Anteroposterior Pelvic Diameter Research Articles

Maternal Physiologic Renal Pelvis Dilatation in Pregnancy: Sonographic Reference Data.

The purpose of this study was to produce sonographic reference data for maternal renal pelvis dilatation in asymptomatic pregnant women. A prospective cross-sectional study was undertaken on pregnant women presenting for outpatient obstetric imaging. For each side, the renal length and axial anteroposterior diameter of the renal pelvis were measured. Maternal demographics, gravidity and parity, number of fetuses, and estimated fetal weight (when available) were recorded. A total of 700 women enrolled, with 191 excluded. The 509 women analyzed included 465 singleton and 44 twin pregnancies. A total of 815 sonographic investigations were performed: 716 in singleton pregnancies and 99 in twin pregnancies. The gestational age range was 10 to 40 weeks. Charts depicting the anteroposterior renal pelvis diameter versus gestational age were constructed to determine normative sonographic reference data for maternal renal pelvis dilatation in singleton pregnancies. Although the mean renal pelvis diameter increased as pregnancy progressed, measurements of greater than 10 mm remained relatively uncommon, being identified in 9.7% of right and 2.1% of left kidneys in the third trimester. Only 4.1% of right and 0.4% of left third-trimester measurements exceeded 15 mm. Right renal pelvis measurements on average were greater than the left by 1.54 mm (95% confidence interval [CI], 1.20 to 1.87 mm). Twins had significantly larger renal pelvis measurements than singletons on average, measuring 2.11 mm (95% CI, 1.50 to 2.72 mm) larger on the right and 1.69 mm (95% CI, 0.73 to 2.65) on the left. We present sonographic reference data for asymptomatic pregnancy-related renal pelvis dilatation in singleton pregnancies from a large cohort of women.

Maternal Urinary Carbohydrate Antigen 19-9 as a Novel Biomarker for Evaluating Fetal Hydronephrosis: A Pilot Study

To evaluate maternal urinary CA19-9 as a potential marker to diagnose severe antenatal hydronephrosis (ANH) during pregnancy and to compare the values with those in normal pregnancies as controls. A total of 20 women in their third pregnancy trimester were enrolled. An anteroposterior pelvic diameter (APD) of ≥15 was considered as severe ANH. Case group consisted of 10 women with a diagnosis of severe ANH. Ten women with similar age, gestational age, fetal sex, normal ultrasonography, and no history of any congenital anomalies were chosen as controls. Urine samples were collected and maternal urinary CA19-9 was measured. The levels in case and control groups were compared using Mann-Whitney U test. Each group consisted of nine mothers with male fetuses and one with female fetus. The APD in the ANH group ranged from 17 to 40 mm. Five of 10 children in the ANH group also had contralateral APD of ≥4 mm (bilateral ANH). The mean age and gestational age of pregnant women in the two groups were comparable. The mean maternal CA19-9 was significantly higher in the ANH group compared with the controls (mean: 134.5 U/mL vs 22.2 U/mL, P < .001). To our best knowledge, this is the first time that maternal urinary CA19-9 has been used as a marker for ANH. Based on these pilot data, CA19-9 levels are significantly higher in the urine of pregnant women carrying fetuses with severe ANH, and it may have the potential to serve as a noninvasive and useful biomarker to diagnose ANH.

Associations of Initial Society for Fetal Urology Grades and Urinary Tract Dilatation Risk Groups with Clinical Outcomes in Patients with Isolated Prenatal Hydronephrosis

There are limited comparative data on the predictive value of the 2most commonly used classification systems, that is SFU (Society for Fetal Urology) hydronephrosis grades and urinary tract dilatation risk groups, in regard to the future risk of surgical intervention and the development of febrile urinary tract infection. We explored this topic in infants with isolated hydronephrosis. After screening 938 patients with prenatal hydronephrosis from 2009 to 2016 we selected 322 patients with ureteropelvic junction obstruction-like hydronephrosis for study. Hydronephrosis grades were prospectively collected at baseline, surgery and last followup. Gender, circumcision status, antibiotic prophylaxis and renal pelvis anteroposterior diameter were captured. The primary outcome was pyeloplasty and the development of febrile urinary tract infection. Comparative analyses between SFU grades/urinary tract dilatation groups and the primary outcome were performed with the Fisher exact and log rank tests. Mean ± SD age at presentation was 3.3 ± 2.6 months and mean followup was 22 ± 19 months. Pyeloplasty was performed in 32% of patients with SFU III/IV vs 31% with urinary tract dilatation 2/3. The rate of febrile urinary tract infection in patients with SFU III/IV was similar to that in those with urinary tract dilatation group 2/3 (8% vs 10%). Children with SFU III/IV showed a significantly higher rate of surgery than those with SFU I/II (32% vs 2%, p<0.01). Similar findings were seen when using urinary tract dilatation groups to compare patients at low risk (1) vs moderate/high risk (2/3). Both grading systems equally allowed for proper risk stratification and prediction of clinical outcomes based on baseline ultrasound. They correctly separated most infants who underwent surgery or in whom febrile urinary tract infection developed from those who could be treated nonsurgically. Use of the new urinary tract dilatation classification should not affect how families of children with isolated hydronephrosis are counseled regarding surgical intervention and the risk of febrile urinary tract infection.

