Microcystic lymphatic malformations in Turner syndrome are due to somatic mosaicism of PIK3CA.

Turner syndrome (45,X) is caused by a complete or partial absence of a single X chromosome. Vascular malformations occur due to abnormal development of blood and/or lymphatic vessels. They arise from either somatic or germline pathogenic variants in the genes regulating growth and apoptosis of vascular channels. Aortic abnormalities are a common, known vascular anomaly of Turner syndrome. However, previous studies have described other vascular malformations as a rare feature of Turner syndrome and suggested that vascular abnormalities in individuals with Turner syndrome may be more generalized. In this study, we describe two individuals with co-occurrence of Turner syndrome and vascular malformations with a lymphatic component. In these individuals, genetic testing of the lesional tissue revealed a somatic pathogenic variant in PIK3CA-a known and common cause of lymphatic malformations. Based on this finding, we conclude that the vascular malformations presented here and likely those previously in the literature are not a rare part of the clinical spectrum of Turner syndrome, but rather a separate clinical entity that may or may not co-occur in individuals with Turner syndrome.

Selective Lymphatic Duct Embolization for Treatment of Thoracic Lymphatic Flow Disorders in Children: Technical Aspects and Comparison with Thoracic Duct Embolization.

PURPOSE: To assess effectiveness of selective lymphatic duct embolization (SLDE) for treatment of thoracic lymphatic flow disorders, performed to maintain patency of the thoracic duct (TD), compared to thoracic duct embolization (TDE). MATERIALS AND METHODS: Records of 39 patients (mean age 7.6±7.1 years) with thoracic lymphatic flow disorders who underwent 43 SLDE procedures were analyzed and compared to a cohort of 104 patients (7.8±7.6 y) who underwent TDE. Relevant clinical and imaging data were collated. All patients presented with chylous effusion and/or plastic bronchitis. For the SLDE cohort, etiology of disorders included single-ventricle heart disease palliation in 28 patients (72%) and vascular malformation/aneuploidy in 8 (21%). For the TDE cohort, 92/104(88%) had single-ventricle heart disease palliation. RESULTS: SLDE was performed with glue via microcatheter in 35 procedures, and dextrose flood technique was used in 26. SLDE via direct needle access was performed in 11. After SLDE, presenting symptoms resolved in 33/39 patients (85%), improved in 5 (13%), and were unchanged in 1 (3%) (mean follow-up 693±523 days). The TD remained patent in all cases. There was a significant difference in outcomes (P=0.001) with the TDE cohort-symptoms resolved or improved in 75/104 patients (72%), were unchanged in 15 (14%); and new leak (e.g., ascites, protein-losing enteropathy) developed in 14 TDE patients (13%) (follow-up 1041±879 d). CONCLUSION: SLDE was effective for treatment of thoracic lymphatic flow disorders, and outcomes were comparable to TDE. Selective techniques preserve the patency of the TD and may have potential benefits that warrant further study.

Percutaneous biopsy for the diagnosis, risk stratification, and molecular profiling of neuroblastoma: A single-center retrospective study.

PURPOSE: To determine whether percutaneous core needle biopsy (PCNB) is adequate for the diagnosis and full molecular characterization of newly diagnosed neuroblastoma. MATERIALS AND METHODS: Patients with newly diagnosed neuroblastoma who underwent PCNB in interventional radiology at a single center over a 5-year period were included. Pre-procedure imaging and procedure details were reviewed. Rates of diagnostic success and sufficiency for International Neuroblastoma Pathology Classification (INPC), risk stratification, and evaluation of genomic markers utilized in the Children's Oncology Group risk stratification, and status of the anaplastic lymphoma kinase (ALK) gene were assessed. RESULTS: Thirty-five patients (13 females, median age 2.4 years [interquartile range, IQR: 0.9-4.4] and median weight 12.4 kg [IQR: 9.6-18]) were included. Most had International Neuroblastoma Risk Group Stage M disease (n = 22, 63%). Median longest axis of tumor target was 8.8 cm [IQR: 6.1-12]. A 16-gauge biopsy instrument was most often used (n = 20, 57%), with a median of 20 cores [IQR: 13-23] obtained. Twenty-five specimens were assessed for adequacy, and 14 procedures utilized contrast-enhanced ultrasound guidance. There were two post-procedure bleeds (5.7%). Thirty-four of 35 procedures (97%) were sufficient for histopathologic diagnosis and risk stratification, 94% (n = 32) were sufficient for INPC, and 85% (n = 29) were sufficient for complete molecular characterization, including ALK testing. Biologic information was otherwise obtained from bone marrow (4/34, 12%) or surgery (1/34, 2.9%). The number of cores did not differ between patients with sufficient versus insufficient biopsies. CONCLUSION: In this study, obtaining multiple cores with PCNB resulted in a high rate of diagnosis and successful molecular profiling for neuroblastoma.

