Apparatus with weeping tip and method of use

• US 20040220536A1
• Filed: 05/26/2004
• Published: 11/04/2004
• Est. Priority Date: 12/20/1999
• Status: Active Grant

• Current Assignee: David R. Holmes Jr, Robert A. Vantassel, Robert Seth Schwartz
• Original Assignee: David R. Holmes Jr, Robert A. Vantassel, Robert Seth Schwartz
• Inventors: Schwartz, Robert S., Holmes, David R. Jr., VanTassel, Robert A.
• Granted Patent: US 6,949,087 B2
• Time in Patent Office: Days
• US Class Current: 604/272
• CPC Class Codes: A61M 2025/0057 Catheters delivering medicament other than through a conventional lumen, e.g. porous walls or hydrogel coatings
• CPC Class Codes: A61M 2025/0073 Tip designed for influencing the flow or the flow velocity of the fluid, e.g. inserts for twisted or vortex flow
• CPC Class Codes: A61M 25/0068 Static characteristics of the catheter tip, e.g. shape, atraumatic tip, curved tip or tip structure
• CPC Class Codes: A61M 5/3286 Needle tip design, e.g. for improved penetration
• CPC Class Codes: A61M 5/3291 Shafts with additional lateral openings
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00

Abstract

The invention provides surgical needles with a porous distal portion from which a liquid injectate will weep or ooze multidirectionally under injection pressure while the porous distal portion of the needle is inserted into a body surface. The porous distal portion of the needle can be fabricated from a porous carbon, metal, ceramic or polymer and preferably has a decreasing gradient of impedance to fluid flowing to the point of the needle to compensate for the falling off of injection pressure as fluid moves towards the point, thereby ensuring uniform weeping of the injectate along the injection course. The needle is adapted for attachment to a catheter or syringe. In another embodiment, a surgical assemblage is provided wherein a porous distal portion having similar fluid flow characteristics is located along the distal end of a catheter, and a needle point is attached to the distal end of the catheter (e.g., a steerable catheter) for piercing tissue. A guidance catheter can be used to direct the invention devices to a remote internal injection site. The invention devices and methods can be used to inject fluids (including those containing nucleic acids for gene therapy) into interior body walls or tissue, such as a beating heart, without substantial loss of fluid and without substantial damage to tissue caused by injectate.

Claims

1. A method of delivering a medical substance to a patient comprising:

providing a delivery device having a proximal end and a porous distal tip whererin said porous distal tip comprises a plurality of microholes distributed substantially uniformally along said porous distal tip;

introducing said delivery device into said patient and guiding said distal tip to an injection site in said patient;

initiating an injection of medical substance through said delivery device; and

,

at least partially closing an end region of said distal tip so as to cause said medical substance to weep and ooze from said plurality of microholes of said distal tip to said injection site in said patient.

2. A method according to claim 1, wherein causing said medical substance to weep includes causing said medical substance to exit microholes having a diameter within the range of about 1.0 micron to about 200 microns.

3. A method according to claim 1, wherein the introducing of said delivery device into said patient includes introducing said delivery device into a body lumen of a patient.

4. A method according to claim 1, wherein at least partially closing an end region of said distal tip includes providing a restrictive tip on said delivery device.

5. A method according to claim 4, wherein providing a restrictive tip on said delivery device includes providing a partially solid plug mechanism at said porous distal tip.

6. A method according to claim 3, wherein the introducing of said delivery device into a body lumen includes introducing a catheter into said body lumen.

7. A method according to claim 2, wherein said microholes have an average diameter of approximately 50 microns.

8. A method according to claim 1, wherein the providing of a delivery device includes providing a delivery device wherein said distal tip has a length in a range of approximately 1 mm to about 20 mm.

9. A method according to claim 1, further comprising maintaining pressure in said delivery device at a state so as to continue to cause said medical substance to weep and ooze from said plurality of microholes of said distal tip throughout substantially an entire injection procedure.

10. A device for delivering a medical substance to a patient comprising:

a conduit having a proximal end, a distal end and an internal lumen disposed therebetween;

said distal end having a porous region disposed thereon;

said porous region including a plurality of pores sized and distributed along said porous region; and

,

said distal end being at least partially closed such that said medical substance is caused to weep and ooze from said distal end of said conduit when pressure is introduced into said device.

11. A device according to claim 10, wherein said plurality of pores have an average diameter within the range of about 1 micron to about 200 microns.

12. A device according to claim 10, wherein said porous region has a length within a range of about 1 mm to about 20 mm.

13. A device according to claim 10, wherein said conduit is a catheter.

14. A device according to claim 10, wherein said distal end includes a restriction device that cooperates with the distal end of said conduit to restrict exit of fluid from said distal end.

15. A device according to claim 14, wherein said restriction device is a partial plug.

16. A device according to claim 14, wherein said restriction device is a solid plug.

17. A device according to claim 10, wherein said conduit is a needle.

18. A method of delivering a medical substance to a patient comprising:

providing a delivery device having a proximal end and a porous distal end whererin said porous distal end comprises a plurality of microholes distributed substantially uniformally along said porous distal end;

introducing said delivery device into said patient and guiding said distal end to an injection site in said patient;

initiating a flow of an injection of medical substance through said delivery device; and

,

restricting said flow at an end region of said distal end so as to cause said medical substance to weep and ooze from said plurality of microholes of said distal end to said injection site in said patient.

19. A method according to claim 18, wherein the restricting of said flow includes partially restricting said flow.

20. A method according to claim 18, wherein the restricting of said flow includes completely restricting said flow.

21. A method according to claim 18, wherein the providing of a delivery device includes providing a catheter.

22. A method according to claim 18, wherein the introducing of said delivery device includes introducing said delivery device into a body lumen of said patient.

23. A method according to claim 22, wherein the introducing of said delivery device into a body lumen includes introducing said delivery device into a blood vessel of said patient.