In Pursuit of the Optimal Dusting Settings with the Thulium Fiber Laser: An In Vitro Assessment.

Objective: Low energy and high frequency settings are used in stone dusting for holmium lasers. Such settings may not be optimal for thulium fiber laser (TFL). With the seemingly endless combination of settings, we aim to provide guidance to the practicing urologists and assess the efficiency of the TFL platform in an automated in vitro "dusting model." Materials/Methods: Three experimental setups were designed to investigate stone dusting produced by an IPG Photonics TLR-50 W TFL system using 200 µm fiber and soft BegoStone phantoms. The most popular 10 and 20 W dusting settings among endourologist familiar with TFL were evaluated. We directly compared short pulse (SP) vs long pulse (LP) mode using various combinations of pulse energy (Ep) and pulse frequency (F). Thereafter, we tested the 10 and 20 W settings and compared them among each other to elucidate the most efficient settings at each power. Treatments were performed under the same total laser energy delivered to the stone at four different standoff distances (SDs) with a clinically relevant scanning speed of either 1 or 2 mm/sec. Ablation volumes were quantified by optical coherence tomography to assess stone dusting efficiency. Fragment size after ablation at different pulse energies was evaluated by sieving and evaluating under a microscope after treatment. Results: Overall, SP provided greater ablation volume when compared with LP. Our dusting efficiency model demonstrated that the maximum stone ablation was achieved at the combination of high energy/low frequency settings (p < 0.005) and at a SD of 0.2 mm. At all tested pulse energies, no stone phantoms were broken into fragments >1 mm. Conclusions: During stone dusting with TFL, SP offers superior ablation to LP settings. Optimal dusting at clinically relevant scanning speeds of 1 and 2 mm/sec occurs at high energy/low frequency settings. Thulium lithotripsy with high Ep does not result in increased fragment size.

Trends and patterns of initial percutaneous nephrolithotomy and subsequent procedures among commercially-insured US adults with urinary system stone disease: a 10-year population-based study.

PURPOSE: To describe trends and patterns of initial percutaneous nephrolithotomy (PCNL) and subsequent procedures from 2010 to 2019 among commercially-insured US adults with urinary system stone disease (USSD). METHODS: Retrospective study of administrative data from the IBM® MarketScan® Database. Eligible patients were aged 18-64 years and underwent PCNL between 1/1/2010 and 12/31/2019. Measures of interest for analysis of trends and patterns included the setting of initial PCNL (inpatient vs. outpatient), percutaneous access (1 vs. 2-step), and the incidence, time course, and type of subsequent procedures (extracorporeal shockwave lithotripsy [SWL], ureteroscopy [URS], and/or PCNL) performed up-to 3 years after initial PCNL. RESULTS: A total of 8,348 patients met the study eligibility criteria. During the study period, there was a substantial shift in the setting of initial PCNL, from 59.9% being inpatient in 2010 to 85.3% being outpatient by 2019 (P < 0.001). The proportion of 1 vs. 2-step initial PCNL fluctuated over time, with a low of 15.1% in 2016 and a high of 22.0% in 2019 but showed no consistent yearly trend (P = 0.137). The Kaplan-Meier estimated probability of subsequent procedures following initial PCNL was 20% at 30 days, 28% at 90 days, and 50% at 3 years, with slight fluctuations by initial PCNL year. From 2010 to 2019, the proportion of subsequent procedures accounted for by URS increased substantially (from 30.8 to 51.8%), whereas SWL decreased substantially (from 39.5 to 14.7%) (P < 0.001). CONCLUSIONS: From 2010 to 2019, PCNL procedures largely shifted to the outpatient setting. Subsequent procedures after initial PCNL were common, with most occurring within 90 days. URS has become the most commonly-used subsequent procedure type.

Small ruminant urinary obstruction: decision trees for treatment.

