Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/02—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by cooling, e.g. cryogenic techniques
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00053—Mechanical features of the instrument of device
  • A61B2018/00214—Expandable means emitting energy, e.g. by elements carried thereon
  • A61B2018/0022—Balloons
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/02—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by cooling, e.g. cryogenic techniques
  • A61B2018/0212—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by cooling, e.g. cryogenic techniques using an instrument inserted into a body lumen, e.g. catheter

Definitions

• the present invention pertains generally to systems and methods for cryoablating internal tissue. More particularly, the present invention pertains to systems and methods for cryoablating conduction blocks to treat patients experiencing heart arrhythmias such as atrial fibrillation.
• the present invention is particularly, but not exclusively, useful for ablating a substantially circumferentially shaped portion of tissue surrounding the ostium of a pulmonary vein in a single step.
• the conduction block must completely block irregular signals and this often requires the ablation of a relatively deep, uniform lesion.
• cryoablation procedures have required multiple, successive contacts between the cryo-element and the tissue around the periphery of an ostium. More specifically, these procedures have required the cryo-element to be successively moved around the ostia to create a patchwork array of ablations. This often results in a non-uniform circumferential ablation that fails to form an adequate conduction block.
• special catheter structures are generally required to give a catheter the agility required to carefully move from one location to the next within the pulmonary vein.
• Fig. 4 is a sectional view of the distal end of the system shown in Fig. 2 as seen along line 4-4 in Fig. 2 showing the balloon in the collapsed configuration;
• Fig. 5 is a sectional view as in Fig. 4 showing the balloon in the expanded configuration
• a substantially circumferentially shaped target tissue 22 is ablated surrounding the ostium of a pulmonary vein 24.
• the resulting lesion which can extend through the wall of the pulmonary vein 24 and into the tissue as shown, can function as a conduction block to prevent the transmission of electrical signals.
• the lesion can prevent electrical signals traveling toward the target tissue 22 from exemplary area 26 of the pulmonary vein 24 from passing through the ablated target tissue 22 to exemplary area 28.
• the ablated target tissue 22 can be used to treat heart arrhythmias such as atrial fibrillation.
• Fig. 2 further shows that the distal end of the system 10 can be passed through the left atrium 30 to access the pulmonary vein 24 and ablate the target tissue 22.
• the articulation segment 34 includes an inner wall 46, an outer wall 48, and a helical spring 50 that is embedded between the inner wall 46 and the outer wall 48. Further, this assembly (i.e. the helical spring 50, inner wall 46 and outer wall 48) establishes a flexural modulus that is typically less than the modulus of the spine 44. Due to the difference in the respective flexural moduli of the assembly (i.e.
• the balloon 16 extends from a distal end 94 to a proximal end 96 and defines a balloon length, Uaiioon therebetween.
• the cryo-element 20 extends from a distal end 98 to a proximal end 100 and defines a cryo-element length, L cr yo-eiement therebetween.
• the balloon 16 can have a balloon length that is longer than the cryo-element length (Uaiioon > Uryo-eiement) to allow the expanded balloon 16 to surround the cryo-element 20 at the distal end 98 and proximal end 100 of the cryo-element 20.
• Fig. 7 shows the distal end of another embodiment (designated system 10") for cryoablating internal target tissue.
• the system 10 includes an elongated cryo-catheter 18" that defines an axis 72".
• the system 10 includes a cylindrical-shaped sleeve 112 for use in positioning an annular shaped balloon 16" at the treatment site.
• the balloon 16" is mounted on the sleeve 112 and the sleeve 112 is slideably mounted over the cryo-catheter 18".
• the sleeve 112 is made of a thermally conductive material to allow heat to flow from the balloon 16" to the cryo-element 20".

Landscapes

• Health & Medical Sciences (AREA)
• Surgery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Biomedical Technology (AREA)
• Engineering & Computer Science (AREA)
• Otolaryngology (AREA)
• Heart & Thoracic Surgery (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Surgical Instruments (AREA)

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Citations (1)

• 2005
  • 2005-03-01 EP EP05724195A patent/EP1768592A4/de not_active Withdrawn

Patent Citations (1)

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