Hospital volume and short-term outcomes after cytoreductive nephrectomy.

PURPOSE: To investigate the impact of hospital volume on short-term outcomes after cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC). METHODS: We identified mRCC patients who underwent CN from 2006 to 2013 in the National Cancer Database. Annual hospital CN volume was categorized as high (top 20th percentile) and low. Multivariable logistic regressions were used to compare 30-day mortality, 90-day mortality, prolonged length of stay (PLOS, ≥7 days), and 30-day readmission rates. Sensitivity analyses were performed with hospital volume considered as a continuous variable. RESULTS: A total of 9789 patients were included with high-volume (n = 1916) defined as ≥8 cases and low-volume (n = 7873) as 1-7 cases annually. Multivariable logistic regression showed that high-volume was associated with lower odds of 30-day mortality (OR = 0.69, P = 0.013), 90-day mortality (OR = 0.65, P < 0.001), PLOS (OR = 0.82, P = 0.002), and 30-day readmission (OR = 0.78, P = 0.028). Sensitivity analyses showed that increasing hospital volume (per case) was associated with lower odds of 30-day mortality (OR = 0.965, P = 0.008), 90-day mortality (OR = 0.966, P < 0.001), PLOS (OR = 0.982, P = 0.001), and 30-day readmission (OR = 0.975, P = 0.012). CONCLUSION: Higher hospital volume was associated with better short-term outcomes after CN. Future studies are needed to validate our findings and explore the potential components leading to better outcomes in the higher volume hospitals.

Hospital volume and outcomes of robot-assisted partial nephrectomy.

OBJECTIVE: To evaluate the impact of hospital volume on outcomes of robot-assisted partial nephrectomy (RAPN). MATERIALS AND METHODS: Patients with renal cell carcinoma who underwent RAPN between 2010 and 2013 were identified in the National Cancer Database. Hospital yearly RAPN volume was categorized into groups by sorting patients as closely as possible into five groups of equal size (quintiles): very low; low; medium; high; and very high volume. Outcomes included 30-day mortality, 90-day mortality, open conversion, prolonged length of hospital stay (PLOS; defined as >3 days), 30-day readmission rate, and positive surgical margin (PSM) rate. Unadjusted analyses and multivariable logistic regressions were used to compare outcomes. Sensitivity analyses with hospital volume considered as a continuous variable were also performed. RESULTS: A total of 18 724 RAPN cases were included. Hospital volume quintiles were: very low volume, 1-7 cases (n = 3 693); low volume, 8-14 cases (n = 3 719); medium volume, 15-23 cases (n = 3 833); high volume, 24-43 cases (n = 3 649); and very high volume, ≥44 cases (n = 3 830). There was no significant difference in 30-day or 90-day mortality among the five groups. Multivariable logistic regression analysis (reference: very low volume) showed that higher hospital volume was associated with lower odds of conversion (low [odds ratio {OR}: 0.88; P = 0.377]; medium [OR: 0.60; P = 0.001]; high [OR: 0.57; P < 0.001]; very high [OR: 0.47; P < 0.001]), lower odds of PLOS (low [OR: 0.93; P = 0.197], medium [OR: 0.75; P < 0.001]; high [OR: 0.62; P < 0.001]; very high [OR: 0.45; P < 0.001]), and lower odds of PSMs (low [OR: 0.76; P < 0.001]; medium [OR: 0.76, P < 0.001]; high [OR: 0.59; P < 0.001]; very high [OR: 0.34; P < 0.001]). Sensitivity analyses confirmed increasing hospital volume (per 1-case increase) was associated with lower odds of conversion (OR: 0.986; P < 0.001), PLOS (OR: 0.989; P < 0.001) and PSMs (OR: 0.984; P < 0.001). A difference in 30-day readmission rate was found in unadjusted analysis but not in adjusted analyses. CONCLUSION: Undergoing RAPN at higher-volume hospitals may have better peri-operative outcomes (conversion to open and LOS) and lower PSM rates. Future studies are needed to explore the detailed components that lead to the superior outcomes in higher-volume hospitals.

Early discharge and post-discharge outcomes in patients undergoing radical cystectomy for bladder cancer.

