Congenital Lung Malformations: A Pictorial Review of Imaging Findings and a Practical Guide for Diagnosis.

The term congenital lung malformation (CLM) is used to describe a wide range of pathological conditions with different imaging and clinical manifestations. These anomalies stem from abnormal embryological lung development, potentially occurring across various stages of prenatal life. Their natural history can be variable, presenting in a wide range of severity levels and encompassing asymptomatic individuals who remain so until adulthood, as well as those who experience respiratory distress in the neonatal period. Through the PubMed database, we performed an extensive review of the literature in the fields of congenital lung abnormalities, including their diagnostic approach and findings. From our RIS-PACS database, we have selected cases with a final diagnosis of congenital lung malformation. Different diagnostic approaches have been selected, including clinical cases studied using plain radiograph, CT scan, prenatal ultrasound, and MR images. The most encountered anomalies can be classified into three categories: bronchopulmonary anomalies (congenital pulmonary airway malformations (CPAMs), congenital lobar hyperinflation, bronchial atresia, and bronchogenic cysts), vascular anomalies (arteriovenous malformation), and combined lung and vascular anomalies (scimitar syndrome and bronchopulmonary sequestration). CLM causes significant morbidity and mortality; therefore, the recognition of these abnormalities is necessary for optimal prenatal counseling and early peri- and postnatal management. This pictorial review aims to report relevant imaging findings in order to offer some clues for differential diagnosis both for radiologists and pediatric consultants.

Narrative review in learning curve and pediatric robotic training program.

Background and Objective: Studying learning curve (LC) for robotic procedures and developing an adequate training program are two fundamental steps to standardize robotic procedures. With this aim, we analyzed the literature to study the LCs of different robotic procedures and the availability of standardized training problems. Methods: The PubMed database was searched in the period from January 1995 to September 2022. Articles presenting LC and potential training programs in the pediatric population were chosen. Key Content and Findings: Twenty papers were screened describing LC of robotic-assisted laparoscopic pyeloplasty (n=12), fundoplication (n=4), cholecystectomy (n=2), choledochal cyst resection (n=1), nephrectomy/partial nephrectomy (n=1) and lingual tonsillectomy (n=1), with a total of 1,251 procedures. In 10 studies there was only one single surgeon; nine had more than one; one did not specify how many surgeons participated. Twelve papers were retrospective single-center, three multicentric retrospective, four prospective and one was compared a retrospective case series to a prospective cohort. Most of these studies focused on operative time as the primary outcome. It was analyzed as the only outcome in three articles, along with complications in 14, time to discharge in eight, blood loss in three and pain killer use in three. The selected studies analyzed LC impacting operative planning (n=20), training (n=10) and costs (n=2). Conclusions: There is still a long way to go to complete a standardized functional training for robotic surgery procedures in pediatric surgery. Moreover, the progressive reduction in costs expected in the years to come will play a key role in progressing the diffusion of this technology enabling the collection of data necessary to create a standardized pediatric surgery robotic training program.

The equivalence of different types of electric pulses for electrochemotherapy with cisplatin - an in vitro study.

BACKGROUND: Electrochemotherapy (ECT) is a treatment involving the administration of chemotherapeutics drugs followed by the application of 8 square monopolar pulses of 100 µs duration at a repetition frequency of 1 Hz or 5000 Hz. However, there is increasing interest in using alternative types of pulses for ECT. The use of high-frequency short bipolar pulses has been shown to mitigate pain and muscle contractions. Conversely, the use of millisecond pulses is interesting when combining ECT with gene electrotransfer for the uptake of DNA-encoding proteins that stimulate the immune response with the aim of converting ECT from a local to systemic treatment. Therefore, the aim of this study was to investigate how alternative types of pulses affect the efficiency of the ECT. MATERIALS AND METHODS: We performed in vitro experiments, exposing Chinese hamster ovary (CHO) cells to conventional ECT pulses, high-frequency bipolar pulses, and millisecond pulses in the presence of different concentrations of cisplatin. We determined cisplatin uptake by inductively coupled plasma mass spectrometry and cisplatin cytotoxicity by the clonogenic assay. RESULTS: We observed that the three tested types of pulses potentiate the uptake and cytotoxicity of cisplatin in an equivalent manner, provided that the electric field is properly adjusted for each pulse type. Furthermore, we quantified that the number of cisplatin molecules, resulting in the eradication of most cells, was 2-7 × 107 per cell. CONCLUSIONS: High-frequency bipolar pulses and millisecond pulses can potentially be used in ECT to reduce pain and muscle contraction and increase the effect of the immune response in combination with gene electrotransfer, respectively.

