Catheter system for release of embolization coils by hydraulic pressure

Abstract

Apparatus and methods are described for treating cardiovascular diseases with an embolization coil placement system utilizing an embolization coil and a pusher device. The embolization coil includes a releasable attachment assembly with a deformable ring-shaped member for connecting the embolization coil to a hydraulic pressure actuated coil release assembly on the pusher device. The coil release assembly includes a coil mounting wire with a bulbous distal portion that extends distally from a proximal tubular portion of the pusher device. A small inflatable balloon is mounted on the pusher device surrounding the coil mounting wire and fluidly connected to the proximal tubular portion. The embolization coil delivery system is prepared for use by crimping the deformable ring-shaped member around the deflated balloon member and the mounting wire. The bulbous distal portion of the mounting wire retains the crimped ring-shaped member on the pusher device. A target site in the vascular system is catheterized with a microcatheter. Then, the pusher device with the embolization coil mounted on it is inserted into the microcatheter and advanced to the target site. Once the embolization coil is in position, the inflatable balloon is pressurized with a syringe or inflation device connected to a hub on the proximal tubular portion of the pusher device. As the inflatable balloon member expands, it deforms the ring-shaped member to release the embolization coil from the pusher device. The balloon member is then deflated and the pusher device is withdrawn. In this way, one or more embolization coils may be inserted to occlude the target site by creating a physical barrier to blood flow and encouraging thrombus formation.