Author Correction: Targeted therapy in patients with PIK3CA-related overgrowth syndrome.

The 'Competing interests' statement of this Article has been updated; see accompanying Amendment for further details.

Surgical Management of Wilms Tumors with Intravenous Extension: A Multicenter Analysis of Clinical Management with Technical Insights.

BACKGROUND: About 5% of Wilms tumors present with vascular extension, which sometimes extends to the right atrium. Vascular extension does not affect the prognosis, but impacts the surgical strategy, which is complex and not fully standardized. Our goal is to identify elements of successful surgical management of Wilms tumors with vascular extensions. PATIENTS AND METHODS: A retrospective study of pediatric Wilms tumors treated at three sites (January 1999-June 2019) was conducted. The inclusion criterion was the presence of a renal vein and vena cava thrombus at diagnosis. Tumor stage, pre and postoperative treatment, preoperative imaging, operative report, pathology, operative complications, and follow-up data were reviewed. RESULTS: Of the 696 pediatric patients with Wilms tumors, 69 (9.9%) met the inclusion criterion. In total, 24 patients (37.5%) had a right atrial extension and two presented with Budd-Chiari syndrome at diagnosis. Two died at diagnosis owing to pulmonary embolism. All patients received neoadjuvant chemotherapy and thrombus regressed in 35.6% of cases. Overall, 14 patients had persistent intra-atrial thrombus extension (58%) and underwent cardiopulmonary bypass. Most thrombi (72%) were removed intact with nephrectomy. Massive intraoperative bleeding occurred during three procedures. Postoperative renal insufficiency was identified as a risk factor for patient survival (p = 0.01). With a median follow-up of 9 years (range: 0.5-20 years), overall survival was 89% and event-free survival was 78%. CONCLUSIONS: Neoadjuvant chemotherapy with proper surgical strategy resulted in a survival rate comparable to that of children with Wilms tumors without intravascular extension. Clinicians should be aware that postoperative renal insufficiency is associated with worse survival outcomes.

The rationale for nephron-sparing surgery in unilateral non-syndromic Wilms tumour.

The central question of nephron-sparing surgery in unilateral non-syndromic Wilms tumour sits at a crossroads between surgery, oncology, and nephrology. There has been a significant paradigm shift in paediatric oncology towards reducing toxicity and addressing long-term treatment-related sequalae amongst childhood cancer survivors. After paediatric nephrectomy and 30-50 years of follow-up, 40% of patients will have chronic kidney disease, including 22% with hypertension and 23% with albuminuria. It is difficult to predict which patients will progress to develop hypertension, reduced glomerular filtration rate, albuminuria, and a higher cardiovascular risk. For these reasons, nephron-sparing surgery when it is technically feasible must be considered. To decrease the incidence of positive surgical margins (viable tumour present at a resection margin), incomplete lymph node sampling, and complications, these procedures should be performed at specialist and experienced reference centres. Based on the impacts of individual treatment pathways, survivors of childhood WT need to be followed through adulthood for early detection of chronic kidney disease, hypertension, and prevention of cardiovascular events.

Post-obstructive diuresis after posterior urethral valve treatment in neonates: a retrospective cohort study.

BACKGROUND: The management of posterior urethral valve (PUV) in neonates requires close monitoring in the intensive care unit because of the risk of post-obstructive diuresis (POD). Our aim was to describe the incidence and factors associated with POD in newborns treated for PUV. METHODS: Retrospective analysis of the medical records of all neonates who underwent surgical intervention for PUV in our neonatal intensive care unit between January 2014 and April 2021. RESULTS: Of the 40 patients included, 15 (37.5%) had POD defined by urine output > 6 ml.kg-1.h-1 during the first 24 h following urinary tract obstruction relief. At prenatal ultrasound examinations, oligohydramnios was more common in the group with POD than in the group without (53.3% vs. 8%, p = 0.002). Preterm birth was more frequent in neonates with POD (66.7% vs. 8%; p < 0.001). Median serum creatinine (212 [137-246] vs. 95 [77-125] µmol.l-1; p < 0.001) and urea (8.5 [5.2-12.2] vs. 4.1 [3.5-4.7] mmol.l-1; p < 0.001) concentrations on the day of obstruction relief were significantly higher in the group with POD than in the group without. After adjustment for prematurity, logistic regression models confirmed correlation between the occurrence of POD and the severity of the consequences of urethral obstruction (i.e., oligohydramnios and serum creatinine levels; ß = 2.90 [0.88; 5.36], p = 0.013 and ß = 0.014 [0.003; 0.031], p = 0.034, respectively). CONCLUSIONS: In neonates, POD is common after the relief of PUV-related obstruction. Our findings may help to identify patients at highest risk. A higher resolution version of the Graphical abstract is available as Supplementary information.

