Claims for Patent: 8,892,190

Summary for Patent: 8,892,190

Title:	Method and apparatus for performing intra-operative angiography
Abstract:	Method for assessing the patency of a patient's blood vessel, advantageously during or after treatment of that vessel by an invasive procedure, comprising administering a fluorescent dye to the patient; obtaining at least one angiographic image of the vessel portion; and evaluating the at least one angiographic image to assess the patency of the vessel portion. Other related methods are contemplated, including methods for assessing perfusion in selected body tissue, methods for evaluating the potential of vessels for use in creation of AV fistulas, methods for determining the diameter of a vessel, and methods for locating a vessel located below the surface of a tissue.
Inventor(s):	Docherty; John C. (Winnipeg, CA), Hewco; Mark (Winnipeg, CA), Mangat; Gurpreet (Markham, CA), Flower; Robert W. (Hunt Valley, MD), Chari; Seshadri M. (Toronto, CA)
Assignee:	National Research Council of Canada (Ontario, CA)
Application Number:	13/419,368
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,892,190
Patent Claims:	1. A method for assessing blood flow moving through a vessel graft anastomosed in fluid communication with an interconnected group of blood vessels in an animal, the vessel graft and at least a portion of the blood vessels being exposed during a surgical procedure on the animal, the method comprising the steps of: (a) administering a fluorescent dye to the animal such that the dye enters the vessel graft and the interconnected group of blood vessels; (b) exciting the fluorescent dye within the vessel graft and said exposed portion of the interconnected group of blood vessels with a source of illumination, thus causing the dye to emit radiation; (c) capturing the radiation emitted by the fluorescent dye with a camera capable of imaging a series of angiographic images within the vessel graft and said exposed portion of the interconnected group of blood vessels, the images including at least an image of a fluorescent wavefront corresponding to an interface between the flowing blood that first contains the fluorescent dye introduced, such image being captured by the camera as the fluorescent wavefront transitions through the exposed vessel graft and interconnected croup of blood vessels; and (d) evaluating the angiographic images to assess blood flow through the vessel graft relative to blood flow through the interconnected group of blood vessels. 2. The method of claim 1, further comprising: modifying said anastomosed vessel graft based on results of said evaluating step, thereby improving resultant blood flow through said vessel graft. 3. A method for assessing blood flow moving through an vessel graft in an animal, the vessel graft being exposed during a surgical procedure on the animal, comprising the steps of: (a) administering a fluorescent dye to the animal such that the dye enters the vessel graft; (b) exciting the fluorescent dye within the vessel graft with a source of illumination, thus causing the dye to emit radiation, the fluorescent dye having a peak absorption and emission in the range of 800 to 850 nm; (c) capturing the radiation emitted by the fluorescent dye with a camera capable of imaging a series of angiographic images of the vessel graft at a rate of at least 15 images per second while the subject's heart is beating, the images including at least an image of a fluorescent wavefront corresponding to an interface between the flowing blood that first contains the fluorescent dye introduced, such image being captured by the camera as the fluorescent wavefront transitions through the exposed vessel graft; and (d) evaluating the angiographic images to assess blood flow through the vessel graft relative to blood flow through a group of blood vessels interconnected to the vessel graft.