Devices, systems and methods for rapid endovascular cooling

A heat exchange catheter system useable to cool blood flowing through the vasculature of a human or animal subject, said system comprising:

• a heat exchange catheter comprising a catheter body having a proximal end, a distal end, a first lumen, a second lumen and a heat exchange balloon connected to said first lumen and said second lumen, said heat exchange balloon having a plurality of lobes that are twisted in a generally helical configuration, said balloon having a collapsed configuration of a first circumscribed diameter D1 and an inflated configuration of a second circumscribed diameter D2, wherein D2 is at least about 3.5 times greater than D1, wherein D1 is less than about 8 mm and D2 is greater than about 14 mm, and further wherein said heat exchange balloon has a cross sectional perimeter greater than 1.5 inches when in the inflated configuration;
• a fluid cooling apparatus comprising a heat exchanger and a condenser for chilling a coolant fluid, the heat exchanger having a first flowpath through which the thermal exchange fluid circulates and a second flowpath through which the chilled coolant fluid circulates, the heat exchanger's first flowpath being isolated from the second flowpath, the heat exchanger's first flowpath being connected to the catheter such that thermal exchange fluid which exits the second lumen of the catheter will circulate through the heath exchanger's first flowpath and flow back into the first lumen of the catheter;
• wherein the catheter body, fluid cooling apparatus and heat exchange balloon are sized, configured and constructed to render the system capable of delivering at least about 400 watts of cooling power when operated within a rigid 22 mm ID tube through which water at a temperature of 37 degrees C. is pumped at a rate of 2.5 liters per minute.

A method for treating a human or animal subject who has a coronary artery obstruction which impairs perfusion of the subject's myocardium prior to performance of reperfusion procedure which removes or bypasses the coronary artery obstruction, said method comprising the steps of:

• A) obtaining or providing a heat exchange catheter device comprising a catheter body and an intracorporeal heat exchanger located on the catheter body, the intracorporeal heat exchanger being initially deployed in a collapsed configuration having a first circumscribed diameter D1 and subsequently expandable to an expanded configuration having a second circumscribed diameter D2, wherein D1 is less than about 8 mm and D2 is larger than about 14 mm and further wherein said heat exchange balloon has a cross sectional perimeter greater than 1.5 inches when in the inflated configuration and an extracorporeal device attached to the catheter body and useable to circulate cooled thermal exchange fluid through the intracorporeal heat exchanger sufficient to provide at least 400 watts of cooling power when operated within a rigid 22 mm ID tube through which water at a temperature of 37 degrees C. is pumped at a rate of 2.5 liters per minute;
• B) inserting the heat exchange catheter device into the subject's vasculature while the heat exchanger is in its collapsed configuration;
• C) expanding the heat exchanger to its expanded configuration;
• and
• D) using the heat exchanger to cool blood that flows past the heat exchanger, thereby cooling the subject's core body temperature to less than about 34 degrees C. before performance of the reperfusion procedure.