Characterization of Experimentally Observed Complex Interplay between Pulse Duration, Electrical Field Strength, and Cell Orientation on Electroporation Outcome Using a Time-Dependent Nonlinear Numerical Model.

Electroporation is a biophysical phenomenon involving an increase in cell membrane permeability to molecules after a high-pulsed electric field is applied to the tissue. Currently, electroporation is being developed for non-thermal ablation of cardiac tissue to treat arrhythmias. Cardiomyocytes have been shown to be more affected by electroporation when oriented with their long axis parallel to the applied electric field. However, recent studies demonstrate that the preferentially affected orientation depends on the pulse parameters. To gain better insight into the influence of cell orientation on electroporation with different pulse parameters, we developed a time-dependent nonlinear numerical model where we calculated the induced transmembrane voltage and pores creation in the membrane due to electroporation. The numerical results show that the onset of electroporation is observed at lower electric field strengths for cells oriented parallel to the electric field for pulse durations ≥10 µs, and cells oriented perpendicular for pulse durations ~100 ns. For pulses of ~1 µs duration, electroporation is not very sensitive to cell orientation. Interestingly, as the electric field strength increases beyond the onset of electroporation, perpendicular cells become more affected irrespective of pulse duration. The results obtained using the developed time-dependent nonlinear model are corroborated by in vitro experimental measurements. Our study will contribute to the process of further development and optimization of pulsed-field ablation and gene therapy in cardiac treatments.

Report of Two Cases of Pediatric IgG4-Related Lymphadenopathy (IgG4-LAD): IgG4-Related Disease (IgG4-RD) or a Distinct Clinical Pathological Entity?

IgG4-related disease (IgG4-RD) is a recently discovered immune-mediated fibroinflammatory condition, uncommon in the pediatric population, that could involve multiple organs and induce cancer-like lesions and organ damage. Its main features are multiple injuries in different sites, a dense lymphoplasmacytic infiltrate rich in IgG4 plasma cells, storiform fibrosis, and often high serological concentrations of IgG4. Autoimmune pancreatitis is the most common manifestation, mainly in adults. Two cases of IgG4-RD in children with lymph node localization of disease are reported. Localized or systemic lymph node involvement is common, but lymph node enlargement as the first and only manifestation of IgG4-RD is unusual, and therefore, hard to differentiate from other diseases. IgG4-related lymphadenopathy (IgG4-LAD) is most likely a distinct disease, described as isolated lymphadenopathy, related to the presence of elevated numbers of IgG4-positive plasma cells. Both disorders are likely to be misdiagnosed in children because they are characterized by rare and polymorphic features. IgG4-RD and IgG4-LAD should be considered in the differential diagnosis of disorders characterized by lymphadenopathy of uncertain etiology.

Models of electroporation and the associated transmembrane molecular transport should be revisited.

Electroporation has become a powerful tool for nonviral delivery of various biomolecules such as nucleic acids, proteins, and chemotherapeutic drugs to virtually any living cell by exposing the cell membrane to an intense pulsed electric field. Different multiphysics and multiscale models have been developed to describe the phenomenon of electroporation and predict molecular transport through the electroporated membrane. In this paper, we critically examine the existing mechanistic, single-cell models which allow spatially and temporally resolved numerical simulations of electroporation-induced transmembrane transport of small molecules by confronting them with different experimental measurements. Furthermore, we assess whether any of the proposed models is universal enough to describe the associated transmembrane transport in general for all the different pulse parameters and small molecules used in electroporation applications. We show that none of the tested models can be universally applied to the full range of experimental measurements. Even more importantly, we show that none of the models has been compared to sufficient amount of experimental data to confirm the model validity. Finally, we provide guidelines and recommendations on how to design and report experiments that can be used to validate an electroporation model and how to improve the development of mechanistic models.

TITF1 Screening in Human Congenital Diaphragmatic Hernia (CDH).

