Pediatric Interventional Radiology Research Articles

Diagnosis and Management of Extracranial Vascular Malformations in Children: Arteriovenous Malformations, Venous Malformations, and Lymphatic Malformations

Abstract Vascular malformations result from congenital abnormalities in vascular morphogenesis most commonly stemming from somatic mutations. This dysregulation results in localized vascular anatomical abnormalities that can result in high-flow vascular malformations (such as arteriovenous malformations) and/or low-flow vascular malformations (such as venous malformations and lymphatic malformations). The severity and types of symptoms patients suffer are highly variable and related to the size and location of the malformation. Pediatric interventional radiologists often play a primary role in diagnosis and management of these lesions. Thus, having a firm grasp on the clinical presentation, diagnostic work-up, therapeutic management, cellular physiology, and pharmacologic mechanism of action of sclerosants/embolics is essential. This review focuses on the interventional radiologist's role in the diagnosis and management of extra-cranial congenital vascular malformations.

Pediatric Interventional Oncology: Endovascular, Percutaneous, and Palliative Procedures

Abstract Interventional oncology (IO) is emerging as a pillar of cancer care in pediatric patients. The minimally invasive techniques employed by IO are increasingly being integrated into the diagnostic, therapeutic, and palliative management of children with cancer. This review provides an evidence-based overview to the endovascular, percutaneous, and supportive and palliative procedures offered by pediatric interventional radiologists. An understanding of the modest but growing literature that supports the safety and efficacy of pediatric IO is important in ensuring the continued adoption of IO in the multidisciplinary care of pediatric cancer patients.

Interventional Radiology's Role in the Treatment of Pediatric Thoracic Disease

Abstract The emergence of minimally invasive procedures has rapidly changed the management of many pediatric thoracic diseases. Previous paradigms of treatment, which often required surgical intervention, are now managed through percutaneous, image-guided procedures. In addition, as skillset, quality and availability of ultrasound and cone-beam tomography increase, previously necessary radiation from conventional CT for image-guided procedures of the thorax can be reduced. The integration of the interventionalist's approach into multi-disciplinary care teams requires IRs to be facile in the multi-modality treatment of these ailments. Clinically, the proceduralist must be aware of trends in practice, common complications and technical details to provide a well-rounded consultation to both patients and referring physicians. This article reviews common pediatric thoracic diseases, including lung masses, empyema, chylous effusions, pulmonary arteriovenous malformations, and bronchiectasis, in which pediatric interventional radiologists play a key role in multi-disciplinary management.

Experience with Compressed Gelfoam Plugs inChildren during Liver Biopsies and Other IR Procedures: A Retrospective Single-Center Case Series.

To analyze the experience using compressed gelfoam plugs (CGPs) in children during liver biopsies and other interventional procedures. This was a single-center, retrospective, consecutive case series of 477 various pediatric interventional radiology procedures using CGPs (January 2012 to December 2016) performed on 397 children (209 males, 188 females; median age, 7 years [range, 9 days-17.8 years]; median weight, 18 kg [range, 2.7-141 kg]). Of 477 procedures, most (n= 371) were liver biopsies, 98 were biopsies of other organs, and 8 were non-biopsy procedures. Analysis focused on liver biopsies. Of liver biopsies, a median of 2 CGPs were used per procedure, and the mean drop in hemoglobin was -0.36 g/dl (-3.0% change). Thirty-seven mild, 8 moderate, 2 severe, and 1 life-threatening (an anaphylaxis to CGP) adverse events (AEs) occurred. Analysis of liver biopsies with AEs showed significant association between number of passes, cores, and focal-type lesions (unadjusted logistic regression: P= .007, P= .022, P= .028, respectively) and age, weight, and number of passes (adjusted multiple logistic regression: P=.006, P= .032, P= .046, respectively). Technical problems relating to CGP deployment were noted in 5 (1%), without any AEs. CGPs were used in a wide variety of procedures and organs in children. There was 1 life-threatening AE resulting from the rare risk of anaphylaxis caused by the gelfoam-containing plug. After liver biopsies, transfusion was required in 2/371 (0.5%) procedures, 1 related to pre-biopsy anemia (0.25%).

