A portable high-intensity focused ultrasound device for noninvasive venous ablation

Abstract

Varicose veins and other vascular abnormalities are common clinical entities. Treatment options include vein stripping, sclerotherapy, and endovenous laser treatment, but all involve some degree of invasive intervention. The purpose of this study was to determine ex vivo the effectiveness of a novel hand-held, battery-operated, high-intensity focused ultrasound (HIFU) device for transcutaneous venous ablation. The ultrasound device is 14 x 9 x 4 cm, weighs 650 g, and is powered by 4 lithium ion battery packs. An ex vivo testing platform consisting of two different models comprised of sequentially layered skin-muscle-vein or skin-fat-vein was developed, and specimens were treated with HIFU. The tissues were then disassembled, imaged, and processed for histology. The luminal cross-sectional area of vein that had been treated with HIFU and nontreated controls were measured, and the values presented as median and interquartile range (IQR). The values were compared using a Wilcoxon rank-sum test, and statistical significance was set at P < .05. On gross and histologic examination, veins that had been treated with HIFU showed evidence of coagulation necrosis. The surface of the muscle in direct contact with the vein had a pinpoint area of coagulation, whereas the adjacent fat appeared undisturbed; the skin, fat, and the surface of the muscle in contact with the transducer remained completely unaffected. The cross-sectional area was 3.79 mm(2) (IQR, 3.38-4.22) of the control vein lumen and 0.16 mm(2) (IQR, 0.04-0.39) in those that had been treated with HIFU (P = .0304). This inexpensive, portable HIFU device has the potential to allow clinicians to easily perform venous ablation in a manner that is entirely noninvasive and without the expense or inconvenience of large, complicated devices. This device represents a significant step forward in the development of new applications for HIFU technology.