Methods and Apparatus for Regional and Whole Body Temperature Modification

Abstract

Methods and apparatus for temperature modification of selected body regions including an induced state of local hypothermia of the brain region for neuroprotection. A heat exchange catheter is provided with heat transfer fins projecting or extending outward from the catheter which may be inserted into selected blood vessels or body regions to transfer heat with blood or fluid in the selected blood vessels or body regions. Another aspect of the invention further provides methods and apparatus for controlling the internal body temperature of a patient. By selectively heating or cooling a portion of the catheter lying within a blood vessel, heat may be transferred to or from blood flowing within the vessel to increase or decrease whole body temperature or the temperature of a target region. Feed back from temperature sensors located within the patient's body allow for control of the heat transfer from the catheter to automatically control the temperature of the patient or of the target region within the patient. The apparatus may include a blood channeling sleeve that directs body fluid over a heat exchanger where the body fluid's temperature is altered, and then is discharged out the distal end of the sleeve to a desired location, for example, cooled blood to the brain for neuroprotection. The catheter may be used alone or in conjunction with other heat exchangers to cool one region of a patient's body while heating another.

1 . A method for endovascular body temperature management in a subject, said method comprising the steps of
 A. preparing a heat exchange catheter device which comprises; i) an elongate, flexible catheter having a proximal end, a distal end, and an insertion portion that is insertable into a patient's body ii) at least one fluid lumen through which a thermal exchange fluid may be circulated and iii) a heat exchanger located on less than the entire insertion portion which is less than the entire length of said insertion portion, said heat exchanger being operative to exchange heat between body fluid which flows in heat exchange proximity to said heat exchanger and the thermal fluid which is circulated through said catheter;   B. selecting a desired body temperature range having an upper limit and a lower limit;   B. inserting the catheter into the subject's vasculature such that blood flows in heat exchange proximity to the heat exchanger;   C. monitoring body temperature of the subject;   D. circulating a heat exchange fluid through the catheter device to alternately warm or cool the heat exchanger as needed to bring or maintain the monitored body temperature within the selected body temperature range.   
     
     
         2 . The method according to  claim 1  wherein the catheter device provided in Step A further comprises a working lumen and wherein the method further comprises the step of infusing a medicament through the working lumen of the catheter. 
     
     
         3 . A method according to  claim 2  wherein the medicament is selected from the group of medicaments consisting of:
 a thrombolytic agent; 
 an anticoagulant; 
 a neuro-protectant; 
 a barbiturate; 
 a anti-seizure agent; 
 an oxygenated perfusate; 
 a vaso-dilator; 
 an agent which prevents vaso-spasm; 
 an agent to prevent platelet activation; and, an agent to deter the adhesion of platelets. 
 
     
     
         4 . A method according to  claim 1  wherein the catheter device provided in Step A further comprises a working lumen and wherein the method further comprises the step of infusing a radiographic contrast agent through the working lumen of the catheter. 
     
     
         5 . A method according to  claim 1  wherein the catheter device provided in Step A further comprises a working lumen and wherein the method further comprises the step of passing a therapeutic apparatus through the working lumen of the catheter and using such therapeutic apparatus to perform a therapeutic task in the selected region of the patient's body. 
     
     
         6 . A method according to  claim 5  wherein the therapeutic apparatus passed through the working lumen of the catheter is selected from the group of therapeutic apparatus consisting of:
 an angioplasty catheter; 
 an embolectomy catheter; 
 an occlusion member delivering catheter; 
 an embolization member delivering catheter; 
 an electro-cautery device; and, 
 a microcatheter. 
 
     
     
         7 . A method according to  claim 1  wherein the catheter device provided in Step A further comprises a working lumen and wherein the method further comprises the step of passing a diagnostic device through the working lumen of the catheter and using such diagnostic device to perform a diagnostic procedure. 
     
     
         8 . A method according to  claim 7  wherein the diagnostic device is selected from the group consisting of:
 an angiographic catheter; 
 a sensor. 
 
     
     
         9 . A method according to  claim 1  wherein Step B comprises setting an upper variance set point and a lower variance point. 
     
     
         10 . A method according to  claim 9  further comprising:
 using a controller to control the heat exchange between an active state when said heat exchanger is active to exchange heat with the body fluid in heat exchange proximity with said heat exchanger and an inactive state so that said heat exchanger is active while said sensed temperature is equal to or greater than said pre-selected temperature; 
 causing heat exchange to enter said inactive state when said sensed temperature is equal to or less than said pre-selected temperature; 
 maintaining the heat exchange in said inactive state until the sensed temperature is equal to or greater than the upper variance set point, or equal to or less than the lower variance set point; and 
 activating the heat exchange to start cooling said body fluid when said sensed temperature is equal to or greater than said upper variance set point and activating the heat exchanger to start warming said body fluid if said sensed temperature is equal to or less than the lower variance set point.