Calibrated-leak balloon: accurate placement of the leak.

The calibrated-leak balloon catheter, used for the selective catheterization of intracranial arteries, originally incorporated a silicone microballoon at its tip [1]. Latex balloons have now proven superior in elasticity and tensile strength when compared with balloons made of silicone [2] . Consequently, most workers construct the calibrated-leak balloon catheter by gluing a leaking latex microballoon to the end of a flexible 2.5 French catheter. However, the formation of a leak at the apex of the balloon enabling fluid to leak directly forward and not obliquely can be technically difficult. Moreover, the size of the leak is a critical factor in determining the speed of balloon deflation. A fast-deflating balloon is advantageous for the rapid delivery of isobutyl 2-cyanoacrylate and subsequent prompt catheter removal during embolization procedures . We devised a method of producing a calibrated leak that is consistent in size and position .