Background Midureteral stenosis is very rare in children and can cause congenital hydronephrosis. We report our experience treating children with congenital midureteral stenosis at our center, focusing on the differences in preoperative diagnosis and treatment compared with other congenital obstructive uropathies. Methods We retrospectively reviewed the medical records of 26 children diagnosed with congenital midureteral stenosis at our center between January 2007 and December 2020, such as preoperative examination methods, intraoperative conditions, and postoperative follow-up results. Results Of the 1625 children treated surgically for ureteral narrowing, only 26 (1.6%) were diagnosed with midureteral stenosis, including 15 infants and 11 children. Eighteen (69.2%) were boys, 13 (50%) were affected on the left side, and 23 (88.5%) had isolated ureteral stenosis. Overall, 13 (50%) of the children presented with prenatal hydronephrosis, and 13 (50%) presented with abdominal pain or a mass. All the children had undergone urinary ultrasound and intravenous urography preoperatively; the diagnostic rate of ultrasound was 92.3%. Only 7 (26.9%) children had undergone pyelography. All the children had undergone surgery. The ureteral stenotic segment was less than 1 cm long in 25 (96.2)% of the children. The mean follow-up duration was 22 months (range: 6–50 months). One child developed anastomotic strictures. Urinary tract obstruction was relieved in the other children without long-term complications. Conclusions Congenital midureteral stenosis is rare, accounting for 1.6% of all ureteral obstructions, and its diagnosis is crucial. Urinary ultrasound has a high diagnostic rate and should be the first choice for midureteral stenosis. Retrograde pyelography can be used when the diagnosis is difficult, but routine retrograde pyelography is not recommended. Congenital ureteral stenosis has a relatively short lesion range, largely within 1 cm. The treatment is mainly resection of the stenotic segment and end-to-end ureteral anastomosis, with a good prognosis.

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Introduction: The complication rates of proximal hypospadias, especially fistula, are much higher than those of distal hypospadias. Urethral coverage is an effective method for reducing fistulas. Acellular dermal matrix (ADM) has been shown to exhibit structural compatibility and biocompatibility, both of which promote tissue healing. Methods: The present non-randomized study evaluated the efficiency, feasibility, and safety of using ADM for urethroplasty coverage in patients with proximal hypospadias. This prospective study enrolled 35 patients (age range Enhanced Digital Features To view enhanced digital features for this article go to https://doi.org/10.6084/ m9.figshare.11798895. Defu Lin and Guannan Wang contributed equally to this work.

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Background Hypospadias is a congenital anomaly of the male urogenital system. Genetics factors play an important role in its pathogenesis. To search for potential causal genes/variants for hypospadias, we performed exome sequencing in a pedigree with three patients across two generations and a cohort of 49 sporadic patients with hypospadias. Results A novel BRAF variant (NM_004333.6: c.362C > A) was found to co-segregate with the hypospadias phenotype in the disease pedigree. In cells overexpressing the BRAF mutant, the phosphorylation level of p38 MAPK was significantly increased as compared with the cells overexpressing the wild-type BRAF or RASopathy-related BRAF mutant. This variant further led to a reduced transcription level of the SRY gene, which is essential for the normal development of the male reproductive system. In the cohort of sporadic patients, we identified two additional variants in p38 MAPK signaling-related genes (TRIM67 and DAB2IP) potentially associated with hypospadias. Conclusion Our study expands the phenotypic spectrum of variants affecting p38 MAPK signaling toward the involvement of hypospadias.

Background: Contrast-enhanced ultrasonography (CEUS) is a new potential modality for the quantitative evaluation of the microvascular perfusion of renal parenchyma.Objective: To prospectively evaluate the diagnostic value of CEUS in assessing renal function in patients with ureteropelvic junction obstruction (UPJO).Methods: The study protocol was approved by the ethics committee of Beijing Children’s Hospital (Beijing,China), and written informed consent was obtained from the patients’ parents or guardians. Ultrasonography (US), CEUS, and radioisotope renography were performed in 51 children (42 boys, 9 girls; mean age, 6.75 ± 4.14 years) with unilateral UPJO. The slope of the ascending curve (A), time to peak (TTP), peak intensity (PI), and area under the curve (AUC) were recorded during CEUS; the quantitative data were calculated by the QLAB system (semiautomated border tracking, Philips Healthcare) software. Sensitivity and specificity values were determined for CEUS and compared with radioisotope renography.Results: A total of 102 kidneys in 51 patients were depicted by CEUS and the perfusion time-intensity curve (TIC).CEUS depicted 102 kidneys in 51 patients, in whom the perfusion time-intensity curve（TIC）was determined. The TIC of renal cortical perfusion in all groups showed an asymmetrical single-peak curve, which could be clearly distinguished between the experimental group and the control group. Compared to the control group, the TTP was markedly prolonged but A was significantly decreased in the experimental group (P < 0.05). There was no significant correlation between AUC, PI and DFR，but the correlation coefficient between TTP, A and DFR remained significant (p<0.001).The receiver operating characteristic （ROC）curve drawn to differentiate the differential renal function (DRF) using the TTP value provided an area under the ROC curve (AUROC) of 0.86. The diagnostic performance of contrast-enhanced US was better than that of US, as the sensitivity and specificity values were 92.86% and 76.14%, respectively.Conclusions: This preliminary experience represents the first report of evaluating the diagnostic value of CEUS in assessing renal function in children with UPJO. CEUS is a highly sensitive, rapid, and diagnostic imaging modality for detecting and monitoring renal function noninvasively.

Background : Contrast enhanced ultrasound (CEUS) has been actively used in the detection of lesions in many organs especially in kidney and liver, but there is no report in evaluation of preoperative chemotherapy for Wilms tumor in children.Methods: 8 children with Wilms tumor were enrolled in this study. All patients accepted preoperative chemotherapy for 4-8 weeks. Each child accepted CEUS examination for 3 times. The image files and the data were analyzed through software. Results: The group included 8 cases with tumor volume from 155.71 to 1624.16 cm3. 6 patients accepted preoperative chemotherapy for 8 weeks before surgery, 2 cases underwent preoperative chemotherapy for 4 weeks. Each child accepted CEUS examination for 3 times and no one showed discomfort to the SonoVue contrast agent. By the comparison from the 3 times CEUS, tumor volume in most of the children was significantly reduced, and the blood perfusion intensity in the tumor was prominently weakened. The results of linear regression showed that the changes of PI between the first and second CEUS examinations and between the second and third CEUS examinations had correlation with the reduction volume of Wilms tumor.Conclusions: It is the first time to apply quantitative analysis of CEUS in evaluation of preoperative chemotherapy for Wilms tumor in children. CEUS is a safe examination in children. CEUS videos could show clearly the changes of tumor perfusion during preoperative chemotherapy. PI can precisely reflect the degree of sensitivity of tumor to chemotherapy in early stage of preoperative chemotherapy.