The effect of alfuzosin on renal resistive index, urinary electrolytes and β2 microglobulin levels and TGF β-1 levels of kidney tissue in rats with unilateral ureteropelvic junction obstruction

Background: In this study, it was aimed to determine the effects of alfuzosin on experimentally generated unilateral partial ureteropelvic junction obstruction (UPO) in rats.Materials and methods: Thirty Long–Evans rats were randomly allocated into five groups. In control group (C), nothing was performed; in group Sham (S) only laparotomy was done; in Alfuzosin group (A) only alfuzosin was administered for two weeks (10 mg/kg/day p.o.) without any surgery; in UPO group, unilateral UP junction obstruction was produced; and in the Group UPT (ureteropelvic obstruction + treatment), alfuzosin was administered for two weeks (10 mg/kg/day p.o.) in addition to UPO production. Renal pelvic anteroposterior diameters were determined with ultrasonography (USG) and renal arterial resistivity indexes by color Doppler USG. Urine was collected both at the beginning and at the end of the experiment for 24 h in all the groups and at the end of the experiment, blood samples were obtained. Blood and urine electrolytes and TGF-β1, urine density, urine β2 microglobulin levels were determined. Renal tissue samples harvested from all of the rats were histopathologically evaluated. Results were determined using one-way ANOVA t-test; p < 0.05 was accepted as significant.Results: Urine density in the UPT group was lower with respect to UPO group and blood electrolytes were preserved as close to normal (p < 0.05). In the UPT group, urine TGF-β1 and blood TGF-β1, blood β2 microglobulin levels and histopathologic damage scores were lower compared to the UPO group (p < 0.05).Conclusion: It is shown in this experimental unilateral partial UPO model that alfuzosin treatment prevents obstructive renal damage.

Percent improvement in renal pelvis antero-posterior diameter (PI-APD): Prospective validation and further exploration of cut-off values that predict success after pediatric pyeloplasty supporting safe monitoring with ultrasound alone

Renograms are frequently obtained post-pyeloplasty in patients with residual hydronephrosis to confirm adequate drainage. Recent evidence suggests that percent improvement in antero-posterior diameter (PI-APD) ≥38 is predictive of success. We sought to further explore PI-APD ranges that would allow identification of patients who would benefit from ultrasound (US) monitoring alone vs. post-operative renal scan, and those more likely to develop recurrent ureteropelvic junction obstruction (rUPJO). A single-center prospectively-collected pyeloplasty database (2008-2015) was queried (n = 151). Only patients with both pre- and post-operative APD measurements were included (n = 138). PI-APD was divided into 3 categories: <20%; 20-39%; ≥40%. The following variables were collected post-operatively: patients monitored with US alone, renogram and US, rUPJO and minimal or resolved hydronephrosis (SFU≤2; UTD ≤1; APD ≤15 mm). Mean age at first and last follow-up were 4.8 (median 4.0; range 0-60) months and 26.6 (median 20.5; range 1-77) months, respectively. Of 138 patients, 84 (61%) had US alone, 54 (39%) had a renogram and US post-operatively, and 6 (4%) developed rUPJO. Of 84 patients who had US alone, 71 (84%; p < 0.01) demonstrated ≥40% PI-APD. Of 54 patients with renogram and US 46 (85%; p < 0.01) had ≥40 PI-APD. Of the 6 patients who developed rUPJO, all were in the <20 PI-APD group (100%; p < 0.01). Resolution of hydronephrosis according to SFU, UTD and APD occurred in 96/138 (70%), 89/138 (64%) and 113/138 (82%) patients respectively. Of these, 87 (91%), 81 (91%), and 108 (95%) occurred in >40% PI-APD group. ≥40% PI-APD at the first post-operative visit strongly predicts pyeloplasty success, as up to 82% of these patients showed resolved hydronephrosis and 61% underwent non-invasive monitoring by US alone. Our data suggests that up to 85% of renograms may have been unnecessary. Finally, <20% PI-APD permitted identification of all rUPJO cases. Stratification of patients based in PI-APD is a promising strategy for further minimizing radiation exposure while safely detecting children at risk for rUPJO.

