Characteristics and outcome of synchronous bilateral Wilms tumour in the SIOP WT 2001 Study: Report from the SIOP Renal Tumour Study Group (SIOP-RTSG).

BACKGROUND: Among patients with nephroblastoma, those with bilateral disease are a unique population where maximising tumour control must be balanced with preserving renal parenchyma. METHODS: The SIOP 2001 protocol recommended surgery after neoadjuvant cycle(s) of Dactinomycin and Vincristine (AV) with response-adapted intensification, if needed. Adjuvant treatment was given based on the lesion with the worst histology. RESULTS: Three hundred and twenty seven patients with stage V disease were evaluable: 174 had bilateral Wilms tumour (BWT), 101 unilateral WT and contralateral nephroblastomatosis (NB) and 52 bilateral nephroblastomatosis. In these three groups, the estimated 5y-EFS was 76.1%, 84.6%, and 74.9%, respectively. AV chemotherapy alone was the successful chemotherapy for 58.7% of all the patients and 65.6% of the non-metastatic patients. Among the 174 patients with BWT, 149 (88.2%) had at least one nephron-sparing surgery. Twenty of 61 bilateral stage I patients were treated with four-week AV postoperatively achieving 94.4% 5y-EFS. At last follow-up, 87% of patients had normal renal function. CONCLUSIONS: This study demonstrates that AV without anthracyclines is sufficient to achieve NSS and good survival in the majority of patients. For patients with bilateral stage I WT and intermediate risk histology, only four weeks adjuvant AV seems to be sufficient. CLINICAL TRIAL REGISTRATION: NCT00047138.

Diagnostic accuracy of image-guided core needle biopsy of non-central nervous system tumors in children.

BACKGROUND AND AIMS: Core needle biopsies (CNB) are less invasive, cause less morbidity, and have lower costs than open biopsies (OB). However, the number of studies reporting CNB accuracy in pediatric tumors is limited and series are small. The aim of this study is to investigate if CNB diagnosis is concordant with the final diagnosis in pediatric solid non-central nervous system (CNS) tumors. METHODS: Data from all patients treated in a single center between November 2014 and December 2019 were collected from the national pathology database and from local medical records. Data collection included age, sex, CNB diagnosis, final diagnosis, number of cores obtained, number of cores used for histology, cumulative core length, greatest dimension of the lesion, lesion volume, and complications. RESULTS: Out of 361 CNB, 95.6% (345/361) provided a diagnosis. A resection or follow-up biopsy was performed in 201 cases. The final diagnosis was concordant with the CNB in 100% (201/201) of cases. The age, number of cores used for histology, and the greatest dimension of the lesion did not significantly differ between diagnostic and nondiagnostic CNB. The cumulative core length of diagnostic CNB was significantly higher than in the nondiagnostic group (24.72 mm vs. 13.37 mm, p-value .022). Complications occurred in 2.1% (7/337) of CNB procedures. Molecular analysis was successful in 228/233 (98%) of cases in which it was performed. CONCLUSIONS: CNB diagnosis is highly concordant with the final diagnosis and the diagnostic rate is high. The complication rate in CNB is low.

Recurrence of a Mediastinal Germ-Cell Tumor as a Somatic-Type Malignancy: A Complex Case Report.

