Safety of Periprocedural Antithrombotics during Pediatric Transplant Liver Biopsies.

The purpose of this study was to compare the adverse event (AE) rates of percutaneous pediatric transplant liver biopsies in patients receiving periprocedural antithrombotic agents with those in patients not receiving them. A 19-year retrospective single-center study of ultrasound-guided transplant liver biopsies was conducted. Patients who received aspirin for <5 days (n = 51) or heparin <4 hours (n = 15) before biopsy were separately grouped. AEs were reported using the Society of Interventional Radiology classification. In 276 biopsy samples from patients with a mean age of 6.75 years ± 5.80, the overall AE (P = .72) and moderate AE (P = .78) rates for control and antithrombotic groups were not significantly different. No severe AEs or deaths occurred. In conclusion, aspirin continuation during percutaneous pediatric transplant liver biopsies may be safe, but more studies are necessary to confirm the safety of periprocedural heparin.

Transplant renal vein stent placement complicated by obstructive hematuria: A case report.

BACKGROUND: Renal vein stenosis is uncommon following transplantation. We report acute renal vein stenosis post-transplant treated with an endovascular stent and complicated by urinary obstruction from clot formation. METHODS: Retrospective case report. RESULTS: A 16-year-old female 3 years post-transplant suffered anuria post-stenting with renal ultrasound demonstrating obstructive clot in the collecting system, a previously unreported complication. Subsequent nephroureteral JJ stent placement resulted in high-volume urine output. CONCLUSION: This article underscores the high index of suspicion required for renal vein stenosis following transplantation and the need to monitor urine output closely following stent placement.

Percutaneous treatment of symptomatic deep vein thrombosis in adolescents using large-bore thrombectomy systems.

BACKGROUND: While large-bore mechanical thrombectomy provides effective venous thrombus removal, often with avoidance of thrombolytics, literature surrounding the application of these devices in pediatric patients is sparse. OBJECTIVE: To report technical success and outcomes following large-bore thrombectomy systems in adolescent patients with deep venous thrombosis. MATERIALS AND METHODS: A retrospective review identified all patients less than 18 years of age undergoing mechanical venous thrombectomy at a single institution between 2018 and 2022. No patients were excluded. Technical success was defined as extraction of thrombus sufficient to restore unimpeded flow in affected segments. Clinical success was defined as resolution of presenting symptoms. RESULTS: Nine consecutive patients (6 females, 3 males; age range 15-17 years) underwent 10 thrombectomy procedures using ClotTriever (n=6; 60%), FlowTriever (n=2; 20%), or both (n=2; 20%). Chronicity of thrombus was categorized as acute (<2 weeks) in 6 (60%), subacute (2-6 weeks) in 1 (10%), and chronic (>6 weeks) in 3 (30%). Distribution of thrombus was lower extremity and/or inferior vena cava (IVC) in 9 (90%) and unilateral axillo-subclavian in 1 (10%). Technical success was achieved in 9 interventions (90%). Clinical success was achieved in 8 patients (88.9%). No patients received thrombolytics. There were no intraprocedural adverse events (AE). Minor complications (Society of Interventional Radiology mild adverse events) were observed in a delayed fashion following 2 interventions (20%). CONCLUSIONS: This preliminary experience demonstrated high rates of technical and clinical success with large-bore deep venous thrombectomy in adolescent patients across a range of thrombus chronicity and locations.

Time-Driven Cost Analysis of Noncuffed Venous Catheter Placement in Infants: Bedside versus IR Suite.