Postnatal Evaluation and Outcome of Prenatal Hydronephrosis.

Background:Prenatal hydronephrosis (PNH) is dilation in urinary collecting system and is the most frequent neonatal urinary tract abnormality with an incidence of 1% to 5% of all pregnancies. PNH is defined as anteroposterior diameter (APD) of renal pelvis ≥ 4 mm at gestational age (GA) of < 33 weeks and APD ≥ 7 mm at GA of ≥ 33 weeks to 2 months after birth. All patients need to be evaluated after birth by postnatal renal ultrasonography (US). In the vast majority of cases, watchful waiting is the only thing to do; others need medical or surgical therapy.Objectives:There is a direct relationship between APD of renal pelvis and outcome of PNH. Therefore we were to find the best cutoff point APD of renal pelvis which leads to surgical outcome.Patients and Methods:In this retrospective cohort study we followed 200 patients 1 to 60 days old with diagnosis of PNH based on before or after birth ultrasonography; as a prenatal or postnatal detected, respectively. These patients were referred to the nephrology clinic in Zahedan Iran during 2011 to 2013. The first step of investigation was a postnatal renal US, by the same expert radiologist and classifying the patients into 3 groups; normal, mild/moderate and severe. The second step was to perform voiding cystourethrogram (VCUG) for mild/moderate to severe cases at 4 - 6 weeks of life. Tc-diethylene triamine-pentaacetic acid (DTPA) was the last step and for those with normal VCUG who did not show improvement in follow-up examination, US to evaluate obstruction and renal function. Finally all patients with mild/moderate to severe PNH received conservative therapy and surgery was preserved only for progressive cases, obstruction or renal function ≤35%. All patients’ data and radiologic information was recorded in separate data forms, and then analyzed by SPSS (version 22).Results:200 screened PNH patients with male to female ratio 3.5:1 underwent first postnatal control US, of whom 65% had normal, 18% mild/moderate and 17% severe hydronephrosis. 167 patients had VCUG of whom 20.82% with VUR. 112 patients performed DTPA with following results: 50 patients had obstruction and 62 patients showed no obstructive finding. Finally 54% of 200 patients recovered by conservative therapy, 12.5% by surgery and remaining improved without any surgical intervention.Conclusions:The best cutoff point of anteroposterior renal pelvis diameter that led to surgery was 15 mm, with sensitivity 88% and specificity 74%.

Follow-up imaging after pediatric pyeloplasty.

Introduction:The duration, methods and frequency of radiographic follow-up after pediatric pyeloplasty is not well-defined. We prospectively evaluated a cohort of children undergoing pyeloplasty to determine the method for follow-up.Methods:Between 2000 and 2008, children undergoing pyeloplasty for unilateral ureteropelvic junction obstruction were evaluated for this study. All patients were evaluated preoperatively with protocol ultrasound (USG) and diuretic renal scan (RS). On the basis of preoperative split renal function (SRF), these patients were divided into four groups – Group I: SRF > 40%, Group II: SRF 30–39%, Group III: SRF 20–29%, and Group IV: SRF 10–19%. In follow-up, USG and RS were done at 3 months and repeated at 6 months, 1 year, and then yearly after surgery for a minimum period of 5 years. Improvement, stability, or worsening of hydronephrosis was based on the changes in anteroposterior (AP) diameter of pelvis and caliectasis on USG. Absolute increase in split renal function (SRF) >5% was considered significant. Failure was defined as increase in AP diameter of pelvis and decrease in cortical thickness on 3 consecutive USG, t½ >20 min with obstructive drainage on RS and/or symptomatic patient.Results:145 children were included in the study. Their mean age was 3.26 years and mean follow-up was 7.5 years. Pre- and post-operative SRF remain unchanged within 5% range in 35 of 41 patients (85%) in Group I. While 9 of 20 patients (45%) in Group II, 23 of 50 patients (46%) in Group III, and 14 of 34 patients (41%) in Group IV exhibited changes >5% after surgery. 5 patients failed, 2 in Group III, and 3 in Group IV. None of the patients deteriorated in Group I and II.Conclusion:After pyeloplasty in children with a baseline split GFR >30%, if a diuretic renogram and USG performed 3 months postoperatively shows nonobstructive drainage with t½ <20 min and decreased hydronephrosis, no further follow-up is required.

