Jenny H. Yiee

Management of fetal hydronephrosis

Prenatally detected hydronephrosis has become a common diagnosis for both pediatric nephrologists and urologists. Hydronephrosis is most commonly assessed by the Society for Fetal Urology grading system or anterior–posterior diameter of the renal pelvis in the transverse plane. Some cases of bilateral obstruction, most commonly from posterior urethral valves, can be life-threatening and require close monitoring or, occasionally, fetal intervention. The majority are unilateral and of no threat to the growing fetus. The crux of postnatal management is the separation of the minority of patients whose renal function is at risk from the majority who will suffer no renal consequences. This management involves a regimen of ultrasounds, voiding cystourethrograms, and nuclear renograms for diagnosis and surveillance. Recent literature has been aimed at the timing and necessity of these studies in order to minimize extraneous studies without compromising renal function.

Environmental Factors in Genitourinary Development

PURPOSE In the last century the world has experienced an increase in the use of industrial chemicals as well as possible increases in the prevalence of hypospadias and cryptorchidism. Because hormones regulate the fetal development of many organs, numerous investigations have explored the role of environmental factors in genitourinary growth. We summarize the data regarding endocrine disruptors in human genitourinary development. MATERIALS AND METHODS A PubMed literature search was performed for human studies from 2004 to 2009. RESULTS Few data exist on environmental influences on the kidneys, ureters or bladder. Studies on the influence of pesticides, vegetarian diets, diethylstilbestrol, oral contraceptives and corticosteroids on hypospadias have yielded varied conclusions. Phthalates appear to increase the odds of hypospadias and anogenital distance. The testicular dysgenesis syndrome postulates that cryptorchidism, hypospadias, poor semen quality and testicular cancer share a common environmental origin. In utero exposure to diethylstilbestrol has been shown to increase the risk of testicular dysgenesis syndrome. However, to our knowledge no other environmental factor has been shown to cause testicular dysgenesis syndrome. Some industrial chemicals as well as the pesticide dichloro-diphenyl-trichloroethane have detrimental effects on semen quality. In cases of documented industrial accidents, chemical exposure has also decreased the male-to-female birth ratio. CONCLUSIONS Data on chemical exposure are largely mixed and inconclusive. Studies of populations with high exposure rates due to industrial accidents or in utero exposure to diethylstilbestrol suggest that endocrine disruptors adversely affect genitourinary development.

Timing of Orchiopexy in the United States: A Quality-of-Care Indicator

OBJECTIVE To investigate whether orchiopexies are occurring later than recommended by American Academy of Pediatrics 1996 guidelines (around age 1). Adherence to guidelines is poorly studied. METHODS The main cohort consisted of 4103 boys insured from birth (Innovus i3, insurance claims database). The complementary cohort consisted of 17 010 insured and noninsured boys (Pediatric Health Information System, PHIS). The inclusion criteria was age ≤ 5 years at time of International Classification of Disease, 9th revision-defined cryptorchidism diagnosis. The primary outcome was timely surgery (orchiopexy by age 18 months). RESULTS In Innovus, 87% of boys who underwent an orchiopexy had a timely orchiopexy. Of those who did not undergo surgery (n = 2738), 90% had at least 1 subsequent well-care visit. Those who underwent timely surgery were referred to a surgeon at a younger age compared with those who underwent late surgery (4.1 vs 16.1 months, P < .00005). Predictors of timely surgery were number of well-care visits (odds ratio 1.5, 95% confidence interval 1.3-1.7), continuity of primary care (odds ratio 1.9, 95% confidence interval 1.3-2.7), and use of laparoscopy (odds ratio 4.5, 95% confidence interval 1.4-14.9). Family/internal medicine as referring provider was predictive of delayed surgery (odds ratio 0.5, 95% confidence interval 0.3-0.8). In the Pediatric Health Information System, 61% of those with private insurance had timely surgery compared with 54% of those without private insurance (P < .0001). CONCLUSION We found an unexpectedly high adherence to guidelines in our continuously insured since birth Innovus population. Primary care continuity and well-care visits were associated with timely surgery. Further studies can confirm these findings in nonprivately insured patients with the ultimate goal of instituting quality improvement initiatives.