PURPOSE: To compare the direct bundled costs of interventional radiology (IR) suite versus bedside placement of noncuffed central venous catheters in infants. METHODS: A single-center retrospective review was performed of all noncuffed upper extremity (peripherally inserted central venous catheter [PICC]) and tunneled femoral (tunneled femoral central venous catheter [TCVC]) catheters placed in infants between January 1, 2018, and December 31, 2018. Propensity score matching was performed adjusting for age, birth weight, procedure weight, and catheter days. Process maps for each procedure were created based on location and sedation type. Technical success and complications were recorded for each placement. The total direct bundled cost for each catheter placement was calculated by summing the procedure and complication costs. RESULTS: A total of 142 procedures were performed on 126 matched patients with a technical success of 96% at the bedside and 100% in the IR suite (P = .08). The complication rates did not significantly differ between the 2 groups (P = .51). The total direct bundled costs for catheter placement were $1421.3 ± 2213.2 at the bedside and $2256.8 ± 3264.7 in the IR suite (P = .001). CONCLUSIONS: The bundled cost of bedside femoral catheter placement is significantly less than that of fluoroscopic TCVC and PICC placement performed in the IR suite, mainly related to differences in sedation costs.

Ultrasound Evaluation of Pediatric Slow-Flow Vascular Malformations: Practical Diagnostic Reporting to Guide Interventional Management.

OBJECTIVE. This article reviews the ultrasound characteristics of pediatric slow-flow vascular malformations and underscores findings that significantly impact diagnosis and treatment. Key imaging features are discussed including lesion size, malformation location, morphology, and mimics. CONCLUSION. Ultrasound findings affect the management of slow-flow vascular malformations and should be emphasized in lesion diagnosis. Superficial, focal lesions with well-defined margins are ideal for ultrasound evaluation.

Line days as a determinant of central line-associated bloodstream infections in pediatric patients with tunneled femoral peripherally inserted central catheters.

BACKGROUND: Ultrasound (US)-guided tunneled femoral peripherally inserted central catheters (PICCs) are a safe central venous access option in infants and neonates. Studies have shown, however, that femoral central venous access has the potential for high central line-associated bloodstream infection (CLABSI) rates with a significant increase in risk around line day 30, though no studies have evaluated these risks exclusively for tunneled femoral PICCs. OBJECTIVE: The primary purpose of this study was to evaluate the relationship between line duration and the risk of CLABSI in tunneled femoral PICCs in children. MATERIALS AND METHODS: Four hundred forty-five patients (196 females, 249 males; median age: 49.4 days; median weight: 3.7 kg) who underwent 573 tunneled femoral PICC placements or exchanges from Jan. 1, 2017, to Jan. 31, 2020, were included in the study. All tunneled femoral PICCs were placed using US technique and catheter specifications, including catheter size (French) and length (cm), were retrieved from the electronic medical record. The location of the PICC placement, the number of lumens, the laterality of placement, and the patient's age and weight were also recorded. Only non-mucosal barrier injury CLABSIs, according to the Centers for Disease Control and Prevention (CDC) definitions, were counted as CLABSI for this study. The number of central line days until a CLABSI event was analyzed with an accelerated failure time model using the exponential, Weibull, and log-normal distributions to determine the probability of a CLABSI over time, taking into consideration the recorded covariates. RESULTS: Tunneled femoral PICC placements accounted for 14,855 line days, during which 20 non-mucosal barrier injury CLABSIs (CLABSI rate of 1.35 per 1,000 line days) occurred during the study period. The highest CLABSI rate occurred in PICCs placed in the neonatal intensive care unit (NICU) at 2.01 per 1,000 line days and the lowest occurred in PICCs placed in interventional radiology at 0.26 per 1,000 line days. Overall, PICCs placed outside of interventional radiology had a CLABSI rate of 1.72 per 1,000 line days. The CLABSI rate during the first 30 days a line was in situ was lower than the rate after 30 days (0.51 per 1,000 line days vs. 3.06 per 1,000 line days, respectively). Statistical modeling and hazard estimation using the Akaike information criterion corrected for small sample size (AICc)-average of log-normal, Weibull and exponential distributions demonstrate the daily risk of CLABSI rapidly increases from day 1 to day 30, with the risk remaining high for the duration of line days. CONCLUSION: While tunneled femoral PICCs are a relatively safe and effective central venous access alternative, the rate of CLABSI appears to rapidly increase with increasing line days until around day 30 and then remains high thereafter.