Management of Vascular Anomalies in Pediatric Interventional Radiology

Management of Vascular Anomalies in Pediatric Interventional Radiology

Abstract No. 560 Fabrication of a custom pediatric phantom for pediatric interventional radiology endovascular simulation and training: technical aspects

Abstract No. 560 Fabrication of a custom pediatric phantom for pediatric interventional radiology endovascular simulation and training: technical aspects

03:27 PM Abstract No. 36 Process map for interventional radiology at a large tertiary children’s hospital: understanding the workflow and identifying areas for improvement

Process mapping can be used to identify healthcare waste and inefficiencies. We chose to observe pediatric interventional radiology (IR) processes for inpatients undergoing procedures with general anesthesia to create a process map and identify delays in patient care. A fourth-year medical student was assigned to observe the process of coordinating inpatient IR procedures (2 IR rooms) at a tertiary care children’s hospital for 2 weeks. The medical student began following a single patient at initiation of transfer from the inpatient floor until the patient exited the IR suite. Predetermined variables were recorded for each patient observation. Post anesthesia Care Unit (PACU) nurses were tasked with recording discharge times from the PACU. During this process, team member duties were recorded chronologically for future integration into a process map. Overall, 19 inpatient procedures were completely tracked. We found notable delays in patient transport times (mean 38 mins, range 22–68 mins), pre-procedure evaluation (mean 22 mins, range 13–31 mins), and preoperative/PACU space availability. Estimated time for scheduling the procedure in the IR suite (mean 68.5 mins, range 60–120 mins) was shown to be an underestimate when compared to the measured procedure duration (mean 77 mins, range 31–181 mins). With all members of the IR team, including IR nurses and radiology technologists, a process map was created to map the roles of each team member. Results from the observation were discussed at a team meeting to receive input and feedback from all members of the IR team. We have implemented changes in our workflow to address these issues. Patient transport is now solicited at earlier times to reflect appropriate transport lags. We found our team to be efficient in preparing the patient for the procedure with most of our delays being attributable to PACU bed availability. By analyzing our processes, inefficiencies in workflow and delays in coordination of patient care were identified. Implementation of targeted changes at our institution should lead to improved efficiency. Process mapping can be used to help other IR departments in identifying their inefficiencies.

03:36 PM Abstract No. 47 Outcomes of tunneled internal jugular venous catheters in children younger than 3 months of age

There is limited data on complications of central lines in younger infants. The purpose of this study is to identify factors which may affect complication rates of tunneled internal jugular (IJ) venous catheters placed in neonates and infants under 3 months of age. This is a retrospective review of patients 90 days of age and under who underwent tunneled IJ venous catheter placements in the pediatric interventional radiology department at a single institution over a 4-year period. Patient demographics, device characteristics, procedural factors, and clinical follow-up were collected for each catheter placed. Complication rates, fluoroscopy times, and procedural times were analyzed based on patient age, weight at time of placement, side of placement, and technique (single-incision or conventional). Complication types (line malfunction, malpositioning, or infection) were analyzed based on duration of placement and method of resolution. 65 lines were placed in 63 patients with a total dwell time of 2,799 line days. A total of 15 complications were observed which required either replacement over a wire or removal (total complication rate 23%). Complications included 3 line malfunctions, 8 malpositioned lines, and 4 infections. There were 7 complications (including 1 infection) that occurred within 30 days of line placement. Catheters placed using the single-incision technique (20) had a statistically significant lower rate of complications compared with conventional technique (45); (5% vs 31%, p = 0.03). Although not statistically significant, patients under 30 days of age had a higher complication rate compared to older patients (27% vs 22%), patients weighing less than 5 kg had a higher complication rate compared to heavier patients (25% vs 20%), and left IJ catheters had a longer average procedure time compared to the right (39 minutes vs 24 minutes). When caring for patients less than 3 months of age who require tunneled internal jugular venous access, a single-incision technique may lead to lower rates of complication. It is also important to be aware of factors which may lead to a higher rate of complication, such as younger age and lighter weight.

Pediatric Traumas and Paradigm Shifts: The Necessary Adaption of the Steerable Microcatheter in Pediatric Interventional Radiology.

The use of traditionally available intra-arterial devices have historically been designed with the adult patient population in mind. Currently, there are not manufactured devices specifically tailored for use during pediatric interventional procedures, pressuring interventional operators to adapt commonplace and readily available devices for interventional management. Experienced interventional operators understand that pediatric and adult interventions can entail vastly different management, affecting patient care and outcomes. To address the pitfalls in pediatric interventional management, an accredited fellowship specifically for pediatric interventional radiology is available. However, devices must equally evolve with the training available in order to adequately address interventional management of the pediatric patient population. Interventional device innovation can be considered the initial step towards bridging the technical and procedural gaps necessary for refining pediatric intervention. The introduction of steerable microcatheters in interventional radiology has innovated procedural protocols, but has never been documented in pediatric patients until this time.

