Apparatus and method for subcutaneous electrode insertion

1. A method of implanting an implantable defibrillator in a patient, the implantable defibrillator including a canister and a lead electrode assembly, the lead electrode assembly having proximal and distal ends, the method comprising:

making an axillary incision near the left axilla of the patient and a xiphoid incision near the xiphoid of the patient;

bluntly dissecting a pocket at the axillary incision for receiving the canister;

advancing a tool having proximal and distal ends through the xiphoid incision toward the axillary incision, the proximal end of the tool having a handle and the distal end of the tool being adapted for dissecting tissue, wherein as the tool is advanced tissue is dissected by the distal end of the tool to create a first subcutaneous tunnel;

accessing the distal end of the tool via the axillary incision and securing the distal end of the lead electrode assembly to the distal end of the tool;

withdrawing the tool through the xiphoid incision such that a portion of the lead electrode assembly is pulled through the axillary incision and into the first subcutaneous tunnel, until the distal end of the lead electrode assembly extends out of the first subcutaneous tunnel and through the xiphoid incision while the proximal end of the lead electrode assembly remains outside of the first subcutaneous tunnel;

reinserting the tool through the xiphoid incision toward a chosen location, while the distal end of the lead electrode assembly remains extended out of the xiphoid incision, to create a second subcutaneous tunnel;

removing the tool via the xiphoid incision; and

inserting the distal end of the lead electrode assembly into the second subcutaneous tunnel.

2. The method of claim 1 wherein:

during the step of advancing the tool through the xiphoid incision toward the axillary incision to create the first subcutaneous tunnel, a splittable sheath is secured on the tool; and

during the step of withdrawing the tool through the xiphoid incision such that a portion of the lead electrode assembly is pulled through the axillary incision and into the first subcutaneous tunnel, the splittable sheath remains secured onto the tool.

3. The method of claim 2 wherein:

during the step of removing the tool from the second subcutaneous tunnel via the xiphoid incision, the splittable sheath is released from the tool and remains in the second subcutaneous tunnel;

when the distal end of the lead electrode assembly is inserted into the second subcutaneous tunnel, the distal end of the lead electrode assembly is advanced into the splittable sheath; and

once the distal end of the lead electrode assembly is inserted into the second subcutaneous tunnel, the method further comprises splitting the splittable sheath and removing it over the lead electrode assembly, leaving the lead electrode assembly in place with the distal end thereof in the second subcutaneous tunnel.

4. The method of claim 3 wherein the second subcutaneous tunnel is generally parallel to the patient's sternum.

5. The method of claim 1 wherein the second subcutaneous tunnel is generally parallel to the patient's sternum.

6. The method of claim 1 , wherein the tool includes a lumen extending from the handle to a port near the distal end of the tool to enable fluid infusion therethrough, and the method further includes infusing a fluid into the patient with the tool.

7. The method of claim 6 , wherein the fluid is an anesthetic.

8. The method of claim 6 wherein the fluid is a tissue adhesive.

9. The method of claim 1 , wherein the tool includes an attachment feature near its distal end, wherein the step of securing the lead electrode assembly to the tool includes using the attachment feature to attach to the lead electrode assembly.

10. The method of claim 9 , wherein the attachment feature includes a suture hole, wherein the step of securing the lead electrode assembly to the tool includes passing a suture through the suture hole and thereby securing the suture to the tool.

11. The method of claim 10 , wherein the tool includes a fluid infusion lumen extending distally from the handle and opening into the suture hole, and the method further comprises infusing a fluid into the patient through the fluid infusion lumen.

12. The method of claim 1 wherein the step of withdrawing the tool through the xiphoid incision such that a portion of the lead electrode assembly is pulled through the axillary incision and into the first subcutaneous tunnel is performed such that the distal end of the lead is exposed to patient tissue in the first subcutaneous tunnel without the protection of a sheath.

13. The method of claim 12 wherein the step of inserting the distal end of the lead electrode assembly into the second subcutaneous tunnel is performed such that the distal end of the lead is not exposed to patient tissue in the second subcutaneous tunnel until it is fully inserted.

14. The method of claim 13 wherein:

a splittable sheath is provided on the tool while the second subcutaneous tunnel is created and the splittable sheath is then left in the second subcutaneous tunnel when the tool is removed via the xiphoid incision from the second subcutaneous tunnel;

the step of inserting the distal end of the lead electrode assembly into the second subcutaneous tunnel is performed by advancing the distal end of the lead electrode assembly into a lumen of a splittable sheath; and

the method further comprises removing the splittable sheath from the second subcutaneous tunnel once the distal end of the lead assembly is inserted into the second subcutaneous tunnel.

15. The method of claim 1 further comprising:

inserting the canister into the pocket; and

closing the axillary and xiphoid incisions after the canister and lead electrode assembly are inserted.