Urolithiasis is the most common cause of urinary tract disease in small ruminants and has significant economic and production impacts worldwide. Urolithiasis is multifactorial in origin and generally begins with the formation of cystoliths followed by urethral obstruction. The condition is most common in males. Clinical signs are variable depending on the severity of the obstruction. Uroliths can be calcium, struvite, or silicate based; however, struvite and amorphous magnesium calcium phosphate are the most common urolith types observed in small ruminants. Although urethral process (vermiform appendage) amputation is widely considered the first line of treatment, reobstruction is common within the first 36 hours. Surgical interventions such as temporary tube cystostomy, perineal urethrostomy (PU), modified proximal perineal urethrostomy, vesico-preputial anastomosis (VPA), and urinary bladder marsupialization (BM) are reported to carry an improved prognosis for long-term survival. PU carries a lower proportion of long-term success (> 12-month survival time) when compared with VPA and BM. Stoma stricture and urine scald are the most commonly observed surgical complications. Currently, the literature provides minimal direction for clinician decision-making in managing these cases while accounting for patient history, client financial ability, composition of calculi, and potential treatment complications. Small ruminant urinary obstructions are challenging and complicated conditions to treat, due to their multifactorial etiology, ruminant urogenital anatomy, and the variety of imperfect treatment options available. The purpose of this article this article is to provide veterinary practitioners with decision trees to guide management and treatment of urolithiasis in small ruminants.

Systematic assessment of information about surgical urinary stone treatment on YouTube.

PURPOSE: To systematically assess the quality of videos on the surgical treatment of urinary stones available on YouTube using validated instruments. METHODS: A systematic search for videos on YouTube addressing treatment options of urinary stones was performed in October 2019. Assessed parameters included basic data (e.g. number of views), the grade of misinformation reporting of conflicts of interest. Quality of content was analyzed using the validated DISCERN questionnaire. Data were analyzed using descriptive statistics. RESULTS: A total of 100 videos with a median of 26,234 views (1020-1,720,521) were included in the analysis. Of these, only 26 videos were rated to contain no misinformation and only nine disclosed potential conflicts of interest. Overall, the median quality of the videos was low (2 out of 5 points for DISCERN question 16). Videos uploaded by healthcare professionals and medical societies/organizations offered significantly higher levels of quality. In particular, the videos provided by the EAU achieved the highest rating with a median score of 3.0. CONCLUSIONS: The majority of videos concerning the surgical treatment of urinary stones have a low quality of content, are potentially subject to commercial bias and do not report on conflicts of interest. Videos provided by medical societies, such as the EAU, provide a higher level of quality. This highlights the importance of active recommendation of evidence-based patient education materials.

Initial prospective study of ambulatory mPCNL on upper urinary tract calculi.

OBJECTIVE: To explore the feasibility and safety of ambulatory mPCNL (mini percutaneous nephrolithotomy) on upper urinary tract calculi. METHODS: Clinical data of 18 patients received ambulatory mPCNL during Aug. 2017 to Jan. 2018 and 23 patients treated with routine inpatient mPCNL of the corresponding period were collected. All the patients included received 16Fr channel PCNL under the guidance of Doppler ultrasound. A 6Fr double J stent was placed in the ureter for internal drainage, and either an indwelling 14Fr open nephrostomy tube was placed or the puncture channel was filled with absorbable hemostatic materials alone, depends on the bleeding condition of the puncture channel and the intraoperative conditions. Preoperative parameters and surgery time, complications, total hospitalization costs and hospital stay time between the two groups were compared. RESULTS: Preoperative parameters regarding age (P=0.057), sex distribution (P=0.380), ASA score (P=0.388), Calculi CT value (P=0.697), and the S.T.O.N.E. score (P=0.122) were comparable between the two groups. Maximum diameter of calculi (cm) of the conventional hospitalization group, however, was larger than the ambulatory surgery group (P=0.041). There were no significant differences in the mean surgery time (P=0.146), postoperative hemoglobin drop (P=0.865), Calculi-free rate on the next day after surgery (P=0.083) and postoperative fever rate (P=0.200) between the two groups. With regard to tubeless rate (P<0.001), total hospitalization costs (P=0.003) and hospital stay time (P<0.001), there were significant advantage favored ambulatory mPCNL. CONCLUSIONS: For patients with simple upper urinary tract calculi and relatively good performance status, ambulatory mPCNL is feasible as it's equally safe and efficient as compared with routine inpatient mPCNL. Moreover, ambulatory mPCNL decreases hospitalization costs and hospital stay time. Nevertheless, perioperative management should be carefully conducted, and well-designed studies are warranted.

