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 specific balloon injection fluid, and euthanized rabbits (1kg). In an initial experiment (5rabbits), we inflated an intratracheal balloon by injecting in 1.0ml of fluid 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 2cases, respectively. In our second experiment (6animals), we inflated the balloon using only 0.5-0.6ml of fluid. In all cases, HIFU either burst (1animal) or deflated (5animals) the balloon and there was substantially decreased injury of the tracheal membranous portion (2cases) or overlying skin (2cases). The total HIFU energy output revealed no significant difference between the first and second experimental groups. In conclusion, the intratracheal balloon placed by FETO can be removed using HIFU alone.
