A modified double-incision technique to place tunneled central lines in children.

In children, there are two main techniques for placing a tunneled central venous catheter: single-incision (single puncture) and conventional (two punctures). Both have unique advantages and disadvantages. The modified single-stick technique combines the two aforementioned techniques to access the central venous system in an optimized way. This technique is feasible to perform particularly in young children and has a short learning curve for adult interventional radiologists.

Selective iliofemoral stent placement for complex pediatric cases: a decade of institutional experience.

BACKGROUND: Pediatric iliofemoral venous thromboembolism that is resistant to conventional treatments poses significant management challenges. Stent placement represents a potentially underutilized strategy in children when stenosis or thrombosis persists intraprocedurally or recurs postoperatively, despite treatments such as venoplasty, lysis, and thrombectomy. OBJECTIVE: This study aims to report our institutional experience with iliofemoral stenting in 17 pediatric patients with recurrent iliofemoral venous thromboembolism or stenosis. MATERIALS AND METHODS: We performed an IRB-approved retrospective review of pediatric patients (<18 years of age) who underwent iliofemoral venous stenting for recurrent stenosis or thrombosis between January 2012 and December 2022 at a single tertiary care institution. Patient demographics, risk factors for venous thromboembolism, presenting symptoms, and procedural characteristics were recorded. The primary outcome was stent patency rates at interval imaging follow-up. RESULTS: Seventeen patients with mean age of 14.6 years (range 7-17) and mean BMI of 27.7 were stented during the study period. Sixteen of 17 patients presented with evidence of May-Thurner anatomy. 14/17 patients presented with acute iliofemoral venous thromboembolism, 2/17 with chronic venous thromboembolism, and 1/17 with left lower extremity swelling without thrombosis. Seventy-three total angiographic procedures were performed, which included angioplasty, lysis, and thrombectomy, and 23 stent placements. Patients underwent an average of 3 procedures (range 1-9) over a mean of 2.8 months (range 0-17 months) prior to undergoing stent placement. Stents were deployed successfully in all patients. The median follow-up was 18 months (range, 1-77 months). Primary and secondary patency rates were 13/17 (76%) and 14/14 (100%) at 12 months and 12/17 (71%) and 14/14 (100%) at 24 months, respectively. CONCLUSION: In our experience of 17 patients, stent placement appears to be a durable option for children with iliofemoral venous thromboembolism following failure to establish vessel patency or development of recurrent thrombosis/stenosis postoperatively.

Ureteral stricture after pediatric kidney transplantation: Is there a role for percutaneous antegrade ureteroplasty?

INTRODUCTION: Ureteral obstruction following pediatric kidney transplantation occurs in 5-8% of cases. We describe our experience with percutaneous antegrade ureteroplasty for the treatment of ureteral stricture in pediatric kidney transplant patients. METHODS: We retrospectively reviewed all pediatric kidney transplantation patients who presented with ureteral stricture and underwent percutaneous antegrade ureteroplasty at our institution from July 2009 to July 2021. Variables included patient demographics, timing of presentation, location and extent of stricture, ureteroplasty technique and clinical outcomes. Our primary outcome was persistent obstruction of the kidney transplant. RESULTS: Twelve patients met inclusion criteria (4.2% of all transplants). Median age at time of ureteroplasty was 11.5 years (range: 3-17.5 years). Median time from kidney transplantation to ureteroplasty was 3 months. Patency was maintained in 50% of patients. Seven patients (58.3%) required additional surgery. Four patients developed vesicoureteral reflux. Patients with persistent obstruction had a longer time from transplant to ureteroplasty compared to those who achieved patency (19.3 vs 1.3 months, p = 0.0163). Of those treated within 6 months after transplantation, two patients (25%) required surgery for persistent obstruction (p = 0.06). All patients treated >1 year after transplantation had persistent obstruction following ureteroplasty (p = 0.06). CONCLUSION: Percutaneous antegrade ureteroplasty can be considered a viable minimally invasive treatment option for pediatric patients who develop early ureteral obstruction (<6 months) following kidney transplantation. In patients who are successfully treated with ureteroplasty, 67% can develop vesicoureteral reflux into the transplant kidney. Patients who fail early percutaneous ureteroplasty or develop obstruction >1 year after transplantation are best managed with surgical intervention.

