Fostering research in pediatric interventional radiology: needs assessment and suggestions for support.

BACKGROUND: Due to the rarity of pediatric diseases, collaborative research is the key to maximizing the impact of research studies. A research needs assessment survey was created to support initiatives to foster pediatric interventional radiology research. OBJECTIVE: To assess the status of pediatric interventional radiology research, identify perceived barriers, obtain community input on areas of research/education/support, and create metrics for evaluating changes/responses to programmatic initiatives. MATERIALS AND METHODS: A survey link was sent to approximately 275 members of the Society for Pediatric Interventional Radiology (SPIR) between May and October 2020. Data was collected using a web-based interface. Data collected included practice setting, clinical role, research experience, research barriers, and suggestions for future initiatives. RESULTS: Fifty-nine surveys were analyzed with a staff physician survey response rate of 28% (56/198). A wide range of practice sizes from 15 countries were represented. Respondents were predominantly staff physicians (95%; 56/59) with an average of 11 years (range: 1-25 years) of clinical experience working at academic or freestanding children's hospitals. A total of 100% (59/59) had research experience, and 70% (41/58) had published research with a mean of 30 peer-reviewed publications (range: 1-200). For job security, 56% (33/59) of respondents were expected or required to publish, but only 19% (11/58) had research support staff, and 42% (25/59) had protected research time, but of those, 36% (9/25) got the time "sometimes or never." Lack of support staff, established collaborative processes, and education were identified as top barriers to performing research. CONCLUSIONS: The needs assessment survey demonstrated active research output despite several identified barriers. There is a widespread interest within the pediatric interventional radiology community for collaborative research.

Trametinib for Refractory Chylous Effusions and Systemic Complications in Children with Noonan Syndrome.

OBJECTIVE: To evaluate the effect of the RAS-MAPK pathway inhibitor trametinib on medically refractory chylous effusions in 3 hospitalized patients with Noonan syndrome. STUDY DESIGN: Pharmacologic MEK1/2 inhibition has been used to treat conditions associated with Noonan syndrome, given that activation of RAS-MAPK pathway variants leads to downstream MEK activation. We describe our experience with 3 patients with Noonan syndrome (owing to variants in 3 distinct genes) and refractory chylous effusions treated successfully with MEK inhibition. A monitoring protocol was established to standardize medication dosing and monitoring of outcome measures. RESULTS: Subjects demonstrated improvement in lymphatic leak with additional findings of improved growth and normalization of cardiac and hematologic measurements. Trametinib was administered safely, with only moderate skin irritation in 1 subject. CONCLUSIONS: Improvements in a variety of quantifiable measurements highlight the potential utility of MEK1/2 inhibition in patients with Noonan syndrome and life-threatening lymphatic disease. Larger, prospective studies are needed to confirm efficacy and assess long-term safety.

Extracorporeal membrane oxygenation as rescue therapy in a pediatric liver transplant recipient with very severe hepatopulmonary syndrome.

BACKGROUND: In children with cirrhosis, the prevalence of HPS ranges from 3% to 20%, resulting in impaired gas exchange due to alterations in pulmonary microvasculature. LT is the gold-standard cure for cirrhosis complicated by HPS and should ideally be performed prior to the development of severe HPS due to increased risk for post-transplant hypoxia, right heart failure, and outflow obstruction. METHODS: We present a case of a 13-year-old man, who underwent pediatric LT for severe HPS complicated by postoperative respiratory collapse, requiring a 92-day course of veno-venous ECMO. RESULTS: Post-transplant, despite BiPAP, inhaled nitric oxide and isoproterenol infusion, he remained hypoxic postoperatively and acutely decompensated on postoperative day 25, requiring veno-venous ECMO. After 84 days on ECMO, a persistent large splenorenal shunt was identified that was embolized by interventional radiology, and 8 days after shunt embolization and ASD closure, he was successfully weaned off ECMO. CONCLUSIONS: This case describes the longest known duration of ECMO in a pediatric LT recipient and a unique improvement in hypoxemia following a portosystemic shunt closure. ECMO presents a heroic rescue measure for pediatric LT recipients with HPS that develops acute respiratory failure postoperatively refractory to alternative measures.