Targeted therapy in patients with PIK3CA-related overgrowth syndrome.

CLOVES syndrome (congenital lipomatous overgrowth, vascular malformations, epidermal naevi, scoliosis/skeletal and spinal syndrome) is a genetic disorder that results from somatic, mosaic gain-of-function mutations of the PIK3CA gene, and belongs to the spectrum of PIK3CA-related overgrowth syndromes (PROS). This rare condition has no specific treatment and a poor survival rate. Here, we describe a postnatal mouse model of PROS/CLOVES that partially recapitulates the human disease, and demonstrate the efficacy of BYL719, an inhibitor of PIK3CA, in preventing and improving organ dysfunction. On the basis of these results, we used BYL719 to treat nineteen patients with PROS. The drug improved the disease symptoms in all patients. Previously intractable vascular tumours became smaller, congestive heart failure was improved, hemihypertrophy was reduced, and scoliosis was attenuated. The treatment was not associated with any substantial side effects. In conclusion, this study provides the first direct evidence supporting PIK3CA inhibition as a promising therapeutic strategy in patients with PROS.

Vesico-ureteral reflux diagnosis after initial kidney abscess: Results from a Paediatric Tertiary Hospital.

AIMS: Guidelines regarding voiding cystourethrogram (VCUG) indications following a paediatric kidney abscess are lacking. This study evaluates vesicoureteral reflux (VUR) prevalence and outcome after a first kidney abscess. METHODS: This retrospective study included all children presenting to a tertiary paediatric reference centre with de-novo kidney abscesses from 2011 to 2022, diagnosed through imaging (ultrasonography or computed tomography). VCUG's clinical utility was assessed by exploring outcomes related to interventions. RESULTS: Among the 17 patients (median age 9 months, IQR; 6 months-6 years), VCUG identified VUR in 7 (41%; 95% CI: 18-65%), including two with grade IV-V. Median abscess size was 19 mm (IQR; 14-27). 7/8 (88%) children with DMSA scan presented scars, including 4 with hypofunctioning (20%-44%), and one with a non-functioning kidney. Scarring on the DMSA scan was similar regardless of identified VUR. Six children had subsequent pyelonephritis. Three of the remaining 11 had grade I-III and two IV-V VUR. Surgery was required in four children overall: three for recurrent pyelonephritis and one for high-grade VUR and scars. CONCLUSION: Among initial kidney abscess cases, 41% had VUR, similar to children experiencing their first uncomplicated pyelonephritis. VCUG results guided antibiotic prophylaxis but not surgical decisions. We suggest considering VCUG following recurrent pyelonephritis/kidney abscess and/or kidney scarring.

Adverse Events and Morbidity in a Multidisciplinary Pediatric Robotic Surgery Program. A prospective, Observational Study.