Appendix to the Society of Interventional Radiology Consensus Guidelines for the Periprocedural Management of Thrombotic and Bleeding Risk in Patients Undergoing Percutaneous Image-Guided Interventions: Pediatric Considerations.

PURPOSE: To provide guidance on the use of anticoagulant and antithrombotic agents in pediatric patients undergoing interventional radiology procedures. MATERIALS AND METHODS: A multidisciplinary writing group conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were developed for procedural risk and medication dosage and withholding. A modified Delphi technique was used to achieve consensus agreement on the recommendations. RESULTS: A total of 24 studies, including systematic reviews and meta-analyses, randomized controlled trials, and prospective and retrospective cohort studies, were identified as relevant. The expert writing group agreed on procedural risk categorization, laboratory testing thresholds, and medication dosage and withholding recommendations specific to pediatric practice. They additionally described the nuances of anticoagulation in clinical conditions specific to pediatrics. CONCLUSIONS: The Society of Interventional Radiology recommends following the guidance provided in the document when developing multidisciplinary management protocols for anticoagulation and antithrombotic treatment in pediatric patients undergoing interventional radiology procedures.

Integration of a dedicated management protocol in the care of pediatric liver cancer: From specialized providers to complication reduction.

INTRODUCTION: Up to a third of children undergoing partial hepatectomy for primary hepatic malignancies experience at least one perioperative complication, with a presumed deleterious effect on both short- and long-term outcomes. We implemented a multidisciplinary treatment protocol in the management of these patients in order to improve complication rates following partial hepatectomy. METHODS: A retrospective chart review was completed for all patients < 18 years of age who underwent liver resection at our institution between 2002 and 2019 for primary hepatic cancer. Demographic, intraoperative, postoperative, pathologic, and outcome data were analyzed for perioperative complications using the CLASSIC and Clavien-Dindo (CD) scales, event-free survival (EFS) and overall survival (OS). RESULTS: A total of 73 patients were included in the analysis with 33 prior-to and 40 after dedicated provider protocol implementation. Perioperative complication rates decreased from 52% to 20% (p = 0.005) with major complications going from 18% to 10% (p = 0.31). On multivariable logistic regression, protocol implementation was associated with a reduction in any (OR 0.29 [95% CI 0.09 - 0.89]) but not major complications. On multivariate cox models, post protocol implementation was associated with improved event free survival (EFS) (HR 0.19 (0.036 - 0.195). Among patients with a diagnosis of hepatoblastoma (n = 62), the occurrence of a major perioperative complication was associated with a worse EFS (HR=5.45, p = 0.03) on multivariate analysis, however this did not translate into an impact on overall survival. CONCLUSIONS: Our results demonstrate that, for children with primary liver malignancies, a dedication of patients to high-volume surgeons can improve rates of complications of liver resections and may improve the oncological outcome of hepatoblastoma.

Surgical Approach to Pediatric Ovarian Growing Teratoma Syndrome: A Case Report.

BACKGROUND: Growing teratoma syndrome is defined as conversion of a metastatic immature tumor to a mature tumor after adjuvant chemotherapy and remains an area of investigation because of its unclear pathogenesis. Because of its risk of malignant transformation, the primary treatment strategy for pediatric patients is surgical resection. CASE: In this report we present a case of a pediatric patient with recurrent growing teratoma syndrome who was treated with chemotherapy, debulking procedures, and cryoablation for the growing nodules throughout her abdominal cavity. The patient has had a good clinical outcome without recurrent malignant tumor. SUMMARY AND CONCLUSION: These masses do not always regress with chemotherapy and complete surgical excision or ablation should be attempted when possible.

Transarterial Radioembolization Treatment as a Bridge to Surgical Resection in Pediatric Hepatocellular Carcinoma.