New Persistent Opioid Use After Outpatient Ureteroscopy for Upper Tract Stone Treatment.

OBJECTIVE: To measure the incidence of persistent opioid use following ureteroscopy (URS). Over 100 Americans die every day from opioid overdose. Recent studies suggest that many opioid addictions surface after surgery. METHODS: Using claims data, we identified adults who underwent outpatient URS for treatment of upper tract stones between January 2008 and December 2016 and filled an opioid prescription attributable to URS. We then measured the rate of new persistent opioid use-defined as continued use of opioids 91-180 days after URS among those who were previously opioid-naive. Finally, we fit multivariable models to assess whether new persistent opioid use was associated with the amount of opioid prescribed at the time of URS. RESULTS: In total, 27,740 patients underwent outpatient URS, 51.2% of whom were opioid-naïve. Nearly 1 in 16 (6.2%) opioid-naïve patients developed new persistent opioid use after URS. Six months following surgery, beneficiaries with new persistent opioid use continued to fill prescriptions with daily doses of 4.2 oral morphine equivalents. Adjusting for measured sociodemographic and clinical differences, patients in the highest tercile of opioids prescribed at the time of URS had 69% higher odds of new persistent opioid use compared to those in the lowest tercile (odds ratio, 1.69; 95% CI, 1.41-2.03). CONCLUSION: Nearly 1 in 16 opioid-naive patients develop new persistent opioid use after URS. New persistent opioid use is associated with the amount of opioid prescribed at the time of URS. Given these findings, urologists should re-evaluate their post-URS opioid prescribing patterns.

Percutaneous Nephrolithotomy in Children: Analysis of Nationwide Hospitalizations and Short-Term Outcomes for the United States, 2001-2014.

OBJECTIVE: To describe population-wide utilization rates and outcomes of percutaneous nephrolithotomy (PCNL) in the management of pediatric upper urinary tract calculi (UUTC). PATIENTS AND METHODS: Patients <18 years with a diagnosis of UUTC, who underwent PCNL between 2001 and 2014 were identified from the National Inpatient Sample database. Annual PCNL rates, based on the at-risk population for each year, were estimated, and change in utilization rate was analyzed using negative binomial regression. Perioperative outcomes, hospital length of stay (LOS), and costs were determined; continuous and categorical variables were analyzed using nonparametric tests and Chi-squared tests, respectively. Trends tests and multivariable analyses (MVAs) were also performed where appropriate. RESULTS: An estimated 3206 pediatric PCNL procedures were performed. Mean annual PCNL rate increased significantly relative to 2001 (incidence rate ratio = 1.40; 95% confidence interval 1.15-1.71, p = 0.001). Proportion of PCNL as a fraction of all inpatient surgical procedures for UUTC also significantly increased over time, from 15.7% in 2001 to 26.4% in 2014 (p < 0.0001). Complications overall occurred in 20.7% of cases, with a significantly rising rate over time period (p < 0.0001). Complication rates were similar across hospital types and geographic regions. Median hospitalization cost was significantly higher for the West than for each of the other regions (p < 0.05 in each case). Median LOS was also highest for the West (4 days vs 3 days for each of the other regions). In MVA, significant predictors of both increased LOS and costs included black race, comorbidities of hypertension, diabetes, coagulopathy and neurologic disease, hospitalization in the South, and presence of complications. Race, gender, comorbidities, and treatment year were among the predictors of complications. CONCLUSIONS: PCNL utilization in the management of pediatric UUTC has significantly increased since 2001, with an associated increase in complication rates, although major complications were uncommon. Regional variations in costs and LOS were evident.

Clinical outcomes and costs of reusable and single-use flexible ureterorenoscopes: a prospective cohort study.

