Cryosurgical catheter

A cryogenic cooling structure comprising:

• a fluid supply;
• a control unit attached to the fluid supply;
• a regulator assembly connecting the fluid supply to the control unit;
• a semi-rigid member having a thermally-transmissive region and defining a fluid path, the semi-rigid member connecting to the control unit such that the fluid path is in fluid communication with fluid supply;
• and
• the thermally-transmissive region including a bellows configuration defining an interior surface, wherein the interior surfaces of the bellows configuration is exposed to the fluid path.

A medical device comprising:

• an elongated member including a proximal portion and a distal portion, the proximal portion having a malleable conformation such that the proximal portion retains a first shape until manipulated to a second shape and the distal portion having a plurality of hollow annular extensions each defining an interior surface;
• a fluid path through the proximal portion to the distal portion and the plurality of hollow annular extension, wherein the interior surfaces of the plurality of hollow annular extensions are exposed to the fluid path;
• and
• an insulation sleeve disposed about the elongated member, the insulation sleeve is configured to expose at least a portion of the distal portion of the elongated member.

A medical device comprising:

• an elongated member including a proximal portion and a distal portion, the distal portion having a plurality of alternating larger and smaller annular diameters in a repetitive pattern along the length of the distal portion, each defining an interior surface;
• a fluid path through the proximal portion to the distal portion and the plurality of alternating larger and smaller annular diameters, wherein the interior surfaces of the plurality of alternating larger and smaller annular diameters are exposed to the fluid path;
• and
• an insulation sleeve disposed about the elongated member, the insulation sleeve is configured to expose at least a portion of the distal portion of the elongated member.