BACKGROUND: Children with unresectable hepatocellular carcinoma (HCC) have a poor prognosis and limited treatment options. Transarterial radioembolization (TARE) using Yttrium-90 (Y90) has emerged as a potential bridge therapy to hepatic resection or transplantation for HCC with very limited studies in children. OBSERVATIONS: Here we present the clinical course of 2 children successfully treated with TARE Y90 for initially unresectable fibrolamellar HCC (FL-HCC) and bridged to partial hemihepatectomy with >1-year overall survival post-TARE. CONCLUSION: Although there have been prior published reports of pediatric patients with HCC being treated with TARE Y90 and some being able to undergo subsequent orthotopic liver transplantation, this is the first report of pediatric HCC patients treated with TARE Y90 as a bridge to nontransplant resections and going on to have >1-year overall survival.

Clinical characteristics and outcomes of combined thrombolysis and anticoagulation for pediatric and young adult lower extremity and inferior vena cava thrombosis.

Effective treatment for acute, extensive, symptomatic lower extremity (LE) thrombosis involves thrombolysis in addition to anticoagulation. There is limited available data on the outcomes and safety of thrombolysis to help guide its use in pediatrics and young adults. A retrospective study of children and young adults (<21 years of age) that received catheter directed thrombolysis (CDT) for LE and inferior vena cava (IVC) thrombosis was performed over a 5-year span at a pediatric tertiary care center. A total of 29 patients were identified for inclusion in the study, 76% (n = 22) received overnight CDT while 24% (n = 7) received tissue plasminogen activator as a bolus dose during a single interventional procedure. The median age of the cohort was 15.8 years (range 0-19.1). All patients were treated with a course of therapeutic anticoagulation. The thromboses represented were extensive, with 93% (n = 27) being occlusive and affecting multiple venous segments. Thrombus resolution occurred in 35% (n = 10) of patients. Rivaroxaban use (p < 0.01) during the course of anticoagulation and estrogen-containing hormonal therapy (p = 0.01) use prior to diagnosis were associated with thrombus resolution, while Hispanic ethnicity (p = 0.06) had a trend toward thrombus persistence. There were one major and 3 minor bleeding events that occurred as complications of thrombolysis and no treatment related deaths. This study provides baseline information that can be used to help guide clinicians treating similar patients and suggests the need to develop an improved, uniform treatment approach for superior resolution rates.

Diagnosis, Clinical Characteristics, and Treatment Modalities of Adolescent May-Thurner Syndrome-associated Deep Venous Thrombosis.

May-Thurner syndrome (MTS) predisposes individuals to develop lower extremity deep venous thrombosis (DVT) because of compression of the left common iliac vein. Diagnosis of the anatomic obstruction is critical for effective therapy, as treatment by interventional radiology is often required in addition to anticoagulation to prevent thrombus progression and recurrence. The authors performed a retrospective review of adolescent patients who presented with MTS-associated DVT at a pediatric tertiary care center from 2009 to 2018 to assess for delays in MTS diagnosis after the presentation. Fourteen patients (median age 16.5 y, range, 13.8 to 17.9 y) were included, no DVTs were provoked by a central venous catheter. The median time from DVT to MTS diagnosis was 0.65 months (range, 0 to 21.5 mo). The initial imaging modalities used for DVT diagnosis were not able to diagnosis MTS. All patients were treated with anticoagulation and 13 underwent interventional therapy. Four patients had thrombus progression or recurrence, whereas 6 had complete thrombus resolution on follow-up imaging. Three patients who had a delayed MTS diagnosis had clinical worsening despite therapeutic anticoagulation requiring rehospitalization. Adolescent patients with "unprovoked" left lower extremity DVT should undergo appropriate imaging to diagnose MTS to allow for adequate medical and interventional therapy.

Response to Denosumab in 2 Children With Recurrent Giant Cell Tumor of the Bone With Pulmonary Metastasis.

Giant cell tumor of the bone (GCTB) is an uncommon bone tumor, usually localized, and rarely presents at <20 years of age. Denosumab, a fully human monoclonal antibody against RANKL (receptor activator of nuclear factor κB ligand), is approved for the treatment of unresectable GCTB in skeletally mature individuals. We present a case series of 2 pediatric patients with recurrent GCTB with pulmonary metastasis, with clinical response to denosumab therapy.

Safely repositioning dual-lumen ECMO cannulas with a transfemoral lasso snare.