Safety and Efficacy of Ethanol for Catheter Salvage and Central Line-Associated Bloodstream Infection Prophylaxis in Polyurethane Catheters in the PICU.

OBJECTIVES: Ethanol lock therapy (ELT) is a potential method of central catheter salvage following central line-associated bloodstream infection (CLABSI) although there is potential risk of catheter damage in polyurethane catheters. Further, there is limited efficacy data across the spectrum of common pediatric catheters, and published ELT protocols describe dwell times that are not feasible for critically ill children. We sought to evaluate the safety and efficacy of ELT in polyurethane catheters using brief (30 min to 2 hr) dwell times in our PICU. DESIGN: Investigational pilot study using historical control data. SETTING: PICU in quaternary care, free-standing children's hospital. INTERVENTIONS: ELT in polyurethane central venous catheters for catheter salvage. RESULTS: ELT with brief dwell times was used in 25 patients, 22 of whom were bacteremic. Ultimately 11 patients, comprising 14 catheters, were diagnosed with a primary CLABSI. The catheter salvage rate in primary CLABSI patients receiving ELT was 92% (13/14) and significantly higher than the salvage rate in patients receiving antibiotics alone (non-ELT) (62%, 39/64; mean difference 0.32, 95% CI [0.14-0.50], p = 0.03). The rate of catheter fracture in all patients receiving ELT was 8% (2/25) while the rate of fracture in the non-ELT group was 13% (8/64; mean difference -0.05, 95% CI [-0.18 to 0.09], p = 0.72). The rate of tissue plasminogen activator (tPA) use in the ELT group was 8% (2/25), whereas the rate of tPA use in the non-ELT group was significantly higher at 42% (26/64; mean difference -0.34, 95% CI [-0.49 to -0.17], p = 0.002). CONCLUSIONS: The use of ELT for catheter salvage and prophylaxis in the PICU is safe in a variety of polyurethane catheters. Dwell times ranging from 30 minutes to 2 hours were effective in sterilizing the catheters while allowing other therapies to continue. This approach may decrease the need for frequent line changes in a medically fragile pediatric population.

Embolization for pediatric trauma.

BACKGROUND: The management of pediatric trauma with trans-arterial embolization is uncommon, even in level 1 trauma centers; hence, there is a dearth of literature on this subject compared to the adult experience. OBJECTIVE: To describe a single-center, level 1 trauma center experience with arterial embolization for pediatric trauma. MATERIALS AND METHODS: A retrospective review was performed to identify demographics, transfusion requirements, pre-procedure imaging, procedural details, adverse events, and arterial embolization outcomes over a 19-year period. Twenty children (age 4.5 months to 17 years, median 13.5 years; weight 3.6 to 108 kg, median 53 kg) were included. Technical success was defined as angiographic resolution of the bleeding-related abnormality on post-embolization angiography or successful empiric embolization in the absence of an angiographic finding. Clinical success was defined as not requiring additional intervention after embolization. RESULTS: Seventy-five percent (n=15/20) of patients required red blood cell transfusions prior to embolization with a mean volume replacement 64 ml/kg (range 12-166 ml/kg) and the median time from injury to intervention was 3 days (range 0-16 days). Technical success was achieved in 100% (20/20) of children while clinical success was achieved in 80% (n=16/20). For the 4 children (20%) with continued bleeding following initial embolization, 2 underwent repeat embolization, 1 underwent surgery, and 1 underwent repeat embolization and surgery. Mortality prior to discharge was 15% (n=3). A post-embolization mild adverse event included one groin hematoma, while a severe adverse event included one common iliac artery pseudoaneurysm requiring open surgical ligation. CONCLUSIONS: In this single-center experience, arterial embolization for hemorrhage control in children after trauma is feasible but can be challenging and the clinical failure rate of 20% in this series reflects this complexity. Standardization of pre-embolization trauma assessment parameters and embolic techniques may improve outcomes.

