Abstract: Surgical ablation instruments are disclosed for creating lesions in tissue, including cardiac tissue for treatment of arrhythmias and other diseases. The hand held instruments are especially useful in open chest or port access cardiac surgery for rapid and efficient creation of curvilinear lesions to serve as conduction blocks. Photoablative instruments are disclosed that can achieve rapid and effective photoablation through the use of distributed (e.g., diffuse or defocused) radiant energy.

Abstract: Ablation methods and instruments are disclosed for creating lesions in tissue, especially cardiac tissue for treatment of arrhythmias and the like. Percutaneous ablation instruments in the form of coaxial catheter bodies are disclosed having at least one central lumen therein and having one or more balloon structures at the distal end region of the instrument. The instruments include an energy emitting element which is independently positionable within the lumen of the instrument and adapted to project radiant energy through a transmissive region of a projection balloon to a target tissue site. The instrument can optionally include at least one expandable anchor balloon disposed about, or incorporated into an inner catheter body designed to be slid over a guidewire. This anchor balloon can serve to position the device within a lumen, such as a pulmonary vein.

Abstract: Methods and systems are disclosed for detecting overheating in an optical device before harmful consequences, such as severe local heating, can result. In one embodiment of the invention, a blackbody emitter is disposed in close proximity to a therapeutic optical fiber to absorb therapeutic radiation at a fault and re-emit blackbody (infrared) radiation. The emitter can be coupled to the fiber but, during normal operation, lies outside the optical path between the output of the laser radiation and the site of treatment. Systems and catheters incorporating such emitters are also described for effective monitoring of the laser power transmitted along the optical fiber within the phototherapy device.

Abstract: An apparatus and method for phototherapy are described in which laser light or other radiation is projected from within a catheter, through a balloon member, and toward the surface of tissue. The light reflected from body fluids or the tissue surface is captured by a collecting device located within the catheter, e.g., within the balloon member, and the intensity of the reflected light is ascertained. The apparatus and method provides for accurately positioning the apparatus against the tissue treatment site.

Abstract: The present invention is directed to a balloon catheter having an irrigation sheath. The balloon catheter has a first expandable membrane forming an occluding balloon. A second membrane forms a sheath about the occluding balloon for providing irrigation to a body lumen. Fluid is provided to the occluding balloon to position the catheter and/or occlude the flow of blood. Fluid is then passed through the sheath to irrigate the target site. In one embodiment of the present invention, the sheath has a plurality of fluid releasing pores.

Abstract: Infrared surgical photoablation instruments are disclosed for creating lesions in tissue, including cardiac tissue for treatment of arrhythmias and other diseases. The hand held instruments are especially useful in open chest or port access cardiac surgery for rapid and efficient creation of curvilinear lesions to serve as conduction blocks. Photoablative instruments are disclosed that emit radiation at a wavelength in a range from about 800 nm to about 1000 nm, and preferably emit at a wavelength in a range of about 915 nm to about 980 nm. Radiation at a wavelength of 915 nm or 980 nm is commonly preferred, in some applications, because of the optimal absorption of infrared radiation by cardiac tissue at these wavelengths.

Abstract: Methods and apparatus are disclosed for forming annular lesions in tissue. The methods include introduction of an optical apparatus proximate to a tissue site, via, for example, a catheter. The optical apparatus includes a pattern-forming optical waveguide in communication with a light transmitting optical fiber. Energy is transmitted through the optical fiber, such that radiation is propagated through the optical fiber and the waveguide projects an annular light pattern, e.g., a circle or a halo.

Abstract: The present invention is directed to a hand held cardiac ablation instrument and methods for irradiating a target ablation site. The instrument can include at least one light transmitting optical fiber and a light diffusing element to create a circumferential or curvilinear lesion. A handle is provided for manual application. The handle can be substantially coaxial or otherwise aligned with the center of the circumferential housing. Light travelling through the light transmitting optical fiber or fibers is scattered in a circular pattern by the light diffusing element. The light diffusing element can include a scattering medium, a reflective end cap, and a reflective surface diametrically opposed to the target ablation site, that interact to provide a substantially uniform distribution of laser radiation throughout the circular target region.

Abstract: Laser energy produced by a laser operating In the mid-infrared region (approximately 2 micrometers) Is delivered by an optical fiber in a catheter to a surgical site for biological tissue removal and repair. Disclosed laser sources which have an output wavelength in this region include: Holmium-doped Yttrium Aluminum Garnet (Ho:YAG), Holmium-doped Yttrium Lithium Fluoride (Ho:YLF), Erbium-doped YAG, Erbium-doped YLF and Thulium-doped YAG. For tissue removal, the lasers are operated with relatively long pulses at energy levels of approximately 1 joule per pulse. For tissue repair, the lasers are operated in a continuous wave mode at low power. Laser output energy is applied to a silica-based optical fiber which has been specially purified to reduce the hydroxyl-ion concentration to a low level. The catheter may be comprised of a single optical fiber or a plurality of optical fibers arranged to give overlapping output patterns for large area coverage.