INTRODUCTION: Dual-lumen cannulas were designed to provide venovenous extracorporeal membrane oxygenation (VV ECMO) with single-vessel access. Anatomic and size considerations may make appropriate placement challenging in children. Dual-lumen cannulas are repositioned in 20-69% of pediatric patients, which can be difficult without transient discontinuation of ECMO support. METHODS: We repositioned three dual-lumen ECMO cannulas introduced via the right internal jugular vein using a transfemoral snare technique under real-time ultrasound and fluoroscopy. RESULTS: Two of three patients were supported on VV ECMO and one on veno-veno-arterial (VV-A) ECMO. Two of the three patients had their dual-lumen cannula repositioned under ultrasound and fluoroscopy guidance and one was repositioned just with ultrasound. No patient experienced a complication from the transfemoral snare technique such as femoral hematoma, hemorrhage or limb ischemia. CONCLUSION: We describe three patients who successfully had dual-lumen cannulas repositioned without cessation of ECMO using a transfemoral "lasso" technique.

Diagnostic sensitivity and specificity of CT angiography for renal artery stenosis in children.

BACKGROUND: Children with suspected renal artery stenosis (RAS) are screened with renal Doppler ultrasonography or computed tomography (CT) angiography/magnetic resonance (MR) angiography depending on institutional preference. CT angiography produces images with superior resolution, allowing higher quality multiplanar two-dimensional reformats and three-dimensional reconstructions. However, there is a paucity of data in the literature regarding the utility and diagnostic performance of renal CT angiography in pediatric RAS. OBJECTIVE: The objective of this study is to retrospectively review our experience with renal CT angiography in the diagnosis of pediatric RAS relative to digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS: All patients 0-18 years of age who underwent CT angiography for evaluation of RAS as a cause of hypertension between January 2012 and May 2019 were identified for the study. A total of 131 patients were identified, 23 of whom had DSA correlation. RESULTS: Twenty-three patients (17 boys, 6 girls) with a mean age of 6 years 3 months (range: 3 months to 14 years 7 months) were included in this study. Of the 59 renal arteries studied by DSA, 22 were abnormal on CT angiography and 20 were abnormal on DSA. Of the 59 renal arteries, CT angiography was true positive in 18 and true negative in 35. The sensitivity and specificity of CT angiography for RAS diagnosis were 90.0% and 89.7%, respectively. CT angiography identified all cases of main RAS. CONCLUSION: Renal CT angiography has a high sensitivity and specificity for pediatric RAS diagnosis in patients referred for DSA.

Renal Lymphangiectasia in a Pediatric Patient.

Renal lymphatic abnormalities are rare, and the understanding of pathophysiology involving renal lymphatics is limited. Symptoms can include hypertension, hematuria, proteinuria, chyluria, and abdominal and lumbar pain. Imaging techniques specific to the renal lymphatics have not been clarified. We review the intrahospital imaging evaluation/workup and clinical course of a 6-year-old male who presented to our institution with a large perirenal cyst. His presentation presented a diagnostic and management challenge. The cyst was determined to be lymphatic in origin and required multiple interventional radiology and surgical procedures for management.

A multidisciplinary approach to VA ECMO cannulation in children.

PURPOSE: Extracorporeal membrane oxygenation (ECMO) supports gas exchange and circulation in critically ill patients. This study describes a multidisciplinary approach to ECMO cannulation using the expertise of pediatric surgery (PS) and interventional radiology (IR). MATERIAL AND METHODS: Pediatric patients (<18 years) undergoing percutaneous cannulation for peripheral veno-arterial (VA) ECMO by PS and IR from April 2017 to May 2018 were included. Cardiac patients and children cannulated by PS alone were excluded. RESULTS: Five patients were included in the series. Median age was 16 [12.5-17] years and 3 were female. Median ECMO arterial and venous catheter sizes were 19 [17-22] Fr and 25 [25-28] Fr, respectively. Both catheters were placed in the common femoral vessels. A 6Fr antegrade distal perfusion cannula (DPC) was also placed in the superficial femoral artery by IR at the time of cannulation. The median time from admission to procedure start was 10 [7-50] hours and the children were on ECMO for a median length of 3.2 [2.3-4.8] days. There were two episodes of bleeding. No patients had loss of limb circulation. CONCLUSION: A multidisciplinary approach to peripheral VA ECMO cannulation is feasible and safe. Maintenance of limb perfusion by percutaneous placement and removal of DPC may be an advantage of this collaborative approach. LEVEL OF EVIDENCE: IV. TYPE OF RESEARCH: Case series.