Background and case: An adolescent male presented with a second mediastinal tumor 1.5 years after treatment of a proven malignant germ-cell tumor in that location. The differential diagnosis included a recurrent germ-cell tumor or a non-germ cell malignancy. Serum tumor markers alpha-fetoprotein (AFP) and human chorionic gonadotrophin (HCG) were negative. The first biopsy was not informative, and the second biopsy gave a broad differential diagnosis including secondary non-germ cell malignancy using histology and immunohistochemistry. DNA methylation profiling, RNA sequencing, and targeted microRNA371a-3p profiling was subsequently performed, without a supportive result. After resection of the tumor the definitive diagnosis yielded two secondary non-germ cell malignancies in the form of a leiomyosarcoma and a solitary neuro endocrine carcinoma (NEC). In spite of the differences between the molecular profiles of the initial germ-cell tumor, the leiomyosarcoma and large-cell NEC are clonally related, as determined by the presence of identical chromosomal breakpoints. The copy number profiles suggest an initial polyploidization step, followed by various independent chromosomal gains and losses. This case demonstrates that germ-cell tumors must be evaluated carefully, including molecularly, in which the non-germ cell malignancy is negative for miR-371a-3p, both in tissue as well as in serum, in contrast to the primary tumor. We conclude that the patient presented with a primary type II mediastinal GCT and, a year and a half later, followed by a leiomyosarcoma and a large-cell NEC presenting as two secondary somatic-type malignancies clonally related to the original GCT. Conclusions: Malignant germ-cell tumors are known to recur as a somatic-type malignancy in very rare cases. This case report illustrates the challenges faced in defining the nature and clonality of the secondary somatic-type malignancies.

Multi-modal 3-Dimensional Visualization of Pediatric Neuroblastoma: Aiding Surgical Planning Beyond Anatomical Information.

BACKGROUND: Patient-specific 3D models of neuroblastoma and relevant anatomy are useful tools for surgical planning. However, these models do not represent the heterogenous biology of neuroblastoma. This heterogeneity is visualized with the ADC and 123I-MIGB-SPECT-CT imaging. Combining these multi-modal data into preoperative 3D heatmaps, may allow differentiation of the areas of vital and non-vital tumor tissue. We developed a workflow to create multi-modal preoperative 3D models for neuroblastoma surgery. METHODS: We included 7 patients who underwent neuroblastoma surgery between 2022 and 2023. We developed 3D models based on the contrast enhanced T1-weighted MRI scans. Subsequently, we aligned the corresponding ADC and 123I-MIBG-SPECT-CT images using rigid transformation. We estimated registration precision using the Dice score and the target registration error (TRE). 3D heatmaps were computed based on ADC and 123I-MIBG uptake. RESULTS: The registration algorithm had a median Dice score of 0.81 (0.75-0.90) for ADC and 0.77 (0.65-0.91) for 123I-MIBG-SPECT. For the ADC registration, the median TRE of renal vessels was 4.90 mm (0.86-10.18) and of the aorta 4.67 mm (1.59-12.20). For the 123I -MIBG-SPECT imaging the TRE of the renal vessels was 5.52 mm (1.71-10.97) and 5.28 mm (3.33-16.77) for the aorta. CONCLUSIONS: We successfully developed a registration workflow to create multi-modal 3D models which allows the surgeon to visualize the tumor and its biological behavior in relation to the surrounding tissue. Future research will include linking of pathological results to imaging data, to validate these multi-modal 3D models. LEVEL OF EVIDENCE: Level IV. TYPE OF STUDY: Clinical Research.

Clinical Application and Further Development of Augmented Reality Guidance for the Surgical Localization of Pediatric Chest Wall Tumors.

BACKGROUND: Surgical treatment of pediatric chest wall tumors requires accurate surgical planning and tumor localization to achieve radical resections while sparing as much healthy tissue as possible. Augmented Reality (AR) could facilitate surgical decision making by improving anatomical understanding and intraoperative tumor localization. We present our clinical experience with the use of an AR system for intraoperative tumor localization during chest wall resections. Furthermore, we present the pre-clinical results of a new registration method to improve our conventional AR system. METHODS: From January 2021, we used the HoloLens 2 for pre-incisional tumor localization during all chest wall resections inside our center. A patient-specific 3D model was projected onto the patient by use of a five-point registration method based on anatomical landmarks. Furthermore, we developed and pre-clinically tested a surface matching method to allow post-incisional AR guidance by performing registration on the exposed surface of the ribs. RESULTS: Successful registration and holographic overlay were achieved in eight patients. The projection seemed most accurate when landmarks were positioned in a non-symmetric configuration in proximity to the tumor. Disagreements between the overlay and expected tumor location were mainly due to user-dependent registration errors. The pre-clinical tests of the surface matching method proved the feasibility of registration on the exposed ribs. CONCLUSIONS: Our results prove the applicability of AR guidance for the pre- and post-incisional localization of pediatric chest wall tumors during surgery. The system has the potential to enable intraoperative 3D visualization, hereby facilitating surgical planning and management of chest wall resections. LEVEL OF EVIDENCE: IV TYPE OF STUDY: Treatment Study.