Confirmatory radiographs have limited utility following ultrasound-guided tunneled femoral central venous catheter placements by interventional radiology.

BACKGROUND: Ultrasonography may reliably visualize both appropriately positioned and malpositioned femoral-approach catheter tips. Radiography may be used to confirm catheter tip position after placement, but its utility following intraprocedural ultrasound (US) catheter tip verification is unclear. OBJECTIVES: To report the utility of confirmatory radiographs after US-guided tunneled femoral central venous catheter (CVC) placements by interventional radiology in pediatric patients. MATERIALS AND METHODS: A total of 484 pediatric patients underwent bedside US-guided tunneled femoral CVC placements in an intensive care setting at a single tertiary children's hospital between Jan. 1, 2016, and April 20, 2020. Technical success, adverse events, post-procedure radiographic practices and inter-modality catheter tip concordance were recorded. All radiographs were performed within 12 h of catheter placement. RESULTS: The mean patient age was 175±508 days (range: 1 day to 19 years), including 257 (53.1%) males and 227 (46.9%) females. Of the 484 attempted placements, 472 (97.5%) were primary placements. Four hundred eighty-one (99.4%) placements were technically successful. There were three (0.6%) technical failures due to previously undiagnosed iliofemoral venous occlusive disease. Five (1.0%) adverse events occurred. Radiographs were obtained within 12 h of CVC placement in 171 (35.3%) patients, in 120 (70.2%) of whom the indication was recent catheter placement. All 171 (100%) post-placement radiographs showed catheter tip location concordance with the intra-procedural US. In one (0.2%) patient, in whom there was nonvisualization of a guidewire and clinical concern for malposition during US-guided placement, post-procedure radiographs, coupled with multiplanar venography, demonstrated inadvertent paravertebral venous plexus catheter placement. CONCLUSION: The concordance between intra-procedural US and confirmatory post-procedure radiographs of CVC placements by interventional radiology obviates the need for routine radiographs. Radiographs may be obtained in instances of proceduralist uncertainty or clinical concern.

Radiofrequency ablation vs microwave ablation for osteoid osteomas: long-term results.

OBJECTIVE: Osteoid osteomas are benign bone tumors commonly treated using thermal ablation. We compare the technical success, complication rates, and long-term efficacy of the two most common ablation types: radiofrequency and microwave. MATERIALS AND METHODS: A retrospective study was performed of all osteoid osteoma ablation procedures between 2007 and 2017. A ten-point numerical pain scale was used to quantify symptoms before and after the procedures with > 12-month follow-up. Complications were reported using the Society of Interventional Radiology Adverse Events reporting criteria. RESULTS: Twenty-nine patients successfully underwent 15 radiofrequency ablations and 15 microwave ablations with a technical success rate of 83% for radiofrequency and 100% for microwave (p = 0.23). Long-term recurrence rates (p = 1.0) and complication rates (p = 0.60) were not significantly different for the groups. One patient developed a skin burn following microwave ablation and another developed 12 months of sciatic neuropathy following radiofrequency ablation. CONCLUSION: Microwave and radiofrequency ablation are safe and effective methods for treating osteoid osteomas with similar long-term efficacies. Although radiofrequency ablation is more commonly reported to result in skin burns, this complication can arise during microwave ablation.

Effects of Mechanical Complications on Radiation Exposure During Fluoroscopically Guided Gastrojejunostomy Exchange in the Pediatric Population.

