Utility of Urinary Biomarkers Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1 as a Marker for Diagnosing the Presence of Renal Scar in Children with Vesicoureteral Reflux (VUR): A Cross-Sectional Study.

Aim: To explore the possibility of using urinary biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) to assess the presence of renal scars in children with Vesicoureteric Reflux (VUR). Materials and Methods: This cross-sectional study was conducted in 94 children aged 0-16 years diagnosed with VUR in the Department of Pediatric Surgery, JIPMER. Urinary biomarkers were measured using the enzyme-linked immunosorbent assay kits, normalized with urinary creatinine (Cr) and compared with severity of VUR (low grade [I and II] and high grade [III, IV, and V]), presence or absence of renal scar in VUR patients and severity of renal scar. Independent Student's t-test, Mann-Whitney U-test, and analysis of variance Kruskal-Wallis test were used for comparison, and receiver operating characteristic (ROC) curve analysis for predicting the accuracy of biomarkers in detecting the presence of renal scars. Results: The median urinary NGAL (uNGAL) value was higher in children with renal scar (1.49 ng/mL) than those without renal scar (0.58 ng/mL) and was statistically significant (<0.001). Whereas median uNGAL/Cr was higher in children with renal scar (0.07) than those without renal scar (0.03) but was not statistically significant (P = 0.06). Urinary KIM-1 and urinary KIM-1/urinary Cr (uKIM-1/Cr) was not found to be a significant predictor of renal scar. The difference of uNGAL/Cr was comparable between the grades of renal scar but was not statistically significant. On ROC curve analysis, uNGAL had area under the ROC curve (AUC) of 0.769 with 71% of both specificity and sensitivity, whereas uNGAL/Cr was found to be a poor predictor of renal scar with AUC of 0.611, 60% sensitivity, and 61.2% specificity. Conclusion: uNGAL can serve as a noninvasive marker for diagnosing the presence of renal scar in children with VUR and a multicentric more extensive cohort study may be needed to strengthen or negate its role.

Calyx to Parenchymal Ratio (CPR): An unexplored tool and its utility in the follow-up of pyeloplasty.

INTRODUCTION: Antero-posterior trans pelvic diameter (APD) and renal scintigraphy play a significant role in the diagnosis of pelvi-ureteric junction (PUJ) obstruction and postoperative follow-up following pyeloplasty. However, the APD varies irrespective of improvement, deterioration, or preserved function in a hydronephrotic kidney and is not a reliable parameter due to various factors (hydration status, compliance, and reduction pyeloplasty). Calyx to Parenchymal Ratio (CPR) is the ratio of the depth of the calyx and parenchymal thickness measured on ultrasound (USG) in coronal image. We assessed the utility of CPR in the follow up of pyeloplasty and compared it with the commonly used APD of the pelvis and renal scintigraphy. MATERIAL AND METHODS: A prospective cohort study was done from July 2016 to October 2017. During this period 73 pyeloplasties were done, and 62 cases meeting the inclusion criteria were enrolled. All the children underwent ultrasound and Technetium-99 m Ethylene dicysteine isotope renogram (EC) scan before and after pyeloplasty. APD and CPR values were measured on USG and compared with isotope renogram outcomes in these children in the preoperative versus postoperative period. Two defined objective variables ΔAPD, percent ΔAPD and ΔCPR, percent ΔCPR were compared with categorical variables that would predict the surgical outcome as - failed, successful or equivocal. Multinomial logistic regression analysis and receiver operating curve (ROC) analysis was used to identify predictive accuracy. RESULTS: The mean (range) APD value recorded in the preoperative period was 3.67 cm (1.40-8.00 cm), which decreased to 1.67 cm (0.40-6.50) postoperatively, which was 54.2% lower (P=<0.001). The mean (range) CPR value decreased from 5.96 (1.20-20.00) in the preoperative period to 2.57 (0.43-10.90) postoperatively, which was 56.8% lower (P=<0.001). On multinomial logistic regression analysis, ΔCPR was found to be a significant predictor of outcome with an overall accuracy of 95.1%, change in CPR was a better predictor of success after pyeloplasty as compared to change in APD, which had an overall accuracy of 85.2% (p = 0.01). Further, on ROC curve analysis, we observed that ΔCPR and %ΔCPR can strongly predict successful pyeloplasty with a sensitivity of each with 96% and 98% respectively and AUC of 0.897 and 0.799 respectively. DISCUSSION: USG (APD) and renogram are the most widely used investigation in follow-up of pyeloplasty; however, APD has its own limitations like operator variability and slower improvement. CPR has the advantages that neither calyceal depth nor parenchymal thickness is directly altered during the surgery, and early resolution of calyceal dilatation and rapid parenchymal growth following pyeloplasty and thus a surgeon independent parameter. Our results have shown that ΔCPR can identify successful pyeloplasty with strong prediction than ΔAPD and thus renal scans can be avoided if there is visible improvement in CPR on follow-up. CONCLUSIONS: Our study identified a change in CPR, i.e., ΔCPR as a strong predictor of surgical outcome, as it is not influenced by extent of pelvis reduction during pyeloplasty and early to change. Using this parameter, we can avoid unnecessary repeated nuclear scans based on persistent high APD values and optimize resource utilization. We recommend the use of CPR in routine practice in the preoperative and postoperative follow-up of PUJ obstruction following pyeloplasty.

Laparoscopic vascular relocation: alternative treatment for renovascular hydronephrosis in children.

AIMS: The standard treatment for pelviureteric junction obstruction (PUJO) has been dismembered pyeloplasty. The open surgical, Hellström procedure in which crossing polar vessels are relocated, has been an option in adult urological practice. We present our experience with laparoscopic vascular relocation in children. METHODS: Data were retrospectively gathered on all patients who underwent laparoscopic relocation of lower pole vessels (LRLPV) at our institution between July 2004 and March 2008. Follow-up ultrasounds and MAG3 were obtained. RESULTS: LRLPV was performed in 10 boys and 9 girls. Patients were between 5.8 and 15.25 years (median 9.9 years). They presented with recurrent abdominal pain (n = 17), urinary tract infections (n = 7) and haematuria (n = 3). On ultrasound, MAG3 and retrograde studies they had hydronephrosis, obstructed drainage and a normal calibre ureter with a sharp cut-off. They were further assessed at laparoscopy and were found to have aberrant lower pole crossing vessels. All underwent laparoscopic mobilization of the lower pole vessels from the region of the PUJ thereby freeing the junction and relocating them superiorly onto the anterior wall of the pelvis. The median operating time was 120 min (range 60-240 min). The median hospital stay was 2 days (range 1-3 days). They were followed up for a median period of 12 months (range 6-36 months). All patients have remained asymptomatic. Ultrasound done at 6 months showed decreased hydronephrosis. MAG3 study showed improved drainage in 17, while 1 had poor drainage. This patient remains symptom free and is under regular follow up. CONCLUSION: Laparoscopic vascular relocation is an unconventional technique in carefully selected patients with PUJO. It obviates disrupting an intrinsically normal PU junction and treats the cause rather than the effect. Our intermediate-term results are encouraging and further long-term assessment is needed.