Transseptal puncture apparatus and method for using the same

A transseptal instrument or accessing a cardiac septal wall within a heart comprising:

• a flexible introducer having an interior lumen, a distal curve, and a distal taper;
• a cannula having an interior lumen, a distal curve, and a distal blunt end;
• where the cannula is telescopically disposed into the flexible introducer;
• where the introducer has an interior lumen with a first proximal lumen inner diameter and a second smaller distal lumen inner diameter, a distal curve, and a distal tap,
• where the distal blunt end of the cannula is able to pass through the first proximal lumen diameter but not though the second smaller distal lumen diameter of the introducer;
• and
• where the flexible introducer is characterized by insufficient columnar strength to access the cardiac septal wall unless the cannula is disposed within the lumen having the first proximal lumen inner diameter.

A transseptal instrument for accessing a cardiac septal wall within a heart comprising:

• a flexible introducer having an interior lumen, a distal curve, and a distal taper;
• a cannula having an interior lumen, a distal curve, and a distal blunt end;
• where the cannula is telescopically disposed into flexible introducer;
• where the introducer has a stepped interior lumen with a first proximal lumen inner diameter and a second smaller distal lumen inner diameter, or an interior lumen having a tapered inner diameter;
• where the introducer also has a distal curve, and an exterior distal taper
• where the distal blunt end cannula is stepped or distally tapered so as to be able to pass through the first proximal lumen diameter and the second smaller distal lumen diameter of the introducer to extend beyond the distal taper of the introducer or beyond the portion of the interior lumen having a tapered inner diameter;
• and
• where the flexible introducer is characterized by insufficient columnar strength to access the cardiac septal wall unless the cannula is disposed within the lumen having the first proximal lumen inner diameter or at least within the interior lumen having a tapered inner diameter.

A method comprising:

• telescopically disposing a blunt end cannula into a flexible introducer having an interior lumen, a distal curve and a distal taper to define a predetermined shape and steerability to at least a distal portion of the introducer, where the flexible introducer has insufficient columnar strength and unsuitable shape for accessing a selected location on the cardiac septal wall when the cannula is not disposed within the interior lumen of the introducer and in close proximity to the distal taper thereof, but is able to access the predetermined location on the cardiac septal wall when the cannula is disposed within the interior lumen of the introducer and in close proximity to the distal taper thereof;
• intravascularly accessing a right atrium of a patient's heart with the introducer;
• steering the distal taper of the introducer to the selected location on a septal wall of the heart to tent the septal wall at the selected location;
• advancing a sharp ended floppy guidewire telescopically disposed within an interior lumen of the cannula while being supported by the cannula to provide sufficient columnar strength to the floppy guidewire to allow it to be pushed through the septal wall into a left atrium of the patient's heart;
• and
• advancing the sharp ended floppy guidewire beyond any support by the cannula to configure the sharp ended floppy guidewire into a prebiased atraumatic shape.

A transseptal puncture device for puncturing the atrial septum of a patient, comprising:

• a guidewire configured for placement within a lumen of a dilator configured to transverse the septum and moveable beyond the distal end of the dilator, the guidewire including a proximal portion, an intermediate portion, and a distal portion;
• wherein the guidewire is formed substantially of a metallic or polymeric material;
• wherein the intermediate portion is more flexible than the proximal portion and has a circumference equal to that of the proximal portion;
• wherein the distal portion is generally curved, is more flexible than the proximal portion, and includes a tip configured to pierce the atrial septum;
• and
• wherein the distal portion has sufficient stiffness such that it is configured to penetrate the atrial septum when the distal portion substantially resides within the dilator and has insufficient stiffness such that it is configured to not penetrate cardiac tissue when the distal portion resides substantially outside of the dilator.

A transseptal puncture device for puncturing the atrial septum of a patient, comprising:

• a guidewire configured for placement within a lumen of a dilator configured to transverse the septum and moveable beyond the distal end of the dilator, the guidewire including a proximal portion, an intermediate portion, and a distal portion;
• wherein the guidewire is formed substantially of metallic or polymeric material;
• wherein the intermediate portion is more flexible than the proximal portion and has a circumference equal to that of the proximal portion;
• wherein the distal portion is generally curved, is generally thinner than the intermediate portion, and includes a tip configured to pierce the atrial septum;
• wherein the distal portion has sufficient stiffness such that it is configured to penetrate the atrial septum when the distal portion substantially resides within the dilator and has insufficient stiffness such that it is configured to not penetrate cardiac tissue when the distal portion resides substantially outside of the dilator;
• and
• wherein at least part of the distal portion is substantially ellipsoidal.

A transseptal puncture device for puncturing the atrial septum of a patient, comprising:

• a guidewire configured for placement within a lumen of a dilator configured to transverse the septum and moveable beyond the distal end of the dilator;
• wherein the guidewire includes a proximal portion, an intermediate portion, and a distal portion having a tip configured to pierce the atrial septum;
• wherein the guidewire is formed substantially of metallic or polymeric material;
• wherein the intermediate portion is more flexible than the proximal portion and has a circumference equal to that of the proximal portion;
• wherein the distal portion has sufficient stiffness such that it is configured to penetrate the atrial septum when the distal portion substantially resides within the dilator and has insufficient stiffness such that it is configured to not penetrate cardiac tissue when the distal portion resides substantially outside of the dilator;
• and
• wherein the distal portion has a central axis biased in a curved configuration to define a distal curve such that the guidewire forms a curved configuration when at least part of the distal portion extends beyond the distal end of the dilator and assumes a generally straight configuration when the distal portion resides within the lumen of the dilator.