Measurement of Differential Renal Function by Scintigraphy in Hydronephrotic Kidneys: Importance of Conjugate Views for Accurate Evaluation

Traditionally a single posterior view is used to measure differential renal function during nuclear renal scintigraphy. Nevertheless, experimental data show important variation in this measurement in the setting of significant hydronephrosis. To date, the impact of degree of hydronephrosis on the accuracy of differential renal function determination has not been addressed. We evaluated the discrepancy between function measured by anterior and posterior views, and the relationship to varying degrees of hydronephrosis. We retrospectively reviewed consecutive mercaptoacetyltriglycine renal scans from 2009 to 2011. Ultrasounds were reviewed and degree of hydronephrosis was recorded using anteroposterior pelvic diameter. Absolute percent difference in differential renal function between each view (anterior minus posterior) was calculated and correlated to anteroposterior pelvic diameter. Patients were stratified into 4 groups according to anteroposterior pelvic diameter, ie less than 10 mm, greater than 10 mm, greater than 15 mm and greater than 25 mm. A total of 519 scans with corresponding ultrasounds were analyzed. Median patient age was 2.26 years. Kidneys with a larger anteroposterior pelvic diameter had a greater discrepancy in function on anterior and posterior views. There was a meaningful discrepancy for anteroposterior pelvic diameter greater than 10 mm (p = 0.034) and greater than 25 mm (p = 0.032). Several statistical models were used to identify a meaningful cut point of 15 mm, where the discrepancy in anterior and posterior views became significant (p = 0.001). The use of single views during nuclear renography for grossly hydronephrotic kidneys is often inaccurate. The discrepancy in differential renal function obtained on the anterior and posterior views is adversely impacted especially as anteroposterior pelvic diameter increases beyond 15 mm. Therefore, we suggest incorporation of conjugate views for estimating differential renal function in patients with hydronephrosis.

Comparison of conventional versus three-dimensional ultrasound in fetal renal pelvis measurement and their potential prediction of neonatal uropathies

Objective: To establish a threshold value for fetal renal pelvis dilatation measured by automatic volume calculation (SonoAVC) in the third trimester of pregnancy to predict neonatal uropathies, and to compare these results with conventional antero–posterior (AP) measurement, fetal kidney 3D volume and renal parenchymal thickness. Methods: In a prospective cohort study, 125 fetuses with renal pelvis AP diameter of ≥5 mm both at 20 weeks of gestation and in the third trimester, underwent an additional 3D volume measurement of the fetal kidney in the third trimester. Receiver operating characteristic (ROC) curves for establishing threshold values for fetal renal pelvis volume, AP measurement, fetal kidney volume and renal parenchymal thickness to predict neonatal uropathies were analyzed. Also, sensitivity, specificity, area under the curve (AUC) and likelihood ratios were calculated. Results: A cut-off point of 1.58 cm³ was identified in the third trimester of pregnancy (AUC 0.865 (95% CI 0.789–0.940), sensitivity 76.3%, specificity 87.4%, LR+ 6.06, LR− 0.27) for measurements with SonoAVC. A cut-off value of 11.5 mm was established in the third trimester of pregnancy (AUC 0.828 (95% CI 0.737–0.918), sensitivity 71.1%, specificity 85.1%, LR+ 4.77, LR− 0.34) for the conventional AP measurement. A cut-off point for fetal kidney volume was calculated at 13.29 cm³ (AUC 0.769 (95% CI 0.657–0.881), sensitivity 71%, specificity 66%, LR+ 2.09, LR− 0.44). For renal parenchymal thickness, a cut-off point of 8.4 mm was established (AUC 0.216 (95% CI 0.117–0.315), sensitivity 31.6%, specificity 32.6%, LR+ 0.47, LR− 2.10). Conclusion: This study demonstrates that 3D fetal renal pelvis volume measurements and AP measurements both have a good and comparable diagnostic performance, fetal renal volume a fair accuracy and renal parenchymal thickness a poor accuracy in predicting postnatal renal outcome.

Sonographic depiction of fetal ureters

Aims: Classic literature states that the fetal ureter should not be visible unless dilated. Our main objective was to produce an effective, reproducible method for fetal ureter depiction during an anatomic survey. Our secondary objectives were to record the frequency of visible ureters among normal fetuses and among fetuses with mild pyelectasis and also to determine the diameter of the sonographically demonstrated ureter. Subjects and methods: One hundred twenty consecutive fetuses undergoing a second trimester scan were enrolled in the study. Ninety-nine anatomically normal fetuses and 21 fetuses with isolated mild pyelectasis (antero-posterior renal pelvis diameter of ≥4 mm and <7 mm) were subjected to a detailed anatomical survey. One hundred twenty fetuses were analyzed bilaterally. Results: A total of 154 (64.2%) ureters were depicted. In the first group 123 (62.1%) ureters, in the second group 31 (73.8%) ureters were depicted (p = 0.06). The diameters of the ureters ranged from 0.4 to 2.7 mm. The majority (n = 80) (52%) were visualized at both proximal and distal segments. Conclusions: Our study demonstrates that the ureter can be demonstrated in normal fetuses and in fetuses with mild pyelectasis. Ureteral depiction is likely to be composed of normal transient passage of urine associated with peristalsis and is not always a pathological finding.

