First name
Stephen
Middle name
A
Last name
Zderic

Title

Urologic care and progression to end-stage kidney disease: a Chronic Kidney Disease in Children (CKiD) nested case-control study.

Year of Publication

2019

Date Published

2019 Mar 16

ISSN Number

1873-4898

Abstract

<p><strong>INTRODUCTION: </strong>Children with chronic kidney disease (CKD) risk progressing to end-stage kidney disease (ESKD). The majority of CKD causes in children are related to congenital anomalies of the kidney and urinary tract, which may be treated by urologic care.</p>

<p><strong>OBJECTIVE: </strong>To examine the association of ESKD with urologic care in children with CKD.</p>

<p><strong>STUDY DESIGN: </strong>This was a nested case-control study within the Chronic Kidney Disease in Children (CKiD) prospective cohort study that included children aged 1-16 years with non-glomerular causes of CKD. The primary exposure was prior urologic referral with or without surgical intervention. Incidence density sampling matched each case of ESKD to up to three controls on duration of time from CKD onset, sex, race, age at baseline visit, and history of low birth weight. Conditional logistic regression analysis was performed to estimate rate ratios (RRs) for the incidence of ESKD.</p>

<p><strong>RESULTS: </strong>Sixty-six cases of ESKD were matched to 153 controls. Median age at baseline study visit was 12 years; 67% were male, and 7% were black. Median follow-up time from CKD onset was 14.9 years. Seventy percent received urologic care, including 100% of obstructive uropathy and 96% of reflux nephropathy diagnoses. Cases had worse renal function at their baseline visit and were less likely to have received prior urologic care. After adjusting for income, education, and insurance status, urology referral with surgery was associated with 50% lower risk of ESKD (RR 0.50 [95% confidence interval [CI] 0.26-0.997), compared to no prior urologic care (Figure). After excluding obstructive uropathy and reflux nephropathy diagnoses, which were highly correlated with urologic surgery, the association was attenuated (RR 0.72, 95% CI 0.24-2.18).</p>

<p><strong>DISCUSSION: </strong>In this study, urologic care was commonly but not uniformly provided to children with non-glomerular causes of CKD. Underlying specific diagnoses play an important role in both the risk of ESKD and potential benefits of urologic surgery.</p>

<p><strong>CONCLUSION: </strong>Within the CKiD cohort, children with non-glomerular causes of CKD often received urologic care. Urology referral with surgery was associated with lower risk of ESKD compared to no prior urologic care but depended on specific underlying diagnoses.</p>

DOI

10.1016/j.jpurol.2019.03.008

Alternate Title

J Pediatr Urol

PMID

30962011

Title

Percutaneous nephrolithotomy in an 8-week-old infant.

Year of Publication

2018

Number of Pages

9363-9365

Date Published

2018 Jun

ISSN Number

1195-9479

Abstract

<p>We report successful percutaneous nephrolithotomy (PCNL) in an 8-week-old, 4.12 kg infant with a combined stone burden of &gt; 2 cm in a solitary kidney. The patient was born with thoracolumbar myelomeningocele and had developed recurrent urinary tract infections. Her size precluded retrograde intrarenal surgery and shockwave lithotripsy would be unlikely to clear the stone burden. Stone analysis revealed hydroxyapatite and carbonate apatite stones, and metabolic work up revealed hypercalciuria for which chlorothiazide was started. To our knowledge, this is the youngest patient to undergo PCNL reported in the literature.</p>

Alternate Title

Can J Urol

PMID

29900827

Title

The natural history of semen parameters in untreated asymptomatic adolescent varicocele patients: A retrospective cohort study.

Year of Publication

2016

Date Published

2016 Oct 24

ISSN Number

1873-4898

Abstract

<p><strong>INTRODUCTION: </strong>Adolescent males with varicoceles present a dilemma for surveillance and treatment. Testicular volumetrics have not been shown to predict SA outcomes. Serial SAs are thus recommended in asymptomatic adolescent males with varicoceles and normal testicular development, but the natural history of semen parameters is unknown.</p>

<p><strong>OBJECTIVE: </strong>To explore the natural history of semen parameters in adolescent boys with a left varicocele under active surveillance.</p>