OBJECTIVE: To assess whether discharging patients early after radical cystectomy (RC) is associated with an increased risk of readmission and post-discharge complications. MATERIALS AND METHODS: The National Surgical Quality Improvement Program database was queried to identify patients who underwent an elective RC from 2012 to 2015. Patients were stratified into two groups: those with a length of hospital stay (LOS) of 4-5 days (early-discharge group) and those with an LOS of 6-9 days (routine-discharge group). We used multivariable logistic regression analyses to assess the impact of early discharge on 30-day readmission and post-discharge complication rates. Sensitivity analyses and subgroup analyses were performed to validate the robustness of our primary analyses. RESULTS: A total of 3 311 patients were included. Unadjusted outcomes comparison showed no difference in readmission rate (21.6% vs 23.0%) or post-discharge complication rate (17.7% vs 19.6%) between the early-discharge and the routine-discharge group. Multivariable logistic regression also showed that early discharge was not associated with increased odds of readmission (odds ratio [OR] 1.00, 95% confidence interval [CI] 0.82-1.22; P = 1.000) or post-discharge complications (OR 0.95, 95% CI 0.77-1.17; P = 0.616). Two-step sensitivity analyses (excluding patients with LOS of 8-9 days, followed by patients with any pre-discharge adverse event) validated the robustness of our primary analyses. Subgroup analyses also yielded similar results in all subgroups except for the subgroup of patients aged ≥85 years. CONCLUSIONS: Early discharge after RC was not associated with increased readmissions or post-discharge complications. Future prospective studies, with defined peri-operative care pathways, are needed to identify potential components that may enable hospitals to discharge patients early without compromising post-discharge outcomes.

Impact of surgical waiting time on survival in patients with upper tract urothelial carcinoma: A national cancer database study.

PURPOSE: To evaluate the impact of surgical waiting time (SWT) on the survival outcome in patients with upper tract urothelial carcinoma (UTUC). MATERIALS AND METHODS: We identified patients with nonmetastatic UTUC who underwent radical nephroureterectomy (RNU) between 2004 and 2013 in the National Cancer Database. The association between SWT and overall survival (OS) was evaluated using Cox proportional hazards regression. SWT was categorized into 6 groups: SWT ≤ 7 days, SWT 8 to 30 days, SWT 31 to 60 days, SWT 61 to 90 days, SWT 91 to 120 days, and SWT 121 to 180 days. Multivariable analyses were adjusted for patient, tumor, and facility-related factors. RESULTS: A total of 3,581 patients were included in the final overall cohort and 2,397 (66.9%) patients had the higher-risk disease (high-grade or ≥pT2). Multivariable Cox regressions showed that patients in the groups of SWT 31 to 60 days, SWT 61 to 90 days, and SWT 91 to 120 days had similar OS compared with patients who had SWT of 8 to 30 days in the overall cohort and higher-risk cohort. Patients with SWT 121 to 180 days had worse OS (HR = 1.61, 95% CI: 1.19-2.19, P = 0.002 in the overall cohort; HR = 1.56, 95% CI: 1.11-2.20, P = 0.010 in the higher-risk cohort). CONCLUSIONS: Increased SWT from diagnosis to RNU appears to be not associated with worse OS within 120 days after the diagnosis of UTUC but SWT>120 days may be associated with worsened survival. These findings might have important implications for trial design in the evaluation of neoadjuvant chemotherapy for UTUC and future clinical practice.

Predischarge Predictors of Readmissions and Postdischarge Complications in Robot-Assisted Radical Prostatectomy.

