Use of radial access sheaths for transfemoral neuroendovascular procedures in children.

PURPOSE: Pediatric neuroendovascular procedures require special considerations. Given small vessel sizes, risk for arterial injury must be weighed against use of larger devices, with the diameter of the sheath being a known association with arterial complications. We recently transitioned to using thin-walled radial sheaths for transfemoral angiography in children, given their lower profile. Here, we report on these sheaths' technical success and complications, comparing against a historical cohort where regular vascular sheaths were employed. METHODS: We retrospectively recorded patient and procedural data from 168 consecutive procedures from September 2017 to January 2019 when radial-specific sheaths were exclusively used at our tertiary pediatric hospital. These results were compared to data from September 2015 to January 2017, when regular vascular sheaths were exclusively used in 152 consecutive procedures. Statistical analysis was performed using unpaired t test or chi-square test, with p < 0.05 considered statistically significant. RESULTS: Patient characteristics (age, sex, weight) were not statistically different between the case and control group. No significant differences were found in the procedural data with the exception of heparin use which was higher in the radial-sheath cohort. There was a decrease in the rate of complications in the case group (1.2%) versus control group (2.6%), though not statistically different. CONCLUSION: Radial-specific sheaths have numerous beneficial characteristics that make them well-suited to the pediatric population. In our study, we show that radial sheaths are equally effective and safe perioperatively. Follow-up research may show if radial sheaths used transfemorally decrease long-term complications such as limb-length discrepancy and mortality.

CT reconstruction and MRI fusion of 3D rotational angiography in the evaluation of pediatric cerebrovascular lesions.

PURPOSE: Complex neurovascular lesions in children require precise anatomic understanding for treatment planning. Although 3DRA is commonly employed for volumetric reformation in neurointerventional procedures, the ability to reconstruct this data into CT-like images (3DRA-CT) is not widely utilized. This study demonstrates the feasibility and usefulness of 3DRA-CT and subsequent MRI fusion for problem solving in pediatric neuroangiography. METHODS: This retrospective study includes 18 3DRA-CT studies in 16 children (age 9.6 ± 3.8 years, range 2-16 years) over 1 year. After biplane 2D-digital subtraction angiography (DSA), 5-second 3DRA was performed with selective vessel injection either with or without subtraction. Images were reconstructed into CT sections which were post-processed to generate multiplanar reformation (MPR) and maximum intensity projection (MIP) images. Fusion was performed with 3D T1 MRI images to precisely demonstrate neurovascular relationships. Quantitative radiation metrics were extracted and compared against those for the entire examination and for corresponding biplane 2D-DSA acquisitions. RESULTS: In all 18 cases, the 3DRA procedure and MRI fusion were technically successful and provided clinically useful information relevant to management. The unsubtracted and subtracted 3DRA acquisitions were measured to deliver 5.9 and 132.2%, respectively, of the mean radiation dose of corresponding biplane 2D-DSA acquisitions and contributed 1.2 and 12.5%, respectively, to the total procedure dose. CONCLUSION: Lower radiation doses, high spatial resolution, and multiplanar reformatting capability make 3DRA-CT a useful adjunct to evaluate neurovascular lesions in children. Fusing 3DRA-CT data with MRI is an additional capability that can further enhance diagnostic information.

MR cone-beam CT fusion image overlay for fluoroscopically guided percutaneous biopsies in pediatric patients.

Lesions only visible on magnetic resonance (MR) imaging cannot easily be targeted for image-guided biopsy using ultrasound or X-rays but instead require MR guidance with MR-compatible needles and long procedure times (acquisition of multiple MR sequences). We developed an alternative method for performing these difficult biopsies in a standard interventional suite, by fusing MR with cone-beam CT images. The MR cone-beam CT fusion image is then used as an overlay to guide a biopsy needle to the target area under live fluoroscopic guidance. Advantages of this technique include (i) the ability for it to be performed in a conventional interventional suite, (ii) three-dimensional planning of the needle trajectory using cross-sectional imaging, (iii) real-time fluoroscopic guidance for needle trajectory correction and (iv) targeting within heterogeneous lesions based on MR signal characteristics to maximize the potential biopsy yield.

Clinical and subclinical microemboli following neuroangiography in children.

BACKGROUND: To assess the frequency, imaging appearances, and risk factors of brain microemboli following pediatric neuroangiography, as assessed by early diffusion-weighted MRI imaging (DWI). METHODS: This single-center, retrospective analysis investigated early DWI post-pediatric neuroangiography. Patients aged 0-18 years who had diagnostic neuroangiography and DWI within a week postprocedure were included. Data on clinical and procedural parameters and MRI findings were recorded. Univariate and multivariate analyses were performed on the following risk factors: age, weight, vasculopathy, antiplatelet drug use, access type, intraprocedural heparin, procedure duration, neck arteries catheterized, and angiographic runs. A p-value<0.05 indicated statistical significance. RESULTS: Eighty-two children were included (40.2% female), mean age 10.1±4.5 years (range: 7 months-17 years). There were no intraprocedural thromboembolic complications recognized. DWI positivity was seen following 3.6% (3/82) procedures: two with transient symptoms, and one instance of silent microemboli. There were no territorial infarcts or clinical stroke. Children with underlying vasculopathy had a higher risk of microemboli from angiography than children without vasculopathy (OR 31.6, p=0.02), and the OR of microemboli following transradial angiography was 79.1 (p=0.005) as compared with transfemoral angiography. Univariate and multivariate analysis showed a significant association between microemboli and number of angiographic runs (p=0.004). Follow-up MRI in all three patients showed no residual abnormal signal. CONCLUSIONS: Cerebral microemboli are unusual following uncomplicated neuroangiography in children. However, in the presence of underlying vasculopathy and with transradial technique, the incidence approaches that reported in the adult literature. An increased association with the number of angiographic runs is an important and controllable factor.

Peripherally Inserted Central Catheters in Pediatric Patients: To Repair or Not Repair.

INTRODUCTION: Preservation of venous access in children is a major concern in pediatric interventional radiology. If a peripherally inserted central catheter (PICC) breaks, there are two options: repair the line with a repair kit or exchange the line over a wire in the interventional suite. The purpose of this study is to assess the outcome of PICC repairs in children and to compare these with the outcomes of PICC exchange. MATERIALS AND METHODS: This is a single-center, retrospective study of central line-associated bloodstream infection (CLABSI) following management of externally broken PICCs (2010-2014). The occurrence of CLABSI within 30 days after repair (Group A) or exchange (Group B) of a line was analyzed, as well as PICCs exchanged following an initial and failed repair. RESULTS: A total of 235 PICC breaks were included in the study, of which 161 were repaired, and 116 of whom were successful (68%, Group A). No repair was performed in 74 PICCs-55/74 of these were exchanged over a wire (74%, Group B), and 19/74 lines were removed. The 30 days post-repair CLABSI rate (Group A) was 2.0 infections per 1000 catheter days, and the calculated risk was 4.3%. In comparison the 30 days post-exchange CLABSI rate (Group B) was 4.0 per 1000 catheter days and the calculated risk 10.9%. This difference was significant when adjusted for antibiotic use (OR 3.87; 95% CI 1.07-14.0, p = 0.039). CONCLUSION: The results of this study support repairing a broken PICC instead of removing or replacing the line.