Mosaic pathogenic variants in AKT3 cause capillary malformation and undergrowth.

Capillary malformations are slow-flow vascular malformations that affect the microcirculation including capillaries and post capillary venules and can be associated with growth differences. Specifically, the association of capillary malformations with undergrowth is a vastly understudied vascular syndrome with few reports of genetic causes including PIK3CA, GNAQ, and GNA11. Recently, a somatic pathogenic variant in AKT3 was identified in one child with a cutaneous vascular syndrome similar to cutis marmorata telangiectatica congenita, undergrowth, and no neurodevelopmental features. Here, we present a male patient with a capillary malformation and undergrowth due to a somatic pathogenic variant in AKT3 to confirm this association. It is essential to consider that mosaic pathogenic variants in AKT3 can cause a wide spectrum of disease. There is a need for future studies focusing on capillary malformations with undergrowth to understand the underlying mechanism.

Characterization and treatment of thoracic duct obstruction in patients with lymphatic flow disorders.

PURPOSE: The contribution of thoracic duct obstruction to lymphatic flow disorders has not been well-characterized. We describe imaging findings, interventions, and outcomes in patients with suspected duct obstruction by imaging or a lympho-venous pressure gradient (LVPG). MATERIALS AND METHODS: Clinical, imaging, and interventional data, including the LVPG, of patients with flow disorders and imaging features of duct obstruction who underwent lymphatic intervention were retrospectively reviewed, collated, and analyzed with descriptive statistics. RESULTS: Eleven patients were found to have obstruction, median age 10.4 years (interquartile range: 8-14.9 years). Pleural effusions were seen in 8/11 (72%), ascites in 8/11 (72%), both in 5/11 (45%), and protein-losing enteropathy in 5 (45%). Eight patients (72%) had congenital heart disease. The most common site of obstruction was at the duct outlet in 7/11 patients (64%). Obstruction was secondary to extrinsic compression or ligation 4 patients (36%). Nine patients (82%) underwent interventions, with balloon dilation in 7/9 (78%), massive lymphatic malformation drainage and sclerotherapy in 1, and lympho-venous anastomosis in 1. There was resolution of symptoms in 7/9 (78% who underwent intervention, with worsening in 1 patient and no change in 1. In these patients, preprocedure mean LVPG was 7.9 ± 5.7 mmHg and postprocedure gradient was 1.6 ± 1.9 mmHg (p = 0.014). Five patients in this series underwent intervention solely to alleviate duct obstruction and in 4/5 (80%) this led to resolution of symptoms (p = 0.05). CONCLUSION: Duct obstruction may be seen in lymphatic flow disorders and can occur from intrinsic and extrinsic causes. Stenosis at the outlet was most common. Obstruction can be demonstrated by an elevated LVPG, and interventions to alleviate the obstruction can be beneficial.

Percutaneous Nephrostomy in Neonates and Young Infants.

PURPOSE: To describe a single-center experience of placing percutaneous nephrostomy (PCN) tubes in neonates and young infants aged ≤3 months. MATERIALS AND METHODS: This retrospective study evaluated PCN placement during a 19-year period. Medical records were reviewed for patient demographics, indications, procedure details, catheter-related adverse events, and outcomes. A total of 45 primary PCN insertions were attempted in 29 children (median age, 11 days [range, first day of life to 3 months]; median weight, 3.5 kg [range, 1.4-7.0 kg]). Salvage procedures resulted in 13 secondary catheters in 6 children. The most common indication was ureteropelvic junction obstruction (40.0%), and the most common urinary tract dilation classification was P3 (88.9%). RESULTS: Technical success for primary placements was 95.6%; both technical failures were due to loss of access in the same patient. Of primary placements, 76.7% were electively removed, 6.9% were dislodged but not replaced, and the remaining 16.3% required salvage procedures. Mechanical adverse events occurred in 20.9% of primary and 53.8% of secondary catheters, including partial retraction, complete dislodgement, and occlusion. Urinary tract infections (UTIs) occurred in 18.6% of primary and 15.4% of secondary catheters. Urosepsis occurred in 2.3% of primary and 7.7% of secondary catheters. Median primary catheter dwell time was 41 days (range, 1-182 days) and median secondary catheter dwell time was 31 days (range, 10-107 days). CONCLUSION: PCN placement in neonates and young infants has a high technical success rate, although not without particular procedural and management challenges of catheter malfunction and UTI.

