Delivery tools in implantable defibrillator systems

A tunneling tool for implantation of an electrical lead for use with an implantable medical device system, the tunneling tool comprising a handle and an elongate shaft extending from the handle, wherein:

• the elongate shaft has a distal tunneling tip having an exterior profile;
• the elongate shaft includes dissection element comprising an expandable spring or linkage having a collapsed configuration which does not extend beyond the exterior profile, and an expanded configuration which does extend beyond the exterior profile;
• the elongate shaft includes a control rod extending therein to the expandable spring or linkage, such that the control rod allows actuation of the expandable spring or linkage from the collapsed configuration to the expanded configuration and back again;
• and
• the handle comprises a control mechanism coupled to the control rod to allow a user to manipulate the expandable spring or linkage.

A method of implanting an electrical lead comprising:

• making an incision in a patient;
• inserting a tunneling tool through the incision, wherein the tunneling tool comprises a handle and an elongate shaft extending from the handle, wherein:
• the elongate shaft has a distal tunneling tip having an exterior profile;
• the elongate shaft includes dissection element comprising an expandable spring or linkage having a collapsed configuration which does not extend beyond the exterior profile, and an expanded configuration which does extend beyond the exterior profile;
• the elongate shaft includes a control rod extending therein to the expandable spring or linkage, such that the control rod allows actuation of the expandable spring or linkage from the collapsed configuration to the expanded configuration and back again;
• and the handle comprises a control mechanism coupled to the control rod to allow a user to manipulate the expandable spring or linkage;
• advancing the distal tunneling tip of the tunneling tool to a desired location;
• actuating the control rod to cause the dissecting element to dissect tissue or separate tissue layers;
• actuating the control rod to retract the dissecting element such that the expandable linkage or spring assumes the collapsed configuration, and removing the tunneling tool;
• and
• implanting the electrical lead.