Pediatric trauma and the role of the interventional radiologist.

PURPOSE: While interventional radiologists occupy a critical role in adult trauma management, the role of interventionalist in pediatric trauma continues to evolve. The indications for transarterial embolization (TAE) are significantly different in pediatric patients in whom non-operative management (NOM) has a much more prominent role than in adults. Contrast extravasation on imaging may not require acute surgical or interventional management as it would in an adult. There are also areas in which pediatric interventional radiology is increasingly useful such as pelvic TAE in failed management, or splenic embolization to treat bleeding without the loss of splenic function inherent to surgical splenectomy. The rapid evolution of techniques and devices in pediatric patients is also changing what interventions are possible in pediatric trauma management which necessitates frequent reassessment of the guidelines and interventional radiology's role in caring for these patients. CONCLUSION: This review seeks to consolidate the recent literature to describe the evolving role of the interventional radiologist in pediatric trauma management.

The use of ultrasound in establishing COVID-19 infection as part of a trauma evaluation.

PURPOSE: The use of lung ultrasound for diagnosis of COVID-19 has emerged during the pandemic as a beneficial diagnostic modality due to its rapid availability, bedside use, and lack of radiation. This study aimed to determine if routine ultrasound (US) imaging of the lungs of trauma patients with COVID-19 infections who undergo extended focused assessment with sonography for trauma (EFAST) correlates with computed tomography (CT) imaging and X-ray findings, as previously reported in other populations. METHODS: This was a prospective, observational feasibility study performed at two level 1 trauma centers. US, CT, and X-ray imaging were retrospectively reviewed by a surgical trainee and a board-certified radiologist to determine any correlation of imaging findings in patients with active COVID-19 infection. RESULTS: There were 53 patients with lung US images from EFAST available for evaluation and COVID-19 testing. The overall COVID-19 positivity rate was 7.5%. COVID-19 infection was accurately identified by one patient on US by the trainee, but there was a 15.1% false-positive rate for infection based on the radiologist examination. CONCLUSIONS: Evaluation of the lung during EFAST cannot be used in the trauma setting to identify patients with active COVID-19 infection or to stratify patients as high or low risk of infection. This is likely due to differences in lung imaging technique and the presence of concomitant thoracic injury.

Guidelines for expert testimony in pediatric radiology.

Pediatric radiologists have the professional and ethical duty to assist, inform and educate the legal system in regard to matters involving medical imaging in children. These guidelines, drafted by the Society for Pediatric Radiology Ethics Committee and approved by the Society for Pediatric Radiology Board of Directors, provide recommendations for expert legal testimony in pediatric radiology and codify minimal ethical norms for the pediatric radiology expert witness in legal proceedings.

Symptom Resolution and Volumetric Reduction of Abdominal Lymphatic Malformations With Sclerotherapy.

BACKGROUND: Lymphatic malformations (LMs) are congenital and arise from errors in vascular embryogenesis. LMs are categorized by cyst size as microcystic, macrocystic, or combined. Abdominal LMs are rare. Surgical resection of abdominal LMs has been the mainstay of therapy, but recurrence and morbidity are high. We sought to determine the effectiveness of sclerotherapy treatment for abdominal LM. METHODS: A single-center, retrospective review from 2014 to 2018 was conducted evaluating pediatric patients with abdominal LM. RESULTS: Ten patients were included, n = 9 had macrocystic LM and one patient had combined disease. The average age at first treatment was 6.8 y. The most common presenting symptoms were abdominal distention, pain, infection, and anemia. Preprocedural imaging was performed for all patients; median pretreatment volume was 1572.9 cm3 (range, 67.2-13,226.4). LMs were accessed using ultrasound guidance and injected with opacified doxycycline. Patients received a mean of 7.1 sclerotherapy injections. Complications included intraperitoneal doxycycline extravasation (n = 1), managed conservatively, and LM infection (n = 1), treated with intravenous antibiotics and drainage. One patient went on to surgical resection due to inability gain stable intracystic access; follow-up ultrasonography showed no recurrence. Postprocedural imaging was available in n = 8. Volume decreased by 96.7% after sclerotherapy. The median remaining volume was 0 cm3 (range, 0-599.7) (P = 0.016). Postsclerotherapy magnetic resonance imaging was obtained in n = 6, with complete resolution in 83.3%. All patients had resolution of presenting symptoms. Follow-up duration was 12.3 mo. CONCLUSIONS: Initial results demonstrate that sclerotherapy is an effective and durable treatment for symptom resolution and volume reduction of abdominal LM.