The purpose of the article is to evaluate the effects of mechanical complications, such as clogging or coiling, of gastrojejunostomy tubes on radiation exposure during exchange in the pediatric population. In this HIPAA-compliant and IRB-approved study, we retrospectively reviewed procedural records for patients undergoing gastrojejunostomy (GJ) tube exchange during a 4-month period in 2014. Success of the procedure, specifications of the tube, age, and sex of the patient as well as radiation exposure during the procedure were included. Radiation exposure was measured in fluoroscopy time and cumulative air kerma. Complications encountered during exchange were also recorded, if available. Patients presenting for gastrostomy to GJ conversions or combined procedures were excluded from the study. Ordinary and mixed effect linear regression models were used to test associations between GJ tube parameters, presence of mechanical complications, and fluoroscopy time and radiation dose. 146 patients undergoing 285 GJ exchanges met inclusion criteria over the 4-month study period (M:F 82:64). All exchanges were successful with 85 demonstrating a form of mechanical complication (44 coiled, 41 clogged). Of the reported GJ tube specifications, only tube length was significantly associated with mechanical complications (p < 0.001). The presence of mechanical complication was significantly associated with increased radiation exposure and fluoroscopy time (p < 0.0001). Mechanical complications of gastrojejunostomy tubes, such as clogging or coiling, are associated with increased radiation exposure during exchange. Strategies to decrease these complications, including re-siting the gastrostomy tract or placement of a surgical jejunostomy in the event of repeated coiling of a tube should be strongly considered.

Long-Term Patency of Arteriovenous Fistulae Salvaged by Balloon Angioplasty with and without Accessory Vein Embolization: A Retrospective Study.

PURPOSE: To investigate whether accessory vein embolization (AVE) improves long-term performance of salvaged nonmaturing arteriovenous fistulae (AVFs). MATERIALS AND METHODS: This retrospective review included 72 patients who underwent percutaneous balloon angioplasty for salvage of nonmaturing AVFs between 2008 and 2014. AVE was performed on 32 patients between 2008 and 2011 (mean age, 59 y [range, 33-85 y]; men, n = 21; women, n = 11; upper arm, n = 17; forearm, n = 15), whereas the procedure was not performed on 40 patients after 2011 (mean age, 62 y [range, 28-85 y]; men, n = 26; women, n = 14; upper arm, n = 26; forearm, n = 14). Endpoints compared between groups included number of procedures required to achieve maturation, time to maturation, number of procedures required to maintain patency, and duration of primary and secondary patency after intervention. RESULTS: There was no statistically significant difference in number of procedures to achieve maturation (2.1 ± 1.4 vs 2.4 ± 1.2; P = .24) or time to maturation (26.1 d ± 56.2 vs 41.1 d ± 54.6; P = .072) between AVE and no embolization groups. Primary (P = .21) and secondary patency (P = .14) after intervention were not significantly different between groups. The number of procedures performed to maintain patency after maturation was significantly greater in the AVE group for patients with forearm AVFs (0.11 ± 0.098 vs 0.04 ± 0.064 per patient year; P = .039) but not for patients with upper arm AVFs. CONCLUSIONS: AVE of AVFs after balloon angioplasty does not lead to significantly improved long-term outcomes. Percutaneous salvage of nonmaturing AVFs in the forearm without AVE resulted in a decreased number of interventions to maintain patency.

Time-Driven Activity-Based Cost Comparison of Osteoid Osteoma Ablation Techniques.