The purpose of this study is to analyze clinical outcomes and costs of single-use flexible ureterorenoscopes in comparison with reusable flexible ureterorenoscopes in a tertiary referral center. Prospectively, 68 flexible ureterorenoscopies utilizing reusable (Flex-X2S, Flex-XC, Karl Storz) and 68 applying single-use flexible ureterorenoscopes (LithoVue, Boston Scientific) were collected. Clinical outcome parameters such as overall success rate, complication rates according to Clavien-Dindo, operation time and radiation exposure time were measured. Cost analysis was based on purchase costs and recurrent costs for repair and reprocessing divided by number of procedures. In each group 68 procedures were available for evaluation. In 91% of reusable and 88% of single-use ureterorenoscopies stone disease was treated with a mean stone burden of 101 ± 226 and 90 ± 244 mm2 and lower pole involvement in 47 and 41%, respectively (p > 0.05). Comparing clinical outcomes of reusable vs. single-use instruments revealed no significant difference for overall success rates (81 vs. 87%), stone-free rates (82 vs. 85%), operation time (76.2 ± 46.8 vs. 76.8 ± 40.2 min), radiation exposure time (3.83 ± 3.15 vs. 3.93 ± 4.43 min) and complication rates (7 vs. 17%) (p > 0.05). A wide range of repair and purchase costs resulted in total to $1212-$1743 per procedure for reusable ureterorenoscopy whereas price of single-use ureterorenoscopy was $1300-$3180 per procedure. The current work provided evidence for equal clinical effectiveness of reusable and single-use flexible ureterorenoscopes. Partially overlapping ranges of costs for single-use and reusable scopes stress the importance to precisely know the expenses and caseload when negotiating purchase prices, repair prices and warranty conditions.

Variation in Spending around Surgical Episodes of Urinary Stone Disease: Findings from Michigan.

PURPOSE: To help rein in surgical spending there is growing interest in the application of payment bundles to common outpatient procedures like ureteroscopy and shock wave lithotripsy. However, before urologists can move to such a payment system they need to know where episode costs are concentrated. MATERIALS AND METHODS: Using claims data from Michigan Value Collaborative we identified patients who underwent ureteroscopy or shock wave lithotripsy at hospitals in Michigan from 2012 to 2015. We then totaled expenditures for all relevant services during the 30-day surgical episodes of these patients and categorized component payments (ie those for the index procedure, subsequent hospitalizations, professional services and postacute care). Finally we quantified the variation in total episode expenditures for ureteroscopy and shock wave lithotripsy across hospitals, examining drivers of this variation. RESULTS: A total of 9,449 ureteroscopy and 6,446 shock wave lithotripsy procedures were performed at 62 hospitals. Among these hospitals there was threefold variation in ureteroscopy and shock wave lithotripsy spending. The index procedure accounted for the largest payment difference between high vs low cost hospitals (ureteroscopy $7,936 vs $4,995 and shock wave lithotripsy $4,832 vs $3,207, each p <0.01), followed by payments for postacute care (ureteroscopy $2,207 vs $1,711 and shock wave lithotripsy $2,138 vs $1,104, each p <0.01). Across hospitals the index procedure explained 68% and 44% of the variation in episode spending for ureteroscopy and shock wave lithotripsy, and postacute care payments explained 15% and 28%, respectively. CONCLUSIONS: There exists substantial variation in ambulatory surgical spending across Michigan hospitals for urinary stone episodes. Most of this variation can be explained by payment differences for the index procedure and for postacute care services.

Comparison of cost of care for tethered versus non-tethered ureteric stents in the management of uncomplicated upper urinary tract stones.