<p><strong>STUDY DESIGN: </strong>Adolescents with an asymptomatic unilateral left varicocele, Tanner V development, normal testicular volumes, and an initial SA were retrospectively reviewed in a single-institution prospectively followed cohort. Total motile count (TMC) was calculated. A cutoff of TMC Z 20 million was used to dichotomize SA results into "normal" or "poor." Those with poor SA were offered repeat SA. Cumulative probabilities of normal TMC over successive rounds of SA were calculated. Bivariate models were used to explore associations of a second consecutive poor TMC with age and varicocele grade.</p>

<p><strong>RESULTS: </strong>A total of 216 patients provided an initial SA between 1992 and 2015. We excluded 17 for a history of cryptorchidism or incomplete SA data for a final cohort of 199 patients with median follow-up of 3.3 years (interquartile range 1.5-5.6 years). The mean age at initial SA was 17.9 years (range 14.8-21.8 years). One hundred and nine out of 199 had an initial normal TMC. Of the 90 out of 199 with an initially poor TMC, 51 had repeat SA and 24 of the 51 patients improved to normal TMC. Of the 27 patients with two consecutive poor TMCs, 15 had a third SA and five out of 15 improved to normal TMC. Thus, cumulatively, 55%, 67%, and 69% of all patients had a normal TMC after an initial, second, and third SA, respectively. However, fewer patients in each round of SA normalized their TMC (Figure). Neither age nor varicocele grade was associated with a second consecutive poor TMC.</p>

<p><strong>DISCUSSION: </strong>Two-thirds of Tanner V boys with an uncorrected varicocele and normal testicular volumes achieve a normal TMC regardless of varicocele grade or age. Despite Tanner V development, 47% with an initial "poor" SA will improve to normal status without surgery. However, a small subgroup of patients will have persistently poor TMC and thus should be targeted in future research for timely intervention.</p>

<p><strong>CONCLUSION: </strong>Semen parameters improve over time. SA should be followed and repeated at least once in symptomatic Tanner V boys with varicoceles.</p>

DOI

10.1016/j.jpurol.2016.09.008

Alternate Title

J Pediatr Urol

PMID

27815047

Title

Does varicocelectomy improve semen analysis outcomes in adolescents without testicular asymmetry?

Year of Publication

2016

Date Published

2016 Oct 26

ISSN Number

1873-4898

Abstract

<p><strong>PURPOSE: </strong>The main indications for adolescent varicocelectomy are testicular hypotrophy or pain. However, we have previously shown that both serial total testicular volume and volume differential are weakly associated with semen quality. The ultimate patient goal is paternity, but semen analysis is critical to appropriate management of varicocele. We hypothesize that varicocelectomy improves total motile count (TMC) among patients who only have abnormal semen analysis (SA) parameters, but not among those with potential hormonal dysfunction such as Klinefelter syndrome or cryptorchidism.</p>

<p><strong>METHODS: </strong>We retrospectively reviewed our registry of adolescent males followed with a clinical left varicocele. For this study, subjects without sustained testicular asymmetry, who were Tanner V, and gave at least one preoperative SA were included. Subjects were excluded if they had embolization for their varicocele or no postoperative SA. Primary outcome was change in TMC before and after surgery, compared using the Wilcoxon signed rank test after stratifying by surgical indication. Secondary outcomes included rates of improved TMC and normalized TMC (&gt;20 million) after surgery, compared across covariates using the Fisher exact test.</p>

<p><strong>RESULTS: </strong>Seventeen patients met the eligibility criteria, 11 of whom underwent repair for only abnormal preoperative TMC. Overall, median age (interquartile range [IQR]) at first preoperative SA was 17.6 (15.9-17.9) years. The median preoperative TMC across all SA was 2.8 (0.7-7.4) million. The median age at surgery was 18.2 (16.8-18.9) years. Postoperatively, the median TMC across all SA increased to 18.2 (3.6-18.2) million (Wilcoxon signed rank test, p&nbsp;&lt;&nbsp;0.01; see Figure). The improvement in TMC occurred primarily in the group who only had abnormal preoperative TMC (82% improved, 55% normalized); lack of improvement was seen in patients who had a history of Klinefelter or orchiopexy for cryptorchidism.</p>

<p><strong>CONCLUSIONS: </strong>Adolescent varicocele patients should undergo SA after development of Tanner V. Varicocelectomy has a high success rate for improving TMC in adolescent or young adult males who only have abnormal TMC and no history of cryptorchidism.</p>

DOI

10.1016/j.jpurol.2016.09.010

Alternate Title

J Pediatr Urol

PMID

27818033

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

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