Embolization microcatheter

• US 10,398,875 B2
• Filed: 01/08/2016
• Issued: 09/03/2019
• Est. Priority Date: 01/09/2015
• Status: Active Grant

• Current Assignee: Accurate Medical Therapeutics Ltd.
• Original Assignee: Accurate Medical Therapeutics Ltd.
• Inventors: Tal, Michael Gabriel, Miller, Eran
• Primary Examiner(s): Bosques, Edelmira
• Application Number:
  US15/542,427
• Publication Number:
  US 20170368306A1
• Time in Patent Office: 1,334 Days
• CPC Class Codes: A61B 17/12109 in a blood vessel
• CPC Class Codes: A61B 17/12186 liquid materials adapted to be injected
• CPC Class Codes: A61B 2017/00345 Micromachines, nanomachines, microsystems
• CPC Class Codes: A61B 2017/00884 enhancing wound closure
• CPC Class Codes: A61B 2017/00893 pharmaceutically effective
• CPC Class Codes: A61B 2017/1205 Introduction devices
• CPC Class Codes: A61M 2025/0024 Expandable catheters or sheaths
• CPC Class Codes: A61M 2025/0042 Microcatheters, cannula or the like having outside diameters around 1 mm or less
• 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 general flow characteristics A61M2206/10
• CPC Class Codes: A61M 2025/0079 Separate user-activated means, e.g. guidewires, guide tubes, balloon catheters or sheaths, for sealing off an orifice, e.g. a lumen or side holes, of a catheter
• CPC Class Codes: A61M 2025/0096 being laterally outward extensions or tools, e.g. hooks or fibres
• CPC Class Codes: A61M 2205/7545 for solid matter, e.g. microaggregates
• CPC Class Codes: A61M 25/0021 characterised by the form of the tubing A61M25/0054 takes precedence
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility
• CPC Class Codes: A61M 25/0067 characterised by the distal end, e.g. tips A61M25/0054, A61M25/04 take precedence; balloon catheters A61M25/10
• 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 25/007 Side holes, e.g. their profiles or arrangements; Provisions to keep side holes unblocked
• CPC Class Codes: A61M 25/0074 Dynamic characteristics of the catheter tip, e.g. openable, closable, expandable or deformable
• CPC Class Codes: A61M 25/0075 Valve means
• CPC Class Codes: A61M 31/005 : for contrast media
• CPC Class Codes: A61M 5/007 : for contrast media

Abstract

Microcatheter for delivering a substance (e.g., infusion agent including embolization material and/or contrast enhancing material) in a small blood vessel towards a target bodily part. Includes a single lumen surrounded by tubular wall having outer diameter and opened at both ends; tubular wall proximal portion is connectable to a pressure source and reservoir containing infusion agent, and tubular wall distal portion ends with a tip; the tubular wall distal portion includes an infusion agent flow disruption section configured to disrupt passage therethrough of incoming retrograded flow of infusion agent, during continuous delivery of infusion suspension from the reservoir to the tip. Disclosed are methods using the microcatheter for performing local embolization in a small blood vessel feeding a (for example, cancerous) target bodily part, and for delivering infusion agent in a small blood vessel towards such target bodily part. Also disclosed are devices and methods for filtering non-target infusion agent.

Claims

1. An embolization microcatheter, comprising an elongated body, a proximal inlet and a distal head section, the distal head section comprising:

(a) a tip having a distal outlet configured for allowing outflow of particles suspended in a fluid delivered to the microcatheter through the proximal inlet; and

(b) a filter section comprising a plurality of slits formed around and along a wall of said filter section, wherein a width of each of said plurality of slits is equal to or less than about 100 microns, thereby preventing outflow at least of particles having a bead diameter ranging between 100 to 1500 microns, while allowing selective lateral outflow of said fluid, wherein said lateral outflow of said fluid is configured to disrupt retrograded flow of said particles, delivered through the distal outlet around a periphery of said tip.

2. The microcatheter of claim 1, wherein the filter section comprises a material being more flexible than that of other wall portions of said embolization microcatheter'"'"'s wall.

3. The microcatheter of claim 2, wherein the filter section is configured to allow selective lateral outflow of said fluid while blocking passage of said particles, when said distal head section is straight, curved and bent.

4. The microcatheter according to of claim 1, wherein said microcatheter is configured as a single integrated structure.

5. The microcatheter of claim 1, wherein a distal most of said plurality of slits is located within a range of between about 0 mm and about 20 mm, proximally to the distal outlet.