BACKGROUND AND OBJECTIVE: Robot-assisted radical prostatectomy (RARP) has become the preferred surgical treatment for localized prostate cancer in the United States. Little is reported about the association between predischarge outcomes and postdischarge outcomes following RARP. The objective of this study was to explore the predischarge predictors of readmissions and postdischarge complications in RARP. MATERIALS AND METHODS: The National Surgery Quality Improvement Program (NSQIP) database was used to identify prostate cancer patients who underwent elective RARP from 2012 to 2014. Multivariable logistic regression was performed to assess potential predischarge predictors of readmissions and NSQIP-defined postdischarge complications within 30 days of RARP. To test the robustness of primary analysis, a secondary multivariable logistic regression was performed in the cohort of patients without any NSQIP-defined predischarge complications. RESULTS: A total of 9975 patients were included. The readmission rate in the cohort was 3.3% (n = 332), and 4.4% (n = 441) had at least one complication. Multivariable logistic regression showed that American Society of Anesthesiologists (ASA) score of 3-4 (odds ratio [OR] = 1.27, 95% confidence interval [CI] = 1.00-1.62, p = 0.050), increasing operative time (OT, per minute) (OR = 1.002, 95% CI = 1.000-1.003, p = 0.012), increasing length of hospital stay (LOS, per day) (OR = 1.36, 95% CI = 1.23-1.49, p < 0.001), and predischarge complication (OR = 2.15, 95% CI = 1.27-3.65, p = 0.004) were associated with readmission. Increasing OT (OR = 1.002, 95% CI = 1.001-1.004, p = 0.002) and increasing LOS (OR = 1.16, 95% CI = 1.02-1.30, p = 0.020) were associated with postdischarge complications. Logistic regression in patients without predischarge complications (n = 9804) confirmed that ASA score of 3-4 (OR = 1.37, 95% CI = 1.07-1.75, p = 0.013), increasing OT (OR = 1.002, 95% CI = 1.000-1.003, p = 0.022), and increasing LOS (OR = 1.34, 95% CI = 1.21-1.49, p < 0.001) were associated with readmissions. Secondary analyses also confirmed that increasing OT (OR = 1.002, 95% CI = 1.001-1.004, p = 0.002) and increasing LOS (OR = 1.18, 95% CI = 1.04-1.34, p = 0.011) were associated with postdischarge complications. CONCLUSIONS: Predischarge complications, OT, and LOS are associated with readmissions and postdischarge complications after RARP. It may be possible to identify patients at a higher risk of postdischarge adverse events to direct prevention interventions. Further prospective studies are needed to validate our findings.

Use of and regional variation in initial CT imaging for kidney stones.

OBJECTIVE: We sought to determine the prevalence of initial computed tomography (CT) utilization and to identify regions in the United States where CT is highly used as the first imaging study for children with nephrolithiasis. METHODS: We performed a cross-sectional study in 9228 commercially insured children aged 1 to 17 years with nephrolithiasis who underwent diagnostic imaging in the United States between 2003 and 2011. Data were obtained from MarketScan, a commercial insurance claims database of 17,827,229 children in all 50 states. We determined the prevalence of initial CT use, defined as CT alone or CT performed before ultrasound in the emergency department, inpatient unit, or outpatient clinic, and identified regions of high CT utilization by using logistic regression. RESULTS: Sixty-three percent of children underwent initial CT study and 24% had ultrasound performed first. By state, the proportion of children who underwent initial CT ranged from 41% to 79%. Regional variations persisted after adjusting for age, gender, year of presentation, and insurance type. Relative to children living in West South Central states, the highest odds of initial CT utilization were observed for children living in the East South Central US Census division (odds ratio: 1.27; 95% confidence interval: 1.06-1.54). The lowest odds of initial CT were observed for children in the New England states (odds ratio: 0.48; 95% confidence interval: 0.38-0.62). CONCLUSIONS: Use of CT as the initial imaging study for children with nephrolithiasis is highly prevalent and shows extensive regional variability in the United States. Current imaging practices deviate substantially from recently published guidelines that recommend ultrasound as the initial imaging study.

Daily mean temperature and clinical kidney stone presentation in five U.S. metropolitan areas: a time-series analysis.