Imaging of pediatric abdominal soft tissue tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

This paper provides imaging recommendations for pediatric abdominal tumors that arise outside of the solid viscera. These tumors are rare in children and have been categorized in two groups: abdominal wall and peritoneal tumors (desmoid tumor and desmoplastic small round cell tumor) and tumors that arise from the gastrointestinal tract (gastrointestinal stromal tumor and gastrointestinal neuroendocrine tumor). Authors offer consensus recommendations for imaging assessment of these tumors at diagnosis, during follow-up, and when off-therapy.

Pathogenic variants in PIK3CA are associated with clinical phenotypes of kaposiform lymphangiomatosis, generalized lymphatic anomaly, and central conducting lymphatic anomaly.

Complex lymphatic anomalies are debilitating conditions characterized by aberrant development of the lymphatic vasculature (lymphangiogenesis). Diagnosis is typically made by history, examination, radiology, and histologic findings. However, there is significant overlap between conditions, making accurate diagnosis difficult. Recently, genetic analysis has been offered as an additional diagnostic modality. Here, we describe four cases of complex lymphatic anomalies, all with PIK3CA variants but with varying clinical phenotypes. Identification of PIK3CA resulted in transition to a targeted inhibitor, alpelisib. These cases highlight the genetic overlap between phenotypically diverse lymphatic anomalies.

Imaging of pediatric liver tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary hepatic malignancies are relatively rare in the pediatric population, accounting for approximately 1%-2% of all pediatric tumors. Hepatoblastoma and hepatocellular carcinoma are the most common primary liver malignancies in children under the age of 5 years and over the age of 10 years, respectively. This paper provides consensus-based imaging recommendations for evaluation of patients with primary hepatic malignancies at diagnosis and follow-up during and after therapy.

Adjunctive techniques for percutaneous enteral access in children: a pictorial review.

Primary percutaneous gastrostomy and gastrojejunostomy tube placements are fundamental procedures performed in pediatric interventional radiology, with both antegrade and retrograde techniques described. In pediatric patients, however, challenges may arise due to smaller patient size and anatomical variations. Several adjunctive techniques may facilitate safe percutaneous access in the setting of a limited percutaneous gastric access window. These include the intra-procedural use of cone beam computed tomography (CT), percutaneous needle decompression in the setting of distended air-filled bowel interposed between the stomach and abdominal wall, post-pyloric balloon occlusion to facilitate gastric distension, ultrasound-guided gastric puncture, and intra-gastric contrast-enhanced ultrasound (ceUS) to define the relationship of the gastric wall and the anterior abdominal wall. Adjunctive techniques may increase successful primary percutaneous gastroenteric tube placement and may improve operator confidence in safe placement.

Dynamic Contrast Magnetic Resonance Lymphangiography Localizes Lymphatic Leak to the Duodenum in Protein-Losing Enteropathy.

OBJECTIVES: Protein-losing enteropathy (PLE) is a disorder of intestinal lymphatic flow resulting in leakage of protein-rich lymph into the gut lumen. Our primary aim was to report the imaging findings of dynamic contrast magnetic resonance lymphangiography (DCMRL) in patients with PLE. Our secondary objective was to use these imaging findings to characterize lymphatic phenotypes. METHODS: Single-center retrospective cohort study of patients with PLE unrelated to single-ventricle circulation who underwent DCMRL. We report imaging findings of intranodal (IN), intrahepatic (IH), and intramesenteric (IM) access points for DCMRL. RESULTS: Nineteen patients 0.3-58 years of age (median 1.2 years) underwent 29 DCMRL studies. Primary intestinal lymphangiectasia (PIL) was the most common referring diagnosis (42%). Other etiologies included constrictive pericarditis, thoracic insufficiency syndrome, and genetic disorders. IN-DCMRL demonstrated a normal central lymphatic system in all patients with an intact thoracic duct and localized duodenal leak in one patient (1/19, 5%). IH-DCMRL detected a duodenal leak in 12 of 17 (71%), and IM-DCMRL detected duodenal leak in 5 of 6 (83%). Independent of etiology, lymphatic leak was only visualized in the duodenum. CONCLUSIONS: In patients with PLE, imaging via DCMRL reveals that leak is localized to the duodenum regardless of etiology. Comprehensive imaging evaluation with three access points can provide detailed information about the site of duodenal leak.