Calculating organ and effective doses in paediatric interventional cardiac radiology based on DICOM structured reports – Is detailed examination data critical to dose estimates?

PurposeTo estimate effective dose (E), equivalent organ doses (HT) and associated conversion coefficients (CCE:KAP = E/KAP, CCHT:KAP = HT/KAP; KAP = Kerma-area product) in paediatric cardiac interventions, using detailed exposure data from radiation dose structured reports (RDSR). These “RDSR dose estimations” have been compared with estimations performed using the approach currently implemented in the clinic that is based on a simplified assumptions method (SAM). MethodsThe Monte Carlo system PCXMC, incorporated into a previously developed framework, was used to calculate E and HT for 202 children. The calculations were performed with input values from RDSR, and also using simplified assumptions, including fixed nominal values for the focus-skin distance, collimated beam size, irradiation geometry and patient size (age, weight and height). ResultsMean HT to critical organs were: 5–25 mSv (lungs), 5–8 mSv (breasts) and 5–22 mSv (heart), with the lower and upper end of the doses associated with the neonatal and 15 years group, respectively. The associated mean CCHT:KAP for the different age groups were: 9.4–1.6 mSv/Gycm2 (lungs), 8.9–0.54 mSv/Gycm2 (breasts) and 9.3–1.4 mSv/Gycm2 (heart). ConclusionsThe extension of the concept of a conversion coefficient for HT is introduced and CCHT:KAP values for paediatric cardiac interventions divided in age groups are presented. This method of linking the KAP to HT is intended for use in epidemiological/cohort studies or in clinics that do not have access to RDSR. Further, the population-averaged conversion coefficients for the critical organs estimated from RDSR, displayed no statistically significant difference compared with the SAM approach.

Non-vascular interventional radiology in the paediatric alimentary tract

Paediatric interventional radiology is an evolving speciality which is able to offer numerous minimally invasive treatments for gastrointestinal tract pathologies. Here we describe interventions performed by paediatric interventional radiologists on the alimentary tract from the mouth to the rectum. The interventions include sclerotherapy, stricture management by dilation, stenting and adjunctive therapies such as Mitomycin C administration and enteral access for feeding, motility assessment and administration of enemas.

345. Italian diagnostic reference levels for diagnostic and interventional radiology

Purpose The Diagnostic reference level (DRL) is recognised as an important tool in identifying high and non-justified exposure levels in diagnostic imaging practice and, in general, in the optimisation practice of patient exposure. In Italy, the D.Lgs. 187/2000 has introduced a set of DRL values and has requested their use in the medical exposure practice. Since many years, it has recognised this set, derived from European guidelines published in the 90’, requires an update to assure the efficacy of the tool. Methods In the last decade, with this in mind professional societies and national institutes have developed national surveys to assess level of patient exposure in different areas of diagnostic imaging. These data, together with relevant European data, have supported the development of the ISS ISTISAN 17/33 publication aiming to propose to the radiology community an updated set of national DRL values for the diagnostic and interventional radiology, i.e. general radiography, fluoroscopy and CT for adult and paediatric patients and interventional radiology for adults [1] . Results and Conclusions The ISS document can serves as a reference in the forthcoming legislative decree implementing the Council Directive 2013/59/EURATOM of 5/12/2013, laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation, has been transposing at national level. Because the Directive identifies in the DRLs a useful tool to support the optimisation also in interventional radiology (IR), a practice rapidly increasing and representing a critical scenario from the point of patient radiation protection, the ISS document is introducing DRLs for the most common IR procedures.

Cone-beam computed tomography guidance with navigational overlay for percutaneous lung nodule biopsy.

