Objectives: Sclerotherapy is a therapeutic method used in the treatment of varicose veins and works by occluding damaged blood vessels with a chemical solution. Foam sclerotherapy is an attractive treatment because the results are more effective than those obtained by using liquid sclerosants. However, serious neurologic complications, which are likely related to air embolism, have been reported after treatment with foams generated by the handmade method (Tessari technique) most often used clinically. We present an alternative ultrasonic technique for preparation of sclerosing foams to treat varicose veins.
Methods: Three methods of foam generation were compared: ultrasound, mechanical agitation, and Tessari techniques.
Results: Optical microscopic analyses showed that low-frequency ultrasound can generate foams with smaller bubble distributions compared to those produced by handmade and mechanical agitation methods: 98% of the bubble population was less than 55 ± 10 μm for sonicated foams (mean ± SD, 19 ± 1.8 μm; maximum bubble size, <138.3 ± 32.5 μm), 196.7 ± 38.2 μm for mechanically agitated foams (mean, 37.1 ± 10.6 μm; maximum bubble size, <350 ± 70.9 μm), and 211.7 ± 20.8 μm for handmade foams (mean, 30.8 ± 3.8 μm; maximum bubble size, <445 ± 32.8 μm).
Conclusions: Low-frequency ultrasonic foam generation yields smaller bubbles and more uniform size distributions than other investigated methods. These properties may reduce serious adverse events reported for sclerotherapy of varicose veins, increasing the safety of foam treatment.
Keywords: bubble size distribution; foam; half-life; sclerotherapy; ultrasound; varicose veins; vascular ultrasound.
© 2017 by the American Institute of Ultrasound in Medicine.