Endovenous radiofrequency ablation using a new bipolar electrode in a canine model: a new endovenous radiofrequency electrode

Purpose@#This study aimed to determine the effectiveness and safety of a newly developed endovenous radiofrequency (RF) catheter compared with that of the existing RF catheter in a canine model. @*Methods@#Seven dogs underwent ablation using 1 control catheter (ClosureFAST, CF; Covidien) and 1 experimental catheter (VENISTAR, VS; STARmed Co., Ltd.) in the femoral and cephalic veins. The ablated vein was evaluated macroscopically (2,3,5-triphenyltetrazolium chloride staining, TTC), microscopically (hematoxylin and eosin staining), and ultrasonographically. Vessel injury score was used to evaluate the ablating effect objectively. Veins from 1 dog were evaluated on the day of ablation, while in the remaining 6 dogs, the ablated veins were evaluated 2 weeks later. @*Results@#A total of 23 veins (CF, 11 veins; VS, 12 veins) were ablated in 7 dogs. Non–TTC-stained vein wall areas were identified in all ablated veins. No significant difference was observed in the mean vessel injury score (2.54 ± 1.16 vs. 2.42 ± 1.13, P = 0.656) and the mean vessel wall thickness (0.32 ± 0.03 mm vs. 0.31 ± 0.05 mm, P = 0.212) between CF and VS. There was no blood flow in all veins ablated with VS, whereas there was remaining blood flow in 1 vein ablated with CF. Perivenous complication was not observed. @*Conclusion@#Endovenous RF ablation using a newly developed VS RF catheter seems to provide comparable occlusion rate and degree of vein wall injury without perivenous adverse events compared to the most commonly used RF catheter (CF).

Hydrophilic guidewire usage under ultrasound guidance in facilitating catheter advancement during endovenous treatment of incompetent great saphenous veins

Purpose@#This study was performed To investigate the use of hydrophilic guidewires for facilitating catheter advancement during varicose vein treatment using radiofrequency ablation (RFA) or cyanoacrylate closure (CAC). @*Methods@#From March 2016 to April 2019, 463 limbs of 285 with incompetent great saphenous veins were subjected to RFA (321 limbs of 197 patients) or CAC (142 limbs of 88 patients). Procedure records were reviewed for the use of a hydrophilic guidewire, reason for the guidewire usage, and diameter of the guidewire. @*Results@#A hydrophilic guidewire was used to facilitate catheter advancement to treat 92 of 463 limbs (19.9%). For RFA, a guidewire was used to treat 53 of 321 limbs (16.5%). Among them, 15 limbs (28.3%) had vasospasm, and 38 limbs (71.7%) had venous tortuosity. For CAC, guidewire was used for 39 of 142 limbs (27.5%). Among them, 10 limbs (25.6%) had vasospasm, 23 limbs (59.0%) had venous tortuosity, and 6 limbs (15.4%) had repeated engagement of a J-tip guidewire into the varicose tributaries. In CAC, the frequency of hydrophilic guidewire usage was higher than that in RFA (P = 0.006). All varicose vein treatment sessions were technically successful. @*Conclusion@#Hydrophilic guidewire usage could facilitate catheter advancement when hindered by vasospasm, tortuosity of the saphenous vein, or repeated engagement into the varicose tributaries.

Management of Complications during Below-the-Knee Endovascular Treatment: A Technical Note

We retrospectively reviewed the cases in which complications occurred during below-the-knee (BTK) endovascular treatmentsthat were performed at our hospital from 2005 to 2014. Several interesting cases have been described herein. All the patientshad diabetes and non-healing wounds on their feet and/or rest pain in their foot or leg, and therefore, endovascular treatmentwas performed for the BTK arteries of the affected lower extremity. The complications that occurred during the procedure wereclassified into six categories—vascular spasm, flow limiting dissection, perforation, broken guidewire, distal thromboembolism,and unusual puncture site bleeding. Each complication has its own solutions and management. We discuss these different classesof complications and describe how cases of each type were managed.

Inter-Vendor and Inter-Session Reliability of Diffusion Tensor Imaging: Implications for Multicenter Clinical Imaging Studies

OBJECTIVE: To evaluate the inter-vendor and inter-session reliability of diffusion tensor imaging (DTI) and relevant parameters. MATERIALS AND METHODS: This prospective study included 10 healthy subjects (5 women and 5 men; age range, 25–33 years). Each subject was scanned twice using 3T magnetic resonance scanners from three different vendors at two different sites. A voxel-wise statistical analysis of diffusion data was performed using Tract-Based Spatial Statistics. Fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) values were calculated for each brain voxel using FMRIB's Diffusion Toolbox. RESULTS: A repeated measures analysis of variance revealed that there were no significant differences in FA values across the vendors or between sessions; however, there were significant differences in MD values between the vendors (p = 0.020). Although there were no significant differences in inter-session MD and inter-session/inter-vendor RD values, a significant group × factor interaction revealed differences in MD and RD values between the 1st and 2nd sessions conducted by the vendors (p = 0.004 and 0.006, respectively). CONCLUSION: Although FA values exhibited good inter-vendor and inter-session reliability, MD and RD values did not show consistent results. Researchers using DTI should be aware of these limitations, especially when implementing DTI in multicenter studies.