = 0.1). DISCUSSION: Change in collecting system roundness and change in RPCSR were the most accurate geometric measurements in predicting pyeloplasty success. Simple visual review of ultrasound images for pyeloplasty success performed as well or better than geometric measurements. However, geometric measurements remain useful as a research tool or to communicate findings between clinicians. CONCLUSIONS: Complex geometric measurements of hydronephrosis or post-operative MAG3 scans are not needed if hydronephrosis is visually significantly improved, as simple visual review is highly sensitive for detecting pyeloplasty failure.

Impact of nephrectomy on long-term renal function in non-syndromic children treated for unifocal Wilms tumor.

OBJECTIVE: The present study is designed to assess the long-term renal function of children who underwent radical nephrectomy for unifocal Wilms tumor. METHODS: A single institution retrospective cohort study of non-syndromic children treated with radical nephrectomy for unifocal Wilms tumor between 1995 and 2011 was performed to identify risk factors for decreased glomerular filtration rate (GFR). The primary endpoint was decrease in age-adjusted GFR below normal published ranges. The secondary endpoint was progression to chronic renal insufficiency (CRI). RESULTS: A total of 55 patients were identified in the cohort. Eight (15%) patients exhibited decreased age-adjusted GFR during the follow-up period, with 2 (4%) progressing to CRI. Increasing time between surgery and the last known GFR follow-up was associated with decreased GFR, with the normal GFR group having median follow-up of 7.32 years versus 11.47 years (p = 0.019) in the decreased GFR group. CONCLUSIONS: A trend toward decline in GFR was detected with longer follow-up. Longer follow-up may reveal that clinically significant decline in renal function occurs years following nephrectomy among a subset of Wilms tumor survivors, even among those who do not progress to end stage renal disease.