Steerable endoluminal punch

1. A method of accessing the left atrium of the heart of a patient, from the right atrium and through the fossa ovalis of the heart, said method comprising the steps of:

providing a punch for punching a hole in the fossa ovalis, said punch characterized by a distal end and a proximal end, said punch comprising:

an outer tube characterized by a proximal end, a distal end, and a flexible region at the distal end, said flexible region characterized by a proximal and a distal end, wherein said flexible region is provided in a form in which the outer tube comprises a segment which is snake-cut with a plurality of radially oriented slots in the wall of the outer tube, said radially oriented slots being substantially radially aligned along one side of the outer tube; and

an inner tube characterized by a proximal end and a distal end, said inner tube having a flexible region near the distal end thereof and a distal tip adapted to pierce body tissue;

said inner tube being disposed within the outer tube, extending from the proximal end of the outer tube to the distal end of the outer tube, and terminating distally beyond the distal end of the outer tube, said inner tube fixed to the outer tube at a point in the outer tube proximate the distal end of the flexible region of the outer tube;

navigating a guide catheter until a distal end of the guide catheter is in the right atrium and proximate the fossa ovalis;

pushing the punch through the guide catheter until the distal tip of the inner tube is within the distal end of the guide catheter;

bending the distal end of the punch by tensioning the inner tube relative to the outer tube, to place the distal tip of the inner tube and the distal end of the guide catheter in apposition to the fossa ovalis;

pushing the punch distally, relative to the guide catheter, to force the distal tip out of the distal end of the guide catheter and through the fossa ovalis to create a puncture in the fossa ovalis;

pushing distal end of the guide catheter through the puncture created by the punch, so that the distal tip of the guide catheter is disposed within the left atrium; and

withdrawing the punch from the guide catheter.

2. The method of claim 1 , wherein the flexible region is provided in a form in which the inner tube comprises a segment of the inner tube with a longitudinally oriented slot, disposed within the snake-cut segment of the outer tube.

3. The method of claim 1 , wherein the flexible region is provided in a form in which the inner tube comprises a segment of the inner tube with a half-pipe configuration, disposed within the snake-cut segment of the outer tube.

4. The method of claim 1 , further comprising providing a radiopaque marker proximate the distal tip of the punch.

5. A method of accessing the left atrium of the heart of a patient, from the right atrium and through the fossa ovalis of the heart, said method comprising the steps of:

providing a punch for punching a hole in the fossa ovalis, said punch characterized by a distal end and a proximal end, said punch comprising:

an outer tube characterized by a proximal end, a distal end, and a flexible region at the distal end, said flexible region characterized by a proximal and a distal end; and

an inner tube characterized by a proximal end and a distal end, said inner tube having a flexible region near the distal end thereof and a distal tip adapted to pierce body tissue, wherein said flexible region is provided in a form in which the inner tube comprises a segment of the inner tube with a longitudinally oriented slot;

said inner tube being disposed within the outer tube, extending from the proximal end of the outer tube to the distal end of the outer tube, and terminating distally beyond the distal end of the outer tube, said inner tube fixed to the outer tube at a point in the outer tube proximate the distal end of the flexible region of the outer tube;

navigating a guide catheter until a distal end of the guide catheter is in the right atrium and proximate the fossa ovalis;

pushing the punch through the guide catheter until the distal tip of the inner tube is within the distal end of the guide catheter;

bending the distal end of the punch by tensioning the inner tube relative to the outer tube, to place the distal tip of the inner tube and the distal end of the guide catheter in apposition to the fossa ovalis;

pushing the punch distally, relative to the guide catheter, to force the distal tip out of the distal end of the guide catheter and through the fossa ovalis to create a puncture in the fossa ovalis;

pushing distal end of the guide catheter through the puncture created by the punch, so that the distal tip of the guide catheter is disposed within the left atrium; and

withdrawing the punch from the guide catheter.

6. The method of claim 5 wherein the longitudinally oriented slot in the inner tube divides the inner tube into two parts which are disconnected from each other along their lengths.

7. The method of claim 5 , further comprising providing a radiopaque marker proximate the distal tip of the punch.

8. A method of accessing the left atrium of the heart of a patient, from the right atrium and through the fossa ovalis of the heart, said method comprising the steps of:

providing a punch for punching a hole in the fossa ovalis, said punch characterized by a distal end and a proximal end, said punch comprising:

an outer tube characterized by a proximal end, a distal end, and a flexible region at the distal end, said flexible region characterized by a proximal and a distal end; and

an inner tube characterized by a proximal end and a distal end, said inner tube having a flexible region near the distal end thereof and a distal tip adapted to pierce body tissue, wherein said flexible region is provided in a form in which the inner tube comprises a half pipe;

said inner tube being disposed within the outer tube, extending from the proximal end of the outer tube to the distal end of the outer tube, and terminating distally beyond the distal end of the outer tube, said inner tube fixed to the outer tube at a point in the outer tube proximate the distal end of the flexible region of the outer tube;