Use of Internal Stent, External Transanastomotic Stent or No Stent During Pediatric Pyeloplasty: A Decision Tree Cost-Effectiveness Analysis

PURPOSE Copious studies exist regarding the use of stents in pediatric pyeloplasty. Most surgeons use either no stent, an internal (Double-J®) stent or an external transanastomotic pyeloureteral stent. We propose the first known study to compare all 3 methods using a decision tree model that incorporates success rates, complications, patient discomfort and costs. MATERIALS AND METHODS We created a deterministic decision tree model. We conducted a literature search querying urinary diversion in pediatric pyeloplasty. We used the largest studies for base inputs and remaining studies for sensitivity analysis. Direct costs from actual patients seen at the University of California San Francisco populated cost inputs. RESULTS Total quality adjusted life-years during a 16-year period for no stents was 12.70851 with a total cost of

Imaging use and cryptorchidism: determinants of practice patterns.

6,122. Total quality adjusted life-years for external stents was 12.71098 at a total cost of

HISTOLOGIC DIFFERENCES BETWEEN EXTRINSIC AND INTRINSIC URETEROPELVIC JUNCTION OBSTRUCTION

5,702. Internal stents resulted in total quality adjusted life-years of 12.69983 and cost of

Management Trends in Prenatally Detected Hydronephrosis: National Survey of Pediatrician Practice Patterns and Antibiotic Use

8,421. Thus, external stents dominated no stents and internal stents, while no stents dominated internal stents. On sensitivity analysis even decreasing complication and failure rates of internal stents to zero did not make them cost effective due to the costs associated with stent removal. In contrast, decreasing complication and pyeloplasty rates of no stents by 20% resulted in an incremental cost-effectiveness ratio of

Use of Urine Testing in Outpatients Treated for Urinary Tract Infection

5,475 per quality adjusted life-year gained compared to external stents. CONCLUSIONS External and no stents are superior to internal stents. Given high overall success rates of pyeloplasty regardless of stent method, perhaps more attention should be given to cost from a health policy standpoint.

Patterns of care in testicular torsion: Influence of hospital transfer on testicular outcomes

PURPOSE We determined the rate of diagnostic imaging use for the preoperative evaluation of boys with cryptorchidism and the factors that influence referring providers to obtain imaging. MATERIALS AND METHODS We conducted a national cross-sectional survey of pediatricians randomly sampled from the American Medical Association Physician Masterfile. The primary outcome was whether the respondent obtained imaging at the initial evaluation of boys with cryptorchidism. Participants were queried regarding practice location and type, length of time in practice, frequency of reading academic journals and the accessibility of surgical subspecialists. For those who ordered imaging, respondents were asked how frequently they ordered imaging, and were asked to select patient factors and professional beliefs that influenced their decision to obtain imaging. Factors associated with imaging use were identified using multivariate logistic regression. RESULTS Of the pediatricians who acknowledged contact by surveyors 47% completed the survey and 34% of respondents reported always or usually ordering imaging. Of those who obtained imaging 96.4% used ultrasound. Pediatricians in practice fewer than 20 years (OR 3.43, 95% CI 1.92-6.16) and those in nonacademic practices (OR 3.00, 95% CI 1.34-6.71) were more likely to order imaging. Pediatricians obtained imaging because of beliefs that imaging reliably identifies a nonpalpable testis, reassures the family and assists the surgeon with operative planning. CONCLUSIONS Ultrasound is heavily used by pediatricians for the preoperative evaluation of cryptorchidism, especially when the testis is nonpalpable. Given the poor diagnostic performance of ultrasound in this setting, we recommend developing strategies to reduce imaging use in cryptorchidism.

Prospective Blinded Laboratory Assessment of Prophylactic Antibiotic Compliance in a Pediatric Outpatient Setting

OBJECTIVE Ureteropelvic junction obstruction (UPJ) can be caused by intrinsic disorganization or extrinsic compression from crossing vessels (CV). What is not clear is whether there is also intrinsic UPJ pathology in patients with CV. Recent surgeries, such as the Hellström vascular hitch procedure, move the CV cephalad without resecting the UPJ, which presumes no intrinsic narrowing. Our aim was to determine whether the histologic features of the 2 types of UPJ obstruction are distinct enough to enable a blinded pathologist to histologically identify the cause of obstruction. METHODS We reviewed all patients undergoing pyeloplasties from 2000 to 2006. All CV cases with available pathology were selected. A random selection of intrinsic cases was used as controls. One blinded pathologist reviewed the histology, specifically scoring muscle and collagen density. RESULTS Sixteen patients were reviewed. Seven had CV and 9 had intrinsic obstruction. Muscle density was different between the 2 groups with CV denser compared with intrinsic (P = .005). The pathologist correctly assigned the cause of obstruction in 5/7 (71%) of CV and 7/9 (78%) of intrinsic cases (P = .039). CONCLUSIONS Identification of a significant CV intraoperatively does translate to a discernible appearance histologically.