Indwelling heat exchange catheter and method of using same

Abstract

A catheter is adapt to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include at least one balloon which is adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. Embodiments including multiple balloons enhance the surface area of contact, and the mixing of both the heat exchange and the body fluid. The catheter car be positioned to produce hypothermia in a selective area of the body without cooling the entire body system. It is of particular advantage in brain surgeries where stroke, trauma or cryogenic tumors can best be addressed under hypothermic conditions.

1 . A catheter adapted to exchange heat with a body fluid flowing in a first direction through a body conduit, the catheter comprising: 
 a shaft having an axis extending between a proximal end and a distal end, the shaft having an input lumen and output lumen;    a heat exchange region disposed at the distal end of the shaft and including an outer surface;    the input lumen of the shaft being coupled to the heat exchange region at a first location, and the output lumen of the shaft being coupled to the heat exchange region at a second location so that a heat exchange fluid introduced into the first lumen will enter the heat exchange region at the first location and will exit the heat exchange region at the second location through the second lumen; and    the first location being disposed in the first direction relative to the second location when the catheter is operatively disposed in the body fluid.    
     
     
         2 . The catheter recited in  claim 1  wherein the second location is distal of the first location.  
     
     
         3 . The catheter recited in  claim 1 , further comprising: 
 at least one balloon disposed in the heat exchange region and having an outer wall forming the outer surface, the balloon being adapted to receive the heat exchange fluid and to exchange heat across its outer wall with the body fluid.    
     
     
         4 . The catheter recited in  claim 3  wherein the heat exchange region includes: 
 a first balloon having a first flow of the heat exchange fluid;  
 a second balloon having a second flow of the heat exchange fluid; and  
 the first flow of the heat exchange fluid in the first balloon is balanced relative to the second flow of the heat exchange fluid in the second balloon.  
 
     
     
         5 . The catheter recited in  claim 3  wherein the balloon has an inner geometry which promotes mixing of the heat exchange fluid.  
     
     
         6 . The catheter recited in  claim 3  wherein the balloon has an outer geometry which promotes mixing of the body fluid.  
     
     
         7 . A heat exchange catheter, comprising: 
 a shaft having an axis, a fluid inlet lumen, and a fluid outlet lumen each extending generally between a proximal end and a distal end of the shaft;    a hub disposed at the proximal end of the shaft and providing access to the fluid inlet lumen and the fluid outlet lumen;    a first balloon disposed at the distal end of the shaft and defining with the shaft an inflatable first cavity;    portions of the shaft define a first inlet hole extending in fluid communication between the fluid inlet lumen of the shaft and the first cavity of the first balloon;    portions of the shaft defining a first outlet hole extending in fluid communication between the first cavity and the fluid outlet lumen of the shaft;    a second balloon disposed relative to the first balloon at the distal end or the shaft and defining with the shaft an inflatable second cavity;    portions of the shaft defining a second inlet hole extending in fluid communication with the fluid inlet lumen of the shaft and the second cavity of the balloon; and    portions of the shaft defining a second outlet hole extending in fluid communication with the second cavity and the fluid outlet lumen.    
     
     
         8 . The heat exchange catheter recited in  claim 7  wherein the first balloon is disposed axially of the second balloon.  
     
     
         9 . The heat exchange catheter recited in  claim 8  wherein the first balloon is disposed distally of the second balloon; and 
 the first inlet hole is larger than the second inlet hole.  
 
     
     
         10 . The heat exchange catheter recited in  claim 8 , wherein: 
 the first outlet hole is larger than the first inlet hole; and    the second outlet hole is larger than the second inlet hole.    
     
     
         11 . The heat exchange catheter recited in  claim 7 , farther comprising: 
 an elastomeric covering disposed to cover a volume between the first balloon and the second balloon to facilitate laminar flow around the catheter.    
     
     
         12 . The heat exchange catheter recited in  claim 11  wherein the elastomeric covering comprises a third balloon disposed to cover the first balloon and the second balloon.  
     
     
         13 . The heat exchange catheter recited in  claim 7  wherein the first balloon is disposed radially of the second balloon.  
     
     
         14 . The heat exchange catheter recited in  claim 13  wherein the first outlet hole is larger than the first inlet hole.  
     
     
         15 . The heat exchange catheter recited in  claim 13  wherein the first inlet hole is disposed distally at the first outlet hole.  
     
     
         16 . The catheter recited in  claim 7  wherein portions of the catheter are provided with properties including thromboresistance.  
     
     
         17 . The catheter recited in  claim 16  wherein the thromboresistance properties are provided in the form of a coating having thromboresistant characteristics.  
     
     
         18 . The catheter recited in  claim 17  wherein the coating includes an anticoagulant.  
     
     
         19 . The catheter recited in  claim 16  wherein the thromboresistant properties are provided in the form of an electrical charge on the portions of the catheter.  
     