Reconstructive Strategies in Pediatric Patients after Oncological Chest Wall Resection: A Systematic Review.

An appropriate reconstruction strategy after surgical resection of chest wall tumors in children is important to optimize outcomes, but there is no consensus on the ideal approach. The aim of this study was to provide an up-to-date systematic review of the literature for different reconstruction strategies for chest wall defects in patients less than 18 years old. A systematic literature search of the complete available literature was performed and results were analyzed. A total of 22 articles were included in the analysis, which described a total of 130 chest wall reconstructions. All were retrospective analyses, including eight case reports. Reconstructive options were divided into primary closure (n = 21 [16.2%]), use of nonautologous materials (n = 83 [63.8%]), autologous tissue repair (n = 2 [1.5%]), or a combination of the latter two (n = 24 [18.5%]). Quality of evidence was poor, and the results mostly heterogeneous. Reconstruction of chest wall defects can be divided into four major categories, with each category including its own advantages and disadvantages. There is a need for higher quality evidence and guidelines, to be able to report uniformly on treatment outcomes and assess the appropriate reconstruction strategy.

Asymptomatic lipofibroadenoma in a 17-year-old male: a case report and literature review of a rare entity.

Background: The most common thymic tumours, thymomas, are derived from thymic epithelium and are generally low-grade neoplasm. Frankly malignant tumours, thymic carcinomas are rarer still. Exceedingly rare thymic tumours contain a mesenchymal tissue component such as fibrous connective tissue and/or mature fat. Lipofibroadenoma (LFA) is a very rare mixed epithelial-mesenchymal thymic tumour, included in the category of thymic epithelial tumors. LFA in addition to a mature adipocytic component, contains variable epithelial and mesenchymal tissue components. Owing to the presence of an epithelial component in LFA, this entity, in contrast to thymolipoma, is included in the World Health Organization (WHO) category of thymic epithelial neoplasm. Currently only 12 LFA cases have been described. The 12 previously reported cases all behaved in a benign fashion, although four cases were associated with a conventional type of thymoma. We here present a new, 13th, case of LFA. Case Description: The LFA was discovered incidentally in a previously healthy 17-year-old male after investigations for suspected pneumonia. On imaging a mass was discovered in the anterior mediastinum which was subsequently surgically removed. The resected tumour was extensively investigated, including the first instance of full molecular analysis of this rare entity and all available literature on LFA was sourced to provide a comprehensive overview. The histology of this LFA was similar to previously described cases. No gene mutations or rearrangements were identified. The patient made an uneventful recovery and after 13 months of follow-up remained well. Conclusions: An additional, 13th case of LFA is presented. Based on the available literature it appears that LFA may be considered a benign composite thymic tumour, although the combination of an additional conventional thymoma component may warrant closer follow-up.

CATERPILLAR-study protocol: an assessor-blinded randomised controlled trial comparing taurolidine-citrate-heparin to heparin-only lock solutions for the prevention of central line-associated bloodstream infections in paediatric oncology patients.

