Non-touch, Quick Destruction of the Tracheal Occluding Balloon Using HIFU

Abstract

The technique of fetal endoscopic tracheal occlusion FETO was developed to totally occlude the fetal trachea using an intratracheal balloon in the treatment of congenital diaphragmatic hernia with lung hypoplasia. To improve this approach, we developed a method for non-contact, rapid destruction of the balloon using high intensity focused ultrasound HIFU , a speci c balloon injection uid, and euthanized rabbits 1 kg. In an initial experiment 5 rabbits , we in ated an intratracheal balloon by injecting in 1.0 ml of uid and demonstrated that HIFU could successfully burst the balloon in all cases, although the tracheal membranous portion and the skin overlying the trachea were injured in 4 and 2 cases, respectively. In our second experiment 6 animals , we in ated the balloon using only 0.5-0.6 ml of fluid. In all cases, HIFU either burst 1 animal or deflated 5 animals the balloon and there was substantially decreased injury of the tracheal membranous portion 2 cases or overlying skin 2 cases. The total HIFU energy output revealed no signi cant difference between the rst and second experimental groups. In conclusion, the intratracheal balloon placed by FETO can be removed using HIFU alone.

Non-touch, Quick Removal of an Occluding Intratracheal Balloon Using High Intensity Focused Ultrasound and Limonene Emulsion

“…Along with the successful balloon bursts, the use of limonene emulsion led to a de nite reduction in the mechanical and thermal collateral damage to the skin in the path of the HIFU beam, which we reported in our previous study 6 . This was probably because the D-limonene monolayer micelles were broken by the intermittent HIFU exposure duty ratio of 67 at time intervals of 30 sec allowing for successful balloon bursts, but producing less intradermal vibrations and heat energy than in our previous study.…”