Significant improvement in hydronephrosis with pyeloplasty prior to 3 months of age in patients with antenatal severe hydronephrosis.

INTRODUCTION: Pyeloplasty is the definitive management of ureteropelvic junction obstruction (UPJO). One of the challenging questions is when to perform pyeloplasty. We studied if improvement post-pyeloplasty in the first 3 months of life could show greater improvement in hydronephrosis than surgery at an older age. PATIENTS AND METHODS: Patients with postnatally diagnosed UPJO and underwent pyeloplasty in the first year of life were retrospectively reviewed. We excluded patients with concomitant vesicoureteral reflux, and patients who had pyeloplasty because of UTI or missed follow-up. Patients were divided into two groups, according to the age at pyeloplasty, before and after the age of 3 months. We collected patients' demographics, anteroposterior diameter of the renal pelvis (APD), SFU grade, renogram data, perioperative data (surgery duration, hospital stay, and ureteral stent duration) and postoperative ultrasound changes. The percentage of change of APD (Δ%APD) was calculatedusing the formula: Δ%APD = [ (initial APD-last APD)/initial APD] *100. RESULTS: We included 90 patients (93 renal units). 36 patients had pyeloplasty during the first 3 months of life and 57 patients at 3 -12 months. Patients' characteristics were similar in both groups except APD which was higher when pyeloplasty was done < 3 months of age (p = 0.02). Both groups had comparable perioperative parameters. After almost similar follow-up period of both groups. The Δ%APD was 58% when pyeloplasty was done < 3 months compared to 33% when was performed > 3 months (p = 0.009). Using Kaplan-Meier analysis, APD significantly improved when pyeloplasty was performed before the age of 3 months (p = 0.001). CONCLUSION: Early pyeloplasty, in the first 3 months of life, showed a significant improvement of APD postoperatively than those had surgery later. It is unclear if this will relate to less loss of renal function yet certainly this would be suspected and feel this finding provides some evidence for early intervention.

Can we improve the usefulness of the diuretic renogram in the diagnosis of ureteropelvic junction obstruction (UPJO) in children? Introduction of mercaptoacetyltriglycine-suspected obstruction scoring system (MAG-SOS).

INTRODUCTION: Mercaptoacetyltriglycine (MAG-3) renogram is one of the gold standard diagnostic tools of ureteropelvic junction obstruction (UPJO); however, there is no widely agreed indications of pyeloplasty based on MAG-3 findings. In this study, we introduce a renogram scoring system that can help improve the prognostic value of MAG-3 renogram and in the decision making of pyeloplasty. PATIENTS AND METHODS: We retrospectively reviewed consecutive pyeloplasties for antenatal hydronephrosis from 2010 to 2020. A control group was included of non-operatively managed SFU grade 3 and 4. The initial renal ultrasound and preoperative MAG-3 Lasix renogram were reviewed for differential renal function (DRF), type of renogram curve and tracer washout half-time (T1/2). A ROC curve was used to evaluate the cut-off points that can be associated with obstruction. A multivariate linear regression model was used to assess the best renogram parameter that can predict surgical intervention. RESULTS: We included 188 patients with 209 renal units. The median age for pyeloplasty was 5.4 months. The mercaptoacetyltriglycine-Suspected Obstruction Scoring System (MAG-SOS) was associated with pyeloplasty (AUC = 0.97, P < 0.001) (Figure A). A score of 5 is 100% specific for obstruction. 78% of units required surgical intervention had a MAG-SOS score of≥5 while all units of the control group had a range of score 0-4. Using the multivariate analysis, the MAG-SOS system showed to the only independent predictor for pyeloplasty (HR = 0.03, p < 0.001). DISCUSSION: This study has some limitations. Firstly, the retrospective nature of the cohort; however, all patients were reviewed by one investigator who was blinded to the line of management. This is a single institutional study; therefor, this MAG-SOS should be evaluated by other centers to ensure its efficiency. Lastly, the pyeloplasty decision was taken by 3 different urologists; nevertheless, all of them adopt the same indications which are similar to those of the Society for Pediatric Urology and the Canadian Urological Association guidelines. CONCLUSION: The MAG-SOS system showed to be a useful tool that can predict pyeloplasty. A score of 5 has 100% specificity for patients having a pyeloplasty performed. Prospective studies are required to confirm the usefulness of this novel tool.

