Systems and methods for attaching a prosthesis within a body lumen or hollow organ
Systems and methods introduce and deploy prosthesis into a blood vessel or hollow body organ by intra-vascular access. The prosthesis is secured in place by fasteners which are implanted by an applier that is also deployed by intra-vascular access. The applier is configured to permit controlled, selective release of the fastener in a step that is independent of the step of implantation.
1. A tool for applying an implantation force to a fastener sized and configured for implantation in tissue in response to an implantation force applied according to prescribed conditions, the tool comprising:
a tool body;
a driven member carried by the tool body and being operable to apply the implantation force;
a mechanism on the driven member to couple the fastener to the driven member to transfer the implantation force from the driven member to the fastener; and
a controller coupled to the driven member, the controller including:
an initial phase operating the driven member to apply the implantation force under conditions than are short of the prescribed conditions;
a lull phase commencing at the end of the initial phase interrupting operation of the driven member;
a final phase operating the driven member under conditions that supplement the conditions of the initial phase to achieve the prescribed conditions,
the controller requiring, after the initial phase, a prescribed command to advance from the lull phase to the final phase;
wherein the prescribed conditions are a prescribed time period or a prescribed number of rotations.
2. The tool of claim 1 , wherein the prescribed command is based, at least in part, upon input from an operator.
3. The tool of claim 1 , wherein the prescribed command is based, at least in part, upon input reflecting a sensed operating condition.
4. The tool of claim 1 , wherein:
the driven member is operable to apply a removal force to withdraw the fastener from tissue; and
the controller includes a removal phase operating the driven member to apply the removal force, the controller requiring, after the initial phase, a different prescribed command to advance from the lull phase to the removal phase.
5. The tool of claim 4 , wherein the driven member is rotated in one direction to apply the implantation force and rotated in an opposite direction to apply the removal force.
6. The tool of claim 1 , further comprising an element configured to tether the fastener to the tool body, the element comprising a frangible portion.
7. The tool of claim 1 , wherein the driven member is rotated to apply the implantation force.
8. The tool of claim 1 , wherein the tool body comprises a tubular member that carries the driven member and the mechanism.
9. The tool of claim 1 , wherein:
the tool body comprises internal threads and the fastener comprises a helical fastener; and
a proximal portion of the helical fastener is retained within the internal threads at the end of the initial phase.
10. The tool of claim 1 , wherein the mechanism comprises a distal portion having a configuration that corresponds to a configuration of a proximal end of the fastener, such that the proximal end of the fastener engages with the distal portion of the mechanism to couple the fastener to the mechanism throughout the initial phase.
11. The tool of claim 10 , wherein the proximal end of the fastener comprises a leg portion that engages with the distal portion of the mechanism throughout the initial phase.
12. The tool of claim 1 , wherein the fastener comprises a helical fastener.