OBJECTIVE: To report one-year morbidity of robotic-assisted laparoscopic surgery (RALS) in a dedicated, multidisciplinary, pediatric robotic surgery program. Summary Background Data. RALS in pediatric surgery is expanding, but data on morbidity in children is limited. METHODS: All children who underwent RALS (Da Vinci Xi, Intuitive Surgical, USA) were prospectively included (October 2016 to May 2020; follow-up ≥1 year). Analyzed data: patient characteristics, surgical indication/procedure, intraoperative adverse events (ClassIntra classification), blood transfusion, hospital stay, postoperative complications (Clavien-Dindo). RESULTS: Three hundred consecutive surgeries were included: urology/gynecology (n=105), digestive surgery (n=83), oncology (n=66), ENT surgery (n=28), thoracic surgery (n=18). Median age and weight at surgery were 9.5 [interquartile range (IQR)=8.8] years and 31 [IQR=29.3] kg, respectively. Over one year, 65 (22%) children presented with ≥1 complication, with Clavien-Dindo ≥III in 14/300 (5%) children at ≤30 days, 7/300 (2%) at 30-90 days, and 12/300 (4%) at >90 days. Perioperative transfusion was necessary in 15 (5%) children, mostly oncological (n=8). Eight (3%) robotic malfunctions were noted, one leading to conversion (laparotomy). Overall conversion rate was 4%. ASA ≥3, weight ≤15 kg, and surgical oncology did not significantly increase the conversion rate, complications, or intraoperative adverse events (ClassIntra ≥2). ASA score was significantly higher in children with complications (Clavien-Dindo ≥III) than without (p=0.01). Median hospital stay was 2 [IQR=3] days. Three children died after a median follow-up of 20 [IQR=16] months. CONCLUSIONS: RALS is safe, even in the most vulnerable children with a wide scope of indications, age, and weight. Robot-specific complications or malfunctions are scarce.

Genuage: visualize and analyze multidimensional single-molecule point cloud data in virtual reality.

Experimentally recorded point cloud data, such as those generated by single-molecule localization microscopy, are continuously increasing in size and dimension. Gaining an intuitive understanding and facilitating the analysis of such multidimensional data remains challenging. Here we report a new open-source software platform, Genuage, that enables the easy perception of, interaction with and analysis of multidimensional point clouds in virtual reality. Genuage is compatible with arbitrary multidimensional data extending beyond single-molecule localization microscopy.

Dextranomer Endoscopic Injections for the Treatment of Urinary Incontinence in Bladder Exstrophy-epispadias Complex.

PURPOSE: Since bladder neck dextranomer/hyaluronic acid copolymer (Deflux) injections can improve urinary incontinence of various etiologies, we hypothesized that incontinent children with bladder exstrophy-epispadias complex would benefit from dextranomer/hyaluronic acid copolymer. We aimed to analyze dextranomer/hyaluronic acid copolymer efficacy and predictors of treatment success in bladder exstrophy-epispadias complex. MATERIALS AND METHODS: Incontinent bladder exstrophy-epispadias complex children aged >4 years undergoing dextranomer/hyaluronic acid copolymer injections in our hospital between October 1997 and January 2021 were included. Medical history, continence, and bladder capacity before injections were recorded. Postoperatively, patients were categorized as "dry," "significantly improved," or "failure." Postoperative complications, bladder emptying mode, and bladder capacity were reported. Failure-free survival was estimated by Kaplan-Meier models. RESULTS: Altogether, 58 patients (27 male epispadias, 9 female epispadias, 22 bladder exstrophy) underwent 105 injections at median age of 8.5 (interquartile range 5.8-12) years. Previous bladder neck reconstruction had been performed in 38 (66%) and 33 (57%) received multiple injections. Complications occurred in 9%. Five-year failure-free survival was 70% (standard error 9.1) in males epispadias compared to 45% (9.0) in females and exstrophy patients (P = .04). Previous bladder neck reconstruction associated with improved 5-year failure-free survival in females and exstrophy patients (58%, SE 11) but not in male epispadias (75%, SE 11). CONCLUSIONS: Dextranomer/hyaluronic acid copolymer injections provided satisfactory and lasting continence in over half of bladder exstrophy-epispadias complex patients. While injections were successful in male epispadias regardless of bladder neck reconstruction timing, results were better in bladder exstrophy and female epispadias after previous bladder neck reconstruction.

Pediatric Tumors and Developmental Anomalies: A French Nationwide Cohort Study.