BACKGROUND: Many surgeons use a stent after ureteroscopic lithotripsy (URSL). For short-term stenting purposes, a surgeon has the choice of either a tethered or a non-tethered stent. Stents may be associated with complications that entail an additional cost to their use. There is a paucity of data on the direct healthcare cost of using stent type after either primary or secondary URSL. METHODS: We retrospectively reviewed medical records for patients who underwent URSL for uncomplicated urolithiasis between January 2013 and December 2013 at two tertiary referral hospitals. Costs data was sourced from the costing department with complete data available for 134 patients. The overall medical care cost was estimated by computing the cost of surgery, stent-related emergency department presentations, re-admissions and stent removal. RESULTS: A total of 113 patients had tethered stents and 21 had non-tethered stents, with similar age and gender composition between the two groups and complications rates. The mean cost of URSL and stent placement was A$3071.7 ± A$906.8 versus A$3423.8 ± A$808.4 (P = 0.049), mean cost of managing complications was A$309.4 ± A$1744.8 versus A$31.3 ± A$98.9 (P = 0.096), mean cost of out-patient clinic stent removal was A$222.5 ± A$60 versus A$1013.6 ± A$75.4 (P < 0.001) for endoscopic stent removal, overall mean cost of care was A$3603.6 ± A$1896.7 versus A$4468.1 ± A$820.8 (P = 0.042) for tethered and non-tethered stents, respectively. CONCLUSION: It is cheaper to use a tethered ureteric stent compared with non-tethered stents for short-term stenting after uncomplicated URSL, with a mean cost saving of A$864.5.

Anticipating the Unintended Consequences of Closing the Door on Physician Self-Referral.

PURPOSE: While physician self-referral has been associated with increased health care use, the downstream effects of the practice remain poorly characterized. Accordingly we identified the relationship between urologist self-referral and downstream health care use in patients with urinary stone disease. MATERIALS AND METHODS: With urologist self-referral status as the exposure of interest, we performed a retrospective cohort study of Medicare beneficiaries from 2008 to 2010 to evaluate the relationship between self-referral and imaging intensity, risk of surgical treatment and time to surgical treatment for urinary stone disease. RESULTS: We identified dose dependent increases in computerized tomography use with increasing stratum of urologist self-referral. Compared to nonself-referring urologists, computerized tomography use was 1.19 times higher (95% CI 1.07-1.34) in episodes ascribed to intermediate frequency (5 to 9) and 1.32 times higher (95% CI 1.16-1.50) in episodes ascribed to high frequency (10+) self-referring urologists. Self-referral was inversely associated with risk of surgical treatment for stone disease. Specifically, patients treated by intermediate and high frequency self-referring urologists were less likely to undergo surgical treatment than those treated by nonself-referring urologists, with HR 0.84 (95% CI 0.71-0.99) and HR 0.81 (95% CI 0.66-0.99), respectively. We identified no statistically significant between-group differences in time to surgical treatment. CONCLUSIONS: Self-referral is associated with increased use of computerized tomography and with decreased use of surgery for stone disease. While policy efforts to further restrict physician self-referral may reduce the use of computerized tomography, they may also result in unintended consequences with respect to patterns of surgical care.

Failing to follow up: predicting patients that will "no-show" for medically advised imaging following endourologic stone surgery.

INTRODUCTION: The purpose of this study is to evaluate predictors of poor compliance after treatment of urinary stone disease. MATERIALS AND METHODS: This study was a retrospective analysis of patients who underwent stent removal following percutaneous nephrolithotomy (PCNL) or ureteroscopy (URS) between 2008-2012. All patients were scheduled for follow up evaluation and renal ultrasound at 4-6 weeks following stent removal. Patients were stratified based on appointment compliance and demographic variables including gender, age, insurance type (Government Assisted Insurance [GAI] or Private Insurance [PI]), initial procedure, season, distance between home and clinic, average monthly gas price at follow up, and median education attainment. Logistic regression was performed to determine independent predictors of missed follow up. RESULTS: A total of 301 patients were included, 153 women (51% female) with a mean age of 54 ± 14.2 years. Of the cohort, 22.6% (n = 68) did not return for follow up. GAI was the only variable associated with a greater risk of non-compliance on univariate analysis (OR 2.13 [95% CI 1.12-3.86] p = 0.011) and multivariate analysis (OR 3.14.10 [95% CI 1.48-6.7], p < 0.01). Gender, age, procedure, season, distance, gas prices, and education were not significant predictors. CONCLUSION: In our study, evaluating characteristics associated with missed follow up after stent removal for PCNL and URS, possession of GAI was the only factor associated with non-compliance. Urologists should be aware that persons with GAI may be at increased risk of missed follow up and should use this information to target interventions to improve compliance.

Quantitative assessment of shockwave lithotripsy accuracy and the effect of respiratory motion.