INTRODUCTION: The efficacy of taurolidine containing lock solutions for the prevention of central line-associated bloodstream infections (CLABSI) in paediatric oncology patients is still unknown. If the taurolidine-citrate-heparin lock appears to decrease the incidence of CLABSIs, we hope to increase the quality of life of children with cancer by subsequently reducing the central venous access device (CVAD)-removal rates, dispense of antibiotics, hospital admissions and incidence of severe sepsis resulting in intensive care unit admission. METHODS AND ANALYSIS: This assessor-blinded randomised controlled trial including 462 patients was designed to compare the taurolidine-citrate-heparin lock to the heparin-only lock for the prevention of CLABSIs in paediatric oncology patients. Patients receiving their first CVAD at the Princess Máxima Centre for Paediatric Oncology, Utrecht, the Netherlands, are eligible for inclusion. The primary outcome of this study is the incidence of first CLABSIs from CVAD insertion until the end of the study, maximum follow-up of 90 days. An intention-to-treat and a per-protocol analysis will be performed. An interim analysis will be performed after the inclusion of 50% of the patients. The results of the interim analysis and overall conduct of the trial will be discussed by a data safety monitoring board. ETHICS AND DISSEMINATION: The medical ethics committee NedMec, Utrecht, the Netherlands, has approved this research (number 20/370). Written informed consent for participation in this trial and publication of the trial data is obtained from all patients and/or their parents/guardians. The results of this trial will be published in a peer-reviewed journal and the data will be made available on reasonable request after publication of the main results manuscript. TRIAL REGISTRATION NUMBERS: NTR6688; NCT05740150.

Virtual Resection: A New Tool for Preparing for Nephron-Sparing Surgery in Wilms Tumor Patients.

Nephron-sparing surgery (NSS) in Wilms tumor (WT) patients is a surgically challenging procedure used in highly selective cases only. Virtual resections can be used for preoperative planning of NSS to estimate the remnant renal volume (RRV) and to virtually mimic radical tumor resection. In this single-center evaluation study, virtual resection for NSS planning and the user experience were evaluated. Virtual resection was performed in nine WT patient cases by two pediatric surgeons and one pediatric urologist. Pre- and postoperative MRI scans were used for 3D visualization. The virtual RRV was acquired after performing virtual resection and a questionnaire was used to assess the ease of use. The actual RRV was derived from the postoperative 3D visualization and compared with the derived virtual RRV. Virtual resection resulted in virtual RRVs that matched nearly perfectly with the actual RRVs. According to the questionnaire, virtual resection appeared to be straightforward and was not considered to be difficult. This study demonstrated the potential of virtual resection as a new planning tool to estimate the RRV after NSS in WT patients. Future research should further evaluate the clinical relevance of virtual resection by relating it to surgical outcome.

Characteristics and Outcome of Children with Wilms Tumor Requiring Intensive Care Admission in First Line Therapy.

Survival rates are excellent for children with Wilms tumor (WT), yet tumor and treatment-related complications may require pediatric intensive care unit (PICU) admission. We assessed the frequency, clinical characteristics, and outcome of children with WT requiring PICU admissions in a multicenter, retrospective study in the Netherlands. Admission reasons of unplanned PICU admissions were described in relation to treatment phase. Unplanned PICU admissions were compared to a control group of no or planned PICU admissions, with regard to patient characteristics and short and long term outcomes. In a multicenter cohort of 175 children with an underlying WT, 50 unplanned PICU admissions were registered in 33 patients. Reasons for admission were diverse and varied per treatment phase. Younger age at diagnosis, intensive chemotherapy regimens, and bilateral tumor surgery were observed in children with unplanned PICU admission versus the other WT patients. Three children required renal replacement therapy, two of which continued dialysis after PICU discharge (both with bilateral disease). Two children died during their PICU stay. During follow-up, hypertension and chronic kidney disease (18.2 vs. 4.2% and 15.2 vs. 0.7%) were more frequently observed in unplanned PICU admitted patients compared to the other patients. No significant differences in cardiac morbidity, relapse, or progression were observed. Almost 20% of children with WT required unplanned PICU admission, with young age and treatment intensity as potential risk factors. Hypertension and renal impairment were frequently observed in these patients, warranting special attention at presentation and during treatment and follow-up.