TITF1 (Thyroid Transcription Factor-1) is a homeodomain-containing transcription factor. Previous studies showed that Titf1 null mice are characterized by failure of tracheo-oesophageal separation and impaired lung morphogenesis resulting in Pulmonary Hypoplasia (PH). In this study, we aim to evaluate the role of TITF1 in the pathogenesis of congenital diaphragmatic hernia (CDH) in humans. We investigated TITF1 expression in human trachea and lungs and performed direct mutation analysis in a CDH population. We studied 13 human fetuses at 14 to 24 weeks of gestation. Five µm sections were fixed in paraformaldehyde and incubated with anti-TITF1 primary antibody. Positive staining was visualized by biotinylated secondary antibody. We also performed TITF1 screening on genomic DNA extracted from peripheral blood of 16 patients affected by CDH and different degrees of PH, searching for mutations, insertions, and/or deletions, by sequencing the exonic regions of the gene. Histochemical studies showed positive brown staining of fetal follicular thyroid epithelium, normal fetal trachea, and normal fetal lung bronchial epithelium. Fetal esophageal wall was immunohistochemically negative. Molecular genetic analysis showed complete identity between the sequences obtained and the Wild Type (WT) form of the gene in all cases. No mutation, insertion and/or deletion was detected. Although TITF1 is expressed in the human fetal lung and has been considered to have a role in the pathogenesis of PH in CDH, the results of our study do not support the hypothesis that TITF1 mutations play a key role in the etiopathogenesis of CDH.

Robotic Surgery in Pediatric Urology: A Critical Appraisal of the GECI and SIVI Consensus of European Experts.

Background: This study aimed to create a consensus statement on the indications, applications, and limitations of robotics in pediatric urology. Methods: After a panel and interactive discussion focused on pediatric robotics, a televoting with 10 questions was administered to 100 pediatric surgeons/urologists attending the joint meeting of the French Group of Pediatric Laparoscopy (GECI)/Italian Society of Videosurgery in Infancy (SIVI) in 2021. The results of televoting were analyzed electronically using Mentometer software. Results: Ninety-four percent of participants stated that the cutoff weight for robotics should be >10-15 kg. A minimum of 20-30 procedures should be performed to become confident in robotics (74%). Pediatric urology is the main field of application (73%) and pyeloplasty is the best indication for robotics (63%). Technical problems may happen intraoperatively in 1/10-15 cases (64%). The mean duration of robotic procedures ranges from 150 to 200 minutes (72%). The main drawbacks of robotics are high costs and limited development of miniaturized instruments (74%). Ninety-five percent believed that the costs of robotics may significantly drop with the availability of more robotic brands. The main advantages of robotics over laparoscopy include improved dexterity, easier suturing, and better ergonomics (100%), whereas the main disadvantage of sharing the robot with other specialties is the wearing out of instruments (100%). Conclusions: This is the first consensus statement, endorsed by the GECI and SIVI societies, on the use of robotics in pediatric urology. The need to introduce more robotic brands on the market to lower the costs and to develop miniaturized instruments to be adopted in infants less than 10 kg emerged. Pediatric urology is the main field of application of pediatric robotics, and robotic pyeloplasty is the most common procedure performed. Proctorship is needed for the first 20-30 procedures and technical problems may occur intraoperatively in 1/10-15 cases. The main advantages of robotics over laparoscopy are improved dexterity, easier suturing, and better surgeon ergonomics.

Spinal cord compression as tumor onset: an unusual case report of Hodgkin lymphoma in a teenager.

BACKGROUND: Spinal cord compression (SCC) is an uncommon, severe complication of Hodgkin lymphoma (HL), occurring in 0.2% of cases at the onset and in 6% during disease progression. We present a teenager with SCC with clinical onset of HL; her pre-existing neurological abnormalities covered the presence of an epidural mass, which could have misled us. CASE PRESENTATION: A 13-year-old girl presented with a three-month history of lower back pain and degrading ability to walk. She suffered from a chronic gait disorder due to her preterm birth. A magnetic resonance imaging of the spine revealed an epidural mass causing collapse of twelfth thoracic vertebra and thus compression and displacement of the spinal cord. Histological examination with immunohistochemical analysis of the epidural mass demonstrated a classic-type Hodgkin lymphoma. Early pathology-specific treatment allowed to avoid urgent surgery, achieve survival and restore of neurological function. CONCLUSIONS: Children and adolescents with back pain and neurological abnormalities should be prioritized to avoid diagnostic delay resulting in potential loss of neurological function. SCC requires a prompt radiological assessment and an expert multidisciplinary management.