Imaging the central conducting lymphatics: initial experience with dynamic MR lymphangiography.

PURPOSE: To describe a dynamic magnetic resonance (MR) lymphangiography technique after intranodal injection of gadolinium-based contrast agent and to assess its feasibility for evaluation of the central conducting lymphatics (CCL) in patients with pathologic disorders that involve the CCL. MATERIALS AND METHODS: A retrospective evaluation of experience with the dynamic MR lymphangiographic technique in six consecutive patients was performed after institutional review board approval. Written informed consent for the percutaneous procedure was obtained from the patient, parent, or the legally responsible guardian. The dynamic MR lymphangiographic technique involves ultrasonographically guided intranodal injection of gadolinium-based contrast material into the inguinal lymph nodes, combined with sequential imaging of the chest and abdomen with a three-dimensional sequence optimized for soft tissue with high spatial resolution that provides time-resolved imaging of lymphatic transit through the CCL. Qualitative assessment of the images was performed for reliability of CCL visualization and for associated findings that could explain the clinical symptoms, including lymphangiectasia, chylolymphatic reflux, and chylous leak. RESULTS: The procedure was technically successful in all six patients. The dynamic MR lymphangiographic findings confirmed the presence of normal CCL morphologic structure in two patients and provided a possible explanation for clinical manifestations in the remaining four patients. The dynamic MR lymphangiographic procedure led to a change in management in two patients, continuation of conservative treatment in three patients, and confirmation of an alternative nonlymphatic diagnosis in one patient. Image quality for visualization of the CCL was considered good in all cases by the two readers. There were no known adverse effects related to the procedure. CONCLUSION: The dynamic MR lymphangiographic technique with intranodal injection of gadolinium-based contrast material is feasible and can provide useful information in a variety of lymphatic flow abnormalities involving the CCL.

Extratesticular masses in children: taking ultrasound beyond paratesticular rhabdomyosarcoma.

Extratesticular cystic and solid scrotal masses are commonly encountered in pediatrics. The most common extratesticular malignancy is paratesticular rhabdomyosarcoma. The remainder of the common pathologies encountered -- appendage torsion, epididymitis and varicoceles -- are mostly benign. These frequently encountered benign lesions are confidently differentiated from paratesticular rhadbomyosarcoma using high-frequency scrotal sonography in combination with clinical features. Less commonly encountered extratesticular masses may not be as easily classified; however, these also have distinguishing features that can enable differentiation from malignancy. This review discusses the sonographic findings, and relevant clinical and pathological manifestations of the more unusual extratesticular masses encountered in two tertiary pediatric institutions during a 10-year period. While these extratesticular pathologies are encountered relatively infrequently, recognition of their manifestations enables appropriate management.

Anticoagulation in Pediatric Patients.