How can we measure the renal pelvic anteroposterior diameter in postnatal isolated hydronephrosis?

INTRODUCTION: The anteroposterior diameter (APD) of the renal pelvis is a commonly used ultrasound parameter in the evaluation and management of hydronephrosis. It has been established that an APD value associated with pyeloplasty is around 25 mm. Some believe the APD should be measured at the innermost part of the renal pelvis while others suggest that it should be done at the renal contour. However, there is no consensus on the optimal APD measurement technique including whether it should be measured supine or prone. This study compared six different techniques of APD measurements, in both supine and prone positions, and further evaluated their association with pyeloplasty. METHODS: Data was obtained by retrospectively reviewing patients' charts that had initial high-grade hydronephrosis (HGH) from 2008 to 2014. We recorded the patients' demographics, ultrasound data and management choice. In the mid-renal transverse plane, the APD was measured by 2 blinded investigators, at the intra-renal, renal contour and extra-renal regions of the renal pelvis in supine and prone positions (Figure A). We compared the six APD measurements based on the outcome of management (pyeloplasty vs. conservative management). The ROC curve obtained was then used to assess the ability of various APD measurements in predicting surgical intervention. The cutoff value chosen that predicts pyeloplasty was the lowest diameter with 100% specificity. RESULTS: We included 129 patients (134 renal units). Forty-four renal units (42 patients) underwent pyeloplasty whereas 90 renal units (87 patients) were managed conservatively. Patients' demographics were grouped by both SFU grade and clinical outcome. Regardless of grade, the APD measurements were different in all 6 techniques. All APD measurement techniques showed good inter-rater reliability. Based on the ROC curve, all APD measurements were associated with pyeloplasty with an AUC from 0.89 to 0.91. The supine extra-renal APD measurement of 24 mm was the most sensitive cutoff value. The cutoff values ranged from 18 to 27 mm when including patients from all grades of hydronephrosis. The median APD measurements were significantly less for SFU grade 3 than grade 4 hydronephrosis in all positions (P < 0.001 for all measurements), yet the predictive cutoff value of 24 mm for the supine extra-renal was similar for both grades. CONCLUSION: APD measurements differ based on the technique, but they are all equally associated with the clinical outcome of pyeloplasty. The inter-rater reliability of all techniques were excellent. Though the median APD measurements are smaller in SFU grade 3, it appears that the cutoff for a predictive renal pelvic APD does not differ between SFU grades 3 and 4 for the supine extra-renal technique. We conclude that the technique for measuring the APD needs to be specified in studies of hydronephrosis and in any grading systems.

Eight-Year Experience With 3-T Intraoperative MRI Integration in Focal Pediatric Epilepsy Surgery: Impact on Extent of Resection, Residual Volumes, and Seizure Outcomes.

OBJECTIVE. The purpose of this study was to investigate the influence of 3-T intraoperative MRI (ioMRI) on the extent of resection of pediatric focal epileptogenic lesions, residual lesion volumes, and postoperative seizure outcomes. MATERIALS AND METHODS. All surgical procedures for focal epilepsy from 2003 to 2017 were retrospectively reviewed. Patients were divided into two groups: those who underwent ioMRI and those who did not. Each group was subdivided into two subcategories according to preoperative MRI visualization of the lesion: those with well-defined and those with poorly defined lesions. The volumes of preoperative lesions and postoperative residual lesions were delineated. Outcome data and patient characteristics were reviewed. The results were compared between the two groups and the two subcategories. RESULTS. Eighty patients were included: 45 in the ioMRI group (24 with well-defined lesions, 21 with poorly defined lesions) and 35 in the non-ioMRI group (18 with well-defined lesions, 17 with poorly defined lesions). The well-defined lesions included tumors and vascular lesions. The poorly defined lesions included malformations of cortical development, hippocampal sclerosis, and tuberous sclerosis. The mean follow-up duration was 5.1 ± 3.3 years. The rate of gross total resection was not significantly different between the ioMRI and non-ioMRI groups (p = 0.46). However, ioMRI findings facilitated further resection during surgery, increasing gross total resection by an additional 11.1%. The ioMRI group had a significant reduction in percentage of residual volume (p < 0.001). Outcome data suggested that ioMRI is protective against poor Engel score (p = 0.048). Although ioMRI prolonged the mean operative time by 1.2 hours (p = 0.002), the additional time was not associated with additional complications. CONCLUSION. Integration of ioMRI into focal epilepsy surgery was associated with smaller residual lesions and was protective against poor Engel score. It prolonged the operative time but without increasing the number of complications.

