Source: http://www.allindianpatents.com/patents/256961-an-ex-vivo-method-of-determining-effects-of-at-least-one-test-substance-or-a-bio-active-agent
Timestamp: 2018-07-16 16:03:45
Document Index: 798224056

Matched Legal Cases: ['Application No. 10', 'Application No. 09', 'Application No. 09', 'Application No. 09', 'Application No. 08', 'Application No. 09', 'Application No. 09', 'Application No. 09', 'Application No. 09', 'Application No. 60', 'Application No. 09', 'Application No. 09']

Indian Patents. 256961:"AN EX VIVO METHOD OF DETERMINING EFFECTS OF AT LEAST ONE TEST SUBSTANCE OR A BIO-ACTIVE AGENT"
"AN EX VIVO METHOD OF DETERMINING EFFECTS OF AT LEAST ONE TEST SUBSTANCE OR A BIO-ACTIVE AGENT"
A method of determining effects of at least one test substance or bioactive agent ex vivo, comprising: perfusing at least one ex vivo organ that has been determined to be unsuitable for transplantation with a first medical fluid such as herein described to preserve the at least one organ; exposing the at least one organ to the at least one test substance or bioactive agent; and gathering data regarding at least one of the at least one organ, the at least one test substance or bioactive agent, and interaction between the at least one organ and the at least one test substance or bioactive agent. The method includes perfusing the organ at hypothermic and/or normothermic temperatures, preferably after hypothermic organ flushing for organ transport and/or storage. The method can be practiced with prior or subsequent static or perfusion hypothermic exposure of the organ. Organ viability is restored by restoring high energy nucleotide (e.g., ATP) levels by perfusing the organ with a medical fluid, such as an oxygenated cross-linked hemoglobin-based bicarbonate medical fluid, at normothermic temperatures. During the period in which the organ is preserved and/or maintained, various drug research and development may be performed on and/or with the organ. The organ may be perfused with a fluid containing a substance such as a test substance or bioactive agent to obtain data regarding the organ, the substance and an interaction of the substance and the organ.
This application is a continuation-in-part of U.S. Patent Application No. 10/617,130 filed July 11,2003 which is a Divisional of Application No. 09/645,525 filed August 25,2000, which is a continuation-in-part of U.S. Patent Application No. 09/537,180, filed March 29,2000, which is a continuation-in-part of U.S. Patent Application No. 09/162,128, filed September 29,1998, the entire contents of which are hereby incorporated by reference. !• Field of Invention
The invention relates to an apparatus and method for perfusing one or more organs to monitor, sustain and/or restore the viability of the organ(s) and/or for transporting and/or storing the organ(s). This invention further relates to determining if the organ(s) is/are a viable candidate for transplantation. Particularly, if the organ(s) is/are not viable transplantation candidates, then mis invention further relates to perfusing the organ(s) with a fluid to acquire data regarding the organ(s) and/or fluid. 2. Description of Related Art
Preservation of organs by machine perfusion has been accomplished at hypothermic temperatures with or without computer control with crystalloid perfusates and without oxygenation. See, for example, U.S. Patents Nos. 5,149,321, 5,395,314,5,584,804,5,709,654 and 5,752,929 and U.S. Patent Application No. 08/484,601 to Klatz et al., which are hereby incorporated by reference. Hypothermic temperatures provide a decrease in organ metabolism, lower the energy requirements, delay the depletion of high energy phosphate reserves and accumulation of lactic acid and retard the morphological and functional deterioration associated with disruption of blood supply. Oxygen can not be utilized efficiently by mitochondria below approximately 20°C to produce energy, and the reduction in catalase/superoxide dismutase production and ascorbyl and glutathione regeneration at low temperatures allows high free radical formation. The removal of oxygen from perfusates during low temperature machine perfusion has even proven helpful in improving organ transplant results by some investigators.
Reduction in potential oxygen damage is also accomplished via the addition of antioxidants to the perfusate. In particular, this has proven useful in reducing organ damage after long warm ischemia times. Numerous other perfusate additives have also been reported to improve the outcome of machine perrasion.
Ideally organs would be procured in a manner that limits their warm ischemia time to essentially zero. Unfortunately, in reality, many organs, especially from non-beating heart donors, are procured after extended warm ischemia time periods (i.e., 45 minutes or more). Th* machine perfusion of these organs at low temperature has demonstrated significant improvement (Transpl Int 1996 Daemeh). Further, prior art teaches that the low temperature machine perfusion of organs is preferred at low pressures (Transpl. mt 1996 Yland) with roller or diaphragm pumps delivering the perfusate at a controlled pressure. Numerous control circuits and pumping configurations have been utilized to achieve mis objective and to machine perfuse organs in general. See, for example, U.S. Patents Nos. 5338,662 and 5,494,822 to Sadri; U.S. Patent No. 4,745,759 to Bauer et al.; U.S. Patents Nos. 5,217,860 and 5,472,876 to Fahy et al.; U.S. Patent No. 5,051,352 to Martindale et al.; U.S. Patent No. 3,995,444 to Clark et al.; U.S* Patent No. 4,629,686 to Gruenberg; U.S. Patents Nos. 3,738,914 and 3,892,628 to Thome et al.; U.S. Patents Nos. 5,285,657 and 5,476,763 to Bacchi et al.- U.S. Patent No. 5,157,930 to McGhee et al.; and U.S Patent No. 5,141,847 to Sugimachi et al However, in some situations the use of such pumps for machine perfusion of organs may increase the risk of overprcssurization of the organ should the organ perfusion apparatus malfunction. High pressure perrusion (e.g., above about 60 mm Hg) can wash off the vascular endothelial lining of the organ and in general damages organ tissue, in particular at hypothermic temperatures where the organ does not have the neurological or endocrinal connections to protect itself by dilating its vasculature under high pressure.
During low temperature machine perfusion of organs that have been damaged
by warm ischemia time or by the machine perfusion itself, the organs will elute intracelhilar and endothelial as well as membrane constituents. Over the years the appearance of various ubiquitous intracellular enzymes, such as lactic dehydrogenase (LDH) and alkaline phosphatase, in the perfusate has been used as a biomarker of organ damage. Recently, the determination of the presence of alpha glutathione-S-transferase (a-GST) and Pi glutatbaone-S-transferase (p-GST) in low temperature machine perrusion perfusates has proven a satisfactory indicator in predicting the functional outcome of non-beating heart donor kidney grafts before transplantation (Transpl 1997 Daemon).
The prior art has also addressed the need to restore or maintain an organ's . physiological function after preservation for an extended period of time at hypothennic temperatures, m particular, U.S. Patent No. 5,066^78 to Wikman-Coffelt discloses an organ preservation solution that contains .large amounts of pyruvate. Wikman-Coffelt teaches that flooding of the organ with pyruvate bypasses glycosis, the step in the cell energy cycle that utilizes adenosine triphosphate (ATP) to produce pyruvate, and pyruvate is then available to the mitochondria for oxidative . phosphorylation producing ATP. Wikman-Coffelt teaches perfusing or washing an organ at a warm temperature with a first preservation solution containing pyruvate for removal of blood or other debris from the organ's vessels and to vasodilate, increase 'flow and load the cells with an energy supply in the form of a clean substrate, namely the pyruvate. Wikman-Coffelt teaches that the pyruvate prevents edema, ischemia, calcium overload and acidosis as well as helps preserve the action potential across the cell membrane. The organ is men perfused with a second perfusion solution containing pyruvate and a small percentage of ethanol in order to stop the organ from working, vasodilate the blood vessels allowing for full vascular flow, continue to load the cells with pyruvate and preserve the energy state of the organ. Finally the organ is stored in a large volume of the first solution for 24 hours or longer at temperatures between 4°C and 10°C.
However, the mitochondria are the source of energy in cells and need significant amounts of oxygen to function. Organs naturally have significant pyruvate levels, and providing an organ with additional pyruvate will not assist in restoring and/or maintaining an organ's full physiological function if the mitochondria are not provided wife sufficient oxygen to function. Further, briefly flooding an organ with
pyruvate may, in fact, facilitate tearing off of the vascular endothelial lining of the organ.
U.S. Patent No. 5,599,659 to Brasile et al. also discloses a preservation solution for warm preservation of tissues, explants, organs and endothelial cells. Brasile et al. teaches disadvantages of cold organ storage, and proposes warm preservation technology as an alternative. Brasile et al. teaches that the solution has an enhanced ability to serve as a medium for the culture of vascular endothelium of tissue, and as a solution for organs for transplantation using a warm preservation technology because it is supplemented with serum albumin as a source of protein and colloid; trace elements to potentiate viability and cellular function; pyruvate and adenosine for oxidative phosphorylation support; transferrin as an attachment factor, insulin and sugars for metabolic support and glutathione to scavenge toxic free radicals as well as a source of impermeant; cyclodextrin as a source of impermeant, scavenger, and potentiate* of cell attachment and growth factors; a high Mg-H-concentration for microvessel metabolism support; mucopolysaccharides, comprising primarily chondroitin sulfates and heparin sulfates, for growth factor potentiation and hemostasis; and ENDO GRO™ as a source of cooloid, impermeant and specific vascular growth promoters. Brasile et al. further teaches warm perfusing an organ for up to 12 hours at 30°C, or merely storing the organ at temperatures of 25°C in the preservation solution.
However, flooding an organ with such chemicals is insufficient to arrest or repair ischemic injury where the mitochondria are not provided with sufficient oxygen to function to produce energy. The oxygen needs of an organ at more than 20°C are substantial and cannot be met by a simple crystalloid at reasonable flows. Further, assessment of the viability of apt organ is necessary before the use of any type of solution can be determined to have been fruitful.
The present invention focuses on avoiding damage to an organ during perfusion while monitoring, sustaining and/or restoring the viability of the organ and preserving the organ for storage, transport, transplantation or other use. The invention is directed to an apparatus and method for perfusing an organ to monitor, sustain and/or restore the viability of the organ and/or for transporting and/or storing and/or using the organ. More particularly, the organ perfusion apparatus and method according to the invention monitor, sustain and/or restore organ viability by perfusing the organ at' hypothennic temperature (hypothermic perfusion mode) and/or normothermic temperatures (normothennic perfusion mode) preferably after flushing of the organ such as by hypothennic flushing followed by static organ storage and/or organ perfusion at hypothennic temperatures for transport and/or storage of the organ.
The restoring of organ viability may be accomplished by restoring high energy nucleotide (e.g., adenosine triphosphate (ATP)) levels and enzyme levels in the organ, which were reduced by warm ischemia time and/or hypoxia, by perfusing the organ with an oxygenated medical fluid, such as an oxygenated cross-linked hemoglobin-based bicarbonate medical fluid, at normothennic or near-normothennic temperatures. The organ may be flushed with a medical fluid prior to perfusion.with the oxygenated medical fluid. Such perfusion can be performed at either normothennic or hypothermic temperatures, preferably at hypothennic temperatures. For hypothermic flush, static storage and hypothermic perfusion, the medical fluid preferably contains little or no oxygen and preferably includes antioxidants, both molecular (e.g., 2-ascorbic acid tocopherol) and enzymatic (e.g., catalase and superoxide dismutase (SOD)). Normothermic and/or hypothermic perfusion, and preferably hypothennic perfusion, can be performed in vivo as well as in vitro. Such perfusion arrests ischemic injury in preparation for transport, storage and/or transplant of the organ.
The normothermic treatment is preferably employed after an organ has been subjected to hypothennic temperatures, statically and/or under perfusion. Such initial hypothennic exposure can occur, for example, during transport and/or storage of an organ after harvesting. The treatment is also suitable for organs that will ultimately be stored and/or transported under hypothermic conditions. In other words, the treatment can be applied to organs prior to cold storage and/or transport.
In the normothennic perfusion mode, gross organ perfusion pressure is preferably provided by a pneumatically pressurized medical fluid reservoir controlled in response to a sensor disposed in an end of tubing placed in the organ, which may be used in combination with a stepping motor/cam valve or pinch valve which provides for perfusion pressure fine tuning, prevents overpressurization and/or provides emergency flow cut-off. Alternatively, the organ may be perfused directly from a pump, such as a roller pump or a peristaltic pump, with proper pump control and/or sufficiently fail-safe controllers to prevent overpressurization of the organ, especially as a result of a system malfunction. Substantially eliminating overpressurization prevents and/or reduces damage to the vascular endothelial lining and to the organ tissue in general. Viability of the organ may be monitored, preferably automatically, in the normothermic perfusion mode, preferably by monitoring organ resistance (pressure/flow) and/or pH, pQz, pCCb, LDH, T/GST,Tprotein, lactate, glucose, base excess and/or ionized calcium levels in the medical fluid that has been perfused through the organ and collected.
Normothermic perfusion may be preceded by and/or followed by hypothermic perfusion. In the hypothermic mode, the organ is perfused with a medical fluid containing substantially no oxygen, preferably a simple crystalloid solution that may preferably be augmented with antioxidants, intermittently or at a slow continuous flow rate. Hypothermic perfusion also can be performed in vivo as well as in vitro prior to removal of the organ from the donor. Hypothennic perfusion reduces the organ's metabolic rate, allowing the organ to be preserved for extended periods of time. The medical fluid is preferably fed into the organ by pressure from an intermediary tank which has a low pressure head so overpressurization of the organ is avoided. Alternatively, in embodiments, gravity can be used to feed the medical fluid into the organ from the intermediary tank, if appropriate. Alternatively, the organ may be perfused directly from a pump, such as a roller pump or a peristaltic pump, with proper pump control and/or sufficiently fail-safe controllers to prevent overpressurization of the organ, especially as a result of a system malfunction. Substantially eliminating overpressurization prevents or reduces damage to the vascular endothelial lining of the organ and to the organ tissue in general, in particular at hypothermic temperatures when the organ has less ability to protect itself by vascular constriction. Viability of the organ may also be monitored, preferably
automatically, during the recovery process, preferably by monitoring organ resistance (pressure/flow) and/or pH, pCh, pCOj, LDH, T/GSTJprotein, lactate, glucose, base excess and/or ionized calcium levels in the medical fluid that has been perfused through the organ and collected.
