Steering an implantable medical lead via a rotational coupling to a stylet
An implantable medical lead has a torsional stiffness and is rotationally coupled to a stylet. Applying rotation directly to the lead in turn causes rotation of the stylet. Where the stylet has a bent tip for purposes of steering the lead, the rotation applied to the lead rotates the bent tip so that the lead can be steered by rotating the lead rather than rotating a hub of the stylet. The rotational coupling may be achieved through one or more features provided for the lead and/or the stylet, such as a feature within a lumen of the lead that mates to a feature along the stylet or a feature of the stylet hub that engages the proximal end of the lead. The torsional stiffness of the lead may be provided by adding a feature within the lead body, such as a braided metal wire or an overlapping foil.
1. A method of guiding an implantable medical lead, comprising:
inserting a stylet with a distal guide bend into a lumen of the implantable medical lead to rotationally couple the stylet to an elongated insulative body of the lead that provides a length of the lead, that provides a coupling feature that engages the stylet, and that defines the lumen such that imparting rotation directly to the implantable medical lead at one or more points along the length imparts rotation to the stylet; and
directing the implantable medical lead in a desired direction by imparting rotation directly to the implantable lead to cause rotation of the stylet to a desired rotational position, wherein the distal guide bend urges the implantable medical lead in the desired direction; and
applying insertion force to the implantable medical lead.
2. The method of claim 1 , wherein the implantable medical lead comprises a shield that creates a torsional stiffness over a length of the implantable medical lead, the torsional stiffness being sufficient to impart rotation over the length when rotation is applied at a point along the length that includes the torsional stiffness.
3. The method of claim 1 , wherein the implantable medical lead rotationally couples to the stylet by mating the coupling feature of the implantable medical lead to a coupling feature of the stylet.
4. The method of claim 1 , wherein the implantable medical lead rotationally couples to the stylet by rotationally coupling a hub of the stylet to a proximal end of the implantable medical lead.
5. The method of claim 1 , wherein the point along the length is spaced longitudinally from the rotational coupling.