OBJECTIVE: Compare the cost of performing an osteoid osteoma ablation using cone beam CT (CBCT) with overlay fluoroscopic guidance to ablation using conventional CT (CCT) guidance and microwave ablation (MWA) to radiofrequency ablation (RFA). METHODS: An 11-year retrospective study was performed of all patients undergoing osteoid osteoma ablation. Ablation equipment included a Cool tip RFA probe (Covidien, Minneapolis, Minnesota) or a Neuwave PR MWA probe (Ethicon, Rariton, New Jersey). The room times as well as immediate recovery time were recorded for each case. Cost analysis was then performed using time-driven activity-based costing for rate-dependent variables including salaries, equipment depreciation, room time, and certain supplies. Time-independent costs included the disposable interventional radiology supplies and ablation systems. Costs were reported for each service providing care and using conventional cost accounting methods with variable and fixed expenditures. RESULTS: A total of 91 patients underwent 96 ablation procedures in either CBCT (n = 66) or CCT (n = 30) using either MWA (n = 51) or RFA (n = 45). The anesthesia induction (22.7 ± 8.7 min versus 15.9 ± 7.2 min, P < .001), procedure (64.7 ± 27.5 min versus 47.3 ± 15.3 min; P = .001), and room times (137.7 ± 33.7 min versus 103.9 ± 22.6. min; P < .001) were significantly longer for CBCT procedures. The procedure time did not differ significantly between MWA and RFA (62.1 ± 27.4 min versus 56.1 ± 23.3 min; P = .27). Multiple regression analysis demonstrated lower age (P = .046), CBCT use (P = .001), RFA use (P = .02), and nonsupine patient position (P = .01) significantly increased the total procedural cost. After controlling for these variables, the total cost of CBCT ($5,981.32 ± $523.93 versus $5,378.93 ± $453.12; P = .001) remained higher than CCT and the total cost of RFA ($5,981.32 ± $523.93 versus $5,674.43 ± $549.14; P = .05) approached a higher cost than MWA. CONCLUSION: The use of CBCT with overlay fluoroscopic guidance for osteoid osteoma ablation resulted in longer in-room times and greater cost when compared with CCT. These cost considerations should be weighed against potential radiation dose advantage of CBCT when choosing an image guidance modality. Younger age, RFA use, and nonsupine patient position additionally contributed to higher costs.

Embolization of pulmonary and systemic mycotic pseudoaneurysms in a pediatric patient.

Mycotic pseudoaneurysm is a rare complication of systemic infection in children. We report a case of a previously healthy 11-year-old female with methicillin-resistant staph aureus (MRSA) bacteremia who developed both pulmonary and systemic arterial pseudoaneurysms. These were detected on magnetic resonance (MR) and computed tomography (CT) imaging and treated with coil embolization.

Initial experience with the Ellipsys Vascular Access System for percutaneous arteriovenous fistula creation in adolescents: A case report.

This retrospective, single center, case report describes the first use of the Ellipsys Vascular Access System for percutaneous arteriovenous fistula (pAVF) creation in children. Two adolescent (<20 year of age) patients (18 and 19-year-old females), one of whom was developmentally delayed, were not considered candidates for traditional surgical arteriovenous fistula creation. pAVF creation was successful in both patients using the Ellipsys device and physiologic maturation of the fistula was achieved within 8 weeks of creation with subsequent 2 needle cannulation. No complications or adverse events were encountered. pAVF creation with the Ellipsys device can be safely performed in adolescents. Further studies will be needed to validate the expanded use of these devices in children.

Migration of n-BCA glue as a complication of venous malformation treatment in children.

Preoperative n-butyl cyanoacrylate (n-BCA) embolization of venous malformations facilitates surgical resection. Although embolization is generally well-tolerated, central venous n-BCA migration can occur. The purpose of this article is to describe 3 cases of glue migration requiring glue embolectomy. Strategies for prevention and treatment of glue migration during embolization of venous malformations are reviewed.

Combined endolymphatic and surgical treatment of a leaking central conducting lymphatic malformation in a neonate.

Lymphatic malformations are congenital alterations of normal embryonic lymphatic development. We present a case of a premature 7-week-old male with a large central conducting lymphatic malformation and significant abdominal chylorrhea. He was successfully treated with combined endolymphatic and surgical approaches. To the authors' knowledge, this is the first case to be described.

Transforaminal intrathecal delivery of nusinersen for older children and adults with spinal muscular atrophy and complex spinal anatomy: an analysis of 200 consecutive injections.