An organ diagnostic apparatus may also be provided to produce diagnostic data such as an organ viability index. The organ diagnostic apparatus includes features of an organ perfusion apparatus, such as sensors and temperature controllers, as well as cassette interface features, and provides analysis of the organ and input and output fluids in a perfusion system. Typically, the organ diagnostic apparatus is a . simplified perfusion apparatus providing diagnostic data in a single pass, in-line perfusion.
An organ viability index may be provided taking into, account the various measured factors identified above, such as vascular resistance, pH etc. The index may be organ specific, or may be adaptable to various organs. The index compiles the monitored parameters into a diagnostic summary to be used for making organ therapy decisions and deciding whether to transplant the organ. The index may be automatically generated and provided to the physician.
The present invention also provides an organ transporter which allows for transportation of an organ over long distances. The organ transporter may be used for various organs, such as the kidneys, and may be adapted to more complex organs, such as the liver, having multiple vasculature structures, for example, the hepatic and portal vasculaturcs of the liver. The organ transporter includes features of an organ perfusion apparatus, such as sensors and temperature controllers, as well as cassette interface features.
The data of the organ, the medical fluid and the interaction therebetween can be compiled. Additionally, an organ data index may be provided to be-used for storing the data generated from perfusing the organ. The data allows for ready research of organ and medical fluid and information may also be directly recovered from the perfusion, diagnostic or transporter apparatus to monitor the organ status. Various types of data and information may be grouped into sub-records or subdirectories to assist in data management and transfer. All the subi-records may be combined to form an overall organ screening record, which may be disseminated to or retrievable by physicians, scientists or other organizations for research purposes. .
The perfusion apparatus, transporter, cassette, and organ diagnostic apparatus may be networked to permit remote management, tracking and monitoring of the location and therapeutic and diagnostic parameters of the organ or organs being stored or transported. The information systems may be used to compile historical data of organ transport and storage, and provide cross-referencing with hospital and United Network for Organ Sharing (UNOS) data on the donor and recipient The systems may also provide outcome data to allow for ready research of perfusion parameters and transplant outcomes.
Fig. 9 is an exploded perspective view showing the modules of Figs. 4-8 assembled together,
Figs. 11A -1 ID show side perspective views of varibus embodiments of an organ cassette according to the invention;
Figs. 18 and ISA show an embodiment of an organ chair according to the present invention;
Figs. 25 and 25 A show motor control of a perfusion pump according to the present invention;
Fig. 26 shows a liver perfasion apparatus according to the present invention;
Fig 31 shows a logic circuit for an organ diagnostic system according to Fie. 28.
- SON OF PREFERRED
For a general understanding of the features of the invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate tike elements.
Figure 1 shows an organ perfusion apparatus 1 according to the invention. Figure 2 is a schematic illustration "of the apparatus of Fig. 1. The apparatus 1 is preferably at least partially microprocessor controlled, and pneumatically actuated, The microprocessor ISO connection to the sensors, valves, thermoelectric units and pumps of the apparatus 1 is schematically shown in Fig. 3. Microprocessor 150 and apparatus 1 may be configured to and are preferably capable of further being connected to a computer network to provide data sharing, for example across a local area network or across the Internet.
The organ perfusion apparatus 1 is capable of perfusing one or more organs simultaneously, at bom nonnothermic and hypothermic temperatures (hereinafter, normothermic and hypothermic perfusion modes). All medical fluid contact surfaces are preferably formed of or coated with materials compatible with the medical fluid used, more preferably non-thrombogenic materials. As shown in Fig. 1, the apparatus 1 includes a housing 2 which includes front cover 4, which is preferably translucent, and a reservoir access door 3. The apparatus preferably has one or more control and display areas Sa, Sb, 5c, 5d for monitoring and controlling perfusion.
As schematically shown in Fig. 2, enclosed within the housing 2 is a reservoir 10 which preferably includes three reservoir tanks 15a, l$b, 11. Two of the reservoir
tanks 15a, 15b are preferably standard one liter infusion bags, each with a respective pressure cuff 16a, 16b. A pressure source 20 can be provided for pressurizing the pressure cuffs 16a, 16b. The pressure source 20 is preferably pneumatic and maybe an pn board compressor unit 21 supplying at least 10 LPM external cuff activation via gas tubes 26,26a,26b, as shown in Fig. 2. The invention, however, is not limited to use of an on board compressor unit as any adequate pressure source can be employed, for example, a compressed gas (e.g., air, CO2, oxygen, nitrogen, etc.) tank (not shown) preferably with a tank volume of 1.5 liters at 100 psi or greater for internal pressurization. Alternatively, an internally pressurized reservoir tank (not shown) may be used. Reservoir tanks 1 Sa, 15b, 17 may, in embodiments, be bottles or other suitably rigid reservoirs mat can supply perfusate by gravity or can be pressurized by compressed gas.
Gas valves 22-23 are provided on the gas tube 26 to allow for control of the pressure provided by the onboard compressor unit 21. Anti-back Sow valves 24a» 24b may be provided respectively on the gas tubes 26a, 26b. Pressure sensors P5, P6 may be provided respectively on the gas tubes 26a, 26~b to relay conditions therein to the microprocessor 150, shown in Fig. 3. Perfusion, diagnostic and/or transporter apparatus may be provided with sensors to monitor perfusion fluid pressure and flow in the particular apparatus to detect faults in the particular apparatus, such as pressure elevated above a suitable level for maintenance of the organ. Gas valves GVj and GVa maybe provided to release pressure from the cuffs 16a, 16b. One or both of gas valves GVi and GVj may be vented to the atmosphere. Gas valve associated with reflux in the gas and/or vent lines. For example, the valves may be configured as anti-reflux valves to prevent reflux. The third reservoir tank 17 is preferably pressurized by pressure released from one of the pressure cuffs via gas valve GV2.
The medical fluid may be blood or a synthetic fluid and may, for example, be a simple crystalloid solution, or maybe augmented with an appropriate oxygen carrier. The oxygen carrier may, for example, be washed, stabilized red blood cells, cross-linked hemoglobin, pegolated hemoglobin or fluorocarbon based emulsions. The medical fluid may also contain antioxidants known to reduce peroxidation or free . radical damage in the physiological environment and specific agents known to aid in tissue protection. As discussed in detail below, an oxygenated (e.g., cross-linked hemoglobin-based bicarbonate) solution is preferred for the normomermic mode while a non-oxygenated (e.g., simple crystalloid solution preferably augmented with antioxidants) solution is preferred for the hypothennic mode. The specific medical fluids used in both the normothermic and hypothennic modes are designed to reduce or prevent the washing away of or damage to the vascular endothelial lining of the organ. For the hypothennic perfusion mode, as well as for flush and/or static storage, a preferred solution is the solution, disclosed in U.S. Patent Application No. 09/628,311, filed July 28,2000, the entire disclosure of which is incorporated herein by reference. Examples of additives which may be used in perfusion solutions for the present invention are also disclosed in U.S. Patent No. 6,046,046 to Hassanein, the entire disclosure of which is incorporated by reference. Of course, other suitable solutions and materials may be used, as is known in the art
The perfusion solution may be provided in a perfusion solution kit, for example, a saleable package preferably containing at least one first container holding a first perfusion solution for normothermic perfusion and at least one second container holding a second, different perfusion solution for hypothennic perfusion, optionally the box 10 shown in Fig. 2. The first perfusion solution may contain at least one oxygen carrier, maybe oxygenated and/or maybe selected from the group consisting of a cross-linked hemoglobin and stabilized red blood cells. The second perfusion solution may be non-oxygenated, may contain at least one anti-oxidant, and/or may contain at least one vasodilator. Additionally, the solution preferably contains no more man 5 mM of dissolved pyruvatc salt. Also, the first container and the second
container may be configured to be operably connected to a perfusion machine as perfusion fluid reservoirs in fluid communication with perfusate conduits of said perfusion machine. Further, one of the first and second containers may be compressible to apply pressiire to the perfusion solution therein. Furthermore, at least one of the first and second containers may include a first opening for passage of a contained perfusion solution out of the container and a second opening passage of a compressed gas into the container. The package may be a cassette configured to be operably connected to a perfusion machine for connection of the first and second containers within the cassette in fluid communication with perfusate conduits or tubing of the perfusion machine.
In other embodiments, the perfusion solution kit may contain at least one first container holding a first perfusion solution for hypothermic perfusion at a first temperature and at least one second container holding a second, different perfusion solution for hypothermic perfusion at a second temperature lower than the first temperature. In the kit, the first perfusion solution may contain at least a crystalloid and may contain at least one vasodilator. The second perfusion solution may be oxygen carrier enhanced, where the oxygen carrier is selected from the group consisting of a hemoglobin and stabilized red blood cells. In addition, the second perfusion solution may, if desired, contain .at least one anti-oxidant or free radical scavenger. Preferably, the second solution contains no more than 5 mM of dissolved
pynrvate salt As above, the first container and the second container may be configured to be operably connected to a perfusion machine as perfusion fluid reservoirs in fluid communication with perfusate conduits of said perfusion machine. Further, one of the first and second containers may be compressible to apply pressure to tine perfusion solution therein. Furthermore, at least one of the first and second containers may include a first opening for passage of a contained perfusion solution out of the container and a second opening passage of a compressed gas into the container. The package may be a cassette configured to be operably connected to a perfusion machine for connection of the first and second containers within the cassette in fluid communication with perfusate conduits or tubing of the perfusion machine.
The medical fluid within reservoir 10 is preferably brought to a predetermined temperature by a first thermoelectric unit 30a in heat transfer communication with the reservoir 10. A temperature sensor T3 relays the temperature within the reservoir 10
to the microprocessor 150, which adjusts the thermoelectric unit 30a to maintain a desired temperature within the reservoir 10 and/or displays the temperature on a control and display areas 5a for manual adjustment Alternatively or in addition, and preferably where the organ perfusion device is going to be transported, the medical fluid within the hypothermic perfusion fluid reservoir can be cooled utilizing a cryogenic fluid heat exchanger apparatus such as that disclosed in co-pending application Serial No. 09/039,443, which is hereby incorporated by reference.
An organ chamber 40 is provided which supports a cassette 65, as shownin Fig. 2, which holds an organ to be perfused, or a plurality of cassettes 65,65,65, as ' . shown in Fig. 12, preferably disposed one adjacent the other. Various embodiments of the cassette 65 are shown in Figs. 1 1 A-l ID. The cassette 65 is preferably formed of a material that is light but durable so that the cassette 65 is highly portable. The material may also be transparent to aUow visual inspection of the organ. .
Preferably the cassette 65 includes side walls 67a, a bottom wall 67b and an organ supporting surface 66, which is preferably formed of a porous or mesh material, to allow fluids to pass therethrough. The cassette 65 may also include a top 67d and may be provided with an openmg(s) 63 for tubing (see, for example, Fig. 1 ID). The openings) 63 may include seals 63a (e.g., septum seals or o-ring seals) and optionally be provided with plugs (not shown) to prevent contamination of the organ and maintain a sterile environment Also, the cassette 65 may be provided with a closeable air vent 61 (see, for example, Fig. 1 ID). Additionally, the cassette 65 may be provided with tubing for connection to the organ or to remove medical fluid from the organ bam and a connection device(s) 64 for connecting the tubing to, for example, tubing 50c, 81, 82, 91 and/or 132 (see, for example, Fig. 1 ID). The cassette 65, and more particularly the organ support, openings), tubmg(s) and/or connection), maybe specifically tailored to the type of organ and/or size of organ to be perfused. • Outer edges 67c of the side support walls 67a can be used to support the cassette 65 disposed in the organ chamber 40. The cassette 65 may further include a handle portion 68 which allows the cassette 65 to be easily handled, as shown, for example, in Figs. 1 1C and 1 ID. Each cassette 65 may also be provided with its own stepping motor/cam valve 75 (for example, in the handle portion 68, as shown in Fig. 1 1C) for fine tuning the pressure of medical fluid perfused into the organ 60 disposed therein, discussed in more detail below. Alternatively, pressure may, in embodiments, be controlled by way of a pneumatic chamber, such as
an individual pneumatic chamber for each organ (not shown), or by any suitable variable valve such as a rotary screw valve or a helical screw valve.