BACKGROUND AND PURPOSE: Effective stone comminution during shockwave lithotripsy (SWL) is dependent on precise three-dimensional targeting of the shockwave. Respiratory motion, imprecise targeting or shockwave alignment, and stone movement may compromise treatment efficacy. The purpose of this study was to evaluate the accuracy of shockwave targeting during SWL treatment and the effect of motion from respiration. PATIENTS AND METHODS: Ten patients underwent SWL for the treatment of 13 renal stones. Stones were targeted fluoroscopically using a Healthtronics Lithotron (five cases) or Dornier Compact Delta II (five cases) shockwave lithotripter. Shocks were delivered at a rate of 1 to 2 Hz with ramping shockwave energy settings of 14 to 26 kV or level 1 to 5. After the low energy pretreatment and protective pause, a commercial diagnostic ultrasound (US) imaging system was used to record images of the stone during active SWL treatment. Shockwave accuracy, defined as the proportion of shockwaves that resulted in stone motion with shockwave delivery, and respiratory stone motion were determined by two independent observers who reviewed the ultrasonographic videos. RESULTS: Mean age was 51 ± 15 years with 60% men, and mean stone size was 10.5 ± 3.7 mm (range 5-18 mm). A mean of 2675 ± 303 shocks was delivered. Shockwave-induced stone motion was observed with every stone. Accurate targeting of the stone occurred in 60% ± 15% of shockwaves. CONCLUSIONS: US imaging during SWL revealed that 40% of shockwaves miss the stone and contribute solely to tissue injury, primarily from movement with respiration. These data support the need for a device to deliver shockwaves only when the stone is in target. US imaging provides real-time assessment of stone targeting and accuracy of shockwave delivery.

In vitro assessment of a novel spearheaded pneumatic intracorporeal lithotriptor.

BACKGROUND AND PURPOSE: Intracorporeal lithotripsy is an important modality used for stone pulverization. To improve the pulverization properties of intracorporeal lithotriptors, a novel intracorporeal "spearheaded lithotriptor" was designed by our institute. It was compared in vitro with the conventional lithotriptor. MATERIALS AND METHODS: The pulverization and propulsion dynamics were evaluated at various pressure settings on an in vitro bench arrangement with phantom stones. Lateral displacement during pulverization was also compared. RESULTS: The spearheaded lithotriptor had a better first hit (P<0.001) and follow-up hit dynamics (P<0.01). Stone propulsion and lateral displacement were low for the spearheaded lithotriptor at all pressure settings (P<0.05). CONCLUSION: The spearheaded lithotriptor improved stone pulverization without increasing the risk of stone migration. Further clinical evaluation of this novel probe is necessary.

Systemic inflammatory response syndrome after percutaneous nephrolithotomy: an assessment of risk factors.

OBJECTIVES: To analyze the risk factors for systemic inflammatory response syndrome (SIRS) after percutaneous nephrolithotomy (PCNL) and to quantitatively predict the probability of SIRS after PCNL. METHODS: Medical records on 209 patients who underwent PCNL were retrospectively analyzed. The chi2 test, the t-test and a logistic regression model were used to identify key risk factors of SIRS after PCNL. A predictive equation was then formulated to assess the risk of SIRS according to the results from the logistic model. Subsequently, the accuracy of the equation by calculating sensitivity, specificity, overall correct percentage, and positive and negative predictive values was tested. RESULTS: The incidence of SIRS after PCNL was 23.4%. The key risk factors for SIRS following PCNL were: the number of tracts, receipt of a blood transfusion, stone size, and presence of pyelocaliectasis. Other factors added no independent risk to the development of SIRS. The calculated values for sensitivity, specificity, overall percentage correct, positive predictive value and negative predictive value were 44.9%, 95.0%, 83.3%, 73.3%, and 84.9%, respectively. CONCLUSIONS: Number of tracts, receipt of a blood transfusion, stone size and presence of pyelocaliectasis are identified as the key risk factors for SIRS after PCNL. The predictive equation allows for an individualized and quantitative assessment of the probability of SIRS after PCNL.