OBJECTIVE: To assess the associations between congenital abnormalities and pediatric malignancies and evaluate the potential underlying molecular basis by collecting information on pediatric patients with cancer and congenital abnormalities. STUDY DESIGN: Tumeur Et Développement is a national, prospective, and retrospective multicenter study recording data of children with cancer and congenital abnormalities. When feasible, blood and tumoral samples are collected for virtual biobanking. RESULTS: From June 2013 to December 2019, 679 associations between pediatric cancers and congenital abnormalities were recorded. The most represented cancers were central nervous system tumors (n = 139; 20%), leukemia and myelodysplastic syndromes (n = 123; 18.1%), and renal tumors (n = 101; 15%). Congenital abnormalities were not related to any known genetic disorder in 66.5% of cases. In this group, the most common anomaly was intellectual disability (22.3%), followed by musculoskeletal (14.2%) and genitourinary anomalies (12.4%). Intellectual disability was mostly associated with hematologic malignancies. Embryonic tumors (neuroblastoma, Wilms tumor, and rhabdomyosarcoma) were associated with consistent abnormalities, sometimes with a close anatomical neighborhood between the abnormality and the neoplasm. CONCLUSIONS: In the first Tumeur Et Développement analysis, 3 major themes have been identified: (1) germline mutations with or without known cancer predisposition, (2) postzygotic events responsible for genomic mosaicism, (3) coincidental associations. New pathways involved in cancer development need to be investigated to improve our understanding of childhood cancers.

Robotic Surgery in Pediatric Oncology: Lessons Learned from the First 100 Tumors-A Nationwide Experience.

BACKGROUND: While robotics has become commonplace in adult oncology, it remains rare in pediatric oncology due to the rarity of childhood cancers. We present the results of a large nationwide experience with robotic oncology, with the aim of providing practical and feasible guidelines for child selection. METHODS: This was a prospective analysis performed over a period of 4 years. Treatment was delivered according to the Société Internationale d'Oncologie Pédiatrique/International Society of Paediatric Oncology Europe Neuroblastoma Group (SIOP/SIOPEN) protocols. Indications were approved by a certified tumor board. RESULTS: Overall, 100 tumors were resected during 93 procedures (abdomen, 67%; thorax, 17%; pelvis, 10%; retroperitoneum, 6%) in 89 children (56 girls). The median age at surgery was 8.2 years (range 3.6-13); 19 children (21%) harbored germinal genetic alterations predisposing to cancer. No intraoperative tumor ruptures occurred. Seven conversions (8%) to an open approach were performed. Neuroblastic tumors (n = 31) comprised the main group (18 neuroblastomas, 4 ganglioneuroblastomas, 9 ganglioneuromas) and renal tumors comprised the second largest group (n = 24, including 20 Wilms' tumors). The remaining 45 tumors included neuroendocrine (n = 12), adrenal (n = 9), germ-cell (n = 7), pancreatic (n = 4), thymic (n = 4), inflammatory myofibroblastic (n = 4), and different rare tumors (n = 5). Overall, 51 tumors were malignant, 2 were borderline, and 47 were benign. The median hospital stay was 3 days (2-4), and five postoperative complications occurred within the first 30 days. During a median follow-up of 2.4 years, one child (Wilms' tumor) presented with pleural recurrence. One girl with Wilms' tumor died of central nervous system metastasis. CONCLUSIONS: Robotic surgery for pediatric tumors is a safe option in highly selected cases. Indications should be discussed by tumor boards to avoid widespread and uncontrolled application.

Three-dimensional architecture of nephrons in the normal and cystic kidney.

Kidney function is crucially dependent on the complex three-dimensional structure of nephrons. Any distortion of their shape may lead to kidney dysfunction. Traditional histological methods present major limitations for three-dimensional tissue reconstruction. Here, we combined tissue clearing, multi-photon microscopy and digital tracing for the reconstruction of single nephrons under physiological and pathological conditions. Sets of nephrons differing in location, shape and size according to their function were identified. Interestingly, nephrons tend to lie in planes. When this technique was applied to a model of cystic kidney disease, cysts were found to develop only in specific nephron segments. Along the same segment, cysts are contiguous within normal non-dilated tubules. Moreover, the shapes of cysts varied according to the nephron segment. Thus, our findings provide a valuable strategy for visualizing the complex structure of kidneys at the single nephron level and, more importantly, provide a basis for understanding pathological processes such as cystogenesis.

Arterial abnormalities identified in kidneys transplanted into children during the COVID-19 pandemic.

