Transseptal puncture needle and needle assemblies

1. A transseptal needle, comprising:

an elongate needle body having a distal end and a proximal end;

a cannular needle tip located proximate the distal end of the elongate needle body, the needle tip having a distal segment, a proximal segment, and a longitudinal axis extending through at least a portion of the distal segment and the proximal segment, the needle tip comprising:

an inner surface defining a passageway spanning at least a portion of the needle tip;

an outer surface,

the inner surface and the outer surface defining therebetween a wall;

a wedge surface at the distal segment of the needle tip, the wedge surface forming a wedge angle of other than 90 degrees relative to the longitudinal axis of the needle tip;

a dome-shaped region at the distal segment of the needle tip;

a first bevel in the dome-shaped region; and

a second bevel in the dome-shaped region,

wherein the first bevel and the second bevel intersect at one or more points on the needle tip, and

wherein a puncture tip leading edge is at least partially defined by an intersection of the first bevel, the second bevel, and the wedge surface.

2. The transseptal needle according to claim 1 , wherein the first bevel and the second bevel intersect along a line on the needle tip to form an interbevel angle.

3. The transseptal needle according to claim 2 , wherein the interbevel angle is between about 80 degrees and about 120 degrees.

4. The transseptal needle according to claim 3 , wherein the interbevel angle is between about 100 degrees and about 110 degrees.

5. The transseptal needle according to claim 4 , wherein the interbevel angle is about 105 degrees.

6. The transseptal needle according to claim 1 , wherein the first bevel and the second bevel intersect at one or more points within the wall.

7. The transseptal needle according to claim 1 , wherein the first bevel and the second bevel intersect at one or more points on the inner surface.

8. The transseptal needle according to claim 1 , wherein the dome-shaped region has a depth between about 0.075 mm and about 0.125 mm and a radius of curvature between about 0.79 mm and about 0.99 mm.

9. The transseptal needle according to claim 8 , wherein the dome-shaped region has a depth of about 0.100 mm and a radius of curvature of about 0.89 mm.

10. The transseptal needle according to claim 1 , wherein the wedge angle is between about 20 degrees and about 50 degrees relative to the longitudinal axis of the needle tip.

11. The transseptal needle according to claim 10 , wherein the wedge angle is about 30 degrees relative to the longitudinal axis of the needle tip.

12. A transseptal needle assembly, comprising:

a tubular elongate needle body terminating in a needle tip, the needle tip comprising:

an inner surface defining a passageway extending through at least a portion of the needle body including the needle tip;

an outer surface;

a wedge surface;

a dome-shaped region intersecting the wedge surface; and

at least two reverse-angled bevels in the dome-shaped surface, each of the at least two reverse-angled bevels intersecting the wedge surface,

wherein the intersection of the at least two reverse-angled bevels and the wedge surface at least partially defines a puncture tip leading edge to facilitate transseptal puncturing.

13. The transseptal needle assembly according to claim 12 , wherein the inner surface and the outer surface define therebetween a wall, and wherein the puncture tip leading edge is located on an upper surface of the wall.

14. The transseptal needle assembly according to claim 12 , wherein the at least two reverse-angled bevels intersect at one or more points within the tubular elongate needle body.

15. The transseptal needle assembly according to claim 14 , wherein the at least two reverse-angled bevels intersect along a line within the tubular elongate needle body.

16. The transseptal needle assembly according to claim 12 , further comprising a needle hub coupled to the proximal end of the transseptal needle.

17. The transseptal needle assembly according to claim 12 , further comprising a stylet adapted for insertion through the tubular elongate needle body.

18. A system for use in transseptal catheterization procedures, the system comprising:

a dilator;

a handle assembly including a sheath hub, a dilator hub removably connected to the sheath hub, and a needle hub removably connected to the dilator hub;

a needle assembly, the needle assembly including a transseptal needle having a needle tip, the needle tip comprising:

a wedge surface;

a dome-shaped region intersecting the wedge surface;

a first reverse-angle bevel in the dome-shaped surface intersecting the wedge surface; and

a second reverse-angle bevel in the dome-shaped surface intersecting the wedge surface and the first reverse-angle bevel; and

a needle advancement mechanism adapted to cooperate with the needle assembly, wherein the needle advancement mechanism allows for selective advancement of the needle assembly from a position within the dilator to a position external to the dilator.

19. An elongated, curved transseptal puncture needle, comprising:

a needle proximal end;

a needle distal end, wherein the needle distal end comprises a working portion including an inner needle tube and an outer needle tube, wherein the inner needle tube and the outer needle tube are conjoined, wherein the inner needle tube comprises a proximal end and a distal end, wherein the outer needle tube comprises a proximal end and a distal end, wherein the proximal end of the inner needle tube is inserted into the distal end of the outer needle tube, creating an embedded portion and an exposed portion of the inner needle tube, and creating a circumscribing portion and a nonoverlapping portion of the outer needle tube, and wherein the conjoined inner and outer needle tubes define a conjoined outer surface including an outer surface of the outer needle tube plus an outer surface of the exposed portion of the inner needle tube; and

a needle tip at the distal end of the inner needle tube, the needle tip comprising:

a puncture tip leading edge;

a puncture tip trailing edge;

a wedge surface extending between the puncture tip leading edge and the puncture tip trailing edge;

a dome-shaped region intersecting the wedge surface; and

a pair of intersecting reverse-angle bevels in the dome-shaped surface, each of the pair of intersecting reverse-angle bevels intersecting the wedge surface;

wherein the puncture tip leading edge is defined by an intersection of the pair of intersecting reverse-angle bevels and the wedge surface.

20. A method of manufacturing a transseptal needle, comprising the steps of:

providing a substantially tubular body having a proximal end and a distal end;

providing a dome-shaped region proximate the distal end;

truncating the substantially tubular body at a wedge angle to create a wedge surface, the wedge surface intersecting the dome-shaped region;

beveling a first reverse-angle bevel into the dome-shaped region intersecting the wedge surface; and

beveling a second reverse-angle bevel into the dome-shaped region intersecting the wedge surface,

thereby forming a puncturing tip leading edge.

21. The method according to claim 20 , wherein the beveling step comprises:

wherein the first reverse-angle bevel and the second reverse-angle bevel intersect at an interbevel angle.

22. The method according to claim 20 , wherein the at least one reverse-angle bevel intersects the wedge surface between an inner diameter of the substantially tubular body and an outer diameter of the substantially tubular body.

23. The method according to claim 20 , wherein the step of providing a dome-shaped region proximate the distal end comprises bending the distal end of the substantially tubular body into a curved configuration prior to the truncating step.