Antegrade pyelography versus unenhanced multidetector CT in the assessment of urinary-tract stones after percutaneous nephrostomy insertion: a prospective blinded study.

BACKGROUND AND PURPOSE: In patients with a percutaneous nephrostomy tube (PCN) inserted for symptomatic stone disease, antegrade pyelography is an accepted modality to assess the collecting system and residual stone status prior to PCN removal. Recently, unenhanced multidetector CT (UMDCT) has shown its superiority for the assessment of urinary-tract stones. Comparison of UMDCT with antegrade pyelography has never been done; hence, our aim was to compare the two methods for the assessment of urinary stones in patients with a PCN. PATIENTS AND METHODS: Between July 2004 and July 2005, we prospectively imaged 49 consecutive patients with known urinary-tract stone disease who had PCN (27 men and 22 women; average age 57 +/- 20 years; range 4-88 years). All patients underwent UMDCT and antegrade pyelography within 24 hours. Both examinations were prospectively and blindly evaluated by two attending radiologists for the presence, location, and size of urinary-tract stones. RESULTS: According to the findings of both imaging modalities, 18 patients were stone free, and 31 patients had urinary stones. In 20 of the latter 31 patients (64.5%), the urinary stones were diagnosed only by UMDCT. Antegrade pyelography missed renal as well as ureteral stones, with a significant mean size (5.1 x 6.2 mm, and 6 x 5.3 mm, respectively). Antegrade pyelography missed radiolucent (8/20) as well as radiopaque (12/20) stones. In 11 of the 31 patients (35.5%), urinary stones were diagnosed by both UMDCT and antegrade pyelography. The average size of these renal stones was 6 x 11 mm, and the mean ureteral stone size was 11 x 13 mm. In 64% (7/11), the stones were radiolucent and in 36% (4/11) radiopaque. There was no patient in whom urinary stones were diagnosed by antegrade pyelography but missed by UMDCT. CONCLUSIONS: Unenhanced multidetector CT is more accurate than antegrade pyelography via a PCN for the assessment of urinary-tract stones, with the advantage of reducing the risks of contrast injection side effects.

Inequalities in rural health care: differences in surgical intervention between metropolitan and rural Western Australia.

BACKGROUND: To compare surgical procedure rates between metropolitan and rural/remote residents in Western Australia (WA). METHODS: The WA Data Linkage System was used to identify all patients who underwent a procedure for cataract, ureteric calculi or urinary outflow obstruction symptoms for the time periods 1981-2000, 1981-1997 and 1981-1995, respectively. Age-standardized procedure rates were calculated and Poisson regression modelling was used to estimate effects of locality of residence and demographic covariates. RESULTS: Overall, rural/remote patients underwent first-time procedures for cataract (IRR 0.92; 95% CI 0.90-0.94), ureteric calculi (0.76; 0.72-0.80), or urinary outflow obstruction (0.71; 0.69-0.74) less frequently than patients in the metropolitan area. They were also significantly less likely to undergo multiple procedures for cataracts (0.90; 0.88-0.91) and ureteric calculi (0.69; 0.67-0.73). CONCLUSION: A distinctly reduced level of surgical intervention was found in rural patients for three generally non-life threatening conditions. The reasons for this require further investigation.

Primary urethral reconstruction: the cost minimized approach to the bulbous urethral stricture.

PURPOSE: Treatment for urethral stricture disease often requires a choice between readily available direct vision internal urethrotomy (DVIU) and highly efficacious but more technically complex open urethral reconstruction. Using the short segment bulbous urethral stricture as a model, we determined which strategy is less costly. MATERIALS AND METHODS: The costs of DVIU and open urethral reconstruction with stricture excision and primary anastomosis for a 2 cm bulbous urethral stricture were compared using a cost minimization decision analysis model. Clinical probability estimates for the DVIU treatment arm were the risk of bleeding, urinary tract infection and the risk of stricture recurrence. Estimates for the primary urethral reconstruction strategy were the risk of wound complications, complications of exaggerated lithotomy and the risk of treatment failure. Direct third party payer costs were determined in 2002 United States dollars. RESULTS: The model predicted that treatment with DVIU was more costly (17,747 dollars per patient) than immediate open urethral reconstruction (16,444 dollars per patient). This yielded an incremental cost savings of $1,304 per patient, favoring urethral reconstruction. Sensitivity analysis revealed that primary treatment with urethroplasty was economically advantageous within the range of clinically relevant events. Treatment with DVIU became more favorable when the long-term risk of stricture recurrence after DVIU was less than 60%. CONCLUSIONS: Treatment for short segment bulbous urethral strictures with primary reconstruction is less costly than treatment with DVIU. From a fiscal standpoint urethral reconstruction should be considered over DVIU in the majority of clinical circumstances.