The use of antithrombotic agents is increasing in infants, children and adolescents. The more recent routine inclusion of children in FDA-monitored clinical trials has propelled the rapid accumulation of safety and efficacy data on these agents in pediatric patients. Antithrombotic agents in current use include indirect or antithrombin-dependent anticoagulants, intravenous direct thrombin inhibitors, direct oral anticoagulants (DOACs) targeting thrombin or factor Xa, antiplatelet agents and thrombolytic therapies. Each class of antithrombotic agent has distinct mechanisms of action, clearance routes, half-lives, safety and dosing. Anticoagulant efficacy is dependent upon the specific clinical indication and stability of the pediatric patient. Duration of anticoagulant course is also dependent upon the clinical indication as well as rate of thrombus resolution. This manuscript reviews the mechanism of action, route of administration, route of clearance and plasma half-life for the antithrombotic agents in current use in children. Use of anticoagulation in the context of thrombolytic therapy is discussed.

Interventional Treatment of Pediatric Venous Thromboembolic Disease.

This review explores the clinical presentation of lower extremity DVT and pulmonary embolism (PE), treatment strategies, and outcomes for venous thromboembolism (VTE) in the pediatric population. Traditional therapy for pediatric VTE was anticoagulation alone with thrombolysis and surgery reserved only in life or limb-threatening cases. Catheter-directed thrombolysis (CDT), pharmacomechanical thrombectomy (PMT) and mechanical thrombectomy (MT) have emerged as effective and safe treatment options for VTE management. Although most data are from adult studies, early pediatric studies suggest that these interventional procedures can be effective in children. The significant clinical impact of post-thrombotic syndrome (PTS) is also discussed, as PTS can lead to lifelong physical symptoms and psychosocial damage.

Congenital Portosystemic Shunts: Variable Clinical Presentations Requiring a Tailored Endovascular or Surgical Approach.

Congenital portosystemic shunts (CPSS) are rare developmental anomalies resulting in diversion of portal flow to the systemic circulation. These shunts allow intestinal blood to reach the systemic circulation directly, and if persistent or large, may lead to long-term complications. CPSS can have a variety of clinical presentations that depend on the substrate that is bypassing hepatic metabolism or the degree of hypoperfusion of the liver. Many intrahepatic shunts spontaneously close by 1 year of age, but extrahepatic and persistent intrahepatic shunts require intervention by a single session or staged closure with a multidisciplinary approach. Early detection and appropriate management are important for a good prognosis. The aim of this case series is to describe the varied clinical presentations, treatment approaches, and outcomes of 5 children with CPSS at our institution. Management of these patients should involve a multidisciplinary team, including interventional radiology, surgery, hepatology, and other medical services as the patient's clinical presentation warrants. Regardless of clinical presentation, if a CPSS persists past 1-2 years of age, closure is recommended.

Use of Point-of-Care Ultrasonography in the NICU for Diagnostic and Procedural Purposes.

Point-of-care ultrasonography (POCUS) refers to the use of portable imaging performed by the provider clinician at the bedside for diagnostic, therapeutic, and procedural purposes. POCUS could be considered an extension of the physical examination but not a substitute for diagnostic imaging. Use of POCUS in emergency situations can be lifesaving in the NICU if performed in a timely fashion for cardiac tamponade, pleural effusions, pneumothorax, etc, with potential for enhancing quality of care and improving outcomes. In the past 2 decades, POCUS has gained significant acceptance in clinical medicine in many parts of the world and in many subspecialties. Formal accredited training and certification programs are available for neonatology trainees as well as for many other subspecialties in Canada, Australia, and New Zealand. Although no formal training program or certification is available to neonatologists in Europe, POCUS is widely available to providers in NICUs. A formal institutional POCUS fellowship is now available in Canada. In the United States, many clinicians have the skills to perform POCUS and have incorporated it in their daily clinical practice. However, appropriate equipment remains limited, and many barriers exist to POCUS program implementation. Recently, the first international evidence-based POCUS guidelines for use in neonatology and pediatric critical care were published. Considering the potential benefits, a recent national survey of neonatologists confirmed that the majority of clinicians were inclined to adopt POCUS in their clinical practice if the barriers could be resolved. This technical report describes many potential POCUS applications in the NICU for diagnostic and procedural purposes.