Steerable guide catheters and methods for their use

A guide catheter having a distal end and a proximal end, comprising an outer catheter shaft and an inner catheter shaft with a first deflectable segment at the distal end of the guide catheter, a main body comprising proximal portions of the outer catheter shaft and inner catheter shaft extending proximally from the deflecting segment to a handle having a pull wire actuator, and a pullwire extending from the deflectable segment to the pull wire actuator, wherein:

• the deflectable segment comprises a PTFE liner surrounded by a wire coil impregnated with pebax with a hardness of 35D, coaxially disposed within a slotted nitinol deflection tube, coaxially disposed within an outer catheter tube comprising a pebax tube of hardness 35D, said deflectable segment having a total wall thickness of about ⅓ mm;
• and
• the deflectable segment is about 2 to 4 cm long, and the slotted nitinol deflection tube is configured to provide a bend arc of about 90° and a bend radius of about 1 cm;
• and
• the main body portion of the inner catheter shaft comprises a PTFE liner surrounded by a flat ribbon braid embedded in pebax having a hardness of 50D for a second segment of about 5 cm length immediately proximal to the deflecting segment, a hardness of about 63D for a third segment of about 12.5 cm immediately proximal to the second segment, and a hardness of about 72D for the length of the inner catheter tube proximal to this second segment;
• and
• the main body portion of the outer catheter shaft comprises a metal braided tube surrounded a Pebax outer jacket having a hardness of 50D for a second segment of about 5 cm length immediately proximal to the deflecting segment, a hardness of about 63D for a third segment of about 12.5 cm immediately proximal to the second segment, and a hardness of about 72D for the length of the inner catheter tube proximal to this second segment.