Yale University

Lawrence I Deckelbaum

Francis P Gasparro

David J Leffell

Bauer E Sumpio

Cyrus R Kapadia

Kenneth M O'Brien

Bauer K Sumpio

Mark L Stetz

John J Scott

A method for inhibiting smooth muscle cell proliferation in an injured blood vessel includes the steps of administering a photoactivatable psoralen to a patient in an amount to achieve local arterial tissue levels of psoralen suitable for light-dependent inhibition of smooth muscle cell growth, and delivering radiation in the visible wavelength range to the injured region of the blood vessel at a level sufficient for photoactivation of the psoralen. The psoralen is preferably 8-methoxypsoralen and can be delivered systemically or locally. The method of the invention can be used for preventing restenosis in a blood vessel following transluminal angioplasty. Both the psoralen and the visible light can be delivered with a laser balloon catheter having a porous balloon. The method of the invention may also be used for inhibiting proliferation of other undesired cell types in a patient's body.

Inhibition of smooth muscle cell proliferation by 8-methoxypsoralen

Methods are provided for laser induced fluorescence intensity feedback and control during laser angioplasty. In a first aspect of the invention, a catheter including an eccentric guidewire lumen and at least one optical fiber is positioned relative to an obstruction in a blood vessel by rotating the catheter and monitoring the fluorescence intensity. When the fluorescence intensity has a maximum value, the optical fiber is aligned with the obstruction. In another aspect of the invention, fluorescence intensity feedback is used to determine when a laser ablation device has crossed an occlusion. An abrupt drop in fluorescence intensity indicates that the ablation device has crossed the occlusion. In a further aspect of the invention, fluorescence intensity feedback is used to determine the effectiveness of fluid flushing in a blood vessel. In yet another aspect of the invention, fluorescence spectroscopy and fluorescence intensity monitoring are performed sequentially for different subsets of optical fibers in a laser catheter to provide precise control over fiber positioning, tissue diagnosis and ablation. Preferably, the fluorescence intensity feedback is used in conjunction with fluorescence spectroscopy.

Methods for laser induced fluorescence intensity feedback control during

A method of detecting pre-malignant lesions in the gastrointestinal tract comprises positioning an opitcal fiber in a patient's gastrointestinal tract and transmitting ultraviolet laser light through said optical fiber means to cause the tissue of the gastrointestinal tract illuminated by the laser to fluoresce in the near visible band of frequencies. The fluorescence spectrum is returned through the optical fiber to a spectrum analyzing means which analyzes the spectrum in the wavelength range of 350 to 700 nm to determine whether the tissue caused to fluoresce is pre-malignant. Tissue so diagnosed may be ablated by a high power laser using the same fiberoptic system.

Endoscopic fiberoptic fluorescence spectrometer

A method and apparatus for inducing fluorescence in human skin, in vivo, and for evaluating certain skin characteristics from the spectral intensity of induced fluorescence. The energy of a helium-cadmium laser is directed to a skin area to be evaluated by a fiberoptic element. The induced fluorescent energy having a wavelength band of interest above that of the laser wavelength, is directed to a device by a fiberoptic path for performing a spectral analysis of the fluorescent intensity. A ratio of chracteristic portions of fluorescent intensity of the skin area under test is developed and used to compare with different test subjects. The developed ratio, when taken in relation to the skin of subjects of different ages, indicates a marked difference in older subjects in comparison to that of very young subjects which correlates with long-term exposure of the skin to ultraviolet radiation. The method and apparatus are useful for evaluating skin pigmentation as well as for evaluating certain solid compounds such as amino acids.

Optical method and apparatus for detecting and measuring aging,

A process and apparatus for ablating atherosclerotic or tumorous tissues is disclosed. Optical fibers direct low power light energy at a section of tissue to be ablated to cause the section to fluoresce. The fluorescence pattern is analyzed to determine whether the fluorescence frequency spectrum is representative of normal or abnormal tissue. A source of high power ultraviolet laser energy directed through an optical fiber at the section of tissue is fired only when the fluorometric analysis indicates that it is directed at abnormal tissue.

Growing community of inventors

Woodbridge, CT, United States of America

Lawrence I Deckelbaum