SMALL-DIAMETER SNARE

摘要

This invention provides a small diameter snare device consisting of a hollow, elongate, thin-walled polymer outer sheath. A single central core wire extends through the entire length of the sheath. The outer diameter of the core wire is sized close to the inner diameter of the sheath while allowing for axial sliding, in order to maximize the support to the body portion of the snare device. The distal end of the core wire has a tapered section of reduced diameter or cross section to provide a "guidewire-like" flexibility to the distal portion of the device. A second wire of about fifty percent of the inner diameter of the sheath is shaped to form a snare loop and the two ends are attached to the distal most portion of the central core wire via welding, soldering, or brazing. After assembly of the core and sheath, a second short, hollow tube is fitted over the proximal end of the central core and attached thereto to provide an actuating handle to slideably move the central core within the sheath, thus exposing and retracting the snare loop from the open distal end of the sheath. The loop is typically circular or oval shaped and can also be multiplanar (for example, a twisted, figure eight shape) so as to increase the ability to ensnare and capture objects. The loop attachment to the core wire is facilitated and strengthened by a wrapped coupling coil formed typically of 0.001-inch platinum wire applied to secure the loop prior to soldering (brazing or other metal-flowing joining techniques), and through which solder flows to permanently secure the loop to the core wire.