Bowel perforation following percutaneous sclerotherapy of an intra-abdominal lymphatic malformation.

Mesenteric lymphatic malformations result from abnormal proliferation of disorganized mesenteric lymphatic channels. Sclerotherapy is often preferred over surgery as it is less invasive and has lower post-procedure morbidity. Sclerotherapy has been described as durable and effective with a low complication rate. We describe a serious complication from sclerotherapy of a lymphatic malformation extending from the mesentery through the bowel wall, highlighting the spectrum of this pathology and the need for multidisciplinary management of complex cases.

MRI for Response Assessment of Extensive Lymphatic Malformations in Children Treated With Sirolimus.

BACKGROUND. Extensive lymphatic malformations (LMs) may cause substantial morbidity. The mammalian target of rapamycin (mTOR) inhibitor sirolimus shows promise for treating vascular anomalies, although response assessment is not standardized. OBJECTIVE. The purpose of this study was to retrospectively characterize changes seen on MRI of children with extensive LMs treated with sirolimus. METHODS. Twenty-five children treated with sirolimus for extensive LMs were included. Baseline MRI was defined as the MRI examination performed closest to therapy initiation; follow-up MRI was defined as the most recent MRI examination performed while the patient was receiving therapy. Two pediatric radiologists independently determined MRI lesion volume by tracing lesion contours on all slices (normalized to patient body surface area expressed in square meters) and determined signal by placing an ROI on the dominant portion of the lesions (normalized to CSF signal) on baseline and follow-up T2-weighted MRI sequences. Interreader agreement was determined, and values were averaged for further analysis. Volume and signal changes were compared with patient, lesion, and treatment characteristics. RESULTS. The mean (± SD) interval between initiation of sirolimus treatment and follow-up MRI was 22.1 ± 13.8 months. The mean lesion volume index on baseline and follow-up MRI was 728 ± 970 and 345 ± 501 mL/m2, respectively (p < .001). Ninety-two percent of children showed a decrease in lesion volume index that was greater than 10% (mean volume change, -46.4% ± 28.2%). Volume change was inversely correlated with age (r = -0.466; p = .02). The mean volume change was -64.7% ± 25.4% in children younger than 2 years old versus -32.0% ± 21.6% in children 2 years old or older (p = .008). The mean volume change was -58.1% ± 24.0% for craniocervical lesions versus -35.5% ± 28.2% for lesions involving the trunk and/or extremities (p = .03). Mean lesion signal ratio on baseline and follow-up MRI was 0.81 ± 0.29 and 0.59 ± 0.26, respectively (p < .001). Mean signal ratio change was -23.8% ± 22.7%. Volume and signal changes were moderately correlated (r = 0.469; p = .02). Volume and signal changes were not associated with sex, lesion subtype, serum concentration of sirolimus, or the interval between sirolimus initiation and follow-up MRI (p > .05). Interreader agreement for volume index change was excellent (intraclass correlation coefficient, 0.983), and that for signal ratio change was moderate to good (intraclass correlation coefficient, 0.764). CONCLUSION. Sirolimus treatment of extensive LMs in children is associated with significant reductions in volume and signal on T2-weighted MRI. The decrease in volume is greater in younger children and craniocervical lesions. CLINICAL IMPACT. The results may facilitate development of standardized MRI-based criteria for assessing the response of vascular malformations to pharmacotherapy.

Magnetic resonance imaging findings of synovial sarcoma in children: location-dependent differences.