BACKGROUND: Nusinersen is the only approved treatment for all spinal muscular atrophy (SMA) subtypes and is delivered intrathecally. Distorted spinal anatomy and instrumentation preclude standard approaches for intrathecal access, necessitating alternative techniques for delivery. The purpose of this study is to report technical success and adverse events of transforaminal intrathecal delivery of nusinersen. METHODS: 28 patients, mean age 24.1±9.8 years (range 10.0-51.0 years), with intermediate or late onset SMA, underwent a combined 200 transforaminal nusinersen injections. All patients had osseous fusion or spinal instrumentation precluding standard posterior access routes. Patients who underwent nusinersen injections using a technique other than transforaminal lumbar puncture (n=113) were excluded. Technical success, adverse events (AEs) and radiation exposure were recorded. RESULTS: 200 (100%) procedures were technically successful; 6 (3%) required a second level of attempt for access. 187 (93.5%) interventions were completed using cone beam computed tomography (CBCT) with two-axis fluoroscopic navigational overlay. 13 (6.5%) procedures were performed with fluoroscopic-guidance only at subsequent sessions. There were 8 (4.0%) mild AEs and 2 (0.5%) severe AEs; one patient received antibiotics for possible traversal of the large bowel but did not develop meningitis, and one patient developed aseptic meningitis. Mean air kerma was 74.5±161.3 mGy (range 5.2-1693.0 mGy). CONCLUSION: Transforaminal intrathecal delivery of nusinersen is feasible and safe for gaining access in patients with distorted spinal anatomy. The use of CBCT delineates anatomy and optimizes needle trajectory during the initial encounter, and may be used selectively for subsequent procedures.

Attenuation of Shear Waves in Normal and Steatotic Livers.

Shear wave propagation in the liver has been a robust subject of research, with shear wave speed receiving the most attention. The correlation between increased shear wave speed and increased fibrosis in the liver has been established as a useful diagnostic tool. In comparison, the precise mechanisms of shear wave attenuation, and its relation to diseased states of the liver, are less well-established. This study focused on the hypothesis that steatosis adds a viscous (lossy) component to the liver, which increases shear wave attenuation. Twenty patients' livers were scanned with ultrasound and with induced shear wave propagation, and the resulting displacement profiles were analyzed using recently developed estimators to derive both the speed and attenuation of the shear waves within 6-cm2 regions of interest. The results were compared with pathology scores obtained from liver biopsies taken under ultrasound guidance. Across these cases, increases in shear wave attenuation were linked to increased steatosis score. This preliminary study supports the hypothesis and indicates the possible utility of the measurements for non-invasive and quantitative assessment of steatosis.

Pulmonary thromboembolic events in patients with congenital lipomatous overgrowth, vascular malformations, epidermal nevi, and spinal/skeletal abnormalities and Klippel-Trénaunay syndrome.

OBJECTIVE: Patients with Klippel-Trénaunay syndrome (KTS) and congenital lipomatous overgrowth, vascular malformations, epidermal nevi, and spinal/skeletal abnormalities (CLOVES) syndrome have central phlebectasia and enlarged persistent embryonic veins that are often incompetent and prone to thromboembolism. The purpose of the study was to determine the presence of phlebectasia and the incidence of symptomatic pulmonary embolism (PE). METHODS: A retrospective review was conducted of patients referred to the Vascular Anomalies Center at our institution during a 21-year period who were diagnosed with KTS and CLOVES syndrome. Of these, the patients who had PE were screened for thromboembolic risk factors in addition to phlebectasia and the presence of persistent embryonic veins. Treatment outcomes following subsequent endovascular and medical therapies were reported. RESULTS: A total of 12 KTS patients of 96 (12.5%) and 10 CLOVES syndrome patients of 110 (9%) suffered PE. Fourteen patients (64%) developed PE after surgery or sclerotherapy. All of the patients had abnormally dilated central or persistent embryonic veins; 20 patients were treated with anticoagulation (1 died at the time of presentation, and no information was available for 1) after PE, and 14 (66%) patients underwent subsequent endovascular treatment. Five patients developed recurrent PE despite anticoagulation. Two of the patients died of PE. No patients treated with endovascular closure of dilated veins had subsequent evidence of PE. CONCLUSIONS: Patients with KTS and CLOVES syndrome are at high risk for PE, particularly in the postoperative period.