navigating a guide catheter until a distal end of the guide catheter is in the right atrium and proximate the fossa ovalis;

pushing the punch through the guide catheter until the distal tip of the inner tube is within the distal end of the guide catheter;

bending the distal end of the punch by tensioning the inner tube relative to the outer tube, to place the distal tip of the inner tube and the distal end of the guide catheter in apposition to the fossa ovalis;

pushing the punch distally, relative to the guide catheter, to force the distal tip out of the distal end of the guide catheter and through the fossa ovalis to create a puncture in the fossa ovalis;

pushing distal end of the guide catheter through the puncture created by the punch, so that the distal tip of the guide catheter is disposed within the left atrium; and

withdrawing the punch from the guide catheter.

9. The method of claim 8 , further comprising providing a radiopaque marker proximate the distal tip of the punch.

10. A method of accessing the left atrium of the heart of a patient, from the right atrium and through the fossa ovalis of the heart, said method comprising the steps of:

inserting a guidewire into the patient's vasculature and routing the guidewire to a location near the fossa ovalis;

advancing a guide catheter over the guidewire to right atrium, proximate the fossa ovalis, wherein the guide catheter has a proximal end, a distal end, and a lumen extending therethrough;

removing the guidewire from the guide catheter;

inserting an axially elongate punch, said punch comprising an integral deflecting mechanism comprising a deflectable region at the distal end of the punch which comprises an inner tube with a flexible region and an outer tube with a flexible region, with the flexible region of the outer tube disposed over the flexible region of the inner tube, and means for tensioning or compressing the inner tube relative to the outer tube, into the lumen of the guide catheter and routing the punch to the fossa ovalis wherein said flexible region of the outer tube is provided in a form in which the outer tube comprises a segment which is snake-cut with a plurality of radially oriented slots in the wall of the outer tube;

maintaining the punch substantially straight and un-curved pushing the punch through the guide catheter, until the deflectable region is disposed within the distal end of the guide catheter; and

deflecting, with the integral deflecting mechanism, the deflectable region near the distal end of the punch so that the punch and surrounding guide catheter are substantially curved at their respective distal ends;

advancing the tip of the punch from the distal end of the guide catheter, and advancing the punch through the fossa ovalis to punch a hole in the fossa ovalis;

advancing the distal end of the guide catheter through the puncture created by the punch, so that the distal tip of the guide catheter is disposed within the left atrium; and

removing the punch from the guide catheter.

11. The method of claim 10 , wherein the flexible region of the inner tube is provided in a form in which the inner tube comprises a segment of the inner tube with a longitudinally oriented slot, disposed within the snake-cut segment of the outer tube.

12. The method of claim 10 , wherein the flexible region of the inner tube is provided in a form in which the inner tube comprises a segment of the inner tube with a half-pipe configuration, disposed within the snake-cut segment of the outer tube.

13. The method of claim 10 , further comprising providing a radiopaque marker proximate the distal tip of the punch.

14. A method of accessing the left atrium of the heart of a patient, from the right atrium and through the fossa ovalis of the heart, said method comprising the steps of:

inserting a guidewire into the patient's vasculature and routing the guidewire to a location near the fossa ovalis;

advancing a guide catheter over the guidewire to right atrium, proximate the fossa ovalis, wherein the guide catheter has a proximal end, a distal end, and a lumen extending therethrough;

removing the guidewire from the guide catheter;

inserting an axially elongate punch, said punch comprising an integral deflecting mechanism comprising a deflectable region at the distal end of the punch which comprises an inner tube with a flexible region and an outer tube with a flexible region, with the flexible region of the outer tube disposed over the flexible region of the inner tube, and means for tensioning or compressing the inner tube relative to the outer tube, into the lumen of the guide catheter and routing the punch to the fossa ovalis wherein said flexible region of the inner tube is provided in a form in which the inner tube comprises a segment of the inner tube with a longitudinally oriented slot;

maintaining the punch substantially straight and un-curved pushing the punch through the guide catheter, until the deflectable region is disposed within the distal end of the guide catheter; and

deflecting, with the integral deflecting mechanism, the deflectable region near the distal end of the punch so that the punch and surrounding guide catheter are substantially curved at their respective distal ends;

advancing the tip of the punch from the distal end of the guide catheter, and advancing the punch through the fossa ovalis to punch a hole in the fossa ovalis;

advancing the distal end of the guide catheter through the puncture created by the punch, so that the distal tip of the guide catheter is disposed within the left atrium; and

removing the punch from the guide catheter.

15. The method of claim 14 wherein the longitudinally oriented slot in the inner tube divides the inner tube into two parts which are disconnected from each other along their lengths.

16. The method of claim 14 , further comprising providing a radiopaque marker proximate the distal tip of the punch.