Fig. 17 shows an alternative embodiment of cassette 65. In Fig. 17, cassette 65 is shown with tubeset 400. Tubeset 400 can be connected to perfusion apparatus 1 or to an organ transporter or an. organ diagnostic apparatus, and allows cassette 65 to be moved between various apparatus without jeopardizing the sterility of the interior of cassette 65. Preferably, cassette 65 is made of a sufficiently durable material that it can withstand penetrat^ and harsh impact Cassette 65 is provided with a lid, preferably two lids, an inner lid 410 and an outer lid 420. The lids 410 and 420 may be removable or may be hinged or otherwise connected to toe body of cassette 65. Clasp 405 provides a mechanism to secure lids 410 and 420 to the top of cassette 65. Clasp 405 may additionally be configured with a lock to provide further security.and stability. A biopsy port 430 may additionally be included in inner lid 410 or both inner lid 410 and outer lid 420. Biopsy port 430 provides access to the organ to allow for additional diagnosis of the organ with minimal disturbance of me organ. Cassette 65 may also have ah overflow trough 440 (shown in Fig. 17A). Overflow trough 440 is a channel present in the top of cassette 65. When lids 410 and 420 are secured on cassette 65, overflow trough 440 provides a region that is easy to check to determine if the inner seal is leaking. Periusaternay be pc^iredmto and out of wasette 65 and may be drained from cassette 65 through a stopcock or removable plug.
Cassette 65 and/or both fids 410 and 420 may be constructed of an optically clear material to allow for viewing of the interior of cassette 65 and monitoring of the organ and to allow for video images or photographs to be taken of the organ. Perfusion apparatus 1 or cassette 65 may be wired and fitted with a video camera or a photographic camera, digital or otherwise, to record the progress and status of the organ, the captured images may be made available over a computer network such as a local area network or the Internet to provide for additional data analysis and remote monitoring. Cassette 65 may also be provided with a tag that would signal, e.g., through a bar code, magnetism, radio frequency, or other means, the location of the cassette, mat the cassette is in the apparatus, and/or the identity of the organ to the perfusion apparatus or transporter. Cassette 65 may be sterile packaged and/or may be packaged or sold as a single-use disposable cassette, such as in a peel-open pouch, A single-use package containing cassette 65 may also include tubeset 400.
Cassette 65 may additionally be provided with an organ chair 1800 shown in Figs. 18 and 18A. Organ chair 1800 is removable and provides a support- surface for the organ within cassette 65. Utilizing a removable organ chair 1800 allows the organ to be cannulated and secured under cold conditions when the organ is recovered from a donor before being placed into cassette 65. Organ chair 1800 may be reusable or singleruse. Organ chair 1800 may be constructed specifically to correspond to each type of organ, such as the kidney, heart or liver. Organ chair 1800 is preferably designed to be form fitting to the organ but to allow for the full anthropometric range of organ sizes.
Preferably, organ chair 1800 is at least partially perforated to allow fluids to pass through organ chair 1800. The perforations in organ chair 1800 may be sized to catch organ debris, or an additional filter layer, preferably constructed of cloth, fabric, nylon, plastic, etc., to catch organ debris of at least 15 microns in diameter. In addition, a separate filter may be used on the tubing mat intakes fluid directly from the perfusate bam to prevent organ debris of a predetermined size, for example at least 10 to 15 microns hi diameter, from entering the perfusion tubing.
Organ chair 1800 may also be configured with a venous outflow sampler 1810. Organ chair 1800 funnels the venous outflow into venous outflow sampler 1810. Venous outflow sampler 1810 provides a readily available source for capturing the venous outflow of the organ. Capturing the venous outflow in this manner permits analysis of the perrusate leaving the organ without carmulating a vein and enables organ viability to be measured with a high degree of sensitivity by analyzing differentially the perrusate flowing into and out of the organ. Alternatively, Venous outflow may be captured directly by carmulating a vein, but this method increases the risk of damaging the vein or the organ. Organ chair 1800 may also be raised and lowered within cassette 65 to facilitate sampling from venous outflow sampler 1810. Alternatively, a sufficient amount of the organ bam may be drained from cassette 65 to obtain access to venous outflow sampler 1810 or to capture venous outflow before the outflow mixes with the rest of the perfusate in the organ bath.
Organ chair 1800 is preferably additionally configured with a cannula 1820 that attaches to the perfused artery, sueh as the renal artery. Cannula 1820 may be reusable or may be suitable for single-use, preferably provided in a sterile package with cassette 65, organ chair 1800 and tubeset 400. Cannula 1820 is provided with a cannula clamp 1830 to secure cannula 1820 around the perfused artery and to preferably provide leak-
tight perfusion. A straight-in flanged cannula may also be used, however clamping around the artery is preferable to prevent contact with the inner surface of the artery, which is easily damaged. Cannula 1820 may also be configured with additional branching connections for accessory arteries. Multiple cannula and cannula clamp sizes may be used to accommodate various artery sizes or an adjustable cannula and cannula clamp may be used to accommodate various sized arteries. Cannula clamp 1830 may be a clam-shell configuration or may be a two-part design. Cannula clamp 1830 may be configured with integral or separate means for tightening cannula clamp 1830 to the proper pressure to provide leak-tight perfusion. In addition, cannula 1820 may be provided with a snap 1840 to hold cannula 1820 closed. Cannula 1820 may also be provided with a vent 1850 to remove air bubbles from cannula 1820.
Organ chair 1800 preferably has a detented region 1860 that corresponds to protrusions 1870 on cannula 1820. Such detents, tracks or grooves on organ chair 1800 allow cammla 1820 to.be positioned at several locations to provide various tensions on the perfused artery. This allows the ideal minimum tension to be set for each artery. Cannula clamp 1830 secures the perfusate tubing to the perfused artery. Cannula 1820 is adjustably .secured to organ chair 1800 to provide for positioning the perfused artery to accommodate variations in organ size and artery length to prevent stretching, twisting, sagging or kinking of the artery. The combination of organ chair 1800, cannula 1820 and additional straps or wide belts provides a secure platform to transport the organ and to transfer the organ between the cassette and the surgical field.
The cassette 65 is configured such that it may be removed from the organ perfusion apparatus 1 and transported to another organ perfusion apparatus in a portable transporter apparatus, such as, for example, a conventional cooler or a portable container such as that disclosed in simultaneously filed co-pending U.S. Application No. 09/161,919, or U.S. Patent No. 5,586,438 to Fahy, which are hereby incorporated by reference in their entirety.
In embodiments, when transported, the organ is disposed on the organ supporting surface 66 and the cassette 65 is preferably enclosed in a preferably sterile bag 69, as shown, for example, in Fig. 11 A. When the organ is perfused with medical fluid, effluent medical fluid collects in the bag 69 to form an organ bath. Alternatively,
the cassette 65 can be formed with a fluid tight lower portion in which the effluent medical fluid may collect, or the effluent medical Quid may collect in the organ chamber 40 to form the organ bath. In either alternative case, the bag 69 would preferably be removed prior to inserting the cassette into the organ chamber 40. Further, where a plurality of organs are to be perfused, an organ chamber may be provided for each organ. Alternatively, cassette 65 can be transported in the dual-lid cassette of Fig. 17 and. additionally carried within a portable organ transporter.
Fig. 19 shows an external view of an embodiment of transporter 1900 of the invention. The transporter 1900 of Fig. 19 has a stable base to facilitate an upright position and handles 1910 for carrying transporter 1900. Transporter 1900 may also be fitted with a shoulder strap and/or wheels to assist in carrying transporter 1900. A control panel 1920 is preferably also provided. Control panel 1920 may display characteristics, such as, but not limited to infusion pressure, power on/off, error or fault condition, flow rate, flow resistance, infusion temperature, bam temperature, pumping time, battery charge, temperature profile (maximums and minimums), cover open or closed, history log or graph, and additional status details and messages, which are preferably further transmittable to a remote location for data storage and/or analysis. Flow and pressure sensors or transducers in transporter 1900 maybe used to calculate various organ characteristics including pump pressure and vascular resistance of an organ, which can be stored in computer memory to allow for analysis of, for example, vascular resistance history, as well as to detect faults in the apparatus, such as elevated . pressure.
Transporter 1900 has latches 1930 that require positive user action to open, thus avoiding the possibility that transporter 1900 inadvertently opens during transport. Latches 1930 hold top 1940 in place on transporter 1900. Top 1940 or a portion thereof may be constructed with an optically clear material to provide for viewing of the cassette and organ perftisiori status. Transporter 1900 maybe configured with a cover open detector that monitors and displays if the cover is open or closed. Transporter 1900 may be configured with an insulating exterior of various thicknesses to allow the user to configure transporter 1900 for varying extents and distances of transport. In embodiments, compartment 1950 maybe provided to hold patient and organ data such as charts, testing supplies, additional batteries, hand-held computing devices and/or other accessories for use wife transporter 1900. Transporter 1900 may also be
configured with means for displaying a UNOS label and/or identification and return shipping information.
Fig. 20 shows a cross-section view of a transporter 1900. Transporter 1900 contains cassette 65 and pump 2010. Cassette 65 may be placed into and taken out of transporter 1900 without disconnecting tubeset 400 from cassette 65, thus maintaining sterility of the organ. Sensors in transporter 1900 can detect the presence of cassette 65 in transporter 1900, and depending on the sensor, can read the organ identity from a barcode or radio frequency or other smart tag that may be integral to cassette 65. this allows for automated identification and tracking of the organ and helps monitor and . control the chain of custody. A global positioning system may be added to transporter 1900 and/or cassette 65 to facilitate tracking of the organ. Transporter 1900 can be interfaced to a computer network by hardwire connection to a local area network or by wireless communication while in transit This interface allows perfusion parameters, vascular resistance, and organ identification and transporter and cassette location to be tracked and displayed in real-time or captured for future analysis.
Transporter 1900 also preferably contains a filter 2020 to remove sediment and other particulate matter, preferably ranging in size from 0.05 to 15 microns in diameter or larger, from the perfusate to prevent clogging of the apparatus or the organ. Transporter 1900 also contains batteries 2030, which may be located at the bottom of transporter 1900 or beneath pump 2010 or at any other location that provides easy access to change batteries 2030. Batteries 2030 may be rechargeable outside of transporter 1900 or while intact within transporter 1900 and/or are preferably hot-swappable one at a time. Batteries 2030 are preferably rechargeable rapidly and without full discharge. Transporter 1900 may .also provide an additional storage space 2040 at the bottom of transporter 1900 for power cords, batteries and other accessories. Transporter 1900 may also include a power port for a DC hookup to a vehicle such as an automobile or airplane and/or for an AC hookup.
Fig, 21 shows a block diagram of transporter 1900. Transporter 1900 of Fig. 21 is intended to provide primarily hypothermic perfusion, and may operate at any temperatures, for example in the range of-25 to 60° C, approximately 0 to 8° C, preferably approximately 4° C. The temperature may be adjusted based on the particular fluids used and adapted to the particular transport details, such as length of time of transport. Transporter 1900 is cooled by coolant 2110, which may be an ice and
water bath or a cryogenic material. In embodiments using cryogenic materials, the design should be such that organ freezing is prevented. The temperature of the perfusate bath surrounding the organ is monitored by temperature transducer 2115. Transporter 1900 also contains filters 2020 to remove sediment and particulate, ranging in size from 0.05 to 15 microns in diameter or larger, from the perfusate to prevent clogging of the apparatus or the organ. Using a filter 2020 downstream of pump 2010 allows for capturing inadvertent pump debris and also dampens pressure spikes from pump 2010.
The flow of perfusate within transporter 1900 is controlled by pump 2010, which is preferably a peristaltic or roller pump. Pump 2010 is preferably not in contact with the perfusate to help maintain sterility. In addition, tubeset 400 may be attached to pump 2010 without opening the tubing circuit Pump 2010 is controlled by a computer or microcontroller. The computer can actively modulate the angular velocity of pump 2010 to reduce the natural pulse actions of pump 2010 to a low level, resulting in essentially non-pulsatile flow. Further computer control can impose a synthesized pressure pulse profile mat can be sinusoidalor physiological or otherwise. The average flow rate and pressure can be made independent of pulse repetition rate by pulse width modulating or amplitude modulating the synthesized pressure pulses. Control over some or all of the pulse parameters can be made available to users through control panel 1920 or over a network. Pulse control can be organ specific. In the case of a liver, a single pump can provide continuous flow to the portal vein at, for example, 1 to 3 liters per minute while providing pulsatile flow to the hepatic artery at, for example, 100 to 300 ml per minute. Synchronizing the shunt valves to the pump controller allows independent pressure regulation of the two flows.
The flow of the perfusate into the organ is monitored by flow sensor 2125. Pressure transducers 2120 may be present to monitor the pressure the perfusate places on the tubing. Pressure transducers 2120 may be used to monitor the pump pressure and/or the infusion pressure. A pressure transducer 2120 may be present just upstream of the organ to monitor the organ infusion pressure. Transporter 1900 may be configured with a bubble detector 2125 to detect bubbles before the perfusate enters bubble trap 2130. Bubble detectors, such as bubble detector 2125, may be used to detect bubbles in, for example, the infuse line and/or in the pump output line. Bubble trap 2130 removes air bubbles from the perfusate and vents the bubbles into the Wash tube. Bubble trap 2130 maybe disposable and maybe constructed integral to tubeset 400.
Perfusate exiting bubble trap 21 30 can either continue through infuse valve 2140 or wash valve 21 50. Wash valve 2150 is normally open and infuse valve 21-40 is normally closed. Preferably, wash valve 2150 and infuse valve 2140 operate dependently in an on/off manner, such that if one valve is open, the other valve is closed. Although infuse valve 2140 is normally closed, if the sensor and monitors all report suitable perfusion parameters present in transporter 1900, then infuse valve 2140 may be opened to allow organ perfusion. In the occurrence of a fault, such as elevated perfusion pressure above a suitable level for the organ, infuse valve 2140 switches back to closed and wash valve 2150 is opened to divert fluid flow into the perfusate bath surrounding the organ. This provides a failsafe mechanism that automatically shunts perfusate flow and prevents organ perfusion in case of a power failure or computer or electnMji(» malfunction. A pressure transducer 2120, such as designated by Pj, .may be hardwired, redundant to the computer and software control, to wash valve 2150 and infuse valve 2140 to quickly deliver a default message to the valves in the case of a pressure malfunction. In embodiments, the diverted fluid may be separately collected in another container or compartment.