BACKGROUND: High ambient temperatures are a risk factor for nephrolithiasis, but the precise relationship between temperature and kidney stone presentation is unknown. OBJECTIVES: Our objective was to estimate associations between mean daily temperature and kidney stone presentation according to lag time and temperatures. METHODS: Using a time-series design and distributed lag nonlinear models, we estimated the relative risk (RR) of kidney stone presentation associated with mean daily temperatures, including cumulative RR for a 20-day period, and RR for individual daily lags through 20 days. Our analysis used data from the MarketScan Commercial Claims database for 60,433 patients who sought medical evaluation or treatment of kidney stones from 2005-2011 in the U.S. cities of Atlanta, Georgia; Chicago, Illinois; Dallas, Texas; Los Angeles, California; and Philadelphia, Pennsylvania. RESULTS: Associations between mean daily temperature and kidney stone presentation were not monotonic, and there was variation in the exposure-response curve shapes and the strength of associations at different temperatures. However, in most cases RRs increased for temperatures above the reference value of 10°C. The cumulative RR for a daily mean temperature of 30°C versus 10°C was 1.38 in Atlanta (95% CI: 1.07, 1.79), 1.37 in Chicago (95% CI: 1.07, 1.76), 1.36 in Dallas (95% CI: 1.10, 1.69), 1.11 in Los Angeles (95% CI: 0.73, 1.68), and 1.47 in Philadelphia (95% CI: 1.00, 2.17). Kidney stone presentations also were positively associated with temperatures < 2°C in Atlanta, and < 10°C in Chicago and Philadelphia. In four cities, the strongest association between kidney stone presentation and a daily mean temperature of 30°C versus 10°C was estimated for lags of ≤ 3 days. CONCLUSIONS: In general, kidney stone presentations increased with higher daily mean temperatures, with the strongest associations estimated for lags of only a few days. These findings further support an adverse effect of high temperatures on nephrolithiasis.

Tamsulosin and spontaneous passage of ureteral stones in children: a multi-institutional cohort study.

PURPOSE: Tamsulosin is associated with increased passage of ureteral stones in adults but its effectiveness in children is uncertain. We determined the association between tamsulosin and the spontaneous passage of ureteral stones in children. MATERIALS AND METHODS: We performed a multi-institutional retrospective cohort study of patients 18 years or younger who presented between 2007 and 2012 with ureteral stones up to 10 mm and who were treated with tamsulosin or oral analgesics alone. The outcome was spontaneous stone passage, defined as radiographic clearance and/or patient report of passage. Subjects prescribed tamsulosin were matched with subjects prescribed analgesics alone, using nearest neighbor propensity score matching to adjust for treatment selection. Conditional logistic regression models were used to estimate the association between tamsulosin and spontaneous passage of ureteral stones, adjusting for stone size and location. RESULTS: Of 449 children with ureteral stones 334 were eligible for inclusion, and complete data were available for 274 patients from 4 institutions (99 receiving tamsulosin, 175 receiving analgesics alone). Following case matching, there were no differences in age, gender, weight, height, stone size or stone location between the 99 subjects prescribed tamsulosin and the 99 propensity score matched subjects prescribed analgesics alone. In the tamsulosin cohort 55% of ureteral stones passed, compared to 44% in the analgesics alone cohort (p=0.03). In multivariate analysis adjusting for stone size and location tamsulosin was associated with spontaneous passage of ureteral stones (OR 3.31, 95% CI 1.49-7.34). CONCLUSIONS: The odds of spontaneous passage of ureteral stones were greater in children prescribed tamsulosin vs analgesics alone.

Renal parenchymal area and risk of ESRD in boys with posterior urethral valves.

BACKGROUND AND OBJECTIVES: Approximately 20% of boys with posterior urethral valves develop ESRD; however, few factors associated with the risk of ESRD have been identified. The objective of this study was to determine if renal parenchymal area, defined as the area of the kidney minus the area of the pelvicaliceal system on first postnatal ultrasound, is associated with the risk of ESRD in infants with posterior urethral valves. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A retrospective cohort of boys who were diagnosed with posterior urethral valves at less than 6 months of age between 1988 and 2011 and followed for at least 1 year at a free-standing children's hospital was assembled. Cox proportional hazard regression and Kaplan-Meier analysis were used to estimate the association between renal parenchymal area and time to ESRD. Cox models were adjusted for age at presentation, minimum creatinine 1 month after bladder decompression, and vesicoureteral reflux. RESULTS: Sixty patients were followed for 393 person-years. Eight patients developed ESRD. Median renal parenchymal area was 15.9 cm(2) (interquartile range=13.0-21.6 cm(2)). Each 1-cm(2) increase in renal parenchymal area was associated with a lower risk of ESRD (hazard ratio, 0.64; 95% confidence interval, 0.42 to 0.98). The rate of time to ESRD was 10 times higher in boys with renal parenchymal area<12.4 cm(2) than boys with renal parenchymal area≥12.4 cm(2) (P<0.001). Renal parenchymal area could best discriminate children at risk for ESRD when the minimum creatinine in the first 1 month after bladder decompression was between 0.8 and 1.1 mg/dl. CONCLUSION: In boys with posterior urethral valves presenting during the first 6 months of life, lower renal parenchymal area is associated with an increased risk of ESRD during childhood. The predictive ability of renal parenchymal area, which is available at time of diagnosis, should be validated in a larger, prospectively-enrolled cohort.