Estimated clinical benefit of combining highly conformal target volumes with Volumetric-Modulated Arc Therapy (VMAT) versus conventional flank irradiation in pediatric renal tumors.

BACKGROUND: For decades, Anterior-Posterior/Posterior-Anterior (AP/PA) photon beams were standard-of-care for flank irradiation in children with renal cancer. Recently, highly conformal flank target volumes were defined correcting for postoperative organ shift and intra-fraction motion.By radiotherapy treatment plan comparison, this study aims to estimate the clinical benefits and potential risks of combining highly conformal target volumes with Volumetric-Modulated Arc Therapy (VMAT) versus conventional target volumes with AP/PA beams for flank irradiation. MATERIALS AND METHODS: Twenty consecutive renal tumor cases (left/right-sided:10/10; median age:3.2 years) were selected. Highly conformal flank target volumes were generated for VMAT, while conventional target volumes were used for AP/PA. For each case, the dose to the organs at risk (OARs) and Total Body Volume (TBV) was calculated to compare VMAT with AP/PA treatment plans for a prescribed dose (PD) of 14.4/1.8 Gy. Dose constraint violation of the tail of the pancreas and spleen (Dmean < 10 Gy), heart (D50 < 5 Gy) or mammary buds (Dmean < 10 Gy) were prioritized as potentially beneficial for clinics. RESULTS: Highly conformal Planning Target Volumes (PTV) were smaller than conventional volumes (mean ΔPTVAP/PA-PTVVMAT: 555 mL, Δ60%, p=<0.01). A mean dose reduction favoring VMAT was observed for almost all OARs. Dose constraints to the tail of the pancreas, spleen, heart and mammary buds were fulfilled in 8/20, 12/20, 16/20 and 19/20 cases with AP/PA, versus 14/20, 17/20, 20/20 and 20/20 cases with VMAT, respectively. In 12/20 cases, VMAT prevented the dose constraint violation of one or more OARs otherwise exceeded by AP/PA. VMAT increased the TBV receiving 10% of the PD, but reduced the amount of irradiated TBV for all higher doses. CONCLUSION: Compared to 14.4 Gy flank irradiation using conventional AP/PA photon beams, an estimated clinical benefit by dose reduction to the OARs can be expected in 60% of the pediatric renal tumor cases using highly conformal flank target volumes combined with VMAT.

The contribution of surgical clips for optimizing highly-conformal image-guided flank irradiation in pediatric renal tumors: A single center experience.

BACKGROUND AND AIMS: Two-opposing photon beams are considered standard of care for flank irradiation in pediatric patients with renal tumors. Nowadays, Image-Guided Radiotherapy (IGRT) techniques allow high-precision dose delivery to complex flank target volumes taking into account postoperative organ shifts and tumor bed motion. This study examines the contribution of a lateral and superior surgical clip on flank target volume delineation intended for IGRT. METHODS: Between 01-2015 and 09-2019, 30/162 newly-diagnosed pediatric patients with renal tumors, lateral/superior surgical clips (n = 30/30) and available 4D-CT-scans (n = 27/30), underwent postoperative flank irradiation. The lateral and superior clip, as respective markers for the lateral tumor extension and intrafraction motion, were analyzed. The positive and negative values depict the lateral/dorsal/cranial or the medial/ventral/caudal direction, respectively. Planning target volumes (PTV) were generated based on lateral clips (PTVlatclip), superior clips with 4D-CT technology (PTVsupclip), and both clips combined (PTVcombined), and compared to an approach without clips (PTVnoclip). RESULTS: Indicated by clips, the mean lateral tumor bed extension along the posterior wall was 74° (range: 50°-93°), while mean intrafraction motion was +1.2 mm (range: -1.8/+4.8 mm), +0.6 mm (range: +0.6/+4.9 mm), -0.3 mm (range: -3.8/+0.7 mm) in craniocaudal, ventrodorsal, mediolateral direction, respectively. The median PTVnoclip (556 mL) was statistically different from the median PTVlatclip (454 mL, p = <0.01), median PTVsupclip (373 mL, p = <0.01) and median PTVcombined (348 mL p = <0.01). CONCLUSION: In pediatric patients with renal tumors, surgical clips at the lateral and superior border of the tumor bed can optimize flank target volume delineation and, consequently, reduce the normal tissue volume receiving high-dose irradiation when IGRT techniques are applied.