Fig. 22 shows various operation states of transporter 1900. For example, using the controls provided on control panel 1 920, a user may select operations such as perfuse, idle, wash and prime. Fig. 22 shows various options depending on the present state of transporter 1900. The labels idle, prime, wash, perfuse and error handling indicate the state of transporter 1900 that is preferably displayed on control panel 1920 during the corresponding operation. For example, when transporter 1900 is in a wash operation, control panel 1920 displays the wash operation indicator,, such as. an LED display. The arrows connecting the various operations of transporter 1900 indicate the manual and automatic actions that may occur to transition transporter 1900 between operation states. Manual actions require the user to act, for example by pressing a button or turning a knob or dial Fig. 22 exemplifies pressing a button or other indicator, for example, to move from a perfusion operation to an idle operation by pressing the stop button (Press Stop). To move directly into a perfuse operation from an idle operation, a user presses the perfuse button (Press Perfuse);
Automatic operations may be controlled by the passage of time and/or by an internal monitor within transporter 1900. Such automatic operation is shown in Fig. 22, for example, connecting the prime operation to the idle operation. If the prime operation
has been completed according to the internal transporter program parameters before the wash button has been pressed, transporter 1900 returns to an idle operation. Another automatic operation occurs during a perfuse operation if a fault or error occurs, such as overpressurization of the organ. When an error or fault occurs, transporter 1900 pan move to an error handling operation to determine the extent or degree of the fault or error. If the fault or error is determined to be a small or correctable error, transporter 1900 moves into awash operation. If transporter 1900 can then adjust the system parameters to handle the fault or error, transporter 1 900 moves back to perfuse (Error Recovery). If transporter 1900 can not adjust the system parameters to handle the fault or error, transporter 1900 moves to an idle operation. If the error or fault detected is determined to be substantial, tranporter 1 900 may move directly into an idle operation,
Fig. 23 shows an alternative cross-section of transporter 1900. Transporter 1900 may have an outer enclosure 23 1 0 constructed of metal, or preferably a plastic or synthetic resin that is sufficiently strong to withstand penetration and impact Transporter 1900 contains insulation 2320, preferably a thermal insulation made of, for example, glass wool or expanded polystyrene. Insulation 2320 may be various thicknesses ranging from 0 J inches to 5 inches thick or more, preferably 1 to 3 inches, such as approximately 2 inches thick. Transporter 1900 is cooled by coolant 2110, which may be, e.g., an ice and water bath or a cryogenic material. In embodiments using cryogenic materials, fee design should be such that organ freezing is prevented. An ice and water mixture is preferably in an initial mixture of approximately 1 to 1, however, in embodiments the ice and water bath may be frozen solid. Transporter 1900 can be configured to hold various amounts of coolant, preferably up to 1 0 to 12 liters. An ice and water bath is preferable because it is inexpensive and can not get cold enough to freeze the organ. Coolant 21 10 preferably lasts for a minimum of 6 to 12 hours and more preferably lasts for a minimum of 30 to 50 hours without changing coolant 21 10. The level of coolant 2110 maybe viewed through a transparent region of transporter 1900 or may be automatically detected and monitored by a sensor. Coolant 2110 can be replaced without stopping perfusion or removing cassette 65 from transporter 1900. Coolant 21 10 is maintained in a watertight compartment 21 15 of transporter 1900. Compartment 2115 prevents the loss of coolant 21 10 in the event transporter 1900 is tipped or inverted. Heat is conducted from the walls of the perfusion reservoir and cassette 65 into coolant 2110 enabling control within the desired
temperature range. Coolant 2110 is a failsafe cooling mechanism because transporter 1900 automatically reverts to cold storage in the case of power loss or electrical or computer malfunction. Transporter 1900 may also be configured with a heater to raise the temperature of the perfusate.
Transporter 1900 may be powered by batteries or by electric power provided through plug 2330. An electronics module 2335 is also provided in transporter 1900. Electronics module 2335 is cooled by vented air convection 2370, and may further be cooled by a fan. Preferably, electronic module 2335 is positioned separate from the perfusion tubes to prevent the perfusate from wetting electronics module 2335 and'to avoid adding extraneous heat from electronics module 2335 to the perfusate. Transporter 1900 has a pump 2010 that provides pressure to perfusate tubing 2360 to deliver perfusate 2340 to organ 2350. Transporter 1900 may be used to perfuse various organs such as a kidney, heart, liver, small intestine and lung. Transporter 1900 and cassette 65 may accommodate various amounts of perfusate 2340, for example up to 3 to 5 liters. Preferably, approximately 1 liter of a hypothermic perfusate 2340 is used to perfuse organ 2350. Organ 2350 may be various organs, including but not limited to a kidney, heart, lung, liver or small intestine.
Cassette 65 and transporter 1900 are preferably constructed to fit or mate such that efficient heat transfer is enabled. The geometric elements of cassette 65 and transporter 1900 are preferably constructed such that when cassette 65 is placed within transporter 1900, the elements are secure for transport
Fig. 24 shows various data structures and information connections that can be facilitated to assist in the overall communication and data transfers mat may be beneficial before, during and after organ transplantation. The perfusion apparatus, transporter, cassette, and organ diagnostic apparatus maybe networked to permit remote management, tracking and monitoring of the location and therapeutic and diagnostic parameters of the organ or organs being stored or transported. The information systems may be used to compile historical data of organ transport and storage, and provide cross-referencing with hospital and UNOS data on the donor and any recipient and/or information on why transplant my be innappropriate. The systems may also provide outcome data to allow for ready research of perfusion parameters and transplant outcomes. For example, information regarding the donor may be entered at the location where an organ is recovered from a donor. Information
may also be directly recovered from the perfusion, diagnostic or transporter apparatus to monitor organ status and location. Various types of information maybe grouped into sub-records Or sub-directories to assist in data management and transfer. All the sub-records may be combined to form an overall transplant record, which may be disseminated to or retrievable by physicians, scientists or other organizations for tracking and monitoring purposes.
Preferred embodiments of transporter 1900 can automatically log much or all
of the perfusion process data and transporter 1900 events into an internal database. A
radio frequency or barcode labeled tag or the like for each cassette 65 allows
transporter 1900 to reference the data uniquely to each organ. When transporter 1900
reaches a docking port, transporter 1900 can upload data to a main database computer
over a LAN. Transporter 1900 can also provide real-time status whenever transporter
1900 is connected to the LAN. Transporter 1900 can also be configured with a
wireless communications setup to provide real-time data transfer during transport.
Perfusion apparatus 1 can also be connected to the LAN and since perfusion apparatus
is generally stationary, data uploads can occur continuously and in real-time. The data
can be cross-referenced with UNOS data to utilize the UNOS data on organ
identification, donor condition, donor logistics, recipient logistics and recipient
outcomes. Data may be displayed and accessed on the Internet to facilitate monitoring
from any location.	•
Within the perfusion, diagnostic and/or transporter apparatus, the organ bath is preferably cooled to a predetermined temperature by a second thermoelectric unit 30b, as shown in Fig. 2, in heat transfer communication with the organ chamber 40. Alternatively and preferably where the organ perfusion device is going to be transported, the medical fluid within reservoir 10 can be cooled utilizing a heat transfer device such as an ice and water bath or a cryogenic fluid heat exchanger apparatus such as that disclosed in co-pending Application No. 09/039,443, which is hereby incorporated by reference. A temperature sensor T2 within the organ chamber 40 relays the temperature of the organ 60 to the microprocessor ISO, which adjusts the thermoelectric unit 30b to maintain a desired organ temperature and/or displays the temperature on the control and display areas 5c for manual adjustment.
Medical fluid maybe fed from the bag 15a directly to an organ 60 disposed in the organ chamber 40 through tubing 50a,50b,50c or from bag 15b through tubing
50d,50e,50c by opening valve LV4 or LVs, respectively. Conventional medical fluid bag and tubing connections may be utilized. All tubing is preferably disposable, easily replaceable and interchangeable. Further, all tubing is preferably formed of or coated with materials compatible with the medical fluids used, more preferably non-thrombogenic materials. An end of the tubing 50c is inserted into the organ 60. The tubing may beconnected to the organ(s) with conventional methods, for example, with sutures. The tubing may include a lip to facilitate connection to the organ. Alternatively, cannula 1820 described above may be used with or without connection to an organ chair 1800. However, the specific methods and connection depend on the type of organs(s) to be perfused.
The microprocessor 150 preferably controls the pressure source 20 in response to signals from the pressure sensor PI to control the pressure of the medical fluid fed into the organ 60. .The microprocessor 150 may display the pressure on the control and display areas 5a, optionally for manual adjustment A fluid flow monitor Fl. may also be provided on the tubing 50c to monitor the flow of medical fluid entering the organ 60 to indicate, for example, whether there are any leaks.present in the organ.
Alternatively, the medical fluid may be fed from the reservoir tank 17 via tubing 51 into an intermediary tank 70 preferably having a pressure head of approximately 5 to 40 mm tig. .Medical fluid is then fed by gravity or, preferably, pressure, from the intermediary tank 70 to the organ 60 along tubing 50c by activating a valve LV6. A level sensor 71 may be provided hi the intermediary tank 70 in order to maintain the pressure head. Where a plurality of organ chambers 40 and organs 60 are provided, the organs 60 are connected in parallel to the reservoir 10 utilizing suitable tubing duplicative of mat shown in Fig. 2. See, for example, Fig. 12. The use of pneumatically pressurized and gravity fed fluid pumps configured to avoid overpressurization even in cases of system failure reduces or prevents general tissue damage to the organ and the washing away of or damage to the vascular endothelial lining of the organ. Thus, organ perfusion in this system can be performed, e.g., with either hydrostatic perfusion (gravity or pressure fed flow) or peristaltic perfusion by introducing flow to me organ from a peristaltic (roller) pump.
A bubble detection system may be installed to sense bubbles in the perfusate. An air sensor and sensor board are preferably used. The output of the sensor activates a debubbler system, such as an open solenoid valve, to rid bubbles from the perfusate
flow prior to organ introduction. As with all of the sensors and detectors in this system, the bubble detector may be positioned at any point in the system that is effective based on the particular parameters or design characteristics of the system. For example, a bubble detector and debubbler system BD may be positioned between the cam valve 205 and pressure sensor PI, as shown in .Fig. 1.
A stepping motor/cam valve 205, or other suitable variable valve such as a rotary screw valve, may be arranged on the tubing 50c to provide pulsatile delivery of the medical fluid to the organ 60, to decrease the pressure of the medical fluid fed into the organ 60, and/or to stop flow of medical fluid into the organ 60 if the perfusion pressure exceeds a predetermined amount Alternatively, a flow diverter or shunt line may be provided in the perfusion apparatus to which the fluid flow is diverted in the occurrence of a fault, such as excess pressure, for example by opening and closing a valve or a series of valves. Specific embodiments of the stepping motor/cam valve are shown in Figs. 13A-13B and 14A-14F. Figs. 13A-13B show a stepping motor/rotational type cam valve.
Fig. 13A is a top view of the apparatus. Tubing, for example, tubing 50c, is interposed between a support 203 and cam 200. Cam 200 is connected by a rod 201 to stepping motor 202. Fig. 13B is a side view of the apparatus. The dashed line shows the rotational span of the cam 200. In Fig. 13B, the cam 200 is in its non-occluding position. Rotated 180 degrees, the cam'200 totally occludes the tubing 50c with varying degrees of occlusion therebetween. This stepping motor/cam valve is relatively fast, for example, with respect to the embodiment shown in Figs. 14A - 14F; however, it requires a strong stepping motor.
Figs. 14A - 14F disclose another stepping motor/cam valve 210 according to the invention. Fig. 14A is a side view of the apparatus while Fig. 14C is a top view. Tubing, for example, tubing 50c, is interposed between cam 220 and support 223. The cam 220 is connected to stepping motor 222 by supports 22la - 22Id and helical screw 225, which is connected to the stepping motor 222 via plate 222a. Fig. 14B shows the supports 221a and plate 222a in front view. As shown in Fig. 14D, where the support 221 d is to the left of the center of the helical screw 225, the tubing 50c is not occluded. However, as the helical screw 225 is turned by the stepping motor 222, the support 221d moves to the left (with respect to Figs. 14D - 14F) toward a position
where the cam 220 partially or fully occludes the tubing 50c. Such apparatus is slower than the apparatus of Figs. 13A - 13B, but is more energy efficient.
Medical fluid expelled from the organ 60 which has collected in the bottom of the bag 69 (the cassette 65 or the organ chamber 40) is either pumped out through tubing 81 by a pump 80 for filtration, passing through a filter unit 82 and being, returned to the organ bam, or is pumped out by a pump 90 for circulation through tubing 91. The pumps 80,90 are preferably conventional roller pumps or peristaltic pumps; however, other types of pumps may also be appropriate.