6. The microcatheter of claim 1, wherein a distal most of said plurality of slits is located within a range of between about 0 mm and about 10 mm, proximally to the distal outlet.

7. The microcatheter of claim 1, wherein said plurality of slits are formed along a longitudinal axis of the filter section.

8. The microcatheter of claim 1, wherein said plurality of slits are angled relative to a long axis of said filter section or/and relative to a radial axis of said filter section.

9. An embolization microcatheter, comprising an elongated body, a proximal inlet and a distal head section, the distal head section comprising:

(a) a tip having a distal outlet configured for allowing outflow of particles suspended in a fluid delivered to the microcatheter through the proximal inlet; and

(b) a filter section comprising a plurality of slits formed around and along a wall of said filter section, the slits configured to prevent outflow of the particles, while allowing lateral outflow of the fluid, wherein the lateral outflow of the fluid is configured to disrupt retrograded flow of the particles, delivered through the distal outlet around a periphery of the tip,

wherein a total opened cross section of the plurality of slits is equal to or greater than a cross section of the distal outlet, thereby allowing sufficient outflow of the fluid, through the plurality of slits to disrupt retrograded flow of particles, delivered through the distal outlet, around a periphery of the tip.

10. The microcatheter of claim 9, wherein the elongated body has an outer diameter equal to or less than about 1 mm.

11. The microcatheter of claim 9, wherein the filter section comprises a material being more flexible than that of other wall portions of said embolization microcatheter'"'"'s wall.

12. The microcatheter of claim 9, wherein the elongated body has an outer diameter equal to or less than about 1 mm.

13. An embolization microcatheter, comprising:

an elongated body, a proximal inlet and a distal head section, the distal head section comprising;

(a) a tip having a distal outlet configured for allowing outflow of particles suspended in a fluid delivered to the microcatheter through the proximal inlet; and

(b) a filter section comprising a plurality of slits formed around and along a wall of the filter section, the slits configured to allow selective lateral outflow of the fluid while blocking passage of the particles, wherein the lateral outflow of the fluid is configured to disrupt retrograded flow of the particles, delivered through the distal outlet around a periphery of the tip;

wherein the filter section is pressure sensitive and configured to disrupt retrograded flow of the infusion agent only when pressure inside the distal head section equals a predetermined expansion pressure; and

wherein the embolization microcatheter further comprises a valve mechanism configured to cover side openings provided at said filter section when pressure inside said distal head section is less than said predetermined pressure, and to uncover said side openings when pressure inside said distal head section is greater than said predetermined pressure.

14. The microcatheter of claim 13, wherein said filter section is configured to stretch from a first average diameter to a second average diameter greater than an outer diameter of the microcatheter when pressure inside said distal head section equals said predetermined pressure, and to collapse back to said first average diameter when said pressure inside said distal head section is less than said predetermined pressure, during said continuous delivery of said infusion suspension from said reservoir to said tip before, during, and after said stretching and collapsing.

15. The microcatheter of claim 13, wherein, under a selected inner pressure being greater than said expansion pressure and less than ambient pressure, said filter section stretches in response to a systole and collapses in response to a diastole.

16. A method for performing local embolization in a small blood vessel, the method comprising:

positioning an embolization microcatheter within a target blood vessel, the embolization microcatheter comprising an elongated body comprising a proximal inlet and a distal head section comprising;

(a) a tip having a distal outlet configured for allowing outflow of particles suspended in a fluid delivered to the microcatheter through the proximal inlet; and

(b) a filter section comprising a plurality of slits formed around and along a wall of said filter section;

wherein each of said plurality of slits has a minimal cross section of 100 microns or less thereby preventing outflow at least of particles having a bead diameter ranging between 100 to 1500 microns,

delivering embolization particles suspended in a fluid through a lumen of the microcatheter.

17. The method of claim 16, further comprising a preliminary step of locating of the target blood vessel using an imaging technique.

18. The method of claim 16, wherein the particles comprise embolization beads, radioactive embolization beads, radio-opaque embolization beads, chemotherapeutic embolization beads drug eluting embolization beads or any combination thereof.

19. The method of claim 16, wherein the fluid comprises saline, a contrast enhancing agent, lipiodol or any combination thereof.

20. The method of claim 16, wherein the selective outflow of the fluid is effected while maintaining said distal head section in a straight, curved or bent configuration.