Locoregional control using highly conformal flank target volumes and volumetric-modulated arc therapy in pediatric renal tumors: Results from the Dutch national cohort.

BACKGROUND AND PURPOSE: In pediatric renal tumors, conventional two opposing photon beams have been used to cover the postoperative flank target volume for decades. This single center study describes the locoregional outcome using highly conformal flank target volumes adjusted for postoperative changes and intra-fraction motion combined with Volumetric-Modulated Arc Therapy (VMAT). MATERIALS AND METHODS: Between 01-2015 and 12-2019, 36/161 newly diagnosed patients with renal tumors underwent flank only irradiation (n = 30) or flank + whole lung irradiation (n = 6) using highly conformal target volumes in line with the SIOP-RTSG consensus statement. VMAT consisted of full-arc 10MV photon beams optimized for constraints of the organs at risk. In case of locoregional relapses, image co-registration and dose reconstruction was performed. Each relapse was classified as either 'infield' (V95%relapse: ≥99.0%), 'marginal' (V95%relapse: 20.0-98.9%) or 'outfield' (V95%relapse: 0-19.9%). RESULTS: At a median follow-up from diagnosis of 3.1 years (range:0.4-5.7), the estimated 2-year Locoregional Control Rate, Disease-Free Interval and Overall Survival were 94%, 91% and 94%, respectively. Locoregional relapse was observed in two patients. One patient had a combined tumor bed and regional recurrence, classified as infield (V95%relapse: 100%) and outfield (V95%relapse: 1.2%). The second patient had a regional relapse in the inferior vena cava classified as marginal recurrence (V95%relapse: 93%). Relapses would not have been adequately covered by conventional beams. CONCLUSIONS: This single center analysis provides encouraging evidence that excellent locoregional control can be obtained by using highly conformal flank target volumes with VMAT in pediatric renal tumors. The safety of this approach will be validated in a prospective multicenter study.

Implementation of a Quality Control System for Laparoscopic Pyloromyotomy in Hypertrophic Pyloric Stenosis: Hurdles and Pitfalls.

BACKGROUND: In 2011, we implemented a new video-based system for quality control of laparoscopic pyloromyotomy. More than 3 years later, we evaluated how the implementation had gone and assessed its usability in predicting postoperative outcomes. MATERIALS AND METHODS: Four key point images or short video-segments were to be recorded perioperatively: prepyloromyotomy, parallel-mobility testing, perforation testing, and postpyloromyotomy. Data of all 134 patients undergoing laparoscopic pyloromyotomy from September 2011 to December 2014 were analyzed retrospectively. Five pediatric surgeons independently assessed the anonymized operative images for predicting reoperation and time to full-enteral feeding. RESULTS: The percentage of operations during which images were recorded increased from 45% in 2012 to 75% in 2014. Over the study period, one or more images were recorded in 89 of the 134 (66%) patients. In only 17 of 89 patients (19%), all four images were documented. The key point images or videos were made for prepyloromyotomy in 49%, parallel-mobility testing in 85%, perforation testing in 42%, and postpyloromyotomy in 94% of 89 patients. Five patients (3.7%) were reoperated for incomplete pyloromyotomy (N = 4) or mucosal perforation (N = 1). Images were recorded during the first operation in four of the five reoperated patients. The need of reoperation was correctly predicted for two of the four patients. Full-enteral feeding within 24 hours was correctly predicted for 67% of the patients (range: 47-88%). CONCLUSION: The increase in recorded images over the years is promising. The implementation of the quality control system did not contribute to a significant decrease in the complication rate, which was already very low. Still, reoperation or a protracted postoperative course could only be predicted with moderate accuracy from the operative images, therefore, for now the use of perioperative images in a medicolegal setting should be advised against. Improved compliance with image recording and better instructions for evaluating the images might improve the usefulness of perioperative images in, e.g., telementoring, education, and medicolegal practice.