Low content of clonogenic progenitors on day+18 is associated with acute graft-versus-host disease and predicts transplant-related mortality.

A marrow reaction associated with acute-graft-versus-host disease (a-GVHD) has been demonstrated in experimental models; its existence in human transplantation is controversial. The aim of the present study was to investigate whether clonogenic marrow precursors are an early marker for a-GVHD and transplant-related mortality (TRM). We prospectively studied 133 patients for colony-forming units-granulocyte-monocyte (CFU-GM) at day +18/+19 posttransplantation. CFU-GM frequency below the 25th percentile was predictive of an acute GVHD score I°-IV° when evaluated in multivariate logistic regression analysis (odds ratio = 13.551, 95% confidence interval [CI]: 1.583-116.031, p = 0.01). In the group with a clonogenic frequency below the 25th percentile, the cumulative incidence of GVHD grades II-IV was significantly more frequent with respect to the group with a frequency greater than the 25th percentile, 86% versus 54% (Gray test: p = 0.02). In multivariate Cox proportional analysis, a CFU-GM frequency below the 25th percentile at day +18 was associated with reduced overall survival (OS) (hazard ratio = 1.778, 95% CI: 1.022-3.093, p = 0.04). Patients with a frequency of CFU-GM greater than the 25th percentile had increased TRM with respect to patients with a clonogenic cell frequency greater than the 25th percentile (33.5% vs. 13.0%, p = 0.01). Patients were divided based on median content of viable CD34+ cells, and measurement of viable CD34+ cells was predictive for OS (p = 0.005) and TRM (p = 0.003). A weak correlation was observed between CFU-GM frequency in marrow at day +18 and levels of IL-2 receptor (IL-2R) in plasma (r = -0.226, p = 0.03). We conclude that marrow progenitor cell counts, on day +18 may be a useful marker for identifying patients at risk for severe a-GVHD, TRM, and inferior survival.

Guidelines of the Italian Society of Videosurgery in Infancy (SIVI) for the minimally invasive treatment of fetal and neonatal ovarian cysts.

In the last three decades, fetal ovarian cysts were diagnosed more frequently, due to technological improvement and the increasing use of prenatal screening ultrasound. Nonetheless, treatment uncertainties are still present, either prenatally or postnatally. Recently, significant innovations on diagnosis and treatment have been proposed and a more conservative, minimally invasive approach may be offered to the Pediatrician or the Surgeon who face with this condition during prenatal or neonatal age. (...).

Guidelines of the Italian Society of Videosurgery (SIVI) in Infancy for the minimally invasive treatment of Hypertrophic Pyloric Stenosis in neonates and infants.

The most appropriate treatment for the infantile Hypertrophic Pyloric Stenosis (HPS) is still debated. The non-surgical conservative treatment with oral or intravenous administration of atropine does not enjoy a widespread appreciation for several factors (...).

Management of COVID-19-Positive Pediatric Patients Undergoing Minimally Invasive Surgical Procedures: Systematic Review and Recommendations of the Board of European Society of Pediatric Endoscopic Surgeons.

Introduction: Hospital response to the COVID-19 outbreak has involved the cancellation of elective, deferrable surgeries throughout Europe in order to ensure capacity for emergent surgery and a selection of elective but non-deferrable surgeries. The purpose of this document is to propose technical strategies to assist the pediatric surgeons to minimize the potential aerosolization of viral particles in COVID-19 patients undergoing urgent or emergent surgical treatment using laparoscopic approaches, based on the currently available literature. The situation and recommendations are subject to change with emerging information. Materials and Methods: The Scientific Committee and the Board of the European Society of Pediatric Endoscopic Surgeons gathered together in order to address the issue of minimally invasive surgery during this COVID-19 pandemic. A systematic search through PubMed, Embase, and World Wide Web of the terms "COVID-19," "Coronavirus," and "SARS-CoV-2" matched with "pneumoperitoneum," "laparoscopy," "thoracoscopy," "retroperitoneoscopy," and "surgery" was performed. Non-English language papers were excluded. A PRISMA report was performed. Criticalities were identified and a consensus was achieved over a number of key aspects. Results: We identified 121 documents. A total of 11 full-text documents were assessed to address all concerns related to the adoption of minimally invasive surgery. All aspect of pediatric minimally invasive surgery, including elective surgery, urgent surgery, laparoscopy, thoracoscopy, retroperitoneoscopy, and pneumoperitoneum creation and maintainance were extensively addressed through systematic review. A consensus regarding urgent laparoscopic procedures, setting and operation techniques was obtained within the Committee and the Board. Conclusions: The ESPES proposes the following recommendations in case minimally invasive surgery is needed in a COVID-19 positive pediatric patients: (1) consider conservative treatment whenever safely possible, (2) dedicate a theater, columns and reusable laparoscopic instrumentation to COVID-19 pediatric patients, (3) prefer disposable instrumentation and cables, (4) use low CO2 insufflation pressures, (5) use low power electrocautery, (6) prefer closed-systems CO2 insufflation and desufflation systems, and (7) avoid leaks through ports. These recommendations are subject to change with emerging information and might be amended in the near future.