     
         20 . A catheter adapted to be disposed in a body conduit to facilitate an exchange of heat between the catheter and a body fluid flowing in the body conduit, comprising: 
 a shaft having an axis, a first lumen, and a second lumen each extending generally between a proximal end and a distal end of the shaft;    a first sheet material disposed to define a first cavity exteriorly of the shaft;    a second sheet material disposed to define a second cavity exteriorly of the shaft;    portions of the shaft defining separate inlet holes providing fluid communication between the first lumen and each of the first cavity and the second cavity;    portions of the shaft defining separate outlet holes providing fluid communication between the second lumen and each of the first cavity and the second cavity; whereby    a heat exchange fluid can be introduced into the first lumen and through the outlet holes to the first and second cavities to facilitate the exchange of heat with the body fluid flowing in the body conduit.    
     
     
         21 . The catheter recited in  claim 20  wherein the body conduit is a vessel and the body fluid is blood.  
     
     
         22 . The catheter recited in  claim 21  wherein the vessel is an artery and the catheter is adapted to be operatively positioned in the artery with the blood flowing distally along the distal end of the catheter.  
     
     
         23 . The catheter recited in  claim 22  wherein the inlet hole is disposed distally of the outlet hole in the first cavity.  
     
     
         24 . The catheter recited in  claim 23  wherein the inlet hole associated with the first cavity is larger than the inlet hole associated with the second cavity.  
     
     
         25 . The catheter recited in  claim 21  wherein the vessel is a vein and the catheter is adapted to be operatively positioned within the vein with the blood flowing proximally along, distal end of the catheter.  
     
     
         26 . The catheter recited in  claim 25  wherein the inlet hole is disposed proximally of the outlet hole in the first cavity.  
     
     
         27 . The catheter recited inclaim. 26  wherein the inlet hole associated with the first cavity is larger than the inlet hole associated with the second cavity.  
     
     
         28 . The catheter recited in  claim 20  wherein the first cavity is formed by a first balloon extending circumferentially of the shaft; 
 the second cavity is formed by a second balloon extending circumferentially of the shaft distally of the first balloon.  
 
     
     
         29 . A method for exchanging heat with a body fluid in a body conduit, comprising the steps of: 
 introducing into the body conduit a catheter having an inlet lumen and an outlet lumen;    providing the catheter with a first cavity in heat transfer relationship with the body fluid in the body conduit;    introducing a heat exchange fluid into the inlet lumen through an inlet hole and into the first cavity;    exchanging heat between the heat exchange fluid and the body fluid in the body conduit; and    removing the heat exchange fluid from each of the first cavity and the second cavity through an outlet hole and the outlet lumen.    
     
     
         30 . The method recited in  claim 29  wherein the introducing step includes the step of introducing the catheter into the body conduit in the direction of flow of the body fluid.  
     
     
         31 . The method recited in  claim 29  wherein the body conduit is an artery and the body fluid is blood.  
     
     
         32 . The method recited in  claim 29  wherein the introducing step includes the step of introducing the catheter into the body conduit against the direction of flow of the body fluid.  
     
     
         33 . The method recited in  claim 29  wherein the providing step includes the step of forming the outlet hole larger than the inlet hole.  
     
     
         34 . The method recited in  claim 29  wherein the providing step includes the step of positioning the outlet hole proximal of the inlet hole.  
     
     
         35 . The method recited in  claim 32  wherein the providing step includes the step of positioning the inlet hole proximally of the outlet hole.  
     
     
         36 . The method recited in  claim 29  wherein the providing step further comprises the step of positioning a first balloon exteriorly of the inlet lumen and the outlet lumen to form the first cavity.  
     
     
         37 . The method recited in  claim 36  wherein the providing step further comprises the steps of: 
 positioning a second balloon exteriorly of the inlet lumen and the outlet lumen to form the second cavity; and  
 positioning a third balloon to cover the first balloon and the second balloon.  
 
     
     
         38 . The method recited in  claim 29  wherein the step of exchanging heat includes the step of withdrawing heat from the body fluid to cool the body fluid.  
     
     
         39 . A method for adjusting the temperature of a specific organ in a body system without significantly adjusting the temperature of other portions of the body system, the specific organ being coupled to a conduit which normally provides a flow of body fluid to the organ at a normal body temperature, the method comprising the steps of: 
 introducing into the body conduit a first fluid having a first temperature different than the body temperature or the body fluid;    introducing into the specific organ the body fluid and the first fluid having a combined temperature between the body temperature and the first temperature, to adjust the temperature of the specific organ;    controlling the first temperature of the first fluid in order to adjust the temperature of the specific organ without significantly adjusting the temperature of the remainder of the body system.    
     
     
         40 . The method recited in  claim 39  wherein the first temperature of the first fluid is less than the body temperature.  
     
     
         41 . The method recited in  claim 39  wherein the body fluid is blood.  
     
     
         42 . The method recited in  claim 39  wherein the specific organ is the brain.  
     
     
         43 . The method recited in  claim 39  wherein the conduit is the carotid artery.  
     
     
         44 . The method recited in  claim 39  wherein the body fluid is blood and the body conduit is an artery.  
     
     
         45 . The method recited in  claim 39  wherein the first fluid is a gas.  
     
     
         46 . The method recited in  claim 45  wherein the gas is an inert gas.  
     
     
         47 . The method recited in  claim 45  wherein the gas is carbon dioxide.