Cone-beam CT is increasingly used in pediatric interventional radiology procedures. However, the feasibility or safety of using this mode of imaging guidance for percutaneous lung nodule biopsy in children has not been assessed. To retrospectively evaluate safety and diagnostic accuracy of percutaneous lung nodule biopsy in people treated at a pediatric hospital using cone-beam CT with navigational overlay. Thirty-six consecutive patients from two large tertiary-care children's hospitals with lung nodules of 48mm or smaller underwent percutaneous lung nodule biopsy using cone-beam CT with navigational overlay. We evaluated patient demographics, pre- and post-biopsy diagnoses, number of biopsy passes, complications, radiation exposure and technical success. Percutaneous lung nodule biopsy was performed for 37 nodules in 36 patients (23 males, 13 females, median age 15.5years, range 8months to 23years). One patient underwent biopsy of two nodules at a single procedure. Median patient weight was 55kg (range 8-97kg). Pre-biopsy diagnoses included metastatic sarcoma or other solid tumor (n=11), leukemia/lymphoma (n=13), infection (n=10), chronic granulomatous disease (n=2) and post-transplant lymphoproliferative disorder (PTLD; n=1). Mean number of passes was 5 (range 2-15). Mean pre-procedure international normalized ratio (INR) was 1.1 and platelet count 193 × 109/L. Diagnostic specimens were obtained in 32 of 36 patients (89%). Thirteen complications were encountered in 12 patients (33% of cohort), including 9 pneumothoraces (4 requiring chest tubes); 1 hemothorax, which required a chest tube; and 3 self-limited pulmonary hemorrhages. Mean and median radiation doses were as follows: fluoroscopy time 3min and 2.4min, dose-area product (DAP) (recorded in 31 patients) 23,402 Gy·cm2 and 12,453 Gy·cm2, and air kerma 88 mGy and 58 mGy. Percutaneous lung nodule needle biopsy can be performed accurately using cone-beam CT with navigational overlay.

Challenges and Opportunities for Continued Success and Growth of Pediatric Interventional Radiology: A Communiqué From the Society for Pediatric Interventional Radiology.

Pediatric interventional radiology (PIR) is a dynamic and growing subspecialty. We will detail our need to evolve like the emerging therapies and innovative imaging options that we provide to children. New interventional radiology training pathways, maintaining competency with small volumes of complex procedures, limited availability of pediatric-specific equipment, questions about the safety of sedation in the developing brain, and the dearth of PIR opportunities outside of North America provide challenges and opportunities for the vibrant community of PIR practitioners.

How to Recognize, Avoid, or Get Out of Trouble in Pediatric Interventional Radiology

The average clinical practice of most interventional radiologists focuses on the care of adults (for practical purposes, defined as most patients over age 15). However, an increasing number of pediatric patients are being referred to Interventional Radiologists for evaluation and possible treatment. In some cases, these patients may not require significant deviation from the normal procedures of the lab (e.g., a 160 pound 14-year-old), although they may be designated as a pediatric patient by the anesthesia support team. In others, modifications must be made to ensure the safe and effective treatment of these patients (e.g., a 0.5 kg neonate). Unlike the specialty of adult interventional radiology (IR), pediatric interventional radiology (PIR) is relatively nascent. Like adult IR 10-15 years ago, PIR still competes for name recognition and even at the largest of pediatric medical centers, is involved in the political skirmishes that might make the most seasoned adult interventionalist smile (or cringe) in reminiscence. The field of PIR is growing rapidly and demands on these specialized practitioners are increasing. Some hospitals/centers have fellowship-trained Pediatric Interventional Radiologists who can attend to these patients, but others defer to the adult IR practitioners. Herein, we offer some thoughts on how to help the pediatric patient for our PIR and adult IR colleagues. These thoughts focus on preprocedural planning, optimizing intraprocedural success, and minimizing procedural morbidity. Throughout the process of preparing for a pediatric patient, it pays to recall the oft-recited mantra from medical school: "Kids are not just small adults."

Abstract No. 604 Simulation in pediatric interventional radiology environment: what lessons are we learning?

Abstract No. 604 Simulation in pediatric interventional radiology environment: what lessons are we learning?

Impact of low dose settings on radiation exposure during pediatric fluoroscopic guided interventions

PurposeTo evaluate the effects of lowering the detector entrance exposure in children undergoing interventional radiology procedures. Materials and MethodsThe study retrospectively investigated radiation dose levels in pediatric patients aged 0–18 years before (n = 39) and after (n = 26) lowering detector entrance dose, undergoing embolization of peripheral Arteriovenous malformations, Portal Vein Interventions or Percutaneous Transhepatic Cholangio Drainage (PTCD) between 2014 and 2017. Patient characteristics, fluoroscopy time, protocols used as well as resulting Skin Dose and Dose Area Product (DAP) were compared in each cohort. Image quality was assessed by two independent readers. ResultsThe two patient cohorts did not differ in terms of patient demographics. Similarly, fluoroscopy time did not differ before and after implementation of the low dose settings. An overall reduction of skin dose of 75.1% for AVM embolizations, 80.5% for Portal Vein Interventions and 85.3% for PTCD placement was observed. The DAP decrease was 82.5% for AVM embolizations, 72.2% for Portal Vein Interventions and 79.8% for PTCD placement. Image quality was generally considered to be good with an insignificant difference between pre and post implementation of the low dose approach and good agreement between the two readers. Manual inroom-switching to higher dose levels was possible, however this was not performed more frequently after implementation of the low dose settings. ConclusionLowering the detector entrance dose in pediatric interventional radiology procedures results in a significant decrease of the radiation dose burden.