The additional value of the arterial phase in the CT assessment of liver vascular injuries after high-energy blunt trauma.

PURPOSE: In the literature, no consensus exists about which CT protocol is to be adopted in patients who underwent high-energy blunt trauma. The aim of the study is to evaluate the additional value of the arterial phase in the CT assessment of vascular injuries of the liver. METHODS: Admission CT examinations for patients with traumatic injury of the liver due to high-energy blunt trauma, performed between 2011 and 2017 in two major trauma centres, were retrospectively reviewed. Images were analysed for presence or absence of liver parenchymal injury, intrahepatic contained vascular injuries and active bleeding in the arterial and portal venous phase of the CT study. RESULTS: Two hundred twelve patients have been identified. Parenchymal injuries were detected as isolated in 90.6% of cases, whereas they were associated with vascular injuries in 9.4% of cases: contained vascular injuries in 3.3% and active bleeding in 6.1%. Out of all parenchymal injuries detected on the CT portal venous phase, 90.5% were also detectable in the arterial phases (p < 0.0001). All of the contained vascular injuries were visible in the CT arterial phase, whereas they were detectable in 28.5% of cases also during the venous phase (p = 0.02). All 13 cases of active bleeding were detected on the CT venous phase, and 76.9% of these cases were also revealed in the arterial phase, thus confirming their arterial origin (p = 0.22). CONCLUSION: The addiction of the arterial phase to the venous phase in the CT assessment of patients who underwent high-energy blunt trauma allows an accurate identification and characterization of traumatic vascular injuries, so distinguishing between patients suitable for conservative management and those requiring interventional or surgical treatment.

Emergence of two novel sequence types (3366 and 3367) NDM-1- and OXA-48-co-producing K. pneumoniae in Italy.

The aim of this study was to analyze the alarming spread of NDM-1- and OXA-48-co-producing Klebsiella pneumoniae clinical isolates, collected between October 2016 and January 2018 in a neonatal intensive care unit of the University Hospital, Catania, Italy, through whole genome sequencing. All confirmed carbapenem-resistant K. pneumoniae (CRKp) isolates were characterized pheno- and geno-typically, as well as by whole genome sequencing (WGS). A total of 13 CRKp isolates were identified from 13 patients. Pulsed-field gel electrophoresis (PFGE) was performed, and the multilocus sequence typing (MLST) scheme used was based on the gene sequence as published on the MLST Pasteur website. Core genome MLST (cgMLST) was also performed. All isolates co-carried blaoxa-48 and blaNDM-1 genes located on different plasmids belonging to the IncM/L and IncA/C2 groups, respectively. The 13 strains had identical PFGE profiles. MLST and cgMLST showed that K. pneumoniae was dominated by CRKp ST101 and two novel STs (ST3666 and ST3367), identified after submission to the MLST database for ST assignment. All isolates shared the same virulence factors such as type 3 fimbriae, genes for yersiniabactin biosynthesis, yersiniabactin receptor, and iron ABC transporter. They carried the wzi137 variant associated with the K17 serotype. To the best of our knowledge, this is the first report of two novel STs, 3366 and 3367, NDM-OXA-48-co-producing K. pneumoniae clinical isolates, in Italy.

The use of high-frequency short bipolar pulses in cisplatin electrochemotherapy in vitro.