Diagnosis of isolated fetal renal pyelectasis during midtrimester and follow-up the outcome in utero by prenatal ultrasonography

Objective To assess the clinical significance of fetal pyelectasis and its changing in utero. Methods One hundred and ninty-seven isolated pyelectasis cases were retrospective reviewed from Jan 2012 to Jul 2014. Isolated pyelectasis was defined as a renal pelvis anteroposterior diameter (RPAPD) of ≥5 mm without other fetal anomaly in second trimester. Persistent or progressive pyelectasis was defined as a RPAPD of ≥10 mm before delivery. They were divided into two groups according to the size of renal pelvis in second trimester: group A (RPAPD 5-10 mm) and group B (RPAPD ≥10 mm). As the same, there were two groups after 32 weeks of gestation: group C (RPAPD <10 mm) and group D (RPAPD ≥10 mm). Results Totally 154 cases were followed up. There were 188 cases (95.4%) in group A, with 41 cases lost, 141 cases (95.9%) RPAPD <10 mm, 6 cases (4.1%) RPAPD ≥10 mm before delivery. There were 9 cases (4.6%) in group B, with 2 cases lost, remained 7 cases RPAPD ≥10 mm before delivery. Conclusions Although most of the fetuses with RPAPD 5-10 mm in second trimester will remain the same or resolved before delivery, those with RPAPD ≥10 mm may persistent or progress.Prenatal assessment of fetal renal pelvis may provide properly consultation. Key words: Ultrasonography, prenatal; Fetus; Pyelectasis; Pregnancy trimester, second

Correction of differential renal function for asymmetric renal area ratio in unilateral hydronephrosis.

Children with unilateral hydronephrosis are followed up with anteroposterior pelvic diameter (APD), hydronephrosis grade, mercaptoacetyltriglycine (MAG-3) drainage pattern and differential renal function (DRF). Indeterminate drainage preserved DRF in higher grades of hydronephrosis, in some situations, complicating the decision-making process. Due to an asymmetric renal area ratio, falsely negative DRF estimations can result in missed optimal surgery times. This study was designed to assess whether correcting the DRF estimation according to kidney area could reflect the clinical situation of a hydronephrotic kidney better than a classical DRF calculation, concurrently with the hydronephrosis grade, APD and MAG-3 drainage pattern. We reviewed the MAG-3, dimercaptosuccinic acid (DMSA) scans and ultrasonography (US) of 23 children (6 girls, 17 boys, mean age: 29 ± 50 months) with unilateral hydronephrosis. MAG-3 and DMSA scans were performed within 3 months (mean 25.4 ± 30.7 days). The closest US findings (mean 41.5 ± 28.2 days) were used. DMSA DRF estimations were obtained using the geometric mean method. Secondary calculations were performed to correct the counts (the total counts divided by the number of pixels in ROI) according to kidney area. The renogram patterns of patients were evaluated and separated into subgroups. The visual assessment of DMSA scans was noted and the hydronephrotic kidney was classified in comparison to the normal contralateral kidney's uptake. The correlations of the DRF values of classical and area-corrected methods with MAG-3 renogram patterns, the visual classification of DMSA scan, the hydronephrosis grade and the APD were assessed. DRF estimations of two methods were statistically different (p: 0.001). The categories of 12 hydronephrotic kidneys were changed. There were no correlations between classical DRF estimations and the hydronephrosis grade, APD, visual classification of the DMSA scan and uptake evaluation. The DRF distributions according to MAG-3 drainage patterns were not different. Area-corrected DRF estimations correlated with all: with an increasing hydronephrosis grade and APD, DRF estimations decreased and MAG-3 drainage patterns worsened. A decrease in DRF (< 45 %) was determined when APD was ≥ 10 mm. When APD was ≥ 26 mm, a reduction of DRF below 40 % was determined. Our results suggest that correcting DRF estimation for asymmetric renal area ratio in unilateral hydronephrosis can be more robust than the classical method, especially for higher grades of hydronephrotic kidneys, under equivocal circumstances.

CT-based assessment of renal function impairment in patients with acute unilateral ureteral obstruction by urinary stones.