Role of interventional radiology in the diagnosis and management of congenital extrahepatic portosystemic shunts: Two case reports.

Congenital extrahepatic portosystemic shunt (CEPS) is a rare splanchnic venous malformation, wherein the portal venous outflow drains into the systemic venous circulation via a pathologic shunt. CEPS exhibits heterogeneous clinical behavior and angiography is the gold standard for evaluation of the portomesenteric communication to systemic vasculature. The potential severity of complications necessitates shunt closure. Here, we present two cases of CEPS. The first patient presented with an asymptomatic hyperammonemia and was found to have a Type 1 CEPS with absence of intrahepatic portal system. The second patient was asymptomatic and was incidentally found to have a Type 2 CEPS on imaging with normal intrahepatic portal system. Both patients were successfully treated with endovascular occlusion of the CEPS.

Transarterial radioembolization with yttrium-90 of unresectable primary hepatic malignancy in children.

BACKGROUND: Primary malignant liver tumors are rare, accounting for 1% to 2% of all childhood cancers. When chemotherapy fails, transarterial radioembolization with yttrium-90 (TARE-Y90) may offer an alternative therapy as a bridge to surgical resection or liver transplant or for palliation. METHODS: We conducted a retrospective review of 10 pediatric patients with histologically confirmed primary liver malignancy who received treatment with TARE-Y90. RESULTS: The median age at treatment was 5.5 years (range, 2-18 years). Median patient survival from initial diagnosis was 12.5 months (range, 10-28 months), and median patient survival after TARE-Y90 was 4 months (range, 2-20 months). Retreatment was well tolerated in three of 10 patients, with these patients demonstrating the longest survival times (range, 17-20 months). One patient was transplanted 6 weeks after TARE-Y90. By RECIST 1.1 criteria of all target lesions, eight of nine patients had stable disease, and one of nine had progressive disease. By mRECIST criteria (requiring postcontrast arterial phase imaging), two of seven patients had a partial response, four of seven had stable disease, and one of seven had progressive disease. CONCLUSION: TARE-Y90 of unresectable primary liver malignancy is both technically feasible and demonstrates an anticancer effect, and retreatment is well tolerated. TARE-Y90 could be considered as adjunctive therapy in pediatric patients with unresectable hepatic malignancies and could be used as a bridge to surgical resection or liver transplant. More research is required to determine the efficacy of this treatment in children and to define the clinical scenarios where benefit is likely to be optimized.

Ultrasound-guided cervical puncture for nusinersen administration in adolescents.

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal-recessive disease affecting motor neurons and is the most common genetic cause of death in infants. Intrathecal nusinersen is the only therapy approved by the U.S. Food and Drug Administration for SMA. Deformities and spinal instrumentation from orthopedic surgeries are common in children with SMA, complicating traditional intrathecal access for nusinersen delivery. Cervical punctures are routinely performed in adults for cervical myelograms and should be considered for children with SMA as a viable form of intrathecal access. OBJECTIVE: This retrospective study assessed technical feasibility and complications of ultrasound-guided cervical puncture for nusinersen administration. MATERIALS AND METHODS: We reviewed 14 consecutive ultrasound-guided cervical punctures for nusinersen administration with local anesthesia. We reviewed technical success and complications. RESULTS: All procedures were technically successful. There were no major complications. Two minor complications included headaches that resolved by observation within 24 h after the procedure. CONCLUSION: Our series describes a successful novel method of ultrasound-guided cervical spine access for intrathecal administration of nusinersen, adding to the armamentarium of procedures for delivering nusinersen to adolescents with challenging lumbar spine access caused by scoliosis and spinal instrumentation. This technique has the advantages of real-time ultrasound guidance and potential avoidance of general anesthesia in children.

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."