Method and system for treating tissue swelling

Abstract

A system and related methods and components for treating a tissue site exhibiting interstitial hypertension, including tissue swelling, and particularly swelling associated with cerebral edema, compartment syndrome, and congestive heart failure, by the use of water removal therapy, in order to remove only water from biological fluids. Included also is a system for such use that incorporates one or more monitors, optionally in addition to the use of water removal therapy. By removing only water, all other biologic agents, including essentially all solutes and formed blood elements (such as cells) are increased in concentration in the remaining bodily fluid(s). WRT can be applied to several clinical conditions in which there is an excess of water, and is ideally used in an extracorporeal fashion, in combination with other functions and related components as well, including ultrafiltration.

1 . A method of treating tissue swelling, the method comprising the step of employing one or more semipermeable membranes in combination with a hydratable medium in order to remove substantially only water through the semipermeable membrane(s) and from a biological fluid associated with the tissue swelling. 
     
     
         2 . A method according to  claim 1 , wherein the biological fluid is associated with either localized tissue swelling or systemic tissue swelling. 
     
     
         3 . A method according to  claim 2  wherein the localized tissue swelling is selected from cerebral edema, pulmonary edema, lymphedema, compartment syndrome, acute renal failure, ischemic heart disease, and solid tumors, and the systemic tissue swelling is selected from congestive heart failure, and acute renal failure. 
     
     
         4 . A method according to  claim 3  wherein the method is used to perform targeted treatment within a tissue site exhibiting localized tissue swelling. 
     
     
         5 . A method according to  claim 1 , further comprising the use of one or more semipermeable membranes in order to perform ultrafiltration on the same or different biological fluid, in order to remove both water and permeable solutes from the biological fluid, and either in series or parallel with the water removal step. 
     
     
         6 . A method according to  claim 5  wherein the method is used to treat swelling associated with congestive heart failure, and provides a desired combination of ultrafiltration to remove water and permeable solutes, together with water removal therapy to remove substantially only water. 
     
     
         7 . A method according to  claim 6  wherein both ultrafiltration and water removal therapy are performed in an extracorporeal fashion comprising respective extracorporeal cartridges in which both ultrafiltration and water removal are performed in parallel on different aliquots of blood. 
     
     
         8 . A method according to  claim 6  comprising respective extracorporeal cartridges in which both ultrafiltration and water removal are performed in series, with water removal therapy performed following ultrafiltration, and on at least a portion of the ultrafiltrate. 
     
     
         9 . A method according to  claim 1  wherein the method comprises an arteriovenous method based on a pressure differential between arterial and venous blood to drive blood through a water therapy removal cartridge. 
     
     
         10 . A method according to  claim 1  wherein the method comprises a venovenous method based upon the pumping action of vaporization itself. 
     
     
         11 . A method according to  claim 1  wherein the cartridges each comprise a plurality of hollow fibers together with extraluminal and intraluminal flow paths, the hydratable medium comprises a desiccated gas delivered to the intraluminal flow path, and the biological fluid comprises blood or ultrafiltrate delivered to the extraluminal flow path. 
     
     
         12 . A method according to  claim 1  wherein the cartridges each comprise a plurality of hollow fibers together with extraluminal and intraluminal flow paths, the hydratable medium comprises a desiccated gas delivered to the extraluminal flow path, and the biological fluid comprises blood or ultrafiltrate delivered to the intraluminal flow path. 
     
     
         13 . An apparatus for treating a tissue site exhibiting interstitial hypertension, comprising one or more semipermeable membranes adapted to be used in combination with a hydratable medium in order to remove substantially only water through the semipermeable membrane(s) and from a biological fluid associated with the hypertension. 
     
     
         14 . An apparatus according to  claim 13 , wherein the apparatus comprises a cartridge containing one or more semipermeable membranes and positioned in an extracorporeal circuit. 
     
     
         15 . An apparatus according to  claim 14  wherein the one or more semipermeable membranes are in the form of hollow fibers. 
     
     
         16 . An apparatus according to  claim 1  wherein the hydratable medium comprises a gas. 
     
     
         17 . An apparatus according to  claim 13  wherein the fibers are formed of materials selected from the group consisting of polyacrylonitrile, polyethersulfone, cellulose and polysulfone. 
     
     
         18 . An apparatus according to  claim 13 , further comprising one or more monitoring components physically and/or functionally integrated with the placement and/or operation of the semipermeable membrane component. 
     
     
         19 . An apparatus according to  claim 18  wherein the monitoring components are associated with the system of this invention, in that that one or more components of the monitoring components are physically and/or functionally integrated with the placement and/or operation of the semipermeable membrane component. 
     
     
         20 . An apparatus for treating tissue swelling, comprising one or more semipermeable membranes adapted to be used in combination with a hydratable medium in order to remove substantially only water from a biological fluid associated with the swelling, wherein the apparatus comprises a plurality of hollow fibers positioned within a cartridge in order to provide corresponding intraluminal and extraluminal flow paths within the cartridge, the flow paths being adapted to position both a biological fluid and a hydratable medium, respectively, on opposite surfaces of the fibers, under conditions suitable to remove substantially only water from the biological fluid. 
     
     
         21 . A method according to  claim 1 , wherein the method is adapted to improve the delivery of systemically or remotely delivered bioactive agents to a confined tissue site within the body. 
     
     
         22 . A method according to  claim 21 , wherein the confined tissue site is a solid or semisolid tumor site exhibiting interstitial hypertension, and the method comprises the steps of:
 a) providing one or more semipermeable water removal catheters,   b) positioning the catheter(s) within a confined tissue site within a body,   c) delivering the bioactive agent to a body fluid in fluid communication with the confined tissue site, and   d) employing the positioned catheter(s) to remove water, and optionally other permeable solutes, from the confined tissue site in a manner sufficient to lower interstitial pressure within the confined tissue site, and in turn, improve the transfer of the bioactive agent, by perfusion, from the fluid to the tissue site.   
     
     
         23 . An apparatus according to  claim 13 , wherein the apparatus is adapted to improve the delivery of systemically or remotely delivered bioactive agents to a confined tissue site within the body. 
     
     
         24 . An apparatus according to  claim 23 , wherein the confined tissue site is a solid or semisolid tumor site, and the apparatus comprises one or more semipermeable water removal catheters.