Methods and systems for treating ischemia

• US 20060142783A1
• Filed: 11/23/2005
• Published: 06/29/2006
• Est. Priority Date: 02/03/1998
• Status: Abandoned Application

• Current Assignee: Brian Douglas Lewis, Lee R. Bolduc
• Original Assignee: Brian Douglas Lewis, Lee R. Bolduc
• Inventors: Lewis, Brian Douglas, Bolduc, Lee R.
• Application Number:
  US11/286,254
• Publication Number:
  US 20060142783A1
• Time in Patent Office: Days
• US Class Current: 606/127
• CPC Class Codes: A61B 17/22 Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for dilators A61M29/00
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2017/22077 with a part piercing the tissue A61B2017/22044 takes precedence
• CPC Class Codes: A61B 2017/22082 after introduction of a substance
• CPC Class Codes: A61B 2017/22084 stone- or thrombus-dissolving
• CPC Class Codes: A61M 2025/0002 with a pressure sensor at the distal end
• CPC Class Codes: A61M 2025/0004 having two or more concentrically arranged tubes for forming a concentric catheter system
• CPC Class Codes: A61M 2025/0035 characterized by a variable lumen cross-section by means of a resilient flexible septum or outer wall
• CPC Class Codes: A61M 2025/0037 characterized by lumina being arranged side-by-side
• CPC Class Codes: A61M 2025/0039 characterized by lumina being arranged coaxially
• 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 2025/1004 Balloons with folds, e.g. folded or multifolded
• CPC Class Codes: A61M 2025/1079 having radio-opaque markers in the region of the balloon
• CPC Class Codes: A61M 2025/1095 with perfusion means for enabling blood circulation while the balloon is in an inflated state or in a deflated state, e.g. permanent by-pass within catheter shaft
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2210/0693 Brain, cerebrum
• CPC Class Codes: A61M 25/0023 by the form of the lumen, e.g. cross-section, variable diameter
• CPC Class Codes: A61M 25/0029 characterized by features relating to least one lumen located at the middle part of the catheter, e.g. slots, flaps, valves, cuffs, apertures, notches, grooves or rapid exchange ports catheter shaft surface irregularities A61M2025/006
• CPC Class Codes: A61M 25/003 : characterized by features relating to least one lumen located at the distal part of the catheter, e.g. filters, plugs or valves catheter tips A61M25/0067
• CPC Class Codes: A61M 25/0032 : characterized by at least one unconventionally shaped lumen, e.g. polygons, ellipsoids, wedges or shapes comprising concave and convex parts
• 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 25/0108 : using radio-opaque or ultrasound markers
• CPC Class Codes: A61M 25/104 : used for angioplasty

Abstract

Methods for treating total and partial occlusions employ a perfusion conduit which is penetrated through the occlusive material. Oxygenated blood or other medium is then perfused through the conduit in a controlled manner, preferably at a controlled pressure below the arterial pressure, to maintain oxygenation and relieve ischemia in tissue distal to the occlusion. In another aspect, interventional devices, such as stents or balloon catheters, are passed through the perfusion catheter to remove obstructions. Optionally, the occlusion may be treated while perfusion is maintained, typically by introducing a thrombolytic or other agent into the occlusive material using the perfusion conduit or by employing mechanical means to remove the obstruction. Such methods are particularly suitable for treating acute stroke to prevent damage to the cerebral tissue.

Claims

1. A method of treating an ischemic bed downstream of an obstruction in a patient'"'"'s cerebral arterial vasculature, comprising the steps of:

introducing a catheter into a patient, the catheter having a distal portion, a distal end and a lumen having at least one outlet;

advancing the catheter to an obstruction in an artery in the patient'"'"'s cerebral vasculature;

passing the distal end of the catheter through the obstruction;

supplying an oxygenated medium downstream of the obstruction; and

maintaining the pressure at the location downstream of the obstruction at a pressure lower than normal for a period of time so that the ischemic bed is not exposed to full arterial pressure.

2. The method of claim 1, wherein:

the introducing step is carried out with the catheter having first means for sensing pressure at a position along the distal portion of the catheter;

the method further comprising the step of measuring the arterial pressure with the first pressure sensing means; and

the maintaining step being carried out by maintaining a selected pressure measured by the first pressure sensing means.

3. The method of claim 2, further comprising:

perfusing the oxygenated medium through the lumen in the catheter at a rate to maintain the selected pressure.

4. The method of claim 2, wherein:

the introducing step is carried out with the catheter having second means for sensing pressure, the second pressure sensing means being positioned proximal of the first pressure sensing means.

5. The method of claim 1, wherein:

the passing step is carried out so that the catheter and obstruction maintain occlusion of the artery.

6. The method of claim 1, further comprising the step of:

providing an expandable member on the catheter, the expandable member being expandable from a collapsed shape to an expanded shape;

expanding the expandable member at a position near or at the obstruction to occlude the artery to prevent the ischemic bed downstream of the occlusion to be exposed to full arterial pressure.

7. The method of claim 1, wherein:

the perfusing step is carried out with the period of time being at least 5 minutes.

8. The method of claim 1, wherein:

the perfusing step is carried out with the period of time being at least 2 hours.

9. The method of claim 1, wherein:

the perfusing step is carried out with the period of time being at least 2 days.

10. The method of claim 1, wherein:

the introducing step is carried out with the catheter having a maximum outer dimension of no more than 3.2 mm at a distal portion of the catheter, the distal portion extending for at least 10 cm from the distal end.

11. The method of claim 1, further comprising:

advancing an obstruction removal device to the obstruction during the supplying step; and

removing the obstruction with the obstruction removal.

12. The method of claim 11, wherein:

the removing step is carried out with the obstruction removal device being a device selected from the group consisting of a mechanical disruption element, an RF electrode, an ultrasound transducer and a laser.

13. The method of claim 11, wherein:

the obstruction removal device passes over the catheter and forms a lumen in a space between the obstruction removal device and the catheter.

14. The method of claim 12, wherein:

the lumen is coupled to a source of liquid which is to be delivered to the obstruction.

16. The method of claim 14, wherein the providing step is carried out with the catheter including a lumen having a cross-sectional area of at least 0.45 mm along a length of 5 cm from a distal end of the lumen.

17. The method of claim 14, wherein the providing step is carried out with the catheter having a y-arm connector coupled to the lumen and a hemostasis valve for receiving another catheter in the lumen.

18. The method of claim 14, further comprising the step of:

advancing the catheter through an obstruction in the cerebral vasculature; and

infusing an oxygenated medium distal to the obstruction through a lumen in the catheter.

19. The method of claim 14, wherein the expanding step is carried out with an outer dimension of the sidewall expanding at least 25% along a portion of the sidewall.

20. The method of claim 14, further comprising the step of:

advancing another catheter through a lumen in the catheter.

15. A method of accessing the cerebral vasculature, comprising the steps of:

providing a catheter having an expandable sidewall;

introducing the catheter into the cerebral vasculature in a collapsed position;

advancing the catheter to a site in the cerebral vasculature; and

expanding the sidewall to an expanded position.