Deflectable hollow stylet guidewire system

A body implantable stimulation lead system for positioning the lead of a body implantable stimulating pulse generator comprising:

• an over-the-wire lead extending between an end surface at a distal end and a proximal end and having a lumen therein and having a passage extending between the end surface and the lumen;
• a hollow stylet having an outer peripheral surface introduced into the lumen of the lead and extending between the distal and proximal ends thereof;
• an annular resilient blood seal within the lumen sealingly positioned between the outer peripheral surface of the stylet and the lead to prevent flow of blood beyond the blood seal and into the lumen in a proximal direction;
• and
• a guidewire slidably received within the hollow stylet and including a tip end projectable through the passage at the distal end of the lead;
• whereby relative movement of the guidewire and the stylet within the lead is enabled while avoiding friction between the blood seal and the guidewire,
• wherein one of the hollow stylet and the guidewire is preshaped to aid in the proper placement of the lead for its engagement with the body tissue at the location being sought;
• and including:
• a flexible retractable sheath slidably received in the lumen between the lead and the hollow stylet and movable between a proximal location and a distal location to thereby straighten the lead, hollow stylet, and/or guidewire and thereby aid in the desired placement of the tip end of the guidewire for engagement with the body tissue at the location being sought.