Segmentation of renal parenchymal area from ultrasound images using level set evolution.

This paper presents a framework for segmentation of renal parenchymal area from ultrasound images based on a 2-step level set method. We used distance regularized level set evolution method to partition the kidney boundary, followed by region-scalable fitting energy minimization method to segment the kidney collecting system, and determined renal parenchymal area by subtracting the area of the collecting system from the gross kidney area. The proposed method demonstrated excellent validity and low inter-observer variability.

Correlation of fundus autofluorescence with fluorescein and indocyanine green angiography in choroidal melanocytic lesions.

PURPOSE: To correlate fundus autofluorescence (FAF) patterns with fluorescein/indocyanine green angiographic (FA/ICGA) features in choroidal melanocytic lesions. METHODS: Retrospective chart review of 30 consecutive patients with choroidal nevi and melanoma who underwent FAF photography and FA/ICGA. The FAF pattern was classified as patchy or diffuse. The FA images were evaluated at the arterial, early venous, late venous, midphase, and late phases. The ICGA images were evaluated at the early and midlate phase. The fluorescence within the tumor was classified as hyperfluorescent, pinpoint hyperfluorescent, isofluorescent, or hypofluorescent with respect to the surrounding retina or choroid. Statistical analysis was performed using two sample t test for continuous data. For categorical or ordinal data, Pearson chi-square or Fisher's exact test was used depending on the sample size being studied. RESULTS: Nineteen of 30 tumors (63.3%) were choroidal melanoma and 11 (36.7%) were choroidal nevus. Thirteen choroidal melanomas had a diffuse FAF pattern. Six choroidal melanomas and 11 choroidal nevi had a patchy FAF pattern. The diffuse FAF pattern was significantly associated with the clinical diagnosis of choroidal melanoma versus choroidal nevus (P = 0.00001), increased tumor thickness (P = 0.00001), and increased tumor base diameter (P = 0.001), partially pigmented or amelanotic versus pigmented lesion color (P = 0.006), early venous hyperfluorescence on FA (P = 0.015), and late hyperfluorescence on FA (P = 0.018). CONCLUSION: Diffuse FAF is more often associated with larger choroidal melanomas as well as early venous and late hyperfluorescence on FA angiography.

A role for excitatory amino acids in diabetic eye disease.

Diabetic retinopathy is a leading cause of vision loss. The primary clinical hallmarks are vascular changes that appear to contribute to the loss of sight. In a number of neurodegenerative disorders there is an appreciation that increased levels of excitatory amino acids are excitotoxic. The primary amino acid responsible appears to be the neurotransmitter glutamate. This review examines the nature of glutamatergic signaling at the retina and the growing evidence from clinical and animal model studies that glutamate may be playing similar excitotoxic roles at the diabetic retina.

Detection of elevated signaling amino acids in human diabetic vitreous by rapid capillary electrophoresis.

Elevated glutamate is implicated in the pathology of PDR. The ability to rapidly assess the glutamate and amino acid content of vitreous provides a more complete picture of the chemical changes occurring at the diabetic retina and may lead to a better understanding of the pathology of PDR. Vitreous humor was collected following vitrectomies of patients with PDR and control conditions of macular hole or epiretinal membrane. A capillary electrophoresis method was developed to quantify glutamate and arginine. The analysis is relatively fast (<6 minutes) and utilizes a poly(ethylene)oxide and sodium dodecylsulfate run buffer. Both amino acid levels show significant increases in PDR patients versus controls and are comparable to other reports. The levels of vitreal glutamate vary inversely with the degree of observed hemorrhage. The results demonstrate a rapid method for assessment of a number of amino acids to characterize the chemical changes at the diabetic retina to better understand tissue changes and potentially identify new treatments.