Shock wave lithotripsy associated with greater prevalence of hypertension.

OBJECTIVES: To determine whether shock wave lithotripsy (SWL) increases the prevalence of hypertension (HTN) at intermediate follow-up. METHODS: All patients were treated with the Medstone STS electrohydraulic lithotripter, and the data were recorded prospectively in a centralized database. The data on the development of HTN after SWL was obtained from a questionnaire mailed to the patients who had undergone SWL from November 1999 and January 2002. Controls matched for age, sex, and body mass index were obtained from the National Health and Nutrition Examination Survey, using the demographic, body measurements, medical conditions, and blood pressure data sets. Two sets of matching controls were used to compare the prevalence of HTN between our patients and the NHANES population at SWL and at the follow-up point. RESULTS: A total of 2041 patients responded to the questionnaire, with a median follow-up of 6 years. No statistically significant difference was found in the HTN prevalence between the patients and matched controls at SWL (26.7% vs 28.0%). At the follow-up point, the prevalence of HTN was greater in our patients (37.8%) than in the controls (32.5%, P=.0009). Of our patients, 15% have developed de novo HTN compared with the predicted rate of 6.25% from the matched controls. Male gender, age, and a greater body mass index were associated with the development of HTN, but none of the SWL parameters (number of shocks, bilateral vs unilateral, and multiple SWL sessions) were significantly associated with HTN. CONCLUSIONS: The results of our study have indicated a small, but significant, increase in the risk of developing HTN after SWL using a third-generation electrohydraulic lithotripter at intermediate follow-up.

Shock wave lithotripsy not associated with development of diabetes mellitus at 6 years of follow-up.

OBJECTIVES: To investigate the hypothesis that extracorporeal shock wave lithotripsy (ESWL) increases the incident risk of new-onset diabetes mellitus (DM). Studies have suggested that ESWL predisposes to DM. METHODS: Using a mail survey, we collected data on the presence and onset of DM in 1947 patients treated with the Medstone-STS electrohydraulic lithotripter from 1999 to 2002. These patients were matched by age, sex, and body mass index to controls from the National Health and Nutrition Examination Survey (NHANES) database. Of the 1947 patients, 4% could not be matched and were excluded, leaving 1869 for analysis, of whom 60.0% were men. The mean age was 51.9 years at ESWL and the median follow-up was 6 years. The mean body mass index at the end of the study was 28.6 kg/m(2). RESULTS: At ESWL, 8.67% of matched patients had a diagnosis of DM. This had increased to 13.9% at the time of survey. In the NHANES group, 8.34% had DM at the time the ESWL group underwent treatment, and this had increased to 14.1% at the NHANES survey. Therefore, the rate of new DM cases in the ESWL group was similar to that in the NHANES group (5.2% vs 5.8%, respectively; P = .47). Multivariate analysis of the patient cohort confirmed that age, sex, body mass index, and family history correlated with development of DM and that the laterality of treatment and number of treatments or shocks given were not significant predictors of DM. CONCLUSIONS: The results of our study have shown that patients treated with ESWL do not develop DM at a greater rate than does the general population at 6 years of follow-up.

Adding renal scan data improves the accuracy of a computational model to predict vesicoureteral reflux resolution.

PURPOSE: We previously developed a computational model to predict vesicoureteral reflux resolution 1 and 2 years after diagnosis. Previous studies suggest that an abnormal renal scan may be a predictor of the failure of vesicoureteral reflux to resolve. We investigated whether the addition of renal scan data would improve the accuracy of our computational model. MATERIALS AND METHODS: Medical records and renal scans were reviewed on 161 children, including 127 girls and 34 boys, with primary reflux between 1988 and 2004. In addition to the 9 input variables from our prior model, we added renal scan data on decreased relative renal function (40% or less in the refluxing kidney) and renal scars. Resolution outcome was evaluated 1 and 2 years after diagnosis. Data sets were prepared for 1 and 2-year outcomes, and randomized into a modeling set of 111 and a cross-validation set of 50. The model was constructed using neUROn++. RESULTS: A logistic regression model had the best fit with an ROC area of 0.945 for predicting reflux resolution in the 2-year model. This was improved compared to our previous model without renal scan data. A prognostic calculator using this model can be deployed for availability on the Internet, allowing input variables to be entered and calculating the odds of resolution. CONCLUSIONS: This computational model uses multiple variables, including renal scan data, to improve individualized prediction of early reflux resolution with almost 95% accuracy. The prognostic calculator is a useful tool for predicting individualized vesicoureteral reflux resolution.

Lithogenic risk factors in the morbidly obese population.