Fig. 25 shows a simplified schematic of a pump and pulse controller 2500' and the interaction of the pump and pulse controller with a perfusion apparatus, such as shown in Fig. 1. Pump and pulse controller 2500 receives pressure sensor data input 2510 from pressure sensor P and tachometer data input 2520.. A tachometer may be used to set the phase angle of the active wave. Pump and pulse controller 2500 converts this information to motor drive output 2530, which powers pump 2540. Fig. 25A shows various modes of operation that pump and pulse controller 2500 can provide and how pump and pulse controller 2500 eliminates pressure pulse waves from the perfusate flow and how it modulates perfusate flow rate while maintaining a constant pressure pulse rate.
A peristaltic pump driven at a constant speed provides a constant pressure wave in the associated tubing. Fig. 25 A shows in the first mode of operation the waveforms that result from a constant drive speed applied to .a peristaltic pump. The second mode of operation, called active continuous, shows how the pressure pulse wave can be eliminated or canceled out by applying a motor drive wave that is opposite to the pressure wave of the pump. In the third mode of operation, called active waveform amplitude modulating, the pump pressure pulse wave is canceled by the motor drive wave, and a selected wave is added with a new amplitude as compared to the original pressure pulse wave amplitude. In the fourth mode of operation, called active waveform pulse width modulating, the pump pressure pulse wave is canceled by the motor drive wave, and a selected wave is added with a new pulse width as compared to the original pressure pulse wave width. In an alternative mode of operation, the frequency may be modulated by adding a new frequency wave to the canceled waves.
A level sensor L2 in communication with the microprocessor 150 (see Fig. 3) ensures that a predetermined level of effluent medical fluid is maintained within the organ chamber 40. As shown in Fig. 2, a temperature sensor Tl disposed in the tubing 91 relays the temperature of the medical fluid pumped out of the organ bath along tubing 91 to the microprocessor 150, which monitors the same. A pressure sensor P2 disposed along the tubing 91 relays the pressure therein to the microprocessor 150, which shuts down the system if the fluid pressure in the tubing 91 exceeds a predetermined limit, or activates an alarm to notify the operator that the system should be shut down, for example, to clean filters or the like.
As the medical fluid is pumped along tubing 91 it preferably passes through a filter unit 95 (e.g., 25u, 8u, 2u, 0.8m °-2H and/or O.lu filters); a CO? scrubber/Oj membrane 100 and an oxygenator 1 10, for example, a JOSTRA™ oxygenator. The COj scrubber/Oj membrane 100 is preferably a hydrophobic macroporous membrane with a hydropbilic (e.g., Hypol) coating in an enclosure. A vacuum source (not shown) is utilized to apply a low vacuum on a side opposite the hydropbilic coating by the activation of valve W*i. A hydrostatic pressure of approximately 100 mm Hg is preferred for aqueous passage through the membrane. The mechanical relief valve (not shown) prevents the pressure differential from attaining this level. Immobilized pegolated carbonic anhydrase may be included in the hydrophilic coating. This allows bicarbonate to.be converted to COi and subsequently removed by vacuum venting. However, with organs such as kidneys which have the ability to eliminate bicarbonate, this may be unnecessary except in certain cases.
The oxygenator 1 10 is preferably a two stage oxygenator which preferably includes a hydrophilically coated low porosity oxygen permeable membrane. A portion of the medical fluid is diverted around the oxygenator along tubing 1 1 1 in which is disposed a viability sensor VI, which senses fluid characteristics, such as organ resistance (pressure/flow), pH, pCh, pCOj, LDH, T/GST, Tprotein, lactate, glucose, base excess and ionized calcium levels indicative of an organ's viability. The viability sensor VI is in communication with the microprocessor 150 and allows the organ's viability to be assessed either automatically or manually. One of two gases, preferably 100% oxygen and 95/5% oxygeti/carbon dioxide, is placed on the opposite side of the membrane depending on the pH level of the diverted medical fluid. Alternatively, another pump (not shown) may be provided which pumps effluent
medical fluid out of the organ chamber 40 and through a viability sensor before returning it to the bath, or the viability sensor can be placed on tubing 8-1 utilizing pump 80. In embodiments, the fluid characteristics may be analyzed in a separate diagnostic apparatus and/or analyzer as shown in Figs. 28-31.
The sensed fluid characteristics, such as organ resistance (pressure/flow), pH, pCh, pCCh, LDH, T/GST, Tprotem, lactate, glucose, base excess and ionized calcium levels may be used to analyze and determine an organ's viability and/or the effect of applied bioactive or other test substance thereon. The characteristics may be analyzed individually or multiple characteristics may be analyzed to determine the effect of. various factors. The characteristics may be measured by capturing the venous outflow of the organ and comparing its chemistry to the perfusate inflow. The venous outflow may be captured directly and measured or the organ bath may be measured to provide a rough approximation of the fluid characteristics for comparisons over a period of time.
The organ viability index provides measurements and normal ranges for each characteristic, such as vascular resistance and perfusate chemistry characteristics based on pH, pOz, pCOs, LDH, T/GST, Tprotein, lactate, glucose, base excess and ionized calcium levels. For example, at approximately 5° C, normal pH may be from 7.00 and 8.00, preferably from 7.25 and 7.75 and more preferably from 7.50 and 7.60
and base excess maybe in the range of from -10 to -40, preferably from -15 to -30, and more preferably from -20 to -25. Measurements that are outside the normal range may be indicated visually, e.g., by an asterisk or other suitable notation, aurally or by machine perceivable signals. The characteristics give the physician insight into the metabolism of the organ, such as stability of the metabolism, consumption of glucose, creation of lactic acid and oxygen consumption.
Returning to Fig. 2 and the flow and/or treatment of the medical fluid or perfusate in perfusion apparatus 1, alternative to the pump 90, filter unit 95, the CQz scrubber/Oz membrane 100 and/or the oxygenator 110, a modular combined pump, filtration, oxygenation and/or debubbler apparatus maybe employed such as mat described in detail in simultaneously filed co-pending U.S. Patent Application No. 09/039,318, which is hereby incorporated by reference. As shown in Figs. 4 - 10, the apparatus 5001 is formed of stackable modules. The apparatus 5001 is capable of pumping a fluid through a system as well as oxygenating, filtering and/or debubbting the
fluid The modules are each formed of a plurality of stackable support members and are easily combinable to form a compact apparatus containing desired components. Filtration, oxygenation and/or degassing membranes are disposed between the support members.
Interposed between the plurality of stackable support member are filtration, oxygenation and/or degassing membranes depending on a particular user's needs. The filtration, oxygenation and/or degassing membranes are preferably commercially
available macro-reticular hydrophobic polymer membranes hydrophilically grafted in a commercially known way, such as, for example, ethoxylation, to prevent protein deprivation, enhance biocompatibitity with, for example, blood and to reduce clotting tendencies. The filtration membranes) is preferably hydrophilically grafted all the way through and preferably has a porosity (pore size) within a range of 15 to 35|i, more preferably 20 to 30|a, to filter debris in a fluid, preferably without filtering out cellular or molecular components of the fluid. The degassing membrane(s) and oxygenation membrane(s) are hydrophilically surface treated to maintain a liquid-gas boundary. The degassing membrane(s) and oxygenation membranes) preferably have a porosity of 15^ or less, more preferably 1 On or less. •
The modules may include a first pump module 5010, as shown in exploded view in Fig. 4; a filtration module 5020, as shown in exploded view in Fig. 5; an oxygenation module 5030, as shown in exploded view in Fig. 6; a debubbler module 5040, as shown in exploded view in Fig. 7; and a second pump module 5050, as . shown in exploded view in Fig, 8. The pump modules are each connected to a source of pump fluid and are actuated either manually or by the microprocessor. The support members are preferably similarly shaped. For example, the support members may . each be plate-shaped; however, other shapes may also be appropriate. As shown in Fig. 10, the support members are preferably removably connected by screws or bolts 5065; however, other fasteners for assembling the apparatus may also be appropriate.
The first (end) support member 5011 is preferably solid and provides.support for the pump module 5010. The first (end) support member 5011 preferably includes a domed-out cavity for receiving pump fluid such as air. Tubing 501 It is provided to allow the pump fluid to enter the pump module 5010. The diaphragm 5013 may be made of any suitable elastic and preferably biocompatible material, and is preferably polyurethane. The third support member 5014 includes a domed-out fluid cavity
5014d and tubing 5014t for receiving fluid, such as, for example, blood or an artificial perfusate, into the cavity 5014d of the pump module 5010. The first pump module, or any of the other modules, may also include a port 5014p for sensors or the like. Preferably hemocompatible anti-backflow valves serve to allow unidirectional flow through the pump module 5010.
The filtration module 5020 preferably includes a filtration membrane 5021m which forms a boundary of cavity 5014d, a first support member 5022 with a cut-out center area 5022c, a degassing membrane 5022m and second and third support members 5023 and 5024. The filtration membrane 5021m is preferably a 25u macro-reticular filtration membrane modified to enhance biocompatibility with, for example, blood and to reduce clotting tendencies (like the other supports, filters and membranes in the device). The degassing membrane 5022m is preferably a 0.2 - 3u macro-reticular degassing membrane with a reverse flow aqueous pressure differential of at least 100 mmHg for CCh removal surface modified to enhance biocompatibility.
The first support 5022 includes robing 5022t for forwarding fluid into the oxygenation module 30, or another adjacent module, if applicable, after it has passed through the filtration membrane 5021m and along the degassing membrane 5022m. The second support member 5023 of the filtration module 5020 includes a domed-out fluid cavity 5023d and tubing 5023t through which a vacuum may be applied to.the . cavity 5023d to draw gas out of the fluid through degassing membrane 5022m. The fourth support member 5024 is preferably solid and provides support for the filtration module 5020. The third support member can also include tubing 5024t through which a vacuum may be applied to draw gas out of the fluid through the degassing membrane 5031m of the oxygenation module 5030 as discussed below. The filtration module 5020, or any of the other modules, may also include a port 5023p for sensors or the like.
The oxygenation module 5030 includes a degassing membrane 5031m, a first support member 5032, a filtration membrane 5033m, an oxygenation membrane 5034m, a second support member 5034 with a cut-out center area 5034c, and third and fourth support members 5035,5036. The degassing membrane 5031m is preferably a 0.2 - 3u macro-reticular degassing membrane with a reverse flow aqueous pressure differential of at least 100 mmHg surface modified to enhance biocompatibility.
The first support member 5032 includes a domed-out fluid cavity 5032d. The surface of the domed-out fluid cavity 5032d preferably forms a tortuous path for the fluid, which enhances the oxygenation and degassing of the fluid. The filtration membrane 5033m is preferably a 25 ji macro-reticular filtration membrane modified to enhance biocompatibility. The oxygenation membrane 5034m is preferably a 0.2 - 1 fi macro-reticular oxygenation membrane with a reverse flow aqueous pressure differential of at least 100 mmHg surface modified to .enhance biocompatibility.
The second support member 5034 includes tubing 5034t for forwarding fluid out of the oxygenation module 5030 into the debubbler module 5040, or another' adjacent module, if applicable. The mird support member 5035 includes a domed-out cavity 5035d and tubing 5035t for receiving oxygen from an external source. The fourth support member 5036 is preferably solid and provides support for the oxygenation module 5030.
The debubbler module 5040 includes a first support member 5041,; a filtration membrane 5042m, a degassing membrane 5043m, a second support member 5043 having a cut-out center area 5043c, and a third support member 5044. The first support member 5041 has a domed-out fluid cavity 5041 d.
The filtration membrane 5042m is preferably a 25 n macro-reticular filtration membrane modified to enhance biocompatibility. The degassing membrane 5043m is preferably a 02 - 3p macro-reticular degassing membrane with a reverse flow aqueous pressure differential of at least 100 mmHg surface modified to enhance biocompatibility. The second support member 5043 has tubing 5043t for forwarding fluid out of the debubbler module 5040 into the pump module 5050, or another adjacent module, if applicable. The third support member 5044 includes a domed-out cavity 5044d and tubing 5044t through which a vacuum may be applied to draw gas out of the fluid through the degassing membrane 5043m.
The second pump module 5050 may correspond to the first pump module 5010. It preferably includes a first support member 5051, a diaphragm 5052, a second support member 5053 with a cut-out center area 5053c, and a third (end) support member 50541 The first support member 5051 includes a domed out fluid cavity 505Id and tubing 505It for allowing fluid to exit the pump module. The diaphragm 5052 is preferably a polyurethane bladder.
In operation, blood and/or other medical fluid enters the first pump module 5010 through tube 5014t passes through the filtration membrane 5021m and along the degassing membrane 5022m. A small vacuum is applied through tubing 5023t to draw gas through the degassing membrane 5022m. Next, the blood and/or medical fluid travels into the oxygenation module 5030 via internal tubing 5022t, passing along the degassing membrane 5031m, through the filtration membrane 5033m and along the oxygenation membrane 5034m. Oxygen is received into the domed-out cavity 5035d of the third support member of the oxygenation module 5030 via tubing 5035t and passes through the oxygenation membrane 5034m into the blood and/or other medical fluid as the blood and/or other medical fluid travels along its surface.
