1. Field of the Invention
Embodiments of this invention are directed to the field of intravascular medical devices, and more particularly to the field of catheters such as angioplasty, neurological and guide catheters, among others, which may be used in various medical procedures such as percutaneous transluminal angioplasty (PTA), percutaneous transluminal coronary angioplasty (PTCA) as well as in procedures involving the placement of medicines and medical devices within the body.
Some embodiments of the invention are directed to all forms of catheters which may be advanced through a body lumen or vessel. Some examples of catheters are over-the-wire (OTW) catheters, such as are described in U.S. Pat. No. 5,047,045; single-operator-exchange (SOE) balloon catheters, such as are described in U.S. Pat. Nos. 5,156,594 and 5,549,552. Other examples of catheters which may incorporate the unique features of the present invention may include rapid-exchange catheters, guide catheters, etc.
2. Description of the Related Art
Intravascular diseases are commonly treated by relatively non-invasive techniques such as PTA and PTCA. These angioplasty techniques typically involve the use of a balloon catheter. In these procedures, a balloon catheter is advanced through the vasculature of a patient such that the balloon is positioned proximate a restriction in a diseased vessel. The balloon is then inflated and the restriction in the vessel is opened. In other uses a catheter may be used to delivery an endoprosthesis such as a stent, graft, stent-graft, vena cava filter or other implantable device or devices herein after collectively referred to as a stent or stents. Where a stent is to be delivered into a body lumen the catheter may include one or more inflatable portions or balloons. Typically, the stent is retained in the predelivery state about the catheter shaft, or a portion thereof such as a balloon, by crimping and/or through the use of a retaining mechanism such as sleeve, sheath or sock.
Balloons and balloon catheters may be particularly useful for the delivery of expandable, implantable medical devices such as stents, grafts, stent-grafts, vena cava filters, hereinafter referred to cumulatively as stents. Stents and catheters used in their delivery are commonly used and as such their structure and function are well known.
A stent is a generally cylindrical prosthesis introduced via a catheter into a lumen of a body vessel in a configuration having a generally reduced diameter and then expanded. In its expanded configuration, the stent supports and reinforces the vessel walls while maintaining the vessel in an open, unobstructed condition.
In order to properly position a stent and/or balloon within a body lumen, the catheter must be advanced through the narrow confines of the body. Typically the balloon and/or stent is located near the distal end of the catheter. In order to advance the distal end of most prior catheters further in to a body lumen, the inner shaft or catheter member is utilized to transmit force to the distal end. However, the inner is typically soft and flexible which often results in poor transmission of push.
The present invention, in accordance with the various embodiments presented herein, addresses the shortcoming of poor push transmission common to many catheters.
Without limiting the scope of the invention, a brief summary of various embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well for the purposes of complying with 37 C.F.R. 1.72.
The entire content of all of patents or other references listed within the present patent application are incorporated herein by reference.