Abstract: Methods and apparatus are disclosed for forming annular lesions in tissue. The methods include introduction of an optical apparatus proximate to a tissue site, via, for example, a catheter. The optical apparatus includes a pattern-forming optical wave guide in communication with a light transmitting optical fiber. Energy is transmitted through the optical fiber, such that radiation is propagated through the optical fiber and the wave guide projects an annular light pattern, e.g., a circle or a halo.

Abstract: A catheter system is formed of a two-lumen rotatable shaft with a working tube extending through one of the lumens and an energy emitting element coupled to the other lumen. Rotation and movement distally of the rotatable shaft, coils the energy emitting element and expands the overall profile of the catheter system. Energy emitted through the coiled energy emitting element provides circular lesions for circumferential treatment on desired tissue. Counter rotating and retracting of the rotatable shaft returns the catheter system to a sleek profile for removal of the catheter system from the biological vessel area. A light diffusing tip with reflective sheath is utilized as the energy emitting element and focuses energy on the target tissue and away from surrounding blood pool.

Abstract: An optical transmissive, light-diffusing, fiber tip assembly having a radiation-scattering particles incorporated therein and a reflective end surface is disclosed for use in phototherapy. As radiation propagates through the fiber tip, a portion of the radiation is scattered in a cylindrical (or partially cylindrical) pattern along the length of the fiber tip. Radiation which is not scattered during this initial pass through the tip is reflected by at least one surface of the assembly and returned through the tip. During this second pass, the remaining radiation (or at least a major portion of this returning radiation) again encounters the scatterers which provide further radial diffusion of the radiation. Preferably, the scattering medium and the reflective end cap interact to provide a substantially uniform axial distribution of laser radiation over the length of the tip apparatus.

Abstract: Phototherapeutic instruments are disclosed having a light transmitting optical fiber with a flexible portion that facilitates passage of the instrument through a tortuous lumen within a patient and an outer support sheath slidably mounted about the fiber. In one preferred embodiment, the instrument includes a rigid light-emitting tip. The support sheath is configured to protect the more delicate optical fiber and provide support for the flexible portion of the optical fiber during penetration of the light-emitting tip into a patient's tissue. During insertion of the instrument into a tortuous lumen, the optical fiber is covered by the support sheath, allowing the light-emitting tip to deflect with ease as it travels along the tortuous lumen.

Abstract: Laser energy produced by a laser operating in the mid-infrared region (approximately 2 micrometers) is delivered by an optical fiber in a catheter to a surgical site for biological tissue removal and repair. Disclosed laser sources which have an output wavelength in this region include: Holmium-doped Yttrium Aluminum Garnet (Ho:YAG), Holmium-doped Yttrium Lithium Fluoride (Ho:YLF), Erbium-doped YAG, Erbium-doped YLF and Thulium-doped YAG. For tissue removal, the lasers are operated with relatively long pulses at energy levels of approximately 1 joule per pulse. For tissue repair, the lasers are operated in a continuous wave mode at low power. Laser output energy is applied to a silica-based optical fiber which has been specially purified to reduce the hydroxyl-ion concentration to a low level. The catheter may be comprised of a single optical fiber or a plurality of optical fibers arranged to give overlapping output patterns for large area coverage.

Abstract: A phototherapy device which can include an optical fiber having a perfluorinated polymer outer buffer coating, and an optical element, such as a GRIN lens or a mirror, disposed at its distal end. A tubular housing encases the optical element and is thermally bonded to at least a portion of the buffer. The component elements of the device can be constructed of materials having similar thermal characteristic to inhibit the effect of heat cycling on the device. In addition, the materials of the device, and in particular the housing, can be selected to inhibit wear and scrapping of the lumen of the delivery instrument during use. A marker band can be positioned about the optical fiber to facilitate viewing of the phototherapy device in-vivo.

Abstract: A low-profile, diffusive tip apparatus adapted for insertion into a body to deliver phototherapeutic radiation by scattering light in a substantially omnidirectional pattern includes a light-transmissive housing that is adapted for mounting, at its proximal end, onto a fiber optic cable, and, at its distal end, the housing defines or is joined to a light-transmissive cap having a diameter which is not substantially greater than the diameter of the optical fiber. The light transmissive cap region encloses a chamber or reservoir filled with an optically scattering medium and, preferably, hemispherical in shape with a radius of curvature substantially equal to the radius of the housing.

Abstract: Phototherapeutic instruments are disclosed for providing substantially uniform energy distribution to a major portion of an area exposed during phototherapy. These instruments include an element for directing radiation toward the walls of a lumen and a device for centering the radiation directing element within the lumen. The instruments also allow the flow of blood, therapeutic fluid, or air past the exposure site. The instruments are particularly useful as part of a fiber optic-based medical laser system for photodynamic therapy within the bronchia of the lung, blood vessels or other liquid-filled lumens.