The purpose of our study was to evaluate computed tomography (CT) imaging factors related to renal function impairment in patients with acute unilateral ureteral obstruction by urinary stones. The study included 94 patients who had acute unilateral ureteral obstruction due to a urinary stone and a normal contralateral kidney. We retrospectively investigated the serum creatinine (SCr) levels immediately prior to CT examination and at least 1week after treatment. CT examinations were performed using a CT urography protocol, including pre- and post-contrast images. The 67 patients with a SCr change of less than 0.3mg/dL constituted group A. The other 27 patients with a SCr decrease of more than 0.3mg/dL constituted group B. To evaluate factors related to renal function impairment, differences in CT imaging factors between the two groups, including the cortical and medullary density, renal and pelvic anteroposterior diameter, and perinephric fluid, were statistically analyzed. The SCr immediately prior to CT examination significantly differed between the two groups. The follow-up SCr after resolution did not significantly differ between the two groups. The difference in the mean cortical and medullary HU on the nephrographic phase between the obstructed kidney and normal kidney was higher in group B than in group A (27.1±23.1 and 69.4±59.1 vs. 5.7±8.8 and 31.8±34.8; p<0.001 and p=0.004, respectively). The cut-off point for the difference in the mean cortical HU on the nephrographic phase between the obstructed kidney and normal kidney for renal function impairment was 15 HU, as determined by a receiver operating characteristic curve analysis. Patients with significantly impaired renal function due to an acute unilateral ureteral obstruction may show a decreased nephrogram of the affected kidney and a significant difference in the HU on the nephrographic phase between the obstructed and normal kidney.

The roles of serum and urinary carbohydrate antigen 19-9 in the management of patients with antenatal hydronephrosis

Serum carbohydrate antigen (CA) 19-9 has been clinically applied as a valuable tumor marker for pancreatic and gastrointestinal carcinoma. CA 19-9 is expressed in normal excretory epithelium tissues. Increased CA 19-9 has also been observed in uroepithelial tumors as well as in nonmalignant conditions including hydronephrosis secondary to ureteral stones. The purpose of this article is to evaluate the role of urinary CA 19-9 as a non-invasive biomarker in the postnatal differentiation of obstructive and non-obstructive hydronephrosis in patients with unilateral antenatal hydronephrosis. Infants with isolated renal pelvic dilatation, defined as the presence of anteroposterior pelvic diameter (APPD) equal to or greater than 7 mm based on antenatal ultrasound after 28 weeks' gestation, underwent systematic investigation for uropathies and were prospectively followed up. The pyeloplasty group consisted of 17 patients with ureteropelvic junction (UPJ) obstruction who had undergone pyeloplasty. The non-obstructive dilatation (NOD) group consisted of 17 patients with non-obstructive hydronephrosis, and the control group consisted of 21 healthy children. Commercial enzyme-linked immunosorbent assay (ELISA) kits were used to measure the urinary and serum CA 19-9 levels. In both hydronephrosis groups (pyeloplasty and non-obstructive dilatation), the correlations between urinary and serum CA 19-9 levels with the anteroposterior pelvic diameter measured at the third trimester and the postnatal initial evaluation and differential renal function were investigated. The initial median urinary CA 19-9 levels were significantly greater in children who underwent pyeloplasty than in both the non-obstructive hydronephrosis (143 ± 38 vs. 68 ± 23, respectively; p = 0.007) and the healthy control groups (143 ± 38 vs. 13 ± 3, respectively; p = 0.001) (Figure). Three months after surgery, the urinary CA 19-9 levels had decreased significantly according to the preoperative levels in the pyeloplasty group (143 ± 38 vs. 55 ± 16, p = 0.039). In both the pyeloplasty and NOD groups, there was a correlation of urinary CA 19-9 levels with differential renal function and a correlation of serum CA 19-9 levels with the initial anteroposterior pelvic diameter. Receiver operator characteristic (ROC) analysis revealed a better diagnostic profile for the urinary CA 19-9 level than for the serum CA 19-9 level in terms of identifying obstruction in the hydronephrosis groups (areas under the curve = 0.8 and 0.7, respectively). The best cut-off value of for urinary CA 19-9 was 85.5 U/mL with 76% sensitivity, 85% specificity. The negative predictive value was 80%. The results suggest that voided urine CA 19-9 levels seems to be a more useful marker than serum CA 19-9 in obstructive dilatation. An appropriate decrease in urinary CA 19-9 levels after pyeloplasty may be used as a predictor of surgical outcome. In addition, the results have a number of important diagnostic implications that should be further validated in a larger study population. Based on these results, we suggest that a high urinary CA 19-9 level is a non-invasive clinically applicable marker for differentiating between obstruction and non-obstructive dilatation.

