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

Definitions

• This invention relates to cryosurgical apparatus, and in particular concerns a cryosurgical probe suitable for intra organ penetration.
• Cryosurgical probes may be used in the treatment of tumours, for example, using techniques in which a probe tip is inserted to the area of tissue required to be removed and then cooled by the passage therethrough of a cryogen to freeze, and therefore destroy, the tissue surrounding the probe tip. It is desirable to control as carefully as possible a number of parameters, including the speed and extent of the freezing, in order to ensure that tumourou ⁇ area is completely destroyed with minimum concomitant damage to surrounding healthy tissue .
• the present invention seeks to provide apparatus which may be inserted deeply within an organ whilst mitigating or obviating damage of healthy tissue.
• a cryosurgical probe comprising an elongate housing having a tip region at one end thereof, a first passageway extending from an inlet to the tip region and a second passageway extending from the tip region to an outlet and in communication with the first passageway at the tip region, and insulating means for insulating the external surface of the housing in a region remote from the tip region.
• cryosurgical apparatus comprising an elongate housing having a closed tip region at one end thereof and inlet means and outlet means for a cryogenic fluid on the housing, a first passageway within the housing in communication with the inlet means for deli ⁇ very of cryogenic fluid along substantially the entire length of the housing to the tip region to cause cooling of the tip region, a second passageway within the hous ⁇ ing for return of cryogenic fluid from the tip region along substantially the entire length of the housing to the outlet means, and means for insulating the external surface of the housing in a region remote from the tip.
• first and second passageways are defined by two tubes of generally circular cross- section.
• One tube may have a smaller diameter than the other and may be located internally thereof.
• the smaller diameter tube is concentric with the larger diameter tube.
• the first passageway in the preferred embodiment is defined by the internal surface of the smaller tube, and the second passageway in the preferred embodiment is annular in cross-section and bounded by the external surface of the smaller tube and the internal surface of the larger tube .
• the insulating means comprises a gas jacket located around the external surface of the larger tube, to form an outer annular chamber.
• the chamber may be air filled, or may be partially evacuated.
• Fig. 1 is a longitudinal sectional view through an apparatus of the invention.
• Pig. 2 is a transverse sectional view on line A-A of Fig . 1.
• the drawings show a cryosurgical probe having an elongate housing 10 comprising a tip region 12. and a main body portion 14.
• An inlet 18 is provided at one end 16 of the main body portion 14.
• the latter is formed substantially along the length thereof by three concentric tubes 20, 24, 28, the respective diameters of the tubes 20, 24, 28 providing an annular passageway 34 defined by the tube 24 around the tube 20, and an annular passageway 30 defined by the tube 28 around the tube 24.
• the tubes 20, 24 extend beyond the tube 28 at the end of the housing remote from the inlet 18 to def ⁇ ine the tip region 12, with the tube 24 having a closed end extending beyond the end of the tube 20 to define a space 22 at the end of the tip region 12.
• the tube 20 is open at the end within the tip region 12 and thereby presents a bore 32 extending from the inlet 18 and communicating with the space 22, the latter also being in communication with the annular passageway 34.
• the body 10 of the probe may conveniently be made of stainless steel, whilst the tip region 12 which must have optimum thermal conductivity may be formed from gold plated brass.
• the probe tip In use, the probe tip is inserted into the centre of the tumour or other tissue area required to be removed.
• a liquid cryogen such as helium or nitrogen is supplied to the inlet 18 and passes along the bore 32 to flood the space 22, and therefore freeze the tip region 12. In causing this cooling effect, cryogen is vapour- ised. The resulting gas passes along the passageway 34 and is exhausted via the outlet 26.
• the annular passageway 30 may be filled or parti ⁇ ally filled with air to provide insulation. When air is present in the annular passageway 30, some liquefaction occurs during circulation of the cryogen, resulting in a partial vacuum.
• the insulating effect of the passageway 30 ensures that the outer surface of the body portion 14 of the probe does not become frozen. Therefore damage to tissue outside the area to be treated is minimised, even in cases where the probe is inserted deeply into the tumour .
• the proportion of the probe housing 10 which is covered by the outer insulating tube 28 may be chosen according to specific requirements in any particular case .
• cryogen inlet and outlet and the arrangement of the delivery and return tubes may be different from that described and shown.

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)

Applications Claiming Priority (3)

Publications (1)

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ID=10704054

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Families Citing this family (15)

Family Cites Families (2)

• 1991
  • 1991-11-05 GB GB919123415A patent/GB9123415D0/en active Pending
• 1992
  • 1992-11-03 JP JP5508263A patent/JPH07503624A/ja active Pending
  • 1992-11-03 WO PCT/GB1992/002028 patent/WO1993008751A1/en not_active Application Discontinuation
  • 1992-11-03 EP EP92922620A patent/EP0611294A1/en not_active Withdrawn

Non-Patent Citations (1)

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