Abstract: Cardiovascular disease is the leading cause of death in the United States. Interpreting the relative danger of a lesion within the vasculature is limited by a lack of information on the composition of lesion. It is believed that a lesion which is high in lipids is more prone to rupture followed by thrombosis than a stable highly calcific, fibrotic, high grade stenosis. To address this recent hypothesis, a method of diagnosing and treating the most problematic vascular lesions is presented. The method employs the selective uptake of a lipophilic fluorescent compound by a lesion followed by the application of excitation light to the fluorescent compound-ladened lesion causing the fluorescent compound to emit fluorescence light.

Abstract: A light diffusing guidewire which has the ability to deliver light to luminal surfaces such as blood vessels for the diagnosis and treatment of medical conditions. The device can be used either in conjunction with another outer catheter such as a balloon catheter or as a stand-alone device. The light diffusing guidewire can be used as a standard guidewire for directing the placement of another catheter. The guidewire has an elongate body portion having a proximal end and a distal (invasive) end. A portion of the body portion transmits light from the proximal end to a light diffusing element within the body portion near the distal end. The guidewire has a floppy tip distal to the light diffusing element and is rigid and highly torqueable proximal to the diffusing element. The outer diameter of the guidewire is similar to that of standard interventional guidewires such as angioplasty guidewires, i.e. 0.014"-0.038".

Abstract: Photodynamic Therapy (PDT) is used as an adjunctive or stand alone procedure for the treatment of cardiovascular disease. When used as an adjunctive therapy to Percutaneous Transluminal Coronary Angioplasty, laser angioplasty, atherectomy, stenting, or any other interventional or surgical procedure, it has been found that the treatment timing is critical to the success of the combined therapies. A photosensitizer is administered prior to the surgical or interventional procedure and then readministered after the procedure to maintain the photosensitizer concentration level in the atheromatous plaque and smooth muscle cells in the vicinity of the lesion for a period of about 5-18 days, the period in which cell proliferation can occur. The photosensitizer inhibits smooth muscle cell proliferation and, thus, minimizes or eliminates the possibility of re-stenosis. The photosensitizer is then illuminated at the end of this period, thereby lysing the atheromatous plaque and smooth muscles.

Abstract: An intra-vascular optical radial imaging system comprising an intra-vascular guidewire-compatible catheter, a source of illumination and a synchronous fluorescence detector. The catheter is inserted into a blood vessel until the tip is adjacent to a section of vessel to be imaged. A narrow beam of light emanating radially from an aperture underlying the segment to be imaged repetitively illuminates segments of the wall of the vessel in a scanning or sweeping manner with the light of a wavelength that induces fluorescence in molecules in the tissue. Fluorescence from molecules in the illuminated tissue enters the catheter through the aperture and is conveyed to a spectral analyzer. Properties of the fluorescence signal are characteristic of the particular tissue and may be used to differentiate healthy tissue from atherosclerotic plaque.

Abstract: A system is described for the delivery of light to, and/or the receiving of light from, a target located on the wall of a tortuous tube such as a blood vessel. The delivery system is generally useful for laterally delivering and receiving light for the detection and photodynamic therapy of target tissue and is particularly useful for the treatment of atherosclerosis. When certain biocompatible photoreactive molecules such as hematoporphyrin or the like are injected into a patient the molecules are selectively taken up by target tissue such as tumors or atheromatous plaque. Subsequent illumination of the target tissue activates the photoreactive molecules causing fluorescence emission from, and destruction of, the host target tissue. The preferred embodiments comprise a hollow optical waveguide terminating in a supple diffuser tip which may be inserted over an intravascular flexible guide wire. The optical delivery catheter is advanced along the guidewire until the diffuser tip reaches the target tissue.