After being oxygenated by the oxygenation module 5030, the blood and/or other medical fluid then travels via internal tubing 50341 into the debubbler module 5040. The blood and/or other medical fluid passes through the filtration membrane 5042m and along the degassing membrane 5043m. A small vacuum force is applied
through tubing 5044t to drew gas out of the blood and/or other medical fluid through the degassing membrane 5043m. After passing through the degassing module 5040, the blood and/or other medical fluid travels into the second pump module 5050 through tubing 5041t, and exits the second pump module 5050 via tubing 505 It
After passing through the oxygenator 110, or alternatively through the combined pump, oxygenation, filtration and/or degassing apparatus 5001, the recirculated medical fluid is selectively either directed to the reservoir 15a or 15b not in use along tubing 92a or 92b, respectively, by activating the respective valve LV2 and LVs on the tubing 92a or 92b, or into the organ chamber 40 to supplement the organ bath by activating valve LVj. Pressure sensors P3 and P4 monitor the pressure of the medical fluid returned to the bag 15a or .15b not in use. A mechanical safety valve MVa is provided on tubing 91 to allow for emergency manual cut off of flow therethrough. Also, tubing 96 and manual valve MVi are provided to allow the
apparatus to be drained after use and to operate under a single pass mode in which perfusate exiting the organ is directed to waste rather than being recirculated (recirculation mode.)
A bicarbonate reservoir 130, syringe pump 131 and tubing 132, and an excretion withdrawal unit 120, in communication with a vacuum (not shown) via vacuum valve W2, and tubing 121a, 122a are also each provided adjacent to and in communication with the organ chamber 40.
The present invention also provides for perfusion apparatus adapted for organs with complex vasculature structures, such as the liver. Using die liver as an example, Fig. 26 shows perfusion apparatus 2600. Perfusion apparatus 2600 has a single pump 2610, which is preferably a roller pump or peristaltic pump. The tubing splits into two or more directions with, for example, three tubes going toward the portal vein side of the liver (portal tubing 2625) and one tube going toward the hepatic artery side of the liver (hepatic tubing 2626). The portal side of perfusion apparatus 2600 has more tubes because the portal side of the liver uses three to ten times the flow that the hepatic side uses. Fig. 27 shows a perspective view of pump 2610 and the tubing split into portal tubing 2625 and hepatic tubing 2626.
Both the portal side and the hepatic side of perfusion apparatus 2600 preferably have a filter 2630, bubble trap 2640, pressure transducer 2650, temperature transducer 2660, and flow sensor 2670. An additional temperature transducer 2660 may be present in fluid return tubing 2620. The organ may be cooled as discussed above, for example by an ice and water bath 2680 or by a cryogenic fluid, hi embodiments using cryogenic fluids, the design should be such mat organ freezing is prevented.
Multiple pumps may be used; however, utilizing multiple pumps generally increases the size and cost of the apparatus. Utilizing a single pump 2610 for both vasculature systems provides a variety of modes that can be used to perfuse a liver. After each bubble trap 2640, the tubing splits into two directions. On the hepatic side, hepatic infusion valve 2685 controls the flow to the hepatic side of the liver .and hepatic wash valve 2686 controls the flow into the organ bath. On the portal side, portal infusion valve 2695 controls the flow to the portal side of the liver and portal wash valve 2696 controls the flow into the organ bath. Preferably, each pair of infusion valves and wash valves operates in an on/off or either/or manner. In other
words, when, for example, the portal side is set to infuse, the portal wash valve 2696 is closed. The following table shows various modes of operation for perfusion apparatus 2600.
Connected to both computer 2810 and analyzer 2820 is an organ evaluation instrument 2830, also shown in Fig. 29. Organ diagnostic system 2800-is preferably provided with suitable displays to show the status of the system and the organ. Organ evaluation instrument 2830 has a perfusate chamber 2840 and an organ .chamber 2850. Connecting analyzer 2820 and organ evaluation instrument 2830 is a transfer line 2860. Organ diagnostic system 2800 provides analysis of ah organ and produces an organ viability index quickly and in a sterile cassette, preferably transferable from perfusion apparatus 1 and/or transporter 1900. The organ viability index is preferably produced by flow and temperature programmed single-pass perfusion and in-line' . automatic analysis. The analysis may be performed in a multi-pass system. The multi-pass system will recirculate the flow for analysis while sustaining and evaluating the organ. Flow may be controlled by a valve (not shown) and may recirculate back to the beginning of the system prior to reaching the analyzer 2820.
A beneficial aspect of the single-pass system is mat it can be configured with a limited number of sensors and requires only enough perfusate to perform the analysis. Single-pass perfusion also allows for an organ inflow with a perfusate having a known and predetermined chemistry. This increases the flexibility of types and contents-of perfusates mat may be delivered such as blood or a synthetic blood carrier or a combination thereof, which can be tailored and modified to the particular analysis in process.
Fig. 29 shows a perspective view of organ evaluation instrument 2830. Organ evaluation instrument 2830 has a perfusate chamber 2840 and an organ chamber 2850. Organ chamber 2850 maybe insulated and preferably has a lid 2910 that maybe
removable or may be hinged. Organ chamber 2850 is preferably configured to receive cassette 65, preferably without opening cassette 65 or jeopardizing the sterility of the interior of cassette 65. Cassette 65 and organ chamber 2850 are preferably constructed to fit or mate such that efficient heat transfer is enabled. The geometric elements of. cassette 65 and organ chamber 2850 are preferably constructed such that when cassette . 65 is placed within organ chamber 2850, the elements are secure for analysis. A port 2920 is also provided to connect transfer line 2860.
Fig. 30 shows a single-pass fluid system of organ diagnostic system 2800. The initial perfusion fluids 3000 are contained in a chamber 3010. Chamber 3010 is .
preferably temperature controlled by a heating and cooling system. Fluid flow within
the system is monitored by flow sensor 3020 and controlled by signaling to pinch valves 3030 and pumps 3040. The fluid system also provides a bubble trap 3050, a pressure transducer 3060 and a temperature .transducer 3070. Heat exchanger 3080 provides temperature control and heating and cooling to the fluid within the system prior to organ perrusion. The organ is perfused in cassette 65. The fluid in the organ bath may be collected, or the venous outflow may be captured, to be analyzed. The fluid is collected and passed via transfer line 2860 to analyzer 2820. Transfer line 2860 may also be provided with a separate heating and cooling unit After the fluid is analyzed, it may be collected hi a waste receptacle 3090.
Fig. 31 shows a logic circuit for organ diagnostic system 2800. The computer provides control parameters and receives results and data from the analyzer.. The logic circuit shows inputs from the sensors to the microcontroller and outputs to hardware elements, such as perfusate coolers, perfusate heaters, pinch valves, pumps, transferline heater/cooler and displays.
The method according to the invention preferably utilizes apparatus such as that discussed above to perfuse an organ to sustain, monitor and/or restore the viability of an organ and/or, to transport and/or store the organ. Preservation of the viability of an organ is important to a successful organ transplant or other use of the organ. Organs are often deprived of oxygen (known as ischemia) for extended periods of time due to disease or injury to the donor body, during removal of the organ from the donor body and/or during storage and/or transport of die organ. The perrusion, • diagnostic, and/or transporter apparatus of the present invention have the ability to detect the cell chemistry of an organ to be transplanted in order to adjust the perfusate and control the cellular metabolism to repair ischemic damage to the organ and to prevent reperfusion injury. One specific outcome of ischemic injury may be apoptosis or programmed cell death. Specific agents and additives provided to an organ by the perrusion, diagnostic and/or transporter apparatus, under conditions controlled by the particular apparatus, may interrupt, decrease and/or reverse apoptosis.
In preferred methods of the present invention, an organ or tissue is treated ex vivo by mechanical, physical, chemical or genetic manipulation and/or modification to treat disease and/or treat damage to and/or enhance the properties of the organ or tissue. An organ or tissue sample may be removed from a first body, modifiedj treated and/or analyzed outside the first body and returned to the first body or transplanted to
a second body or otherwise used. An advantage of the apparatus is that it enlarges the time that an organ may be available for ex vivo treatment, e.g., for hours (e.g. 2,4,6, 8,10,12 or more hours) or even days (e.g. 2,4,6,8,10,12 or more days) or weeks (e.g. 1,2,3,4,5,6,7,8 or more weeks). In preferred embodiments, the perfusion, diagnostic and/or transporter apparatus of the present invention may be used to provide particular solutions or chemicals or agents to an organ or tissue or may be used to perform particular treatments including flushing or washing an organ or tissue with particular solutions or chemicals. Ex vivo treatments may be performed on. tissue or an organ to be transplanted, may be performed on tissue or. an organ that has been removed from a patient and is to be returned to the patient after the desired procedure is performed, or may be performed on tissue or an organ thai is to .be used in substance testing or the Kke. Ex vivo treatments include but are not limited to treatment of tissue or an organ that has endured a period .or periods of ischemia and/or apoxia. Ex vivo treatments may involve performing surgical techniques on an organ, such as cutting and suturing an organ, for example to remove necrotic tissue. Any surgical or other treatment technique that may be performed on tissue or an .organ in vivo may also be performed on tissue or an organ ex vivo. The benefit of such ex vivo treatment may be seen, for example, in the application of radiation or chemotherapy to treat a tumor present in or on an organ, to prevent other portions of the patient from being subjected to extraneous radiation or chemotherapy during treatment The perfusion and transporter apparatus of the present invention also provide additional time for a physician to maintain the tissue or organ before, during and/or after performing a particular technique on the tissue or organ.
Particles trapped in an organ's vasculature may prevent the organ from perfusing properly, or may cause the organ to function improperly, before and/or after transplantation. Perfusion, diagnostic and transporter apparatus of the invention provide ex vivo techniques include perfusing, flushing or washing an organ with suitable amounts of a mrombolytic agent, such as stfeptokinase, to dissolve blood clots that have formed or to prevent the formation of blood clots in an organ and to open the vasculature of the organ. Such techniques are disclosed, for example, in U.S. Patent Application 09/938,597, filed August 25,2000, Attorney Docket No. 106996, the entire disclosure of which is hereby incorporated by reference.
Another cqncern with organ transplantation is the degree to which a recipient may be medicated to prevent organ rejection. In organ transplantation, a further ex vivo technique involves modifying the organ to avoid having it activate the immune system of the donee to prevent or reduce organ rejection and to limit or prevent the need to suppress the donee's immune system before, during and/or after organ transplantation so as to increase the tolerance of the donee to the transplanted organ. Modifications of an organ may, for example, encourage the donee body to recognize the transplanted organ as autologous.
The perfusion, diagnostic and/or transporter apparatus of the present invention may deliver substances such as chemical compounds, natural or modified antibodies, immunotoxins or the like, to an organ and may assist the organ to adsorb, absorb or metabolize such substances to increase the likelihood that the organ will not be rejected. These substances may also mask the organ by blocking, killing, depleting and/or preventing the maturation of allostimulatory cells (dendritic cells, passenger leukocytes, antigen presenting cells, etc.) so that the recipient's immune system does not recognize it or otherwise recognizes the organ as autologous. An organ may be treated just prior to transplantation or may be pretreated hours, days or weeks before transplantation. Such techniques are further described in U.S. Provisional Patent Application No. 60/227,841, filed August 25,2000, Attorney Docket No. 100034, the entire disclosure of which is hereby incorporated by reference.
Substances, such as modified or unmodified ixnmunoglobulin, steroids and/or a solution containing polyethylene glycol (PEG) and an antioxidant such as glutathione, may also be provided to an organ or tissue to mask the organ or to treat the onset of intimal hyperplasia during cryopreservation and/or organ or tissue transplantation. These solutions may be provided to an organ or tissue by perfusion, diagnostic and/or transporter apparatus of the invention. Exemplary such solutions and methods are disclosed in U.S. Patent Application No. 09/499,520, the entire disclosure of which is hereby incorporated by reference.
As discussed above, the present invention involves avoiding damage to an organ during perfusion while monitoring, sustaining arid/or restoring the viability of the organ and preserving the organ for storage and/or transport. However, not all organs that are .donated and perfused according to the exemplary embodiments discussed above, are ultimately transplanted in a donee. After careful analysis, a
determination might be made that the organ might not be suitable for transplanting. The organ, however, should not be unnecessarily discarded. That is, that same organ determined not to be suitable for transplantation may serve another purpose.
According to further exemplary embodiments of this invention, the organ may be perfused with medical fluids for the purpose of screening bioactive or other test agents and providing data for research and development. Since the organ or tissue may be maintained and/or analyzed at or near physiologic parameters, an organ may be tested for the effects of various treatments using substances such as bioactive agents.or drugs, on the organ or tissue, ex vivo. The ex vivo treatment can be utilized for organs of small mammals, large mammals including livestock animals such as cattle, pigs, sheep, and goats, and/or humans. Further, the ex vivo treatment of organs may be used for various organs, such as the kidneys, gut, pancreas, heart and lungs, and may be adapted to more complex organs, such as the liver, having multiple vasculature structures, for example, the hepatic and portal vasculatures of the liver.
The perfusion, diagnostic and transporter apparatus of the invention may be used in conjunction, with the above techniques and methods and/or in conjunction with further techniques and methods, to perform research on an organ or tissue. The various apparatus may preserve and/or maintain the organ and allow the organ to be available for ex vivo use.
During the period in which the organ is preserved and/or maintained, various
activities may be performed on and/or with the organ. For example, the organ, or
multiple organs simultaneously, may be perfused with a fluid containing a substance,
such as one or more bioactive agents or other (e.g. putatively inert agents) to obtain
data regarding the behavior of the substance and/or the organ and/or the interaction
between the substance and the organ.	.	.
