Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
  • A61N5/1001—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy using radiation sources introduced into or applied onto the body; brachytherapy
  • A61N5/1002—Intraluminal radiation therapy
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/36—Image-producing devices or illumination devices not otherwise provided for
  • A61B90/37—Surgical systems with images on a monitor during operation
  • A61B2090/378—Surgical systems with images on a monitor during operation using ultrasound
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
  • A61N5/1001—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy using radiation sources introduced into or applied onto the body; brachytherapy
  • A61N5/1002—Intraluminal radiation therapy
  • A61N2005/1005—Intraluminal radiation therapy with asymmetrical radiation pattern

Definitions

• the present invention relates to the field of invasive radioactive treatment of bodily tissue, particularly for the treatment of diseased (atherosclerotic) and obstructed vessel segments.
• vessel disease extent can be non- circumferential, thereby demonstrating a segment of the vessel wall that is not-thickened and unaffected by the disease.
• the incidence of eccentric lesions is 69% (Hausmann et al , American Journal of Cardiology 1994 Nov 1; 74(9): 857-63). Since non- proportional irradiation of biological tissue may destroy cells, making it possible, in vessels, for aneurysm development or rupture to occur, this morphological pattern of vessel obstruction deserves selective side irradiation sothat non-diseased wall segments are spared from radioactive traumatization.
• a number of catheter assemblies were introduced to address catheter- based radioactive therapeutics. These techniques focus on transcathter introduction of radioactive source to the target segment of the vessel. When positioned in the diseased segment, the radioactive source provides treatment to the lesion.
• the Weinstem et al patent describes method and apparatus with particles or crystals of radioactive catheter materials embedded on a tube provide ⁇ inside the balloon catnetei During operation, the stenosec segmer J_ ⁇ irradiated.
• the patent tc Dake et al shows a radioactive catheter merely indicating that an elongated flexible catheter is transported to the area of the stenosis after a balloon catheter has been withdrawn.
• the patent to Teirstem describes a radioactive wire with inflatable balloon or coil -shaped loops, this should provide adequately central position of the radioactive source within the coil balloon and vessel lume .
• the patent issued to Liprie describes an apparatus for treatir ⁇ the location of a stenosis in a blood vessel by introducing a radioactive source into the catheter and is maneuvered to the site of treatment.
• the patent issued to Diedrich describes an catheter having a multi element array of piezoceramic transducers to provide thermal therapy for tumors and benign tissues using heat generated from acoustic energy.
• the patents issued to Williams and Thornton ⁇ emonstrate two different types of inflatable apparatuses for treatment of diseased conduits or vessels.
• the inflatable devices are filled with a radioactive treatment fluid.
• the PCT document to Passafaro et al describes an mtravascular probe assembly provided with both ultrasonic imaging and laser ablation capabilities
• the device includes a distaliy positioned rotable housirg havmg an ultrasonic transduce'" anc " optica.
• f_ber opert__vely f_xed therein so as to respectively emit acoustic energy and laser radiation along a common path generally parallel to the housing axis
• the device provides 360° (circumferential) imaging and laser ablation
• none of the aforementioned methods and devices proposes the radioactive energy to be selectively laterally directed so that, within a stenosis caused by non - circumferential disease, the opposite, non diseased vessel wall segments are spared from radioactive traumatization .
• the invention proposes an ultrasound catheter assembly to be introduced in bodily vessels, cavities, conduits, ducts etc. (vessel) with the capability of incorporating a radioactive source in order to provide irradiation treatment to a diseased site.
• the proposed catheter has a tapered distal tip.
• Ultrasound arrays (multiple transducer elements) system is installed proximate to tne distal catheter tip and distal or at the level of the radioactive aperture, providin ⁇ cross - sectional imaging of tissue.
• the catheter incorporates a separate channel for the introduction of a radioactive source (radioactive lumen/cnannel )
• the radioactive lumen passes tnrough the entire length of the catheter Proximally, the radioactive lumen communicates with a radioactive port for the introduction of a radioactive source during treatment Distally, the radioactive lumen terminates in a radioactive chamber
• the wall of tre radioactive chamber comprises at least segmentallv of radioac ively transparent material
• a radioactively transparent part of the wall of the radioactive chamber occupies a segment of the exterior catheter surface (side irradiation, radioactive aperture) .
• the proposed catheter design must demonstrate a circular and uniform external perimeter along the entire length thereof.
• Transducer- elements located within tne radioactive aperture, or on the circumferential catheter segment which corresponds to the radioactive aperture send additional electrical signals. These signals are reconstructed as an additional sectorial area indicating the position of the radioactive aperture and is displayed simultaneously on the cross- sectional ultrasonic tissue image.
• Fig.l The Distal Portion Of Tne Catneter
• Figure.2 Cross - sectional Views Through The Various Levels of The Distal Portion Of The Catheter (* electrical cables)
• Figure.2E Another Preferred Embodiment Of the Proposed Invention: The Radioactive Chamber Is Located At the Level Of Ultrasound Arrays (* electrical cables)
