Minimally invasive methods for implanting a sacral stimulation lead
View Patent ↗Methods and apparatus for implanting a neural stimulation lead in a patient's body are described. A lead assembly for minimally invasive implantation of a stimulation lead comprises a pointed-tip stylet, a stimulation lead, and an optional tube to deploy fixation element attached on the lead. One embodiment of the implant methods starts with inserting the pointed-tip lead assembly directly into tissue. The desired implant position is determined by electric stimulation either through stimulation lead or the pointed tip. Afterwards, the pointed-tip component is separated from the stimulation lead and removed from the tissue, leaves the stimulation lead implanted. In one variation, a needle is inserted to identify the optimal stimulation site first, after mark the needle path and position, the needle is removed and a pointed-tip stimulation lead assembly is inserted along the needle path marked. After confirmation of stimulation lead in the right tissue location, the pointed-tip component of the lead assembly is removed from the body and leaves the stimulation lead in place. The stimulation lead can be connected to the neurostimulator to delivery therapies to treat neural disorders, such as urinary control disorders, fecal control disorders, sexual dysfunction, and pelvic pain, etc.
1. A stimulation lead assembly, which comprises:
a) a stimulation lead, comprising:
i) an elongated, insulated lead body having a length extending from a proximal lead portion having a proximal lead end to a distal lead portion having a distal lead end;
ii) at least one stimulation electrode at the distal lead portion, at least one electrical connector at the proximal lead portion, and at least one conductor providing electrical continuity from the connector to the electrode;
iii) a hollow lumen extending along the entire length of the lead body from the proximal lead end to the distal lead end; and
iv) at least two fixation fingers, each having an attachment end secured to the outer surface of the lead body and a free end that is movable from a first position closely spaced to the outer surface thereof to a second, deployed position spaced from the lead body a greater radial distance than that of the first position, and
v) wherein a first axial distance from a distal end of the lead to where the attached end of a first one of the fingers is secured to the lead body is substantially different than a second axial distance measured from the distal end of the lead to where the attached end of the second one of the fingers is secured to the lead body; and
b) a tube that is sized to slide over the outer surface of the lead body to contact the at least two fixation fingers and more them from the first position into the second, deployed position, wherein the tube includes at least two longitudinal slots of different depths that correspond to the different axial distances that the at least two fixation fingers attached to the lead body are spaced from the distal end of the lead to thereby simultaneously deploy the fixation fingers at different axial distances from the distal lead end when the tube is slid over the outer surface of the lead body and out of contact with the fixation fingers.
2. The lead assembly of claim 1 wherein each fixation finger has a length that is significantly longer that either its width or diameter taken along a cross-section perpendicular to the length.
3. The lead assembly of claim 1 wherein there are three fixation fingers, each finger having its attachment end secured to the lead body at a significantly different axial distance measured from the distal lead end than the other two fixation fingers.
4. The lead assembly of claim 1 wherein the lead body and the at least two fixation fingers are of polymeric materials selected from the group consisting of silicone, polyurethane, and mixtures thereof.
5. The lead assembly of claim 1 wherein the lead body and the at least two fixation fingers are of polymeric materials that are either the same or different.
6. The lead assembly of claim 1 including a pointed-tip stylet sized to be housed inside the lumen extending through the lead body.
7. The lead assembly of claim 6 wherein the stylet is longer than the lead body so that with a proximal end of the stylet detachably secured to the proximal end of the lead, a distal end of the stylet extends out past the distal end of the lead.
8. A stimulation lead assembly, which comprises:
a) a stimulation lead, comprising:
i) an elongated, insulated lead body having a length extending from a proximal lead portion having a proximal lead end to a distal lead portion having a distal lead end;
ii) at least one stimulation electrode at the distal lead portion, at least one electrical connector at the proximal lead portion, and at least one conductor providing electrical continuity from the connector to the electrode;
iii) at least two fixation fingers, each having an attachment end secured to the outer surface of the lead body and a free end that is movable from a first position closely spaced to the outer surface thereof to a second, deployed position spaced from the lead body a greater radial distance than that of the first position, and
iv) wherein a first axial distance from a distal end of the lead to where the attached end of a first one of the fingers is secured to the lead body is substantially different than a second axial distance measured from the distal end of the lead to where the attached end of the second one of the fingers is secured to the lead body; and
b) a tube that is sized to slide over the outer surface of the lead body to contact the at least two fixation fingers and move them from the first position into the second, deployed position, wherein the tube includes at least two longitudinal slots of different depths that correspond to the different axial distances that the at least two fixation fingers attached to the lead body are spaced from the distal end of the lead to thereby simultaneously deploy the fixation fingers at different axial distances from the distal lead end when the tube is slid over the outer surface of the lead body and out of contact with the fixation fingers.
9. The lead assembly of claim 8 wherein each fixation finger has a length that is significantly longer that either its width or diameter taken along a cross-section perpendicular to the length.
10. The lead assembly of claim 8 wherein there are three fixation fingers, each finger having its attachment end secured to the lead body at a significantly different axial distance measured from the distal lead end than the other two fixation fingers.
11. The lead assembly of claim 8 wherein the lead body and the at least two fixation fingers are of polymeric materials selected from the group consisting of silicone, polyurethane, and mixtures thereof.
12. The lead assembly of claim 8 wherein the lead body and the at least two fixation fingers are of polymeric materials that are either the same or different.