Reduced-dose C-arm computed tomography applications at a pediatric institution.

Reduced-dose C-arm computed tomography (CT) uses flat-panel detectors to acquire real-time 3-D images in the interventional radiology suite to assist with anatomical localization and procedure planning. To describe dose-reduction techniques for C-arm CT at a pediatric institution and to provide guidance for implementation. We conducted a 5-year retrospective study on procedures using an institution-specific reduced-dose protocol: 5 or 8s Dyna Rotation, 248/396 projection images/acquisition and 0.1-0.17 μGy/projection dose at the detector with 0.3/0.6/0.9-mm copper (Cu) filtration. We categorized cases by procedure type and average patient age and calculated C-arm CT and total dose area product (DAP). Two hundred twenty-two C-arm CT-guided procedures were performed with a dose-reduction protocol. The most common procedures were temporomandibular and sacroiliac joint injections (48.6%) and sclerotherapy (34.2%). C-arm CT was utilized in cases of difficult percutaneous access in less common applications such as cecostomy and gastrostomy placement, foreign body retrieval and thoracentesis. C-arm CT accounted for between 9.9% and 80.7% of the total procedural DAP. Dose-reducing techniques can preserve image quality for intervention while reducing radiation exposure to the child. This technology has multiple applications within pediatric interventional radiology and can be considered as an adjunctive imaging tool in a variety of procedures, particularly when percutaneous access is challenging despite routine fluoroscopic or ultrasound guidance.

Percutaneous sclerotherapy of pediatric lymphatic malformations: Experience and outcomes according to the agent used

ObjectiveAnalyze statistically the success, number of sessions required and complete duration of treatment of agents used in pediatric percutaneous sclerotherapy of lymphatic malformations, to determine the most suitable. Material and methodsRetrospective study based on outcomes from percutaneous sclerotherapy performed on lymphatic malformations of 56 patients conducted by pediatric interventional radiologist for 14 years. As first approach, the procedure consists of ultrasound-guided introduction of sclerosing agent. Sessions were repeated until clinical resolution. Success, number of sessions and the duration of treatment were recorded and statistical treatment of the data was performed to obtain further conclusions. ResultsLost patients in follow up and other minority agents used were excluded from the data. Eventually, 52 patients treated with OK432 (n=29), Ethibloc (n=5) and combination therapy (n=18) were included. The average number of sessions and duration in months of treatment was respectively 2.38 and 8.6 for OK432, 1.4 and 5.6 for Ethibloc, and 1.83 and 2.30 for dual therapy. The results were statistically significant for the difference in duration between OK432 and dual therapy. Also, 60–80 per cent of patients reached proper results related to success, but the difference was no significant among the agents. Other demographic and anatomical variables were analyzed, not showing any difference, which supports the homogeneity of the sample. ConclusionsDespite of no significant difference in success and number of sessions among agents, longer duration of treatment with OK432 than dual therapy could mean greater health costs and probably greater disturb for patient and family.

Tratamiento percutáneo de las malformaciones linfáticas en edad pediátrica: experiencia y resultados según el esclerosante empleado

ObjectiveAnalyze statistically the success, number of sessions required and complete duration of treatment of agents used in pediatric percutaneous sclerotherapy of lymphatic malformations, to determine the most suitable. Material and methodsRetrospective study based on outcomes from percutaneous sclerotherapy performed on lymphatic malformations of 56 patients conducted by pediatric interventional radiologist for 14 years. As first approach, the procedure consists of ultrasound-guided introduction of sclerosing agent. Sessions were repeated until clinical resolution. Success, number of sessions and the duration of treatment were recorded and statistical treatment of the data was performed to obtain further conclusions. ResultsLost patients in follow up and other minority agents used were excluded from the data. Eventually, 52 patients treated with OK432 (n=29), Ethibloc (n=5) and combination therapy (n=18) were included. The average number of sessions and duration in months of treatment was respectively 2.38 and 8.6 for OK432, 1.4 and 5.6 for Ethibloc, and 1.83 and 2.30 for dual therapy. The results were statistically significant for the difference in duration between OK432 and dual therapy. Also, 60-80% of patients reached proper results related to success, but the difference was no significant among the agents. Other demographic and anatomical variables were analyzed, not showing any difference, which supports the homogeneity of the sample. ConclusionsDespite of no significant difference in success and number of sessions among agents, longer duration of treatment with OK432 than dual therapy could mean greater health costs and probably greater disturb for patient and family.