• Figure 3 The Proposed Catheter During Operation In Coronary Vessels
• Fig. 3A (Ultrasound Image) Area indicating The Position Of Radioactive Aperture
• the invention proposes a catheter assembly (1) to be introduced in bodily vessels, cavities, conduits, ducts etc (vessel) in ordei to selectively apply radioactive treatment to a diseased site located eccentrically (non circumferentially) on or within the wall of the vessel .
• the proposed catheter has a tapered distal tip (2) .
• the catheter incorporates a channel (3) for guidewire (4), which passes at least partially through the catheter.
• a system of ultrasound arrays (5) (plurality of ultrasound emitting and receiving transducers) are installed to provide cross sectional ultrasound imaging while introducing and maneuvering of the catheter into the diseased region
• the catheter of the proposed invention would act as a conduit to allow a radiation source (6) to be introduced to the site of treatment, it is proposed that the catheter should incorporate a separate channel (7) for safely retaining tne radioactive source (radioactive lumen, 7)
• the radioactive lumen (7) passes through the entire length of the catheter Proximally, the radioactive lumen communicates with a radioactive port (8) for the introduction of a radioactive source during treatment Distally, the radioactive lumen terminates in a radioactive chamber (9) .
• the radioactive chamber is a blind end of the radioactive lumen, which ensures retaining the radioactive source within the catheter. At least one segment of the wall of the radioactive chamber is made of radioactively- transparent material.
• the radioactive chamber is located at a peripheral, not central position in the catheter, so that the radioactively transparent segment (10) of the wall of the radioactive chamber (9) occupies a segment of the exterior catheter surface (11).
• This radioactively transparent segment of the exterior catheter surface which is formed by a segment of the radioactive chamber will be regerred to hereunder as radioactive aperture (10) .
• the rest of the catheter circumference is built by the various catheter material and layers.
• the catheter comprises at least an outer layer with radioactive shielding properties.
• the wall of the radioactive chamber within the radioactive chamber is radioactively transparent, unlike the rest of the catheter material (radioactively shielding material), the above construction ensures a selective lateral transparency for radiation during operation (side irradiation, 10) .
• the ultrasound system The ultrasound system:
• imaging means will be employed to aftord a translummal image of a diseased region of the treatment region.
• ultrasonic transducer (s) (12) will be used to generate the imaging medium
• a oreterred transducer, its associated circuitry and a preferred o ⁇ e of operation are described PCT/WO/9 ⁇ /17734 (eberle et al) incorporated herein by reference.
• a system of ultrasound arrays (multiple transducer elements 12) is installed distal or at the level of the radiation aperture
• the transducer elements are responsible for seque ⁇ tia_.lv transmitting and receiv re electrical signals m the ul ⁇ aso n ⁇ c r ⁇ equency range, which are tt r - processed and sent (13) to the external signal processing system
• the present invention proposes that the transducer elements (14) located within the radioactive aperture, or on the circumferential catheter sector which corresponds to the radioactive aperture, send additional electrical signals (15) to the external signal processing system.
• These additional signals can be recognized by an image reconstruction system, which reconstructs an additional sectorial area indicating the position of the radioactive aperture, this position indicating area of the radioactive aperture can be displayed on the cross sectional ultrasonic image ( Figure 3A) .
• Such configuration would aid the physician in navigating the vessel wall morphology, detecting eccentric lesions, and thereby steering the radioactive aperture to the proper treatment site (cross- sectional mapping) .
• the longitudinal locational relationship between the radioactive chamber/radioactive aperture and the ultrasound array system may vary. Basically, the ultrasound array-system can he installed distal to the radioactive chamber/radiation aperture, this will aid the physician m locating and targeting the eccentric lesion, before the radioactive aperture is advanced to engage the region of treatment ( Figure 3) . It would be helpful if the level of radioactive chamber/radioactive aperture is provided with radiopaque markers for additional roentgenologic precision and/or roadmapp g. In another preferred design (Figure 2E), the radioactive chamber/radioactive aperture could be installed within the ultrasound array system, this would aid in monitoring of the radiation aperture position and the treatment region while performing endovascular irradiation simul aneously
• the proposed catheter has been explained with respect to treatment of obstructive vessel disease, it is noted that the treatment could be conducted in virtually any conduit, duct, cavity of the body.
• This catheter can be also used to treat cancer in various areas of the body, such as the common bile duct, the bladder, the prostate gland, the liver, the lungs etc. employing the technique of side irradiation, with the aid of simultaneous tomographic ultrasound guidance.

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Cited By (24)

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Citations (12)

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• 1997
  • 1997-09-01 AT AT0146297A patent/AT407009B/de not_active IP Right Cessation
• 1998
  • 1998-09-01 WO PCT/IB1998/001363 patent/WO1999011325A1/en active Application Filing

Patent Citations (13)

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