PURPOSE: To our knowledge baseline lithogenic risk factors in the morbidly obese population are currently unknown. Prior studies evaluated known stone formers and correlated risk with increasing body mass index. We describe risk factors for urinary stone formation in a group of unselected morbidly obese patients. MATERIALS AND METHODS: Patients scheduled for gastric bypass provided a 24-hour urine collection before surgery. Patient demographics, medications and supplement consumption were recorded. A dietary intake diary was converted into daily kcal, Ca, Na and protein consumption. Differences between groups based on gender, history of diabetes or nephrolithiasis, diuretic use and Ca supplementation were evaluated. Correlation of stone risk parameters with body mass index was evaluated. RESULTS: A total of 45 patients provided samples for analysis. Mean +/- SD body mass index was 49.5 +/- 9.1 kg/m(2) and mean age was 47.0 +/- 10.5 years. Overall 97.8% of patients had at least 1 lithogenic risk factor identified. Low urinary volume was the most common abnormality, affecting 71.1% of patients. Male patients excreted significantly more Ox (p = 0.0014), Na (p = 0.020), PO(4) (p = 0.0083) and SO(4) (p = 0.0014) than females. Patients with a history of nephrolithiasis excreted significantly more oxalate (p = 0.018) and had higher relative Na urate supersaturation (p = 0.00093) than nonstone formers. Hydrochlorothiazide use was associated with significantly increased Na urate relative supersaturation (p = 0.0097). Increasing body mass index was inversely associated with Mg (r = -0.38, p = 0.01) and brushite (r = -0.30, p = 0.04). CONCLUSIONS: Of our cohort of morbidly obese patients 98% had at least 1 lithogenic risk factor identified on 24-hour urine collection. This study identified a high urinary stone risk in the morbidly obese and suggests possible avenues for dietary and/or pharmacological preventive measures. Future studies will determine how bariatric surgery alters these risk factors.

Therapeutic testis biopsy for sperm retrieval.

PURPOSE OF REVIEW: The introduction of IVF and intracytoplasmic sperm injection revolutionized the treatment of male infertility by requiring a minimal number of sperm to achieve pregnancy. We describe the various methods for testicular sperm retrieval in different types of azoospermia. RECENT FINDINGS: Different techniques for surgical sperm retrieval are available, including testicular sperm aspiration, single, multisite and microdissection testicular sperm extraction, as well as percutaneous and microsurgical epididymal sperm aspiration. While these methods have similar retrieval outcomes in obstructive azoospermia, testicular sperm extraction procedures appear to be more beneficial in cases of nonobstructive azoospermia. A reliable algorithm for predicting the outcome of microdissection testicular sperm extraction using clinical parameters is still lacking, and may be difficult to develop, given the fact that this method is designed to detect and sample even minute areas of focal spermatogenesis. SUMMARY: A variety of surgical sperm retrieval procedures can be performed for the purpose of subsequent or simultaneous IVF/intracytoplasmic sperm injection. The decision regarding the type of procedure should be based on the type of azoospermia, specific clinical circumstances, as well as on the surgeon's preference and experience.

Computational model for predicting the chance of early resolution in children with vesicoureteral reflux.

PURPOSE: Minimally invasive treatment options and concern regarding long-term antibiotics have increased emphasis on predicting the chance of early vesicoureteral reflux resolution. Computational models, such as artificial neural networks, have been used to assist decision making in the clinical setting using complex numeric constructs to solve multivariable problems. We investigated various computational models to enhance the prediction of vesicoureteral reflux resolution. MATERIALS AND METHODS: We reviewed the records of 205 children with vesicoureteral reflux, including 163 females and 42 males. In addition to reflux grade, several clinical variables were recorded from the diagnostic visit. Outcome was noted as resolved or unresolved at 1 and 2 years after diagnosis. Two separate data sets were prepared for the 1 and 2-year outcomes, sharing the same input features. The data sets were randomized into a modeling set of 155 and a cross-validation set of 50. The model was constructed with several constructs using neUROn++, a set of C++ programs that we developed, to best fit the data. RESULTS: A linear support vector machine was found to have the highest accuracy with a test set ROC curve area of 0.819 and 0.86 for the 1 and 2-year models, respectively. The model was deployed in JavaScript for ready availability on the Internet, allowing all input variables to be entered and calculating the odds of 1 and 2-year resolution. CONCLUSIONS: This computational model allowed the use of multiple variables to improve the individualized prediction of early reflux resolution. This is a potentially useful clinical tool regarding treatment decisions for vesicoureteral reflux.

Perioperative costs and charges of prostate brachytherapy and prostatectomy.

OBJECTIVES: To compare the costs and charges incurred for transrectal ultrasound-guided brachytherapy (USBT) and radical prostatectomy (RP) at a single institution. METHODS: From February 1998 to March 1999, 66 consecutive patients underwent potentially curative therapy for clinically localized prostate cancer. Thirty-seven were treated by USBT using palladium-103 brachytherapy and 29 by RP. Hospital costs and charges and professional fees were obtained for a 2-month period beginning 1 month before RP or USBT and compared between the two procedures. RESULTS: The mean total charges for USBT ($26,320) and RP ($22,660) were not significantly different. Compared with RP, USBT incurred significantly lower operating room time cost ($628 for USBT versus $2093 for RP, P <0.05). The average cost of seeds for USBT was $6184, which resulted in higher technical costs for USBT than for RP ($12,209 versus $7746, P <0.05). This was offset by lower professional fees for USBT ($7575 versus $9531). The ratio of charge to cost was lower for USBT than for RP (2.2 versus 3.0). CONCLUSIONS: The total charges associated with brachytherapy appear similar to those associated with RP, although RP had relatively lower technical costs. Without a clear cost advantage of USBT over RP, the choice of therapy should continue to be primarily influenced by tumor characteristics, treatment efficacy, and patient preference.