Background In electrochemotherapy (ECT), chemotherapeutics are first administered, followed by short 100 µs monopolar pulses. However, these pulses cause pain and muscle contractions. It is thus necessary to administer muscle relaxants, general anesthesia and synchronize pulses with the heart rhythm of the patient, which makes the treatment more complex. It was suggested in ablation with irreversible electroporation, that bursts of short high-frequency bipolar pulses could alleviate these problems. Therefore, we designed our study to verify if it is possible to use high-frequency bipolar pulses (HF-EP pulses) in electrochemotherapy. Materials and methods We performed in vitro experiments on mouse skin melanoma (B16-F1) cells by adding 1-330 µM cisplatin and delivering either (a) eight 100 µs long monopolar pulses, 0.4-1.2 kV/cm, 1 Hz (ECT pulses) or (b) eight bursts at 1 Hz, consisting of 50 bipolar pulses. One bipolar pulse consisted of a series of 1 µs long positive and 1 µs long negative pulse (0.5-5 kV/cm) with a 1 µs delay in-between. Results With both types of pulses, the combination of electric pulses and cisplatin was more efficient in killing cells than cisplatin or electric pulses only. However, we needed to apply a higher electric field in HF-EP (3 kV/cm) than in ECT (1.2 kV/cm) to obtain comparable cytotoxicity. Conclusions It is possible to use HF-EP in electrochemotherapy; however, at the expense of applying higher electric fields than in classical ECT. The results obtained, nevertheless, offer an evidence that HF-EP could be used in electrochemotherapy with potentially alleviated muscle contractions and pain.

Gastroesophageal reflux and respiratory diseases: does a real link exist?

INTRODUCTION: Gastro-esophageal reflux disease (GERD) indicates a gastroesophageal reflux that causes symptoms such as pain, and needs medical therapy, and may result in complications such as erosive esophagitis, aspiration pneumonia. Here, we review if it exists a real link between clinical presentation of some respiratory diseases such as asthma, chronic cough, cystic fibrosis and laryngopharyngitis and GERD. EVIDENCE ACQUISITION: This review was conducted employing 2 databases: PubMed and Science Direct. EVIDENCE SYNTHESIS: Asthma may lead to reflux, and reflux could exacerbate asthma or cause asthma-like symptoms. Prevalence of GERD in children with asthma ranged from as low 32% to as high 80%. There are several studies where the use of proton pump inhibitors (PPIs) and histamine H2 receptor antagonists lead to inconclusive results. The relation of chronic unexplained cough to GERD remains controversial in children and pediatric guidelines do not currently recommend empirical GERD treatment trials for pediatric chronic cough. Gastroesophageal reflux is more frequent in patients with cystic fibrosis (CF) than general population. Although PPIs are regularly prescribed in approximately half of the patients with CF, there are no specific guidelines for treatment of reflux in CF and it was shown that chronic treatment with PPIs was correlated to possible increased risk of exacerbations. CONCLUSIONS: The pathogenesis of GER-related respiratory symptoms is multifactorial. The causal relationship between these two conditions may be difficult to prove also with the aid of supporting tests. Multichannel intraluminal impedance associated with pH-metry (pH/MII) detect all gastroesophageal reflux episodes accompanied with a bolus movement and classify GER episodes according to their content (liquid, gas and mixed), pH value and proximal extension. There are no consistent evidences confirming the validity of medical therapy in reflux with respiratory symptoms.

Guidelines of the Italian Society of Videosurgery in Infancy for the minimally invasive treatment of the esophageal atresia.

Esophageal Atresia (EA) is defined as an interruption in esophageal continuity that results in a proximal tract that ends in a blind pouch in 98% of cases, and a distal tract that in 87% of cases arises via a Fistula from the Trachea (TEF). (...).

Guidelines of the Italian Society of Videosurgery in Infancy for the minimally invasive treatment of pediatric nephrectomy and partial nephrectomy.

Throughout history, the pediatric laparoscopic nephrectomy was first described at the beginning of the Nineties by Erlich and colleagues in a child and by Koyle and colleagues in an unweaned patient. (...).

Guidelines of the Italian Society of Videosurgery in Infancy for the minimally invasive treatment of the ureteropelvic-junction obstruction.

The hydronephrosis, characterized by the dilation of the renal pelvicalyceal system with possible functional damage to the renal parenchyma, is the most common congenital abnormality of the urinary system detected in utero through the prenatal ultrasound screening. (...).