Delivery catheter with constraining sheath and methods of deploying medical devices into a body lumen
A delivery catheter includes a constraining sheath coupled to a distal end of the catheter, and a medical device, such as an embolic protection device (EPD) or a stent, constrained by the sheath. A wire may extend proximally from the constraining sheath and be coupled thereto. A proximal pulling force on the wire causes the wire to tear the constraining sheath, thereby releasing the medical device from a constrained configuration to an expanded configuration.
1. A delivery catheter for delivering a medical device, the delivery catheter comprising:
a constraining sheath having a proximal end coupled to a distal end of the delivery catheter and a free distal end, said constraining sheath holding the medical device in a constrained state, the constraining sheath including spaced-apart holes arranged longitudinally from the free distal end of the constraining sheath;
a wire threaded through the holes proximally starting from the free distal end of the sheath, the wire having a first free end section extending proximally therefrom and a second free distal end; and
a said cutting member at the second free distal end of said wire, said cutting member having a cutting edge directed toward said proximal end such that cutting member tears the constraining sheath longitudinally when a pulling force is applied proximally to the first free end section, thereby releasing the medical device from a constrained configuration to an expanded configuration.
2. The delivery catheter of claim 1 , wherein the medical device is an embolic protection device (EPD).
3. The delivery catheter of claim 1 , wherein the medical device is a stent.
4. The delivery catheter of claim 1 , wherein the cutting member comprises an enlarged end portion, such that when the wire is pulled in a proximal direction the enlarged portion forces the sheath to tear longitudinally in a predictable manner along a line substantially aligned with the longitudinally spaced-apart holes.
5. The delivery catheter of claim 1 , wherein the cutting member comprises a sickle-shaped element oriented to present a proximally-directed cutting surface relative to the proximal end of the sheath.