Distal Perfusion Cooling Mechanism

A catheter comprising:

• a flexible heat transfer element provided on an outer surface of the catheter;
• a conduit arranged to supply an inflation fluid for inflating the flexible heat transfer element so as to form an inflated balloon;
• a cooling element encompassed by the flexible heat transfer element;
• a first tube having a proximal end that is couplable to a supply of coolant;
• and,
• a second tube,
• wherein the cooling element comprises an elongate tubular wall defining an elongate cooling chamber therein having a first end that is coupled to a distal end of the second tube end and a second end that is closed;
• wherein the distal end of the second tube is configured to receive a flow of coolant from the cooling element such that the second tube provides a flow path of the coolant from the distal end of the second tube to a proximal end of the second tube;
• and,
• wherein a permeable distal portion of the first tube is positioned within the elongate cooling chamber, the permeable distal portion comprising a plurality of holes in an outer surface of the first tube such that when the coolant is supplied via the proximal end of the first tube as a liquid at least some of the coolant passes through the plurality of holes and undergoes a phase change in the elongate cooling chamber.