Graft artery stenosis can have a significant short- and long-term negative impact on renal graft function. From the beginning of the COVID-19 pandemic, we noticed an unusual number of graft arterial anomalies following kidney transplant (KTx) in children. Nine children received a KTx at our center between February and July 2020, eight boys and one girl, of median age of 10 years. Seven presented Doppler features suggesting arterial stenosis, with an unusual extensive pattern. For comparison, over the previous 5-year period, persistent spectral Doppler arterial anomalies (focal anastomotic stenoses) following KTx were seen in 5% of children at our center. We retrospectively evidenced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in five of seven children with arterial stenosis. The remaining two patients had received a graft from a deceased adolescent donor with a positive serology at D0. These data led us to suspect immune postviral graft vasculitis, triggered by SARS-CoV-2. Because the diagnosis of COVID-19 is challenging in children, we recommend pretransplant monitoring of graft recipients and their parents by monthly RT-PCR and serology. We suggest balancing the risk of postviral graft vasculitis against the risk of prolonged dialysis when considering transplantation in a child during the pandemic.

Double-face preputial island flap revisited: is it a reliable one-stage repair for severe hypospadias?

PURPOSE: We have studied outcome of double-face preputial island flap (DFPIF) technique in severe types of hypospadias: penoscrotal, scrotal and perineal. METHODS: We have used DFPIF in 75 boys at a median age of 1.1 years (1.0-1.5). The meatus was penoscrotal, scrotal or perineal after de-gloving the penis. The inner face of the foreskin was used for urethroplasty and the outer face for ventral skin covering. Modifications were added: proximal anastomosis was protected by a spongioplasty; in case of urethral plate transection, we anastomosed on onlay proximal and distal segments of the flap (onlay-tube-onlay) and the tubularized part was sutured to corpus cavernosa. FU was scheduled at one month then every 3 months for a year then annually. At each consultation, the surgeon filled out a detailed cosmetic and functional sheet including flowmeter. RESULTS: Thirty-four patients had onlay preputial flap repair with urethral plate preservation. Forty-one had the onlay-tube-onlay technique. All children had a curvature, 19 had a significant residual curvature after dissection, corrected by dorsal plication (n = 9) and ventral lengthening (n = 10). Median FU was 4.2 years (2.7-6.5). 36 children (48%) had complications and needed redo surgery: 12 fistulas, 11 diverticula, 7 meatal stenosis, 3 strictures and 2 residual curvatures. All children but three voided within the normal limits for their age. CONCLUSION: DFPIF remains a good option for a one-stage repair of severe hypospadias. After a median of 1.8 procedures, the final success rate was 96%. The healthy well-vascularized ventral skin allows safe redo surgery when needed.

Robot-assisted laparoscopic pyeloplasty (RALP) in children with complex pelvi-ureteric junction obstruction (PUJO): results of a multicenter European report.

PURPOSE: This study aimed to report a multi-institutional retrospective case series of outcomes after robot-assisted laparoscopic pyeloplasty (RALP) in pediatric patients with complex pelvi-ureteric junction obstruction (PUJO). METHODS: All patients undergoing complex RALP over the last 5 years were included. RALP was defined complex in the following cases of PUJO: anatomic variations including ectopic, malrotated, horseshoe, or duplex kidney and recurrent PUJO after failed open pyeloplasty. RESULTS: Forty-eight patients underwent complex RALP in four European centers in the study period and included 18 girls and 30 boys with a median age of 8 years (range 5-12). The PUJO was associated with anatomic variations in 35/48 (72.9%), whereas a recurrent PUJO was present in 13/48 (27.1%). A dismembered Anderson-Hynes pyeloplasty was performed in all patients. The median operative time including docking was 178.5 min (range 117-255) and the median anastomotic time was 64.8 min (range 50-76). All patients were discharged on 2nd postoperative day (POD). The median follow-up was 18.2 months (range 14-43). The overall success rate was 95.8% (46/48). Early postoperative complications (< 30th POD) included urinary tract infections (UTIs) and stent-related irritative symptoms in 4/48 (8.3%) [II Clavien], whereas late complications (> 30th POD) included recurrence of PUJO in 2/48 (4.2%), who needed re-operation [IIIb Clavien]. CONCLUSIONS: RALP was safe, feasible, and with good mid-term outcome in complex PUJO. An accurate pre-operative planning, a standardized technique, and an experienced surgical robotic team represented key points to manage successfully such complex cases.