Assessment of basic endoscopic performance using a virtual reality simulator.

BACKGROUND: The objective of this study was to evaluate the effect of supervised training using a state-of-the-art virtual reality (VR) genitourinary endoscopy simulator on the basic endoscopic skills of novice endoscopists. STUDY DESIGN: We evaluated 21 medical students performing an initial VR case scenario (pretest) requiring rigid cystoscopy, flexible ureteroscopy with laser lithotripsy, and basket retrieval of a proximal ureteral stone. All students were evaluated with objective parameters assessed by the VR simulator and by two experienced evaluators using a global rating scale. Students were then randomized to a control group receiving no further training or a training group, which received five supervised training sessions using the VR simulator. All students were then evaluated again in the same manner using the same case scenario (posttest). RESULTS: Comparing the results of pre- and posttests, no major differences were demonstrated for any variable in the control group. In the trained group, posttest results revealed statistically significant improvement from baseline in the following parameters: total procedure time (p = 0.002), time to introduce a ureteral guidewire (p = 0.039), self-evaluation (p < 0.001), and evaluator assessment (p < 0.001). Comparing the posttest results of the control and trained arms, we found significantly better posttest scores in the trained group for the following parameters: ability to perform the task (p = 0.035), overall performance (p = 0.004), and total evaluator score (p < or = 0.001). CONCLUSIONS: Students trained on the VR simulator demonstrated statistically significant improvement on repeat testing, but the control group showed no improvement. Endourologic training using VR simulation facilitates performance of basic endourologic tasks and might translate into better performance in the operating room.

[Clinico-epidemiologic behavior of urolithiasis in a rural Caribbean region]. / Comportamiento clínico-epidemiológico de la urolitiasis en un área rural del Caribe.

OBJECTIVE: The aim of this clinicoepidemiologic study is to determine the frequency, risk factors, morbidity and socioeconomic impact or urolithiasis in the general population of a Caribbean, subtropical rural area. METHODS: A representative sample of 1,504 subjects were randomly selected from the general population of 15,591 inhabitants in the area whose health services were provided by the Policlinico Julio Trujillo using the two-stage and equal probability functions with 95% CI. After informed consent was obtained, a survey was conducted to identify the subjects in the sample that had developed urolithiasis at some time or another. All subjects with a history of urolithiasis were included in a second survey to obtain the data required to complete the study. RESULTS: The prevalence rate was found to be similar to the 2.52% prevalence estimated worldwide. Urolithiasis was more common in the 20-29 years age group for both genders, and prevalent in the caucasians (3.2%) and male gender (3.2%). 36.8% of the subjects that had developed urolithiasis at some time or another had a family history of urolithiasis. Urinary tract infection, arterial hypertension, ischemic heart disease and diabetes mellitus were frequently associated with this condition. The incidence of stone formation was higher for the hottest period. High intake of food rich in oxalic acid, carbohydrates, proteins-purines and dairy products and low intake of fluids were closely linked with lithiasis. 97.2% s had one and 78.3% had more than one episode of nephric colic. 68.4% had one and 61.5% more than one recurrence of urolithiasis. 15.7% required surgery and 42.1% required hospitalization. Only 42.1% of the cases had unspecific medical treatment. No case had specific treatment. CONCLUSIONS: The behavior of urolithiasis in this rural population is the same as that reported in other studies for urban areas. It showed a high frequency, similar risk factors, high morbidity and important socioeconomic impact. Only half of the patients received treatment that is considered to be the least costly.