For example, as discussed with respect to Figures 28-31 of the present invention, the organ diagnostic system 2800 has a computer 2810 and an analyzer
2820. Connected to both computer 2810 and analyzer 2820 is an organ evaluation instrument 2830 to provide automatic sampling. The systems and method of the invention allow for manual sampling. The organ diagnostic system 2800 provides analysis of an organ and the perfusate. According to embodiments of this invention, perfusion of the organ allows for an organ inflow with a perfusate having a known and predetermined chemistry. This increases the flexibility of types and contents of perfusates that may be delivered such as blood or a synthetic blood carrier or a combination thereof, which may be tailored and/or modified to the particular analysis in process.
Fluid flow within the system is monitored by flow sensor 3020. The fluid is collected and passed via transfer line 2860 to analyzer 2820. The sensed characteristics may be measured by capturing any measurable outflow of the organ, such as venous, bile, mtrahnninal, and urine outflow, and airway measurements from • organs such as the lungs and comparing the sensed characteristics, for example, to characteristics of the inflow or of other actual or idealized organs. The venous outflow may be captured directly and measured or the organ bath may be measured to provide a rough approximation of the fluid characteristics far comparisons.
As discussed above, the organ and medical fluid characteristics .may optionally . be analyzed^ for example, m a separate diagnostic apparatus and/or analyzer as shown in Figs. 28-31.. The sensed characteristics provide researchers a determination of how much of a test substance went into the organ and how much came out. Further, the test substance can be labeled with radioisotopes to help track it and its interaction, if any, with the organ. The radioisotopes can be tracked with instruments such as a mass spectrometer. The result of such sensed characteristics may allow the researcher to analyze organ screening results such as absorption, distribution, metabolism, excretion, phannacoknietics,pharmacodynamics and toxicity may be used to provide data, for example, for drag development in which the data ultimately may help determine drug efficacy and/or toxicity. The sensed characteristics may be analyzed individually or multiple characteristics maybe analyzed to determine the effect upon and/or interaction between the medical fluid containing a substance and the organ.
While, as discussed above, the organ diagnostic system 2800 analyzes the organ and/or the perfusate and/or the interaction there between, data may be generated regarding the outcome of the analysis. As discussed above, Fig. 31 shows a logic
circuit for organ diagnostic system 2800. The computer provides control parameters and receives results and data from the analyzer 2820. The computer further controls features of the present invention such as auto sampling, control over maintenance of sampling and other quality assurance features. Data gathered in accordance with embodiments of the invention provide for efficiency in gathering of data regarding for. example, absorption, distribution, metabolism and excretion (ADME). The data can be generated and displayed in real time, stored, transmitted to a remote site, and/or transferred to a recording medium. Gathering of this type of data allows for scientists and researchers to determine what the substance is doing to the organ and conversely, what the organ is doing to the substance. With this data, researchers are able to contribute to a more effective and safe research process and analyze substances and their effects, if any, on organs prior to testing of such substances on a whole animal level. Additionally, data that may be determined according to the various exemplary embodiments discussed above, includes data relating to presystemic elimination,, absorption and drug delivery, pharmacokinetics and metabolism, phannacodynamics, toxicoldnetics, drug-drug interactions, and the like. It is within the spirit and scope of the present invention that the various exemplary embodiments of this invention allow for the gathering of any data relating to the substances, the organ, and the interaction therebetween.
Various data structures and information connections and analysis sub records can be facilitated to assist in the overall communication and data transfers mat may be beneficial before, during and.after treatment of an organ. The perfusion apparatus, transporter, and organ diagnostic apparatus may be networked to permit remote management and monitoring of the organ, medical fluids and test substances. The information systems may be used to compile data of the organ, the medical fluid, the test substance, and the interaction therebetween. The systems may also be used for compiling data regarding chemical cleanliness and chemical integrity of the systems themselves and providing information regarding trace amounts of chemical in the system. The systems may also provide outcome data to allow for ready research of organ and medical fluid and substance, and information may also be directly recovered from the perfusion, diagnostic or transporter apparatus to monitor such data. Various types of data and information may be grouped into sub-records or subdirectories to assist in data management and transfer. All the sub-records may be
combined to form an overall record, which may be disseminated to or retrievable by physicians, scientists or other organizations for research purposes.
According to exemplary embodiments, an organ data index is generated taking into account the various measured and analyzed factors identified above. The data index may be organ specific, or may be adaptable to various organs. The data index compiles the sensed characteristics and data into a diagnostic summary to be used for making organ treatment and research decisions. The data index may be automatically generated and provided to the researcher or physician. The index is preferably computer generated via a connection to the perfusion apparatus, transporter, and/or organ diagnostic apparatus, m embodiments, the index may be made available over a computer network such as a local area network or the internet for quick comparison, remote analysis and data storage. The organ data index may provide measurements and. normal ranges for each characteristic, such as for absorption, distribution, metabolism, excretion, phannacokinetics, pbannacodynamics and toxicity. Measurements mat are outside the normal range may be indicated visually, e.g., by an asterisk or other suitable visible notation, aurally or by machine perceivable signals. The characteristics give the physician or researcher insight into effects such as the metabolism of the organ, such as stability of the metabolism, consumption of glucose, creation of lactic acid and oxygen consumption.
The methods according to the invention preferably utilize apparatus such as that discussed above to perfuse an organ to sustain, monitor and/or restore the viability of an organ and/or to transport and/or store the organ. Organs are often deprived of oxygen (known as ischemia) for extended periods of time due to disease or injury to the donor body, during removal of the organ from the donor body and/or during storage and/or transport. The perfusion, diagnostic, and/or transporter apparatus of the present invention have the ability to detect the cell chemistry of an organ in order to adjust the perfusate and control the cellular metabolism to repair ischemic damage to the organ and to prevent reperfusion injury. One specific
outcome of ischemic injury may be apoptosis or programmed cell death. Specific agents and additives provided to an organ by the perfusion, diagnostic and/or transporter apparatus, under conditions controlled by the particular apparatus, may interrupt, decrease and/or reverse apoptosis.
Preferred methods according to the present invention focus on three concepts in order to preserve an organ's viability prior to transplant of the organ into a donee body, or prior, to use of the organ for research and development: treating the cellular .mitochondria to maintain and/or restore pre-ischemia energy and enzyme levels, preventing general tissue damage to the organ, and preventing the washing away of or damage to the vascular endothelial lining of the organ.
The mitochondria are the energy source in cells. They need large amounts of oxygen to function. When deprived of oxygen, then- capacity to produce energy is reduced or inhibited. Additionally, at temperatures below 20 °C Hie mitochondria are unable to utiKze oxygen to produce energy. By perfusing me organ with an oxygen rich medical fluid at normothermic temperatures, the mitochondria are provided with sufficient amounts of oxygen so mat pre-ischemia levels of reserve high energy nucleotide, mat is, ATP levels, in the organ reduced by the lack of oxygen are maintained and/or restored along with levels of enzymes mat protect the organ's cells from free radical scavengers. Pyruvate rich solutions, such as that disclosed hi U.S. Patent No. 5,066,579, are incapable of maintaining and/or restoring an organ's pre-ischemia energy levels, and only function in the short term to raise the level of ATP a small amount. That is, organs naturally have significant pyruvate levels. Providing an organ with additional pyruvate will not assist in restoring and/or maintaining the organ's pre-ischemia energy levels if the mitochondria are not provided with sufficient oxygen to produce energy. Thus, the normothermic perfusion fluid may contain pyruvate but may also contain little or no pyruvate. For example, it can contain less man 6 inM of pyruvate, 5 mM, 4 mM, or even no pyruvate. Other known preservation solutions, such as mat disclosed in U.S. Patent No. 5,599,659, also fail to contain sufficient oxygen to restore and/or maintain pre-ischemia energy and enzyme levels.
After maintaining and/or restoring the organ's pre-ischemia energy levels by perfusing the organ with an oxygen rich first medical fluid at normothermic or near-normothermic temperatures (the normothermic mode), the organ may be perfused
with a second medical fluid at hypothermic temperatures (the hypothermic mode). The hypothermic temperatures slow the organ's metabolism and conserve energy during storage and/or transport of the organ. The medical fluid utilized in the hypothermic mode contains little or no oxygen, which cannot be utilized by mitochondria to produce energy below approximately 20°C. The medical fluid may include antioxidants and other tissue protecting agents, such as, for example, ascorbic acid, glutatbione, water soluble vitamin E, catalase, or superoxide dismutase to protect against high free radical formation which occurs at low temperatures due to the reduction in catalase/superoxide dismutase production. Further, various drugs and agents such as hormones, vitamins, nutrients, antibiotics and others may be added to either solution where appropriate. Additionally, vasodilators, such as, for example, peptides, may be added to the medical fluid to maintain flow even in condition of injury.
Prior to any nonnothermic perfusion with the oxygen rich first medical fluid at normothermic temperatures, the organ may be flushed with a medical solution containing little or no oxygen and preferably containing antioxidants. The flushing is usually performed at hypothermic temperatures but can, if desired and/or as necessary, be performed at normothermic or near-normothermic temperatures. Flushing can be followed by one or more of hypothermic perfusion, normothermic perfusion, and/or static storage, in any necessary and/or desired order. In some cases, normothermic
perfusion or hypothermic perfusion may not be necessary.
The normothermic perfusion, with or without prior hypothermic flushing, may also be perfonned on an organ that has already been subjected to hypothermic temperatures under static or perfusion conditions, as well as on normothermic organs.
Tbe organ may be perfused at normothermic or near-normothermic temperatures to sustain, monitor and/or restore its viability prior and/or subsequent to being perfused at hypothermic temperatures for storage and then may be transported without or preferably with hypothermic perfusion. Also, the normothermic perfusion may be performed in vivo prior to removal of the organ from the donor body. Further, the organ may be perfused at normothermic temperatures to sustain, monitor and/or restore its viability prior to being perfused at hypothermic temperatures preparatory to storage and/or transport. Then the organ may be transplanted into a donee body or used for other research while remair'ng at hypothermic temperatures, or it may first
be subjected to normothennic perfusion to help it recover from the effects of storage and/or transport. In the latter case, it may then be transplanted or used at norrnothermic temperatures, or preferably, be hyporaermically perfused again for transplantation at hypothermia temperatures. Alter transplant, fee organ may optionally again be perfused at normothermic temperatures in vivo, or allowed to warm up from the circulation of the donee. Substance research is preferably conducted at nonnothermic temperatures. Further, it is preferable to conduct substance testing in conditions that are close to normal physiological conditions.. For example, temperature, oxygen levels, and the like.
By way of example only, and without being limited thereto, Fig, 16 shows an exemplary diagram of possible processing steps according to the invention. The Figure shows various possible processing steps of multiple organ recovery (MOR) from organ explant from the organ donor through implant in the donee (or other use), including possible WIT (warm ischemia time) and hypoxia damage assessment . Several exemplary scenarios are set form in the following discussion.
For example, in one embodiment of the present invention, the organ can be harvested from the donor under beating heart conditions. Following harvesting, the organ can be flushed, such as with any suitable solution or material including, but not limited to VIASPAN (a preservation solution available from DuPont), other crystalloid solution, dextran, HES (hydroxyethyl starch), solutions described in U.S. Patent Application 09/628,311, filed July 28,2000, the entire disclosure of which is hereby incorporated by reference, or the like. The organ can then be stored statically, for example, at ice temperatures (for example of from about 1 to about 10°C).
In another embodiment, such as where the organ has minimal WIT and minimal vascular occlusion, a different procedure can be used. Here, the organ can again be harvested under beating heart conditions, followed by flushing, preferably at hypothermic temperatures. If necessary, the organ can be stored hi a suitable transporter, at, for example, ice temperatures. Flow to the organ can be controlled by a set pressure maximum, where preset pressure minimum and pressure maximum values control the pulse wave configuration. If necessary to store the organ for a longer period of time, such as for greater than 24 hours, the organ can be placed in the MOR. hi the MOR, a suitable perfusate can be used, such as a crystalloid solution, dextran or the like, and preferably at hypothermic temperatures. Preferably, the
hypothermia temperatures are from about 4 to about 10°C, but higher or lower temperatures can be used, as desired and/or necessary. Preferably, the perfusate solution contains specific markers to allow for damage assessment, although damage assessment can also be made by other known procedures. When desired, the organ can then be returned to the transporter.
As a variation of the above procedure, an organ having minimal WIT and minimal vascular occlusion can be harvested under non-beating heart conditions. Here, the organ can flushed, preferably at hypothennic temperatures and, if necessary, stored for transport in a suitable transporter at, for example, ice temperatures. As above, flow to the organ can be controlled by a set pressure maximum, where preset pressure minimum and pressure maximum values control the pulse wave configuration. The organ can be placed in the MOR, either for extended storage and/or for damage assessment and/or repari. la the MOR, a suitable perfusate can be used, such as a crystalloid solution* dextran or the like, and preferably at hypothennic temperatures. Preferably, the hypothennic temperatures are from about 4 to about 10°C, but higher or lower temperatures can be used, as desired and/or necessary. Preferably, the perfusate solution contains specific markers to allow for damage assessment, although damage assessment can also be made by other known procedures. Following hypothennic perfusion, a second perfusion can be utilized, preferably at normothermic temperatures. Any suitable perfusion solution can be used
for this process, including solutions that contain, as desired, oxygenated media, nutrients, and/or growth factors. Preferably, the normothermic temperatures are from about 12 to about 24°C, but higher or lower temperatures, including about 37°C can be used, as desired and/or necessary. The normothermic perfusion can be conducted for any suitable period of time, for example, for from about 1 hour to about 24 hours. Following recovery from the normomermic perfusion, the organ is preferably returned to a hypothennic perfusion using, for example, a suitable solution such as a crystalloid solution, dextran or the like, and preferably at hypothennic temperatures. When desired, the organ can men be returned to the transporter.
