Interventional medical device system having an elongation retarding portion and method of using the same
View Patent ↗An interventional medical device system operable while within a body vessel is provided with a generally hollow tubular proximal portion, distal portion, and intermediate portion. The proximal portion and at least part of the distal portion remains outside of the body in use, with the remainder of the distal portion positioned within the body. The intermediate portion includes a spiral ribbon having adjacent turns, with at least one frangible bridge member between two adjacent turns. The proximal and distal portions are movable away from each other by elongating the spiral ribbon and, eventually, breaking the frangible bridge member. According to a method of using such a system to deploy an implantable medical device, such as an embolic coil, an actuation member is moved proximally with the proximal portion to disengage a bond or joint between the actuation member and the implantable medical device.
1. A tubular member of a system for delivering an interventional medical device within a body vessel, the tubular member comprising:
a proximal portion handle having a passageway therethrough, the proximal portion handle being outside the body when in use;
a distal portion which is at least partially within the body when in use and that has a passageway therethrough;
an intermediate portion between said proximal portion handle and said distal portion, said intermediate portion is a hypotube with a spiral cut-out section, the spiral cut-out hypotube having a passageway therethrough and comprising a proximal cut-out helical section adjacent to the proximal portion handle, a distal cut-out helical section adjacent to the distal portion, and an intermediate cut-out helical section between said proximal and distal helical sections, wherein each of said proximal helical section, said distal helical section and said intermediate helical section includes a plurality of adjacent helical turns between adjacent open cut-out helical sections, and said intermediate helical section further comprises an interrupted cut-out spiral section having a plurality of frangible bridge members, each frangible bridge member being a closed section of the hypotube between two adjacent open cut-out helical sections of the intermediate helical section, each closed section frangible bridge member lying along the helical path along which the two cut-out open helical sections lie, the proximal and distal cut-out helical sections being uninterrupted by any bridge member;
an actuation member fixedly connected to the proximal portion handle and extending through the tubular carrier member; and
whereby proximally directed axial movement of the proximal portion handle and of the activation member initiated outside of the body away from the distal portion axially elongates and breaks one or more of said frangible bridge members thereby disengaging a bond or joint between the actuation member and an interventional medical device in order to deploy the interventional medical device within a body vessel.
2. The system of claim 1 , wherein said proximal helical section axially elongates when the proximal portion handle is moved relative to the distal portion.
3. The system of claim 1 , wherein the distal helical section axially elongates when the proximal portion handle is moved relative to the distal portion.
4. The system of claim 1 , wherein said proximal helical section and said distal helical section axially elongate when the proximal portion handle is moved relative to the distal portion.
5. The system of claim 1 , wherein at least one of the turns of one of the proximal helical section and the distal helical section is wider than at least one turn of the intermediate helical section.
6. The system of claim 5 , wherein the turns of the proximal helical section are substantially identical to the turns of the distal helical section, the turns of the intermediate helical section are substantially identical to each other, and the turns of the proximal helical section and the turns of the distal helical section are wider than the turns of the intermediate helical section.
7. The system of claim 1 , wherein said actuation member extends through the passageway of the proximal portion handle and through the passageway of the distal portion.