Device and method for dilation of a tubular anatomical structure
Described is a method and device for dilating a tubular anatomical structure. The device and method can be useful for extracting a blood clot in an artery of a mammal by concentrically irradiating an inner wall of the occluded artery using an ultraviolet (UV) laser beam delivered by an optical fiber. Dilation results from photophysical production and release of nitric oxide from the cells lining the arterial wall when UV laser light is projected as a ring beam onto the inner arterial wall.
1 . A method for dilating a tubular anatomical structure in a body of a patient, said method comprising the steps of:
providing a combination guidewire and optical fiber capable of carrying UV laser light, wherein said guidewire is formed as a hollow tube and has disposed within the hollow tube the optical fiber in a locked or unlocked position, wherein the optical fiber has a distal end having a configuration selected from the group consisting of an external cone and an inverted cone, wherein the distal end of the optical fiber is congruent with and shielded by the end of the guidewire until placement in the desired location within the tubular anatomical structure; and
refractively emitting UV laser light energy from the distal end of the optical fiber at a wavelength of about 300-400 nm and an intensity of about 3-20 Watts/cm 2 to impinge as an annular ring beam onto smooth muscle cells lining an inner wall of the tubular anatomical structure to stimulate photophysical production and release of nitric oxide (NO·) from stores of nitrites (NO 2 − ) present in said smooth muscle cells, whereby the released nitric oxide causes relaxation of the smooth muscle cells and dilation of the tubular anatomical structure with minimal damage to the endothelial cells of the inner wall of the tubular anatomical structure.
2 . The method of claim 1 , wherein the tubular anatomical structure is an artery.
3 . The method of claim 2 , wherein the artery is at least partially occluded by a thrombus or blood clot.
4 . The method of claim 3 , wherein the method further comprises:
positioning the combination guidewire and optical fiber within about 1-10 vessel diameters of the thrombus or blood clot within the artery;
emitting UV light energy from the optical fiber as an annular ring beam onto smooth muscle cells lining an inner wall of the artery to stimulate photophysical production and release of nitric oxide (NO·) from stores of nitrites (NO 2 − ) present in said artery, whereby the nitric oxide causes relaxation of the smooth muscle cells and dilation of the artery; and
removing the thrombus or blood clot mechanically by a thrombectomy procedure.
5 . The method of claim 4 , wherein the thrombectomy procedure employs a balloon catheter.
6 . The method of claim 4 , wherein the thrombectomy procedure employs an aspiration catheter.
7 . The method of claim 4 , wherein the thrombectomy procedure employs a stentriever.
8 . The method of claim 1 , wherein the tubular anatomical structure is selected from the group consisting of an anatomical canal, tube or tubule, bronchiole, ureter, and a vas.
9 . The method of claim 1 , wherein the hollow guidewire and optical fiber capable of carrying UV laser light are affixed to one another.
10 . The method of claim 1 , wherein the optical fiber is silica, ALON, sapphire, or a custom polymeric material.
11 . The method of claim 1 , wherein the distal end of the optical fiber capable of carrying UV laser light is provided as a separate tip in optical communication with the optical fiber.
12 . The method of claim 11 , wherein the separate tip in optical communication with the optical fiber comprises diamond.
13 . The method of claim 11 , wherein the separate tip in optical communication with the optical fiber comprises zirconium oxide.
14 . The method of claim 1 , wherein the UV laser light is emitted at a wavelength of about 355 nm.