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.

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.

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.

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.

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.

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.

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.

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.

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."

Comparison of pediatric radiation dose and vessel visibility on angiographic systems using piglets as a surrogate: antiscatter grid removal vs. lower detector air kerma settings with a grid - a preclinical investigation.

The purpose of this study was to reduce pediatric doses while maintaining or improv-ing image quality scores without removing the grid from X-ray beam. This study was approved by the Institutional Animal Care and Use Committee. Three piglets (5, 14, and 20 kg) were imaged using six different selectable detector air kerma (Kair) per frame values (100%, 70%, 50%, 35%, 25%, 17.5%) with and without the grid. Number of distal branches visualized with diagnostic confidence relative to the injected vessel defined image quality score. Five pediatric interventional radiologists evaluated all images. Image quality score and piglet Kair were statistically compared using analysis of variance and receiver operating curve analysis to define the preferred dose setting and use of grid for a visibility of 2nd and 3rd order vessel branches. Grid removal reduced both dose to subject and imaging quality by 26%. Third order branches could only be visualized with the grid present; 100% detector Kair was required for smallest pig, while 70% detector Kair was adequate for the two larger pigs. Second order branches could be visualized with grid at 17.5% detector Kair for all three pig sizes. Without the grid, 50%, 35%, and 35% detector Kair were required for smallest to largest pig, respectively. Grid removal reduces both dose and image quality score. Image quality scores can be maintained with less dose to subject with the grid in the beam as opposed to removed. Smaller anatomy requires more dose to the detector to achieve the same image quality score.

Outcomes in children with deep vein thrombosis managed with percutaneous endovascular thrombolysis.

BACKGROUND: Our center has developed a multidisciplinary approach to percutaneous endovascular thrombolysis with the goal of improving outcomes in children with thrombosis. There is little data describing the safety and efficacy of endovascular thrombolysis and the frequency of post-thrombotic syndrome after thrombolysis in children. OBJECTIVE: Retrospective analysis of children undergoing percutaneous endovascular thrombolysis to determine (1) the safety and efficacy of this procedure and (2) the frequency of the diagnosis of post-thrombotic syndrome after thrombolysis. MATERIALS AND METHODS: We reviewed the medical and imaging databases for children who underwent percutaneous endovascular thrombolysis for deep venous thrombosis (DVT) between November 2008 and June 2013 at our institution. Demographic data were reviewed for the technical success and complications of thrombolysis and the last assigned post-thrombotic syndrome score using standardized scoring tools. RESULTS: Forty-one children ages 3 months to 21 years (median age: 15 years; 44% male) underwent percutaneous endovascular thrombolysis between November 2008 and June 2013. Upper extremity DVT occurred in 13 patients (32%); lower extremity DVT occurred in 28 patients (68%). All 41 patients received thrombolysis grading; 90% of those patients achieved greater than 50% thrombus lysis. Twenty-eight patients received formal post-thrombotic syndrome scoring and 4 (14%) met diagnostic criteria for post-thrombotic syndrome. One major bleeding episode and one pulmonary embolism occurred with no long-term sequelae. CONCLUSION: Endovascular thrombolysis for DVT in children is safe, effective at thrombus removal and may reduce the incidence of post-thrombotic syndrome. Randomized or larger clinical trials would be needed to determine the long-term benefits of endovascular thrombolysis.

Endovascular venous thrombolysis in children younger than 24 months.

PURPOSE: To evaluate the technical feasibility and safety of percutaneous endovascular thrombolysis for extremity deep venous thrombosis (DVT) in children < 24 months old. MATERIALS AND METHODS: A retrospective chart review of a clinical and imaging database was performed for pediatric patients who underwent endovascular therapy for DVT between January 2010 and July 2013. Indications, techniques, technical and clinical success, and complications were reviewed. Techniques for thrombolysis included catheter-directed therapy (CDT) using alteplase infusion via a multi-side hole catheter, mechanical thrombectomy, and angioplasty. Short-term outcomes were assessed using surgical and imaging follow-up examinations for patency of the targeted vessel. Patients included 11 children (mean age, 9 mo; range, 3 wk-23 mo) who consecutively underwent endovascular thrombolysis for upper extremity (n = 6) or lower extremity (n = 5) DVT. The most common indication was preservation of venous access for future cardiac surgery or medical therapy. RESULTS: The most common risk factor was the presence of a central venous catheter (10 of 11 patients). All patients with upper extremity DVT had congenital heart disease. CDT and angioplasty were performed in all patients. Venous patency was established in all patients. A grade III (95%-100%) thrombolysis response was achieved in seven patients, and a grade II (50%-95%) thrombolysis response was achieved in four patients. A major complication of pulmonary embolism occurred in one patient with upper extremity thrombolysis and was managed by intravenous systemic alteplase and heparin. No recurrence of thrombosis was found on average follow-up of 11.8 months (range, 1-41 mo). CONCLUSIONS: Percutaneous endovascular thrombolysis for extremity DVT is safe and technically feasible in children < 24 months old.

