Instrument for implanting vascular prostheses
View Patent ↗An instrument for implanting an expandable cylindrical vascular prosthesis includes an outer tube and an inner tube which can be displaced relative to one another. The inner tube is longitudinally slotted on the distal end, at least in an area thereof, and ensheathes the stent with this area which includes the longitudinal slot. In order to implant the stent, the outer tube is retracted. The stent then expands with continuous retracting movement of the outer tube and the inner tube is pressed open along the longitudinal slot. Implantation is terminated, when the outer tube is retracted along the entire length of the stent. The implantation is reversible by pushing the outer tube forward, as long as the stent has not yet fully exited the instrument. In this way, the inner tube is constricted together with the stent, and compressed to an initial position.
1. An instrument for implanting an expandable cylindrical prosthesis, in particular a stent or an endoprosthesis, comprising an outer tube and an inner tube which are moveable relative to one another, wherein the inner tube has a distal end which includes a slot having a first portion extending in a proximal-distal direction adjacent the distal end of the inner tube and a second portion that extends in a circumferential direction about the inner tube, wherein at least a portion of the first portion extends substantially parallel to a longitudinal axis of the inner tube and at least a portion of the second portion extends substantially perpendicular to the longitudinal axis of the inner tube, and wherein the outer tube is configured to be retracted relative to the inner tube to deploy the prosthesis such that said slot of the inner tube is configured to distend as the prosthesis expands and is deployed from the outer tube.
2. The instrument of claim 1 and further comprising a loading aid is provided on one end of the outer tube for radial constriction of the prosthesis disposed in the inner tube.
3. The instrument of claim 2 , wherein the loading aid is constructed so as to be coolable.
4. The instrument of claim 1 , wherein at least a portion of the first portion extends substantially parallel to a longitudinal axis of the inner tube and at least a portion of the second portion extends substantially perpendicular to the longitudinal axis of the inner tube when the inner tube is completely disposed within the outer tube.
5. An instrument for implanting an expandable prosthesis, comprising an outer tube and an inner tube which are moveable relative to one another, said inner tube including a slot having a first portion extending in a proximal-distal direction adjacent a distal end of the inner tube and a second portion extending in a circumferential direction about the inner tube along a predetermined length to define an area for receiving a prosthesis, wherein at least a portion of the first portion extends substantially parallel to a longitudinal axis of the inner tube and at least a portion of the second portion extends substantially perpendicular to the longitudinal axis of the inner tube, and wherein the outer tube is configured to be retracted relative to the inner tube to deploy the prosthesis such that said slot of the inner tube is configured to distend as the prosthesis expands and is deployed from the outer tube.
6. The instrument of claim 5 , and further comprising a loading aid provided on one end of the outer tube for radial constriction of the prosthesis in the inner tube.
7. The instrument of claim 6 , wherein the loading aid is constructed so as to be coolable.
8. The instrument of claim 6 , wherein the outer tube has a funnel-shaped configuration.
9. The instrument of claim 6 , wherein the loading aid is an integral part of the outer tube.
10. The instrument of claim 6 , wherein the loading aid is a separate part from the outer tube.
11. The instrument of claim 5 , wherein the inner and outer tubes are made of flexible material.
12. The instrument of claim 5 , wherein the inner and outer tubes are made of Teflon.
13. A method of deploying a prosthesis in a lumen of a person's body, comprising the steps of:
a) placing a prosthesis in an inner tube of a delivery instrument;
b) moving an outer tube of the delivery instrument over the inner tube to compress the inner tube and the contained prosthesis;
c) positioning the delivery instrument in a region of a stenosis;
d) retracting the outer tube relative to the inner tube to thereby allow the prosthesis to expand and to thereby distend the inner tube on one side along a slot formed in the inner tube, wherein the slot includes a first portion extending in a proximal-distal direction adjacent the distal end of the inner tube and a second portion extending in a circumferential direction about the inner tube, wherein at least a portion of the first portion extends substantially parallel to a longitudinal axis of the inner tube and at least a portion of the second portion extends substantially perpendicular to the longitudinal axis of the inner tube; and
e) continuing retraction of the outer tube until the prosthesis is fully expanded.
14. The method of claim 13 , and further comprising the step of pushing the outer tube relative to the inner tube before step e) to re-compress the prosthesis.