Comparison of 3-Dimensional and Augmented Reality Kidney Models With Conventional Imaging Data in the Preoperative Assessment of Children With Wilms Tumors.

Importance: Nephron-sparing surgery can be considered in well-defined cases of unilateral and bilateral Wilms tumors, but the surgical procedure can be very challenging for the pediatric surgeon to perform. Objective: To assess the added value of personalized 3-dimensional (3-D) kidney models derived from conventional imaging data to enhance preoperative surgical planning. Design, Setting, and Participants: In a survey study, the conventional imaging data of 10 Dutch children with Wilms tumors were converted to 3-D prints and augmented reality (AR) holograms and a panel of pediatric oncology surgeons (n = 7) assessed the quality of the different imaging methods during preoperative evaluation. Kidney models were created with 3-D printing and AR using a mixed reality headset for visualization. Main Outcomes and Measures: Differences in the assessment of 4 anatomical structures (tumor, arteries, veins, and urinary collecting structures) using questionnaires. A Likert scale measured differences between the imaging methods, with scores ranging from 1 (completely disagree) to 5 (completely agree). Results: Of the 10 patients, 7 were girls, and the mean (SD) age was 3.7 (1.7) years. Compared with conventional imaging, the 3-D print and the AR hologram models were evaluated by the surgeons to be superior for all anatomical structures: tumor (median scores for conventional imaging, 4.07; interquartile range [IQR], 3.62-4.15 vs 3-D print, 4.67; IQR, 4.14-4.71; P = .008 and AR hologram, 4.71; IQR, 4.26-4.75; P = .002); arteries (conventional imaging, 3.62; IQR, 3.43-3.93 vs 3-D print, 4.54; IQR, 4.32-4.71; P = .002 and AR hologram, 4.83; IQR, 4.64-4.86; P < .001), veins (conventional imaging, 3.46; IQR 3.39-3.62 vs 3-D print, 4.50; IQR, 4.39-4.68; P < .001 and AR hologram, 4.83; IQR, 4.71-4.86; P < .001), and urinary collecting structures (conventional imaging, 2.76; IQR, 2.42-3.00 vs 3-D print, 3.86; IQR, 3.64-4.39; P < .001 and AR hologram, 4.00; IQR, 3.93-4.58; P < .001). There were no differences in anatomical assessment between the two 3-D techniques (the 3-D print and AR hologram). Conclusions and Relevance: In this study, the 3-D kidney models were associated with improved anatomical understanding among the surgeons and can be helpful in future preoperative planning of nephron-sparing surgery for Wilms tumors. These models may be considered as a supplementary visualization in clinical care.

Incidence, severity and outcome of central line related complications in pediatric oncology patients; A single center study.