BACKGROUND: While overall survival for children is greater than that for adults, synovial sarcoma remains an aggressive neoplasm with a potentially poor prognosis, and its magnetic resonance imaging (MRI) findings in children are not well described. OBJECTIVE: We aimed to characterize the spectrum of MRI findings of synovial sarcoma in children with respect to anatomical location and outcome. MATERIALS AND METHODS: Children with histologically confirmed synovial sarcoma and preoperative MRI performed within the past 11 years (2009-2020) were included. Two radiologists retrospectively reviewed each MRI to categorize location, signal characteristics and associated findings. Chi-square and Fisher exact tests were used to assess associations with locations and outcomes. RESULTS: This study included 23 children (13 girls, 10 boys; mean age: 12.7±4.2 years) with 7 axial, 8 proximal and 8 distal appendicular lesions. Kappa ranged from 0.53 to 1. MRI findings differed significantly between locations with axial lesions measuring larger (P=0.01) and more likely to contain fluid levels (P=0.02), triple sign (P=0.02), inhomogeneous signal (T1-weighted images, P=0.003; T2-weighted images, P=0.02, contrast-enhanced images, P=0.03) with all lesions containing partially solid composition (P=0.03). At a median follow-up of 14 months (interquartile range: 7-33 months), 39% relapsed. Predictors of relapse (P<0.05) included metastasis at presentation, larger lesions, axial lesions and MRI findings of fluid level, T1-weighted hyperintensity, inhomogeneous signal (T1- and T2-weighted images) and poorly circumscribed margins. CONCLUSION: A significant association was found between location and MRI findings in our cohort of children with synovial sarcoma. Axial lesions were more likely to be larger, appear heterogeneous and be associated with a worse outcome.

Contrast-enhanced ultrasound in pediatric interventional radiology.

There is growing interest in the use of contrast-enhanced ultrasound (CEUS) in diagnostic and interventional radiology. CEUS applications in interventional radiology are performed with intravascular or intracavitary administration of microbubble-based US contrast agents to allow for real-time evaluation of their distribution within the vascular bed or in body cavities, respectively, providing additional information beyond gray-scale US alone. The most common interventional-radiology-related CEUS applications in children have been extrapolated from those in adults, and they include the use of CEUS to guide lesion biopsy and to confirm drain placement in pleural effusions and intra-abdominal fluid collections. Other applications are emerging in interventional radiology for use in adults and children, including CEUS to optimize sclerotherapy of vascular malformations, to guide arthrography, and for lymphatic interventions. In this review article we present a wide range of interventional-radiology-related CEUS applications, emphasizing the current and potential uses in children. We highlight the technical parameters of the CEUS examination and discuss the main imaging findings.

Starting a pediatric contrast ultrasound service: made simple!

The addition of contrast US to an existing pediatric US service requires several preparatory steps. This overview provides a guide to simplify the process. Initially, it is important to communicate to all stakeholders the justifications for pediatric contrast US, including (1) its comparable or better diagnostic results relative to other modalities; (2) its reduction in procedural sedation or anesthesia by avoiding MRI or CT; (3) its reduction or elimination of radiation exposure by not having to perform fluoroscopy or CT; (4) the higher safety profile of US contrast agents (UCA) compared to other contrast agents; (5) the improved exam comfort and ease inherent to US, leading to better patient and family experience, including bedside US exams for children who cannot be transported; (6) the need for another diagnostic option in light of increasing demand by parents and providers; and (7) its status as an approved and reimbursable exam. It is necessary to have an UCA incorporated into the pharmacy formulary noting that only SonoVue/Lumason is currently approved for pediatric use. In the United States this UCA is approved for intravenous administration for cardiac and liver imaging and for vesicoureteric reflux detection with intravesical application. In Europe and China it is only approved for the intravesical use in children. All other applications are off-label. The US scanner needs to be equipped with contrast-specific software. The UCA has to be prepared just before the exam and it is important to strictly follow the steps as outlined in the packaging inserts in order to prevent premature destruction of the microbubbles. The initial training in contrast US is best focused on the frontline staff actually performing the US studies; these might be sonographers, pediatric or interventional radiologists, or trainees. It is important from the outset to educate the referring physicians about contrast US. It is helpful to participate in existing contrast US courses, particularly those with hands-on components.

Intramesenteric dynamic contrast pediatric MR lymphangiography: initial experience and comparison with intranodal and intrahepatic MR lymphangiography.

