Introducer assembly and implantable medical device
View Patent ↗An introducer for deploying an implantable medical device such as a stent ( 60 ), stent graft ( 80 ) or other similar device is provided with an outer sheath ( 132,232 ) which is provided with a series of internally longitudinally extending channels ( 136. 236 ) and interdigitating protrusions ( 134, 234 ) extending therein. At least on stent ring ( 0 ) of the medical device is provided with one or more barbs ( 104 ) which point radially outwardly of the device, including when this is compressed onto the introducer. The barbs ( 104 ) lie within the channels ( 136, 236 ) which the remainder of the medical device is retained in its compressed form by the elongate protrusions ( 134, 234 ). The channels ( 136, 236 ) allow for the provision of relatively stiff barbs ( 104 ). The barbs ( 104 ) can be better suited to ensuring the correct placement of the medical device than flexible barb arrangements.
1. An introducer assembly including an introducer and an implantable medical device comprising a stent carried in the introducer and including a single plurality of non-compressible barbs each having a free end that extends radially outwardly of the medical device, which introducer is provided with an outer sheath operable to cover the implantable medical device until deployment, the outer sheath including an inner wall provided with one or more channels extending in a longitudinal direction of the sheath, such that each non-compressible barb is located in the or a respective channel of the sheath, and one or more projections extending towards a radial center-point of the sheath for compressing the implantable medical device towards the radial center-point such that each barb can extend into the channel without contacting the inner wall of the sheath,
wherein each barb maintains its shape and position relative to the stent upon expansion,
wherein the medical device comprises struts having an inner surface and an outer surface and each barb extends only from the outer surface of a strut with no part of the barb extending from the inner surface of a strut,
wherein each of the struts from which a barb extends further includes a framework disposed about the barb,
wherein the stent has a radial periphery in a compressed configuration within the sheath and in the compressed configuration, the barbs extend outside the radial periphery of the stent and out of the plane of the struts and the framework,
wherein the barbs retain their configuration both during storage of the medical device on the introducer, during deployment of the medical device and once the medical device is in situ in a patient, and
wherein each barb is integral with and formed out of the strut.
2. An introducer assembly according to claim 1 , wherein the channel or channels extend to a distal end of the sheath.
3. An introducer assembly according to claim 1 , wherein the channel or channels extend along the internal wall of the sheath for a distance at least equivalent to the length of the implantable medical device.
4. An introducer assembly according to claim 1 , wherein the projection or projections are in the form of one or more ribs extending in a longitudinal direction of the sheath.
5. An introducer assembly according to claim 1 , wherein there are provided at least two projections, spaced from one another in a radial direction of the sheath, wherein the space between the projections provides a channel.
6. An introducer assembly according to claim 1 , wherein there is provided a plurality of channels within the internal wall of the sheath and wherein the channels are substantially evenly spaced in a radial direction around the inner wall of the sheath.
7. An introducer assembly according to claim 1 , wherein a major portion of the sheath has a substantially smooth internal wall.
8. An introducer assembly according to claim 1 , wherein the sheath is substantially round in transverse cross-section.