Neurofibromatosis Type 1: Description of a Novel Diagnostic Scoring System in Pediatric Optic Nerve Glioma.

OBJECTIVE: Neurofibromatosis type 1 (NF1) is a multisystemic genetic disease in which patients develop benign tumors including optic nerve gliomas (ONG). Optic nerve thickening and tortuosity are radiologic markers of tumors but can also be present in children with NF1 who do not have gliomas, thus complicating screening and diagnosis. We undertook this study to retrospectively determine quantitative and qualitative diagnostic criteria using MRI of the orbits for ONG in children with NF1. MATERIALS AND METHODS: MR images of the orbits obtained from 2003 to 2016 for children with and without NF1 were reviewed. Optic nerves were divided into three groups: NF1 with glioma (n = 71 nerves), NF1 without glioma (n = 151 nerves), and healthy control subjects (n = 66 nerves). The diameter of each nerve was measured at multiple locations. Two radiologists assessed tortuosity using validated criteria, and subarachnoid dilatation was quantified. Last, a composite score using both optic nerve diameter and tortuosity was proposed. RESULTS: The mean diameter of the optic nerve was significantly larger in patients with NF1 with glioma compared with those with NF1 without glioma and with control subjects at all locations. Maximal nerve diameter greater than 2 SD above the mean maximal diameter for control nerves was considered abnormally enlarged. The tortuosity parameters were all significantly associated with ONG compared with absence of ONG in NF1. A scoring system derived from these data were highly reliable in differentiating ONG from absence of ONG in NF1. CONCLUSION: The radiologic diagnosis of ONG in patients with NF1 is challenging. The scoring systems we describe provide a framework for simple radiologic criteria for ONG in these patients.

Is the renal pyramidal thickness a good predictor for pyeloplasty in postnatal hydronephrosis?

OBJECTIVES: We evaluated the feasibility and value of renal pyramidal thickness (PT) as a predictor of pyeloplasty in high-grade postnatal hydronephrosis. PATIENTS AND METHODS: We retrospectively reviewed the charts of patients who presented with postnatal hydronephrosis from 2008 to 2013. Included cases had grade 3 or 4 hydronephrosis. We included only units diagnosed as ureteropelvic junction obstruction. Gender, laterality, hydronephrosis side, renogram data, and follow-up data were recorded. Two investigators reviewed all patients' ultrasounds images. We measured PT and pelvic anteroposterior diameter (APD) in the last ultrasound before surgery. For those managed conservatively, measurements were obtained from the ultrasound with worst hydronephrosis. PT was measured in supine position in the middle third of the sagittal plane (Figure). We assessed the reliability of PT measurement using the intraclass correlation coefficient (ICC). Univariate and multivariate analyses were used to correlate the collected parameters to pyeloplasty incidence. Receiver operating characteristic curve was used to evaluate the cutoff value of PT that predicts pyeloplasty. RESULTS: The total included cases were 155 patients (165 units). One hundred and fourteen units had grade 3 hydronephrosis and 51 units had grade 4 hydronephrosis. Fifty-two cases (55 units) underwent pyeloplasty. The median follow-up period was 37.6 months. PT measurement was reliable (ICC = 0.94). Univariate analysis revealed that SFU grading, APD, PT, T1/2, and MAG-3 curves were associated with surgery. Multivariate analysis showed that PT was a single independent predictor for pyeloplasty. PT ≤ 3 mm had 98.1% sensitivity and 89.7% specificity in predicting pyeloplasty. DISCUSSION: PT is the first portion of renal parenchyma that is affected in high-grade hydronephrosis. Moreover, it changes little over the first 9 years of life. PT measurement in hydronephrosis was not previously evaluated. We found that PT was easily measured in most kidneys with high negative predictive value. The PT value as an indicator for pyeloplasty should undergo extensive assessment by other institutions with different protocols. CONCLUSION: Being a slowly growing part of the parenchyma, PT can be a good measurable parameter to predict pyeloplasty. Measurement of PT in hydronephrosis is reliable. PT ≤ 3 mm can predict pyeloplasty with 98.1% sensitivity and 89.7% specificity.