Critical point drying systems and methods for in situ tissue preservation

Abstract

Methods and systems for preserving tissues in situ using critical point drying are disclosed. Such methods and systems are particularly applicable to the preservation of a deceased body, such as a deceased person or animal, with or without removal of internal tissues or organs. A fixative can be perfused through the vascular system of the body while blood is removed from the body. The exterior of the body can also be immersed in a bath of fixative. The fixative in the vascular system and the bath can be replaced by subsequent washes of buffer, de-ionized water, and/or alcohol. The alcohol-infused and fixated body can be disposed in a pressure chamber and subjected to a critical point drying process using carbon dioxide. After the critical point drying process, the body is in a preserved state.

1 - 23 . (canceled) 
     
     
         24 . A system for preservation of a body or an organ thereof, the system comprising:
 a pressure chamber having at least one fluid inlet and a vascular inlet line, the vascular inlet line being constructed to connect to the vascular system of the body or the organ, the pressure chamber being sized and shaped so as to allow the body or the organ to be enclosed therein;   a flow module configured to supply liquid carbon dioxide to the pressure chamber through the at least one fluid inlet and to the vascular system through the vascular inlet line;   a temperature module configured to control the temperature of the pressure chamber; and   a system controller configured to control the flow module to fill the pressure chamber and the vascular system with liquid carbon dioxide and to control the temperature module to heat the liquid carbon dioxide in the chamber and the vascular system above the carbon dioxide critical point temperature and pressure,   wherein the pressure chamber is constructed to withstand a temperature and pressure of at least said carbon dioxide critical point temperature and pressure.   
     
     
         25 . The system of  claim 24 , wherein the vascular inlet line is constructed to connect to the vascular system of the body by way of one of the ventricles of the heart. 
     
     
         26 . The system of  claim 24 , wherein the system controller controls the temperature module to cool the pressure chamber prior to the chamber being filled with liquid carbon dioxide. 
     
     
         27 . The system of  claim 24 , wherein the flow module is further configured to supply a fixative to the pressure chamber through the at least one fluid inlet and to the vascular system through the vascular inlet line, and the system controller controls the flow module to fill the chamber and the vascular system with fixative prior to filling the chamber and the vascular system with liquid carbon dioxide. 
     
     
         28 . The system of  claim 24 , wherein the fixative includes at least one of glutaraldehyde and formaldehyde. 
     
     
         29 . The system of  claim 24 , wherein the pressure chamber has a volume between 100 L and 600 L. 
     
     
         30 . The system of  claim 24 , wherein the body or the organ is of an animal. 
     
     
         31 . The system of  claim 30 , wherein the body or the organ is of a human. 
     
     
         32 . A method for preserving a body or an organ thereof, the method comprising:
 providing a preservation system, the preservation system comprising:
 a pressure chamber having at least one fluid inlet and a vascular inlet line, the pressure chamber being sized and shaped so as to allow the body or the organ to be enclosed therein; 
 a flow module configured to supply at least liquid carbon dioxide via the fluid inlet and the vascular inlet line; 
 a temperature module configured to control the temperature of the pressure chamber; and 
 a system controller configured to control the flow module and the temperature module, 
 the pressure chamber being constructed to withstand a temperature and a pressure of at least a critical point temperature and pressure for carbon dioxide; 
   perfusing the body or the organ with liquid carbon dioxide by way of the vascular inlet line connected to the vascular system of the body or organ while the body or the organ is in the pressure chamber;   exposing external surfaces of the body or the organ to liquid carbon dioxide supplied via said at least one fluid inlet while the body or the organ is in the pressure chamber;   heating the body or the organ in the sealed pressure chamber until the temperature and pressure in said pressure chamber meet or exceed the critical point for carbon dioxide; and   after the heating, exhausting carbon dioxide from the pressure chamber and the body or the organ therein.   
     
     
         33 . The method of  claim 32 , wherein the exposing to liquid carbon dioxide is performed simultaneously with the perfusing liquid carbon dioxide. 
     
     
         34 . The method of  claim 33 , wherein the exposing to liquid carbon dioxide includes flowing liquid carbon dioxide over the external surfaces of the body or the organ. 
     
     
         35 . The method of  claim 32 , wherein the external surfaces include the epithelial cells of the integumentary system and the gastrointestinal tract of the body. 
     
     
         36 . The method of  claim 32 , further comprising:
 prior to the perfusing with liquid carbon dioxide, perfusing the body or the organ with fixative by way of the vascular inlet line connected to the vascular system of the body or organ; and   at a same time as the perfusing with fixative, exposing external surfaces of the body or organ to fixative supplied via said at least one fluid inlet while the body or organ is in the pressure chamber.   
     
     
         37 . The method of  claim 32 , wherein the body or the organ is of an animal. 
     
     
         38 . The method of  claim 37 , wherein the body or the organ is of a human. 
     
     
         39 . A method for preserving a recently deceased human body, the method comprising:
 (a) providing a preservation system, the preservation system comprising:
 a pressure chamber having at least one fluid inlet and a vascular inlet line, the pressure chamber being sized and shaped so as to allow the deceased human body to be enclosed therein; 
 a flow module configured to supply at least liquid carbon dioxide and a fixative via the fluid inlet and the vascular inlet line; 
 a temperature module configured to control the temperature of the pressure chamber; and 
 a system controller configured to control the flow module and the temperature module, 
 the pressure chamber being constructed to withstand a temperature and a pressure of at least a critical point temperature and pressure for carbon dioxide; 
   (b) connecting the vascular inlet line to the vascular system of the deceased human body;   (c) after (b), flowing the fixative into the vascular system of the deceased human body and into the pressure chamber via the fluid inlet so as to immerse the deceased human body in fixative, the fixative including at least one of glutaraldehyde and formaldehyde;   (d) after (c), flowing a buffer solution into the vascular system and into the pressure chamber via the fluid inlet so as to immerse the deceased human body in buffer solution;   (e) after (d), flowing water into the vascular system and into the pressure chamber via the fluid inlet so as to immerse the deceased human body in water;   (f) after (e), flowing alcohol into the vascular system and into the pressure chamber via the fluid inlet so as to immerse the deceased human body in alcohol;   (g) after (f), flowing liquid carbon dioxide into the vascular system and into the pressure chamber via the fluid inlet so as to immerse the deceased human body in liquid carbon dioxide; and   (h) after (g), heating the deceased human body in the pressure chamber until the temperature and pressure in said pressure chamber meet or exceed the critical temperature and critical pressure for carbon dioxide.   
     
     
         40 . The method of  claim 39 , wherein the connecting includes opening the deceased human body's thoracic cavity so as to access the heart, wherein the cavity remains open between the connecting and the heating. 
     
     
         41 . The method of  claim 39 , wherein the connecting includes connecting the vascular inlet line to the left ventricle of the heart and a vascular outlet line to the right ventricle of the heart. 
     
     
         42 . The method of  claim 39 , wherein the connecting includes connecting the vascular inlet line to an arterial port or access and a vascular outlet line to a venous port or access. 
     
     
         43 . The method of  claim 39 , wherein (c) through (h) occur with the human body sealed within the pressure chamber. 
     
     
         44 . The method of  claim 39 , wherein the fixative includes 1.5% glutaraldehyde in a buffer, and the alcohol includes isopropyl alcohol or ethanol.