Feasibility and safety of magnetic-end double-J ureteral stent insertion and removal in children.

PURPOSE: The need for surgical removal of a double-J ureteral stent (DJUS) is considered one of its disadvantages. Apart from increased cost, repeated exposure to general anesthesia is a concern in children. Alternative techniques have been described, all failing to become integrated into mainstream practice. Stents with a distal magnetic end, although introduced in the early 1980s, have only recently gained acceptance. We report the feasibility and safety of insertion and removal of a magnetic-end double-J ureteral stent (MEDJUS) in a pediatric population. MATERIALS AND METHODS: We retrospectively analyzed the use of the Magnetic Black-Star Urotech® MEDJUS between 11/2016 and 12/2019 in children. Stents were removed in the outpatient clinic using a transurethral catheter with a magnetic tip. RESULTS: MEDJUS insertion was attempted in 100 patients (65 boys). Mean age was 7.8 years (0.5-18). The stent was placed in an antegrade procedure (n = 47), by a retrograde route (n = 10), and during open surgery (n = 43). Stent insertion was successful in 84 cases (84%). All 16 failures occurred during the antegrade approach in laparoscopic pyeloplasty, with inability to push the stent and its magnet through the ureterovesical junction in 14. Magnetic removal was attempted in 83 patients, successful in 81 (98%). There was no added morbidity with the MEDJUS. CONCLUSIONS: The use of MEDJUS is a safe and effective strategy that obviates the need for additional general anesthesia in children. Its insertion is similar to that with regular DJUS, and its easy and less time-consuming removal benefits both the patient and the hospital and validates its clinical use.

The spectrum of kidney function alterations in adolescents with a solitary functioning kidney.

BACKGROUND: A precise assessment of glomerular filtration rate is key to delineate the care of children with a solitary functioning kidney (SFK). Data regarding measured GFR (mGFR) in this population is restricted to a single study of 77 individuals, which suggested that a GFR estimation (eGFR) method based on creatinine and cystatin C (eGFR-CKiD2) performed better than Schwartz's equation (eGFR-Schwartz). METHODS: We measured GFR in 210 consecutive adolescents (7 to 22 years old) with an SFK referred to our institution between 2014 and 2019 and in 43 young candidates for kidney donation (18 to 25 years old). We compared the distribution of mGFR in both groups and determined the factors associated with reduced mGFR in adolescents with an SFK. We further compared different eGFR formulas with mGFR and assessed the association of mGFR and eGFRs with PTH and FGF23, two early indicators of GFR reduction. RESULTS: While adolescents with an SFK had a similar median mGFR to healthy controls (103 ± 24ml/min/1.73m2 vs. 107 ± 12 ml/min/1.73m2), the fraction of individuals with an mGFR below 90 ml/min/1.73m2 was higher in patients with SFK (23% vs. 5% in controls; P = 0.005). Multiple linear regression identified older age, ipsilateral abnormalities of the urinary tract, lack of compensatory hypertrophy, and treated hypertension as independent factors associated with reduced mGFR. A smaller bias using eGFR-Schwartz (95% confidence interval (95%CI): 3 to 7) was revealed when compared to other eGFR. Compared to eGFR-Schwartz, mGFR showed a stronger correlation with PTH (r = 0.04 vs. r = 0.1) and FGF23 (r = 0.03 vs. r = 0.05). CONCLUSION: SFK is not a benign condition, since 20% of the patients display altered kidney function. Our results raise caution regarding the use of the cystatin-based equation. mGFR shows a better ability than eGFR-Schwartz to differentiate patients showing early homeostatic adaptation to GFR reduction.

Long-term kidney and liver outcome in 50 children with autosomal recessive polycystic kidney disease.

