First name
Jose
Middle name
E
Last name
Pulido

Title

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

Year of Publication

2014

Number of Pages

499-505

Date Published

2014 Mar

ISSN Number

1555-905X

Abstract

<p><strong>BACKGROUND AND OBJECTIVES: </strong>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.</p>

<p><strong>DESIGN, SETTING, PARTICIPANTS, &amp; MEASUREMENTS: </strong>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.</p>

<p><strong>RESULTS: </strong>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&lt;12.4 cm(2) than boys with renal parenchymal area≥12.4 cm(2) (P&lt;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.</p>

<p><strong>CONCLUSION: </strong>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.</p>

DOI

10.2215/CJN.08700813

Alternate Title

Clin J Am Soc Nephrol

PMID

24311709

Title

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

Year of Publication

2014

Number of Pages

506-11

Date Published

2014 Aug

ISSN Number

1527-3792

Abstract

<p><strong>PURPOSE: </strong>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.</p>

<p><strong>MATERIALS AND METHODS: </strong>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.</p>

<p><strong>RESULTS: </strong>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).</p>

<p><strong>CONCLUSIONS: </strong>The odds of spontaneous passage of ureteral stones were greater in children prescribed tamsulosin vs analgesics alone.</p>

DOI

10.1016/j.juro.2014.01.091

Alternate Title

J. Urol.

PMID

24518765

Title

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

Year of Publication

2014

Number of Pages

1081-7

Date Published

2014 Oct

ISSN Number

1552-9924

Abstract

<p><strong>BACKGROUND: </strong>High ambient temperatures are a risk factor for nephrolithiasis, but the precise relationship between temperature and kidney stone presentation is unknown.</p>

<p><strong>OBJECTIVES: </strong>Our objective was to estimate associations between mean daily temperature and kidney stone presentation according to lag time and temperatures.</p>

<p><strong>METHODS: </strong>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.</p>

<p><strong>RESULTS: </strong>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 &lt; 2°C in Atlanta, and &lt; 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.</p>

<p><strong>CONCLUSIONS: </strong>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.</p>

DOI

10.1289/ehp.1307703

Alternate Title

Environ. Health Perspect.

PMID

25009122

Title

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

Year of Publication

2014

Number of Pages

909-15

Date Published

2014 Nov

ISSN Number

1098-4275

Abstract

<p><strong>OBJECTIVE: </strong>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.</p>

<p><strong>METHODS: </strong>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.</p>

<p><strong>RESULTS: </strong>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).</p>

<p><strong>CONCLUSIONS: </strong>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.</p>

DOI

10.1542/peds.2014-1694

Alternate Title

Pediatrics

PMID

25349323

Title

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

Year of Publication

2014

Number of Pages

4703-6

Date Published

2014

ISSN Number

1557-170X

Abstract

<p>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.</p>

DOI

10.1109/EMBC.2014.6944674

Alternate Title

Conf Proc IEEE Eng Med Biol Soc

PMID

25571042

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