Retrograde tissue splitter and method

A device for retrograde hole opening through tissue comprising:

• a member elongate relative to an axis thereof and being substantially longer than its cross sectional dimensions, the member adapted for insertion through tissue in a direction generally along its axis through external tissue of a human or animal body during a placement procedure and wherein the member includes a passage therethrough located substantially along the axis of the member connected with a source of fluid for moving said fluid through the member;
• a distal end and a proximal end on the member, the distal end for first entering the tissue during placement and the proximal end for control of the distal end of the member while remaining outside the tissue;
• a tip at the distal end of the member adapted for placement through the external tissue of a human or animal;
• a deployable tissue divider having one or more tissue parting elements and each with means for splitting, the tissue parting elements located within a storage position carried within the member, each of the tissue parting elements movable relative to the axis of the member for placement in an exposed position relative to the member when shifted from the storage position so that the means for splitting thereof splits tissue during retrograde extraction by contacting tissue during retrograde movement of the member along the axis and wherein the deployable tissue divider includes an electrode insulatively associated with the member for transmitting radio frequency energy from the proximal end to at least each means for splitting and wherein the member is a non-conductive electric insulator, and a conductor is positioned on the member slightly proximal of each means for splitting for providing an electrosurgical effect therebetween;
• an energy supply connecting with the electrode at the proximal end for supplying radio frequency energy between the proximal end and each means for splitting, wherein a return path is between each means for splitting and the energy supply;
• an electrosurgical generator for providing said radio frequency energy, the electrosurgical generator including a control to regulate the amplitude and frequency of the energy, and
• a linkage between the proximal end and the deployable tissue divider for use in the selective disposition thereof by manipulation of the linkage at the proximal end to position and retain each of the tissue parting elements with its means for splitting in the exposed position so that upon withdrawal of the member after placement through the external tissue the tissue parting elements enlarge the initial puncture or incision simply while moving retrograde through the tissue and wherein a handle is associated with the proximal end for control and manipulation of the distal end and a trigger is carried on the handle for operation of the linkage and wherein a resilient load is on the deployable tissue divider to urge the one or more tissue parting elements from storage to the exposed position and a lock is associated with the linkage to retain the tissue parting elements in the storage position so that upon release of the lock, movement of the tissue parting elements relative to the axis of the member is allowed by means of axial motion of the linkage initiated by force applied to the linkage at the proximal end.