Clinically useful dilution factors for iodine and gadolinium contrast material: an animal model of pediatric digital subtraction angiography using state-of-the-art flat-panel detectors.

BACKGROUND: Iodinated and gadolinium contrast agents pose some risk for certain pediatric patients, including allergic-like reactions, contrast-induced nephropathy (CIN) and nephrogenic systemic fibrosis (NSF). Digital flat-panel detectors enhance image quality during angiography and might allow use of more dilute contrast material to decrease risk of complications that might be dose-dependent, such as CIN and NSF. OBJECTIVE: To assess the maximum dilution factors for iodine- and gadolinium-based contrast agents suitable for vascular imaging with fluoroscopy and digital subtraction angiography (DSA) on digital flat-panel detectors in an animal model. MATERIALS AND METHODS: We performed selective catheterization of the abdominal aorta, renal artery and common carotid artery on a rabbit. In each vessel we performed fluoroscopy and DSA during contrast material injection using iodinated and gadolinium contrast material at 100%, 80%, 50%, 33% and 20% dilutions. An image quality score (0 to 3) was assigned by each of eight evaluators. Intracorrelation coefficient, paired t-test, one-way repeated analysis of variance, Spearman correlation and receiver operating characteristic curve analysis were applied to the data. RESULTS: Overall the image quality scores correlated linearly with dilution levels. For iodinated contrast material, the optimum cut-off level for DSA when a score of at least 2 is acceptable is above 33%; it is above 50% when a score of 3 is necessary. For gadolinium contrast material, the optimum cut-off for DSA images is above 50% when a score of at least 2 is acceptable and above 80% when a score of 3 is necessary. CONCLUSION: Knowledge of the relationship between image quality and contrast material dilution might allow a decrease in overall contrast load while maintaining appropriate image quality when using digital flat-panel detectors.

Symptomatic upper-extremity deep venous thrombosis after pacemaker placement in a pediatric patient: how to treat?

Symptomatic upper-extremity deep venous thrombosis (UEDVT) after pacemaker placement in adults has been reported, but the occurrence of UEDVT in pediatric patients is poorly defined, and no treatment guidelines exist. This report describes a 14-year old girl with a history of complete atrioventricular block who experienced a symptomatic UEDVT 8 months after placement of a transvenous pacemaker. The girl was treated initially with anticoagulation including subcutaneous enoxaparin and a heparin drip, which did not resolve the venous obstruction. In the interventional laboratory, a venogram demonstrated complete obstruction of the left subclavian vein, which was treated successfully with catheter-directed alteplase, direct thrombus removal by manual suctioning, and balloon angioplasty. Warfarin therapy was continued for an additional 6 months, with follow-up venous ultrasounds demonstrating left subclavian vein patency. Soon after completing warfarin therapy, the girl presented with minimal edema of her left distal extremity and was thought to have post-thrombotic syndrome, which resolved quickly. She continued to receive aspirin therapy, with no recurrence of symptoms. In conclusion, symptomatic UEDVT after pacemaker placement in a pediatric patient can be treated successfully with both anticoagulation and interventional therapies. Further studies are needed to evaluate the incidence of thrombus formation among children with transvenous pacemaker placement together with the development of guidelines based on the safety and effectiveness of differing treatments.

Inferior vena cava filters in children: our experience and suggested guidelines.

Although use of inferior vena cava (IVC) filters for prophylaxis against pulmonary embolism (PE) is well reported in adults, long-term studies in children are lacking. We performed retrospective review of imaging and clinical database of IVC filters for the last 12 years. Thirty-five patients (mean age: 15.5 y) underwent filter placement and/or retrieval. Indications for placement were contraindication to anticoagulation with known deep venous thrombosis (DVT) (18) or high risk of venous thromboembolism (5), recurrent DVT despite anticoagulation (1), and prophylaxis before endovascular thrombolysis (8). All filter placements were technically successful without any complications. Filter retrieval was successful in 15 of 19 attempted (79%) at a mean of 42 days. Two complications occurred during retrieval: IVC stenosis successfully treated with angioplasty and contained IVC perforation. Endothelialization of filter prevented retrieval in 4 patients. Mean follow-up was 29.3 months. No patients had IVC thrombosis, breakthrough pulmonary embolism, filter fracture, or embolism. Two patients had recurrent DVT. Our results indicate that IVC filters can be successfully placed and retrieved in children with minimal procedural complications; follow-up demonstrates acceptable complication rate owing to presence of filters. Prophylactic IVC filter placement may be considered before endovascular thrombolysis for lower extremity DVT. Retrievable filters should be used in children for appropriate indications.