BACKGROUND: Central venous access device (CVAD)-related complications are associated with high morbidity rates. This study was performed to underline the importance of CVAD-complication prevention and treatment. METHODS: An audit of practice of CVAD-related complications in pediatric oncology patients receiving a CVAD between January 2015 and June 2017 was performed. CVADs included were totally implantable venous access ports (TIVAPs), Hickman-Broviac® (HB), nontunneled, and peripherally inserted CVADs. RESULTS: A total of 201 children, with 307 CVADs, were analyzed. The incidence rates per 1000 CVAD-days for the most common complications were 1.66 for malfunctions, and 1.51 for central line-associated bloodstream infections (CLABSIs). Of all CVADs inserted, 37.1% were removed owing to complications, of which 45.6% were owing to CLABSIs. In 42% of the CLABSIs, the CLABSI could be successfully cured with systemic antibiotic treatment only. Of all included patients, 5.0% were admitted to the intensive care unit owing to CLABSI. The HB-CVAD compared to the TIVAP was a risk factor for CVAD-related complications, CLABSIs and dislocations in particular. CONCLUSIONS: The incidence of CVAD-related complications is high. Research on the prevention and treatment of CVAD-related complications in pediatric oncology patients should be a high priority for all health care professionals. TYPE OF STUDY: Prognosis study (retrospective). LEVEL OF EVIDENCE: Level II.

Increased incidence of hypertrophic pyloric stenosis in esophageal atresia patients.

INTRODUCTION: Around half of patients with esophageal atresia (EA) have additional congenital anomalies. Hypertrophic pyloric stenosis (HPS) in these patients is less known, with only 36 cases reported in the past literature. This retrospective study aimed to establish the incidence and clinical presentation of EA patients in combination with HPS in our hospital. MATERIALS AND METHODS: A retrospective study was based on the medical histories from all patients with EA who underwent surgical repair in our hospital from 1988 through 2012. RESULTS: Of 267 patients with EA, 20 also developed HPS (7.5%). The latter group showed male predominance, 90 versus 60% in the EA without HPS group. The first symptoms of HPS were mostly vomiting and/or feeding intolerance (n = 19). The diagnosis was mostly delayed, with a median of 6 days (range, 1-21 days). CONCLUSIONS: This is the first report on the high incidence of HPS in a large series of EA patients. The incidence found is 30 times higher than that in the normal population. HPS should be considered when patients show recurrent or persisting vomiting and feeding intolerance after surgery. The reason for the higher incidence should be further investigated.

Morphologic changes and methodological issues in the rabbit experimental model for diaphragmatic hernia.

Fetal lung development may be impaired by some congenital anomalies or in utero events. Animal models are used to understand the pathophysiology of these diseases and explore therapeutic strategies. Our group has an interest in the prenatal management of congenital diaphragmatic hernia (CDH). Isolated CDH remains associated with a 30% mortality because of lung hypoplasia and pulmonary hypertension. On day 23 of gestation (pseudoglandular stage) CDH was created in both ovarian-end fetuses (n= 28) in 14 time-mated pregnant white rabbits (hybrid of Dendermonde and New-Zealand White). At term (day 30) all survived operated fetuses and size-matched controls were harvested. Fetuses/lungs were assigned randomly to formalin fixation either under pressure of 25 cm H2O (CDH25 n=5; CTR25 n=5) or without (0 cm H2O (CDH0 n=7; CTR0 n=7). Fetuses and lungs were first weighed, and then the lungs were processed for morphometry. Pulmonary development was evaluated by lung-to-body weight ratio (LBWR) and airway and vascular morphometry. Surgical induction of CDH does reduce the LBWR to hypoplastic levels. The contralateral lung weight is 81% of what is expected, whereas the ipsilateral lung is only 46% of the normal. This was accompagnied by a loss of conducting airway generations, precisely, terminal bronchioles (TB), which were surrounded by less alveoli. The ipsilateral CDH lung demonstrated a thickened media in the peripheral arteries as well. As a result, in the severely hypoplastic ipsilateral lung, an airway fixation pressure of 25 H2O has no significant effect on the morphometric indices. The contralateral lung has a normal amount of alveoli around a single TB, which also behave like alveoli of the normal lung, i.e. expand under pressure fixation. The present study on severely hypoplastic lungs that never respirated, shows that in contrast to normal lungs, the morphometric indices are not significantly influenced by a difference in fixation pressure. Increasing fixation pressure seems to expand the lung only when sufficient alveolated parenchyma is present.