Diagnostic accuracy of neonatal kidney ultrasound in children having antenatal hydronephrosis without ureter and bladder abnormalities

To determine the diagnostic accuracy of anteroposterior renal pelvic diameter (APD) measurement and the society for fetal urology (SFU) grading in neonatal ultrasonography (USG) for detecting uropathy in newborns having antenatal isolated hydronephrosis (IH), characterized by hydronephrosis without ureter and bladder abnormalities, and to study time to resolution and factors predicting resolution of insignificant hydronephrosis. Ninety-six healthy newborns (129 kidneys) with IH, who underwent USG at age 7-30 days and voiding cystourethrography (VCUG) in conjunction with diuretic renography (DR) if APD > 10 mm or SFU grade 3-4 in neonatal USG, and at least a 12-month follow-up were divided into significant and insignificant hydronephrosis using the combined data of sequential USG, VCUG, and DR as the reference standard. Areas under the receiver operating characteristic plots (95 % CI) were 0.86 (0.79-0.94) versus 0.81 (0.73-0.89); p = 0.08, and 87.6 versus 79.8 % of cases were correctly classified, for APD ≥ 16 mm versus SFU grade 4, respectively. Ureteropelvic junction obstruction (UPJO) was the most common uropathy diagnosed. Of 85 kidneys with insignificant hydronephrosis, 57 underwent spontaneous resolution. The resolution rates were 24, 40, and 68 % at age 6, 12, and 24 months, respectively. APD was the only independent factor predicting resolution with the hazard ratio of 0.83 (95 % CI 0.74-0.92; p = 0.001). In IH, neonatal USG was a useful diagnostic tool to detect uropathy, mainly UPJO. Further investigation should be recommended when APD ≥ 16 mm or SFU grade 4.

Diuretic 99mTc DTPA renography in assessment of renal function and drainage in infants with antenatally detected hydronephrosis.

The controversy over the postnatal management of infants with antenataly detected hydronephrosis (ANH) still exists. We presented the results of diuretic 99mTc diethylenetriamine pentaacetic acid (DTPA) renography in 30 infants with the antenatal diagnosis of unilateral renal pelvic dilatation. The aim of this study was to assess the renal function determined by the pattern of drainage and split renal function (SRF) on diuretic renography and to correlate these findings with anteroposterior pelvic diameter (APD) estimated by ultrasonography. A total of 30 infants with 60 renal units (RU) (25 boys and 5 girls, median age 6.0 months, range 2-24) presented with unilateral hydronephrosis on ultrasound in the newborn period, underwent DTPA diuretic renal scintigraphy (F+15 protocol). The median APD evaluated on perinatal ultrasound was 15 mm (range 5-30). The postnatal associated clinical diagnosis were pelviureteric junction obstruction (PUJ), simple hydronephrosis, megaureter, vesicoureteral reflux (VUR) and posterior urethral valves in 11, 10, 6, 2 and 1 infant, respectively. Images and Tmax/2 after diuretic stimulation on the background subtracted renographic curves were used as the criteria for classifying the drainage as good, partial, and poor or no drainage. The SRF was calculated with the integral method. Good drainage was shown in 36/60, partial drainage in 13/60 and poor or no drainage in 11/60 RU. The SRF > 40% was observed in 55/60 RU, with no RU showing SRF lower than 23.5%. In infants with severe ANH the obstruction was not excluded in 94.1%. Diuretic renography in antenatally detected hydronephrosis should be a useful tool in postnatal follow up, especially in differentiating nonobstructive hydronephrosis from obstructive. It is also importanat to assess and monitor the SRF. Our results suggest that even in the presence of partial or no drainage, SRF may not be significantly impaired.

Outcome of antenatal hydronephrosis in northeastern Thailand

Abstract Background: Antenatal hydronephrosis (ANH) is a condition characterized by fetal renal pelvic dilatation during pregnancy. It is detected in 1%-5% of all pregnancies. Most cases of ANH are physiological in nature, but some are pathological and can cause morbidity. Objective: To determine: (a) the causes of ANH; (b) the factors associated with complications; and, (c) the factors associated with surgical intervention. Methods: We reviewed the medical records of infants diagnosed with ANH; defined by a renal pelvic anteroposterior diameter ≥5 mm (based on antenatal ultrasonography) and being followed-up at Srinagarind Hospital. Results: Forty-six infants (32 boys and 14 girls) with ANH were identified. Over half (57%) were born in our hospital (in-hospital) with the condition. The two most common causes of ANH were ureteropelvic junction obstruction (32%) and transient hydronephrosis (22%). Of the 63 abnormal kidneys, 52% needed surgical intervention. Twenty-two patients (48%) had urinary tract infections and most had more than 1 episode. None of the 46 patients had end-stage renal disease, but one died because of lung hypoplasia during the neonatal period. The severity of ANH and time of first postnatal ultrasonography were related to medical complications, while bilateral ANH and more severe ANH were associated with the need for surgical intervention. A milder degree of ANH and postnatal ultrasound findings were significantly associated with transient hydronephrosis. Conclusion: Most cases of ANH were pathological and half required surgical intervention. Severe ANH and delayed investigation were associated with poor outcomes.

