Cryoprobe with stiffening element

A cryosurgical system comprising a cryoprobe and a source of cryofluid and a control configured to control a delivery of cryofluid to the cryoprobe:

• the cryoprobe comprising:
• an elongate shaft having a distal end and a proximate end;
• and
• an operating head at the distal end of the elongate shaft, wherein the operating head comprises an expansion chamber, the operating head being configured to ablate tissue that comes into contact with the operating head the expansion chamber being configured to accommodate high pressure expansion of a high pressure gas such that the cryoprobe produces ice balls in excess of 10 millimeters in diameter within minutes;
• the elongate shaft comprising:
• a first passageway configured to provide the high pressure gas to the expansion chamber and wherein the first passageway terminates in a Joule-Thomson orifice at its distal end;
• a second passageway for evacuating gas from the expansion chamber, wherein the second passageway is coaxially arranged around the first passageway;
• and
• a vacuum chamber coaxially arranged around the first passageway and the second passageway, the vacuum chamber is coextensive with a majority of a length of the second passageway;
• the cryoprobe additionally comprising an elongate stiffening element located towards the distal end of the elongate shaft configured to reduce flexing of the elongate shaft;
• wherein the elongate stiffening element comprises a grip portion having an inner diameter that is greater than a vacuum chamber wall and proximal and distal tapered regions that provide a step down in the inner diameter to the vacuum chamber wall to hold the grip portion in place relative to the vacuum chamber at the proximal and distal ends of the grip portion, the grip portion being arranged about the elongate shaft such that the grip portion is circumferentially spaced apart from the vacuum chamber wall to thereby form an insulating space therebetween and arranged along the elongate shaft such that the grip portion is spaced apart from the operating head by a portion of the elongate shaft such that the grip portion is spaced apart the tissue to be ablated when the operating head is ablating the tissue;
• and
• wherein the grip portion is provided by a first sleeve and further comprising a coating provided over the first sleeve to thereby seal the first sleeve to the vacuum chamber wall, the cryoprobe further comprising a covering extending at least from the grip portion to a proximal portion of a tail portion of the shaft to thereby provide protection to the tail portion and reduce kinking within the tail portion, and wherein the coating is provided by a second sleeve that covers at least a distal portion of the covering.

A method of ablating a patient tissue, the method comprising:

• placing a tip of a cryoprobe within or adjacent to a tissue to be ablated, the cryoprobe comprising:
• an elongate shaft having a distal end and a proximate end, a cross section of the elongate shaft of the cryoprobe being about 1.2 mm in diameter;
• an operating head at the distal end of the elongate shaft, wherein the operating head comprises an expansion chamber, the operating head being configured to ablate tissue that comes into contact with the operating head;
• the elongate shaft comprising:
• a first passageway configured to provide high pressure gas to the expansion chamber and wherein the first passageway terminates in a Joule-Thomson orifice at its distal end;
• a second passageway for evacuating gas from the expansion chamber, wherein the second passageway is coaxially arranged around the first passageway;
• and
• a vacuum chamber coaxially arranged around the first passageway and the second passageway, the vacuum chamber is uniformly coextensive with a majority of a length of the second passageway;
• the cryoprobe additionally comprising an elongate stiffening element located towards the distal end of the elongate shaft configured to reduce flexing of the elongate shaft;
• delivering a cryogas to the Joule-Thomson orifice, via the first passageway, at a pressure sufficient to cause cooling of a probe tip of the cryoprobe to a cryogenic temperature to freeze the tissue that is in contact with the probe tip, wherein the elongate stiffening element comprises a grip portion having an inner diameter that is greater than a vacuum chamber wall and proximal and distal tapered regions that provide a step down in the inner diameter to the vacuum chamber wall to hold the grip portion in place relative to the vacuum chamber at the proximal and distal ends of the grip portion, the grip portion being arranged about the elongate shaft such that the grip portion is circumferentially spaced apart from the vacuum chamber wall to thereby form an insulating space therebetween and arranged along the elongate shaft such that the grip portion is spaced apart from the operating head by a portion of the elongate shaft such that the grip portion is spaced apart the tissue to be ablated when the operating head is ablating the tissue, wherein the grip portion is provided by a first sleeve and further comprising a coating provided over the first sleeve to thereby seal the first sleeve to the vacuum chamber wall,
• the cryoprobe further comprising a covering extending at least from the grip portion to a proximal portion of a tail portion of the shaft to thereby provide protection to the tail portion and reduce kinking within the tail portion, and wherein the coating is provided by a second sleeve that covers at least a distal portion of the covering;
• and
• subsequently thawing the tissue.