In embodiments where the organ has high WIT, and/or where there is a high likelihood of or actual vascular occlusion, variations on the above processes can be used. For example, in the case where the organ is harvested under non-beating heart conditions, the organ can be flushed as described above. In addition; however, free
radical scavengers can be added to the flush solution, if desired. As above, the organ can be stored for transport in a. suitable transporter at, for example, ice temperatures, where flow to the organ can be controlled by a set pressure maximum, and where preset pressure rnir>i"»"" and pressure maximum values control the pulse wave configuration. The organ can be placed in the MOR, either for extended storage and/or for damage assessment and/or repari. In the MOR, a suitable perfusate can be used, such as a crystalloid solution, dextran or the like, and preferably at hypothermic .temperatures. Preferably, the hypothermic temperatures are from about 4 to about 10°C, but higher or lower temperatures can be used, as desired and/or necessary.' . Preferably, the perfusate solution contains specific markers to allow for damage assessment, although damage assessment can also be made by other known procedures. Fonowmghypothennicperfi^on,asecondperfusioncanbeutiUzed, preferably at normothermic temperatures. Any suitable perfusion solution can be used for this process, including solutions that contain, as desired, oxygenated media, nutrients, and/or growth factors. Preferably, the normothermic temperatures are from about 12 to about 24°C, but higher or lower temperatures can be used, as desired and/or necessary. The normothermic perfusion can be conducted for any suitable period of time, for example, for from about 1 hour to about 24 hours. If desired, and particularly in the event that vascular occlusion is determined or assumed to be present, a further perfusion can be conducted at higher normothermic temperatures, for example of from about 24 to about 37°C This further perfusion can be conducted using a suitable solution that contains a desired material to retard the vascular occlusion. Such materials include, for example, clotbusters such as streptokinase. Following recovery from the normothermic perfusion(s), the organ may be returned to a hypothermic perfusion using, for example, a suitable solution such as a crystalloid solution, dextran or the like, and preferably at hypothermic temperatures. When desired, the organ can then be returned to the transporter.
The organ cassette according to the present invention allows an organ(s) to be easily transported to an organ recipient and/or between organ perfusion, diagnostic and/or portable transporter apparatus, such as, for example, transporter 1900 described above or a conventional cooler or a portable container such as that disclosed in co-pending U.S. Application No. 09/161,919. Because the organ cassette maybe provided
with openings to allow the insertion of tubing of an organ perfusion, transporter or
diagnostic apparatus into the cassette for connection to an organ disposed therein, or may be provided with its own tubing and connection device or devices to allow connection to tubing from an organ perfusion, transporter or diagnostic apparatus and/or also with its own valve, it provides a protective environment for an organ for storage, analysis and/or transport while facilitating insertion of the organ into and/or connection of an organ to the tubing of an organ perfusion, transporter or diagnostic device. Further, the organ cassette may also include a handle to facilitate transport of the cassette and may be formed of a transparent material so the organ may be visually monitored.
The method of the invention will be discussed below in terms of the operation of the apparatus shown in Fig. 2. However other apparatus may be used to perform the inventive method.
As previously discussed, the apparatus discussed above can operate in two modes: a normothermic perfusion mode and & hypothermic perfusion mode. The normothermic perfusion mode will be discussed first followed by a discussion of hypothermic perfusion mode. Repetitive description will be omitted as much as possible.
In the normothermic or near-normothermic perfusion mode, .an organ is perfused for preferably Mi to 6 hours, more preferably V* to 4 hours, most preferably Vi to 1 hour, with a medical fluid maintained preferably within a range of approximately 10°C to 38°C, more preferably 12°C to 35°C, most preferably 12°C to 24°C or 18°C to 24°C (for example, room temperature.22-23°C) by the thermoelectric unit 30a disposed in heat exchange communication with the medical fluid reservoir 10.
As discussed above, in this mode, the medical fluid is preferably an oxygenated cross-linked hemoglobin-based bicarbonate solution. Cross-linked hemoglobin-based medical fluids can deliver up to 150 times more oxygen to an organ per perfusate volume than, for example, a simple University of Wisconsin (UW) gluconate type perfusate. This allows normothermic perfusion for one to two hours to partially or totally restore depleted ATP levels. However, the invention is not limited
to this preservation solution. Other preservation solutions, such as those disclosed in U.S. Patents Nos. 5,149,321,5,234,405 and 5,395,314 and co-pending U.S. Patent Applications Nos. 08/484,601and U.S. Patent Application 09/628,311, filed July 28, 2000, Attorney Docket No. 101311, the entire disclosures of which are hereby incorporated by reference, may also be appropriate.
In the normothermic perfusion mode, the medical fluid is fed directly to an organ disposed within the organ chamber 40 from one or the .other of bags 15a, 15b via tubing 50a,50b,50c or 50d^0e,50c, respectively. The organ is perfused at flow rates preferably within a range of approximately 3 to 5 ml/gram/min. Pressure sensor PI relays the perfusion pressure to the microprocessor 150, which varies the pressure supplied by the pressure source 20 to control the perfusion pressure and/or displays the pressure on the control and display areas 5a for manual adjustment The pressure is preferably controlled within a range of approximately 10 to 100 mm Hg, preferably 50 to 90 mm Hg, by the combination of the pressure source 20 and pressure cuff 15a, 15b in use and the stepping motor/cam valve 65. The. compressor and cuffs provide, gross pressure control. The stepping motor/cam valve 65 (or other variable valve or pressure regulator), which is also controlled by the operator, or by the microprocessor 150 in response to signals from the pressure sensor PI, further reduces and fine tunes the pressure and/or puts a pulse wave on the flow into the organ 60» If the perfusion pressure exceeds a predetermined limit, the stepping motor/earn valve 65 may be activated to shut off fluid flow to the organ 60.
The specific pressures, flow rates and length of perfusion time at the particular temperatures will vary depending on the particular organ or .organs, being perfused. For example, hearts and kidneys are preferably perfused at a pressure of approximately 10 to 100 mm Hg and a flow rate of approximately 3 to 5 ml/gram/min. for up to approximately 2 to 4 hours at normothermic temperatures to maintain and/or restore the viability of the organ by restoring and/or maintaining pre-ischemia energy levels of the organ, and are then preferably perfused at a pressure of approximately 10 to 30 mm Hg and a flow rate of approximately 1 to 2 ml/gram/min. for as long as approximately 72 hours to 7 days at hypothennic temperatures for storage and/or transport. However, these criteria will vary depending on the condition of the particular organ, the donor body and/or the donee body, the intended use, and/or on
the size of the particular organ. One of ordinary skill in the art can select appropriate conditions without undue experimentation in view of the guidance set forth herein.
Effluent medical fluid collects in the bottom of the organ chamber 40 and is maintained within the stated temperature range by the second thermoelectric unit 30b. The temperature sensor T2 relays the organ temperature to the microprocessor 150, which controls the thermoelectric unit 30a to adjust the temperature of the medical fluid and organ bam to maintain the organ 60 at the desired temperature, and/or displays the temperature on the control and display areas 5c for manual adjustment
Collected effluent medical fluid is pumped out by the pump 80 via tubing 81 through the filter unit 82 and men returned to the organ bath. This filters out surgical and/or cellular debris from the effluent medical fluid and men returns filtered medical fluid to act as the bath for the organ 60. Once the level sensor L2 senses that a predetermined level of effluent medical fluid is present in the organ chamber 40 (preferably enough to maintain the organ 60 immersed in effluent medical fluid), additional effluent medical fluid is pumped out by the pump 90 through tubing 91. The temperature sensor Tl relays the temperature of the organ bath to the microprocessor 150, which controls the thermoelectric unit 30b to adjust the temperature of the medical fluid to maintain the organ 60 at the desired temperature and/or displays the temperature on the control and display area 5c for manual adjustment and monitoring.
Next, the recirculated medical fluid is pumped through the CO? scrubber/02 membrane 100. The medical fluid passes over the hydrophobic macroporous membrane with a hydrophilic coating (for example, Hypol) and a low vacuum is applied on the opposite side by activating valve Wj which removes CO2 from the recirculated medical fluid.
Subsequently, a portion of the medical fluid then enters the oxygenator 1 10 (for example, a JOSTRA™ oxygenator) and a portion is diverted therearound. passing via tubing 1 11 1ix>ugh the pH,pO2,pCO2,LDH,T/GST and Tpjotein sensor VI. At this point two gases, preferably 100% oxygen and 95/5% oxygen/carbon dioxide, are respectively placed on the opposite sides of the membrane depending on the pH level of the diverted medical fluid. The gases are applied at a pressure of up to 200 mm Hg, preferably 50 to 100 mm Hg, preferably through a micrometer gas valve GVY The cross-linked hemoglobin-based bicarbonate medical fluid may be formulated to require a pCCfe of approximately 40 mm Hg to be at the mid point (735) of a preferred pH range of 7.25-7.45.
If the medical fluid exiting the oxygenator is within the preferred pH range
(e.g., 725-7.45), 100% oxygen is delivered to the gas exchange chamber, and valve
LVi is then not opened, allowing the perfusate to return to the reservoir 1 0 into the
• bag 15a or 1 5b not in use. If the returning perfusate pH is outside the range on the
acidic side (e.g., less man 7.25), 100% oxygen is delivered to the gas exchange
chamber and valve LVi is then opened allowing the perfusate to return to the organ
chamber 40. Actuation of syringe pump 131 pumps, for example, one cc of a
bicarbonate solution from the bicarbonate reservoir 130, via tubing 132 into the organ
bath. Medical fluids with high hemoglobin content provide significant buffering
capacity. The addition of bicarbonate aids in buffering capacity and providing a
reversible pH control mechanism.	.	.
If the returning perfusate pH is outside the range on the basic side (e.g., greater than 7.25), 95/5% oxygen/carbon dioxide is delivered to the gas exchange chamber and valve LVi is not actuated, allowing the perfusate to return to the bag 15a or 15b not in use. The baglSa or 15b not in use is allowed to degas (e.g., any excess oxygen) through valve GV* When the bag 15a or 15b in use has approximately 250ml or less of medical fluid remaining therein, its respective cuff 16a, 16b is allowed to vent via its respective gas valve GVj, GV2. Then, the respective cuff J6a, 1 6b of the bag 15a or 15b previously not in use is supplied with gas from the compressed gas source 20 to deliver medical fluid to the organ to continue perfiision of the organ.
In the hypothermic mode, an organ is perfused with a cooled medical fluid, preferably at a temperature within a range of approximately 1°C to 15°C, more
preferably 4 °C to 10 °C, roost preferably around 10 °C. The medical fluid is preferably a crystalloid perfusate without oxygenan'on and preferably supplemented with antioxidants and other tissue protecting agents* such as, for example, ascorbic acid, glutathione, water soluble vitamin E, catalase, or superoxide dismutase.
Instead of feeding the medical fluid directly to the organ, the medical fluid may be fed from the reservoir tank 17 via tubing 51 into an intermediary tank 70 preferably having a pressure head of approximately 5 to 40 mm Hg, more preferably 10 to 30 mm Hg, most preferably around 20 mm Hg. Medical fluid is then fed by gravity or, preferably, pressure, from the intermediary tank 70 to the organ 60 along tubing SOc by activating a valve LV6. The level sensor 71 in the intermediary tank 70 is used to control the feed from reservoir tank 17 to maintain the desired pressure head. Because the medical fluid is fed to the organ by gravity or, preferably, pressure, in the hypothermic mode, mere is less perrusion pressure induced damage to the delicate microvasculature of the organ. In fact, the pressure at which the organ is perfused is .limited by fee pressure head to at most 40 mm Hg.
The stepping motor/cam valve 205 (or other variable valve or pressure
regulator) may be arranged on the tubing SOc to provide pulsatile delivery of the
medical fluid to the organ 60, to decrease the pressure of the medical fluid fed into the
organ 60 for control purposes, or to.stop flow of medical fluid into the organ 60, as
described above.	.
Further, in the hypothermic mode,-because the organ 60 has less of a demand for nutrients, the medical fluid may be provided to the organ 60 intermittently (e.g., every two hours at a flow rate of up to approximately 100 ml/rnin.), or at a slow continuous flow rate (e.g., up to approximately 100 ml/min.) over a long period of time. Intermittent perrusion can be implemented in the single pass mode or recirculation mode. The pump 80, filter unit 82 and tube 81 may be used to filter the organ bath along with use of the pH, po2, pCOj, LDH, T/GST and Tprotein sensor; however, because the organ is unable to utilize oxygen at hypothermic temperatures, the oxygenator is not used. If desired and/or necessary, adequate oxygen can be obtained from filtered room air or other suitable source.
Both the perfusate flow and the temperature regulation can be automatically controlled! Such automatic control allows a rapid and reliable response to perrusion conditions during operation. Automatic flow control can be based on the parameters
measured from the system, including the perfusate flow rate, the perfusate pH exiting the organ, the organ inlet pressure or tuned sequences such as pre-selected flow rates or switching between perfusate modes. Preferably, the flow control is based on pressure monitoring of the perfusate inflow into the organ. The benefits of automatic flow control include maintaining proper oxygenadon and pH control while operating under continuous flow or controlled intermittent flow. Thermal control of the thermoelectric devices (TED) can regulate the temperature of the organ cassette or container and