Early Pyeloplasty for Recovery of Parenchymal Thickness in Children with Unilateral Ureteropelvic Junction Obstruction

Objective: We compared renal function before and after pyeloplasty in children with unilateral ureteropelvic junction obstruction (UPJO) according to the children's age. Methods: We reviewed the medical records of 36 children with UPJO who had undergone pyeloplasty and showed improved urine drainage on postoperative diuretic renal scan. The children were divided into two groups according to their age at the time of surgery: group I, ≤1 year of age (n = 15), and group II, >1 year of age (n = 21). Parenchymal thickness (PT) and pelvic anteroposterior diameter measured by ultrasonography and renal function measured by ^99mTc-MAG3 renal scan were compared before and after surgery. Results: Group I patients, who underwent pyeloplasty within 1 year of birth, showed significant recovery of the PT ratio at follow-up evaluation (from 0.50 ± 0.13 preoperatively to 0.83 ± 0.23 postoperatively; p = 0.029) compared with that in group II (from 0.74 ± 0.23 preoperatively to 0.75 ± 0.18 postoperatively; NS). The mean differences in the PT ratio before and after surgery were 0.29 ± 0.25 and 0.02 ± 0.18 in groups I and II, respectively. Conclusion: This result suggests that early surgery improves subsequent parenchymal growth of the involved renal unit.

Early experience of using transumbilical multi-stab laparoscopic pyeloplasty for infants younger than 3 months

ObjectiveMinimally invasive surgery is increasingly being adopted in pediatric urology practice. The aim of this study is to investigate the feasibility and the safety of transumbilical multi-stab laparoscopic pyeloplasty (TMLP) as a treatment for infants younger than 3 months with severe hydronephrosis. MethodsWe retrospectively reviewed 63 infants younger than 3 months with severe hydronephrosis who underwent TMLP from June 2010 to March 2013. The operative indications included: 1) prenatal diagnosis of hydronephrosis with anteroposterior renal pelvic diameter greater than 3 cm and Society of Fetal Urology (SFU) Grade 4 hydronephrosis; 2) ipsilateral differential renal function being less than 40%. Patients were followed up with physical examinations, ultrasound and radionuclide scans. ResultsThe operations were successfully performed in all 63 patients. There was no conversion, no requirement of additional trocar placement and no intraoperative complication. The median age was 54 (47–87) days. The median operative time was 75 (53–118) minutes. The patients were followed up for 12 (6–36) months. The anastomoses were proved to be patent and the renal parenchymal thickness increased. The renal pelvic anteroposterior diameters were reduced and the renal functions were improved (p < 0.01). In addition, the scars were barely noticeable. ConclusionsTMLP for infants younger than 3 months with severe hydronephrosis is feasible, safe and minimally invasive. The cosmetic results are excellent.

Fetal hydronephrosis: natural history and risk factors for postnatal surgery

The objective of this study was to assess the ability of prenatal ultrasound to predict an unfavorable outcome and the need for postnatal surgery in cases of fetal hydronephrosis (HY). Antenatal HY was classified according to the renal pelvis anteroposterior (AP) diameter in the third trimester. Postnatal outcome was considered favorable in the presence of spontaneous resolution or postnatal diagnosis of HY <20 mm, and unfavorable in the presence of postnatal diagnosis of >20 mm HY or urinary tract pathologies. Prenatal diagnosis of HY was made in 120 fetuses (for a total of 161 abnormal renal units). The rates of postnatal urinary tract pathology were 14, 27 and 53% for antenatal HY of ≤7, 8-15 and >15 mm, respectively. An AP diameter ≥7 mm in the third trimester had a sensitivity of 100% and a specificity of 23% to predict unfavorable outcome. A formula inclusive of AP diameter and presence or absence of urinary tract anomalies can predict the need for postnatal surgery. The majority of infants with congenital HY have a favorable postnatal outcome. Risk of unfavorable outcome increases with the degree of dilatation of the renal pelvis and the presence of urinary tract anomalies. An AP diameter ≥7 mm in the third trimester warrants postnatal follow-up.