BACKGROUND: Autosomal recessive polycystic kidney disease (ARPKD) is a rare ciliopathy characterized by congenital hepatic fibrosis and cystic kidney disease. Lack of data about long-term follow-up makes it difficult to discuss timing and type of organ transplantation. Our objectives were to evaluate long-term evolution and indications for transplantation, from birth to adulthood. METHODS: Neonatal survivors and patients diagnosed in postnatal period with ARPKD between 1985 January and 2017 December from 3 French pediatric centers were retrospectively enrolled in the study. RESULTS: Fifty patients with mean follow-up 12.5 ± 1 years were enrolled. ARPKD was diagnosed before birth in 24%, and at mean age 1.8 years in others. Thirty-three patients were < 1 year of age at first symptoms, which were mostly kidney-related. These most often presented high blood pressure during follow-up. Portal hypertension was diagnosed in 29 patients (58%), 4 of them with bleeding from esophageal varices. Eight patients presented cholangitis (> 3 episodes in three children). Liver function was normal in all patients. Nine children received a kidney transplant without liver complications. A 20-year-old patient received a combined liver-kidney transplant (CLKT) for recurrent cholangitis, and a 15-year-old boy an isolated liver transplant for uncontrollable variceal bleeding despite portosystemic shunt. CONCLUSIONS: Long-term outcome in patients with ARPKD is heterogeneous, and in this cohort did not depend on age at diagnosis except for blood pressure. Few patients required liver transplantation. Indications for liver or combined liver-kidney transplantation were limited to recurrent cholangitis or uncontrollable portal hypertension. Liver complications after kidney transplantation were not significant.

Laparoscopic retroperitoneal approach for retrocaval ureter in children.

PURPOSE: Retrocaval ureter (RCU) is a rare congenital anomaly and published data on pediatric laparoscopic management are poor. The aim of this study was to report our experience of retroperitoneal laparoscopic approach for management of RCU in children. METHODS: A retrospective review of data from patients treated for RCU between 2002 and 2018 in our institution was performed. All patients were positioned in a flank position and underwent a three-port (5-mm optical trocar and two 3-mm trocars) laparoscopic retroperitoneal ureteroureterostomy. Anastomosis was made by 6/0 absorbable sutures. A JJ stent was always inserted. RESULTS: Five patients with a median age of 94 months (5-152) were operated on and followed up for a median time of 103 months (46-201). Median operating time was 200 min (160-270). No conversion and no transfusion occurred. Median hospital stay was 2 days (1-4). Ureteral stent was removed after 52 days (47-82). Complications included pyelonephretis (N = 1). In all cases, hydronephrosis decreased postoperatively. CONCLUSIONS: Retroperitoneal laparoscopic approach for RCU is safe and effective in children. Our video demonstrates different patients with specific surgical details to show how to manage these children. The global vision of the upper tract by laparoscopy leads to optimal management of these children even if the anomaly was not detected preoperatively.

Minimally invasive surgery for unilateral Wilms tumors: Multicenter retrospective analysis of 50 transperitoneal laparoscopic total nephrectomies.

PURPOSE: To evaluate feasibility and outcomes of minimally invasive surgery (MIS) in Wilms tumor (WT). METHODS: International multicenter review of MIS total nephrectomies for WT between 2006 and 2018. Medical records of confirmed WT were retrospectively assessed for demographic, imaging, treatment, pathology, and oncological outcome data. RESULTS: Fifty patients, with a median age of 38 months (6-181), were included in 10 centers. All patients received neoadjuvant chemotherapy, as per SIOP protocol. Median tumor volume post-chemotherapy was 673 mL (18-3331), 16 tumors crossed the lateral border of the spine, and three crossed the midline. Six patients with tumors that crossed the lateral border of the spine (tumor volumes 1560 mL [299-2480]) were converted to an open approach. There was no intraoperative tumor rupture. Overall, MIS was completed in 19% of the 195 nephrectomies for WT presenting during the study period. Tumor was stage I in 29, II in 16, and III in 5, and histology was reported as low in three, intermediate in 42, and high risk in five. Three patients had positive tumor margins. After a median follow-up of 34 months (2-138), there were two local recurrences (both stage I, intermediate risk, 7 and 9 months after surgery) and one metastatic relapse (stage III, high risk, four months after surgery). The three-year event-free survival was 94%. CONCLUSION: MIS is feasible in 20% of WT, with oncological outcomes comparable with open surgery, no intraoperative rupture, and a low rate of local relapse. Ongoing surveillance is, however, needed to evaluate this technique as it becomes widespread.