Catheter apparatus and methodology for generating a fistula on-demand between closely associated blood vessels at a pre-chosen anatomic site in-vivo
View Patent ↗The present invention provides catheter apparatus and catheterization methodology for generating an arteriovenous fistula or a veno-venous fistula on-demand between closely associated blood vessels and at a chosen anatomic site in-vivo. The catheter apparatus is preferably employed in pairs, each catheter of the pair being suitable for percutaneous introduction into and extension through a blood vessel. The catheterization methodology employs the catheter apparatus preferably in conjunction with conventional radiological techniques in order to place, verify, and confirm a proper alignment, orientation, and positioning for the catheters in-vivo prior to activating the perforation means for generating a fistula. The invention permits the generation of arteriovenous fistulae and veno-venous fistulae anatomically anywhere in the vascular system of a patient; nevertheless, the invention is most desirably employed in the peripheral vascular system as exists in the extremities of the body to aid in the treatment of the patient under a variety of different medical ailments and pathologies.
1. A method for generating an arteriovenous fistula between an artery and a vein in-vivo, said method comprising the steps of:
(a) providing a first catheter that is positionable in the vein and a second catheter that is positionable in the artery, said first and second catheters having magnetic members thereon and at least one of said first and second catheters having a sliding perforation member that moves axially to perforate the artery and vein at adjacent locations to thereby create a fistula between the artery and vein;
(b) positioning the first catheter within the vein;
(c) positioning the second catheter within the artery;
(d) causing a magnetic attraction between the magnetic members; and
(e) causing the perforation member to move axially resulting in perforation of the artery and vein at adjacent locations to thereby create a fistula between the artery and vein.
2. A method according to claim 1 wherein ultrasound imaging is used to facilitate positioning of at least one of the catheters.
3. A method according to claim 1 wherein intravascular ultrasound imaging is used to facilitate positioning of at least one of the catheters.
4. A method according to claim 1 wherein fluoroscopy is used to facilitate positioning of at least one of the catheters.
5. A method according to claim 1 wherein fluoroscopy with contrast medium is used to facilitate positioning of at least one of the catheters.
6. A method according to claim 1 wherein the first and second catheters have radiopaque markers thereon and wherein said radiopaque markers are used to facilitate positioning of the catheters relative to one another.
7. A method according to claim 1 wherein the magnet members on the catheters provided in Step a comprise rare earth magnets.
8. A method according to claim 1 wherein the magnetic attraction between the magnetic members results in adjustment of the positions of the catheters relative to one another.
9. A method according to claim 1 wherein the magnetic attraction between the magnetic members draws the artery and vein closer to each other.
10. A method according to claim 1 wherein the perforation member on at least one of the first and second catheters provided in Step a comprises a radiofrequency electrode.
11. A method according to claim 10 wherein Step e comprises actuating the radiofrequency electrode.
12. A method according to claim 11 wherein the axial movement of the electrode in Step e creates slit perforations in the walls of the artery and vein.
13. A method according to claim 1 further comprising the step of introducing boluses of carbon dioxide into the artery and vein adjacent to the location where the fistula is formed.