OBJECTIVES: To report on our initial experience with intramesenteric (IM) dynamic contrast magnetic resonance lymphangiography (DCMRL) for evaluation of the lymphatics in patients with concern for mesenteric lymphatic flow disorders and to compare IM-DCMRL with intrahepatic (IH) and intranodal (IN) DCMRL. METHODS: This is a retrospective review of imaging findings in 15 consecutive patients who presented with protein losing enteropathy (PLE) and/or ascites undergoing IM-DCMRL, IH-DCMRL, and IN-DCMRL. The IM-DCMRL technique involves the injection of a gadolinium contrast agent into the mesenteric lymphatic ducts or lymph nodes followed by imaging of the abdomen and chest with dynamic time-resolved MR lymphangiography. RESULTS: IM-DCMRL was successfully performed in 14/15 (93%) of the patients. When comparing IN-DCMRL with IM-DCMRL, there was a significant difference in the visualization of dermal backflow (p = 0.014), duodenal perfusion (p = 0.003), duodenal leak (p = 0.014), and peritoneal leak (p = 0.003). IM-DCMRL demonstrated peritoneal leak in 7 patients in contrast to IH-DCMRL which demonstrated leak in 4 patients and IN-DCMRL which did not demonstrate any peritoneal leaks. Duodenal leaks were seen by IH-DCMRL in 9 patients versus 5 with IM-DCMRL and none with IN-DCMRL. In one patient with congenital PLE, the three modalities showed different disconnected flow patterns with duodenal leak only seen by IM-DCMRL. There were no short-term complications from the procedures. CONCLUSIONS: IM-DCMRL is a feasible imaging technique for evaluation of the mesenteric lymphatics. In certain mesenteric lymphatic flow abnormalities, such as PLE and ascites, this imaging may be helpful for diagnosis and the planning of interventions and warrants further studies. KEY POINTS: • Intramesenteric dynamic contrast magnetic resonance lymphangiography (IM-DCMRL) is a new imaging technique to evaluate mesenteric lymphatic flow disorders such as ascites. • IM-DCMRL is able to image lymphatic leaks in patients with ascites and protein losing enteropathy not seen with intranodal (IN-DCMRL) imaging.

Implantable venous access devices in children with severe hemophilia: a tertiary pediatric institutional experience.

BACKGROUND: Clotting factor replacement forms the pillar of treatment for children with hemophilia. Most children can be treated using peripheral venipuncture, but very young children and children with poor venous access might require a central venous catheter. Short-term and long-term complications of implantable venous access device placement (also known as port placement) can result in important morbidity and mortality in children with hemophilia. OBJECTIVE: The purpose of this study is to describe our experience with port placement in children and adolescents with severe hemophilia (<1% of the Factors VIII or IX). MATERIALS AND METHODS: We performed a retrospective review over a 10-year period to identify port placement in pediatric patients with severe hemophilia. We reviewed demographic and procedural information, access frequency, mechanical complications, and central-line-associated bloodstream infections (CLABSI). Eighteen males were included, with median age at insertion of 3.9 years (0.7-22.7 years). Fifteen of the 18 patients had hemophilia Type A and 3/18 had Type B. Thirteen had high neutralizing inhibitor titers. RESULTS: Technical success in port placement was achieved in 26/27 (96.3%) patients, with 1 port failure caused by venous occlusion from prior catheter placement. Port catheter size ranged from 5 French (Fr) to 7.5 Fr. All were single-lumen and placed via right (76.9%) or left (23.1%) internal jugular vein; 59.3% were placed during general anesthesia, and all had factor replacement prophylaxis. A peripherally inserted central catheter (PICC) was placed concurrently in 69.2% of the cases; per hospital policy, the port was only accessed 15 days post-placement to reduce the risk of site hematoma. Two patients were lost to follow-up. The total catheter days was 15,893. Ports were removed in 14/24 cases, most commonly because of CLABSI (7/24; 29.2%) and transition to peripheral infusion (3/24; 12.5%). Bleeding was the most common complication in the first 30 days after placement. There were nine CLABSI events (0.57 per 1,000 catheter days), all in patients with high neutralizing inhibitor titers. A higher frequency of port access (more or equal to daily vs. less than daily) correlated with higher infection rates (P=0.02). Median time from port insertion to first infection was 348 days (range 167-1,055 days). There were four fibrin-sheath-related catheter occlusions (0.25 per 1,000 catheter days): three catheters were salvaged with intra-catheter tissue plasminogen activator (tPA) instillation resulting in a salvage of an additional 1,214 catheter days, and one catheter was removed after tPA failure (0.06 per 1,000 catheter days). CONCLUSION: Port maintenance in boys with severe hemophilia is challenging given the need for long-term frequent device access that is associated with catheter-related infections. The rate of bleeding or infection did not differ in patients whether the device was accessed immediately or 15 days post placement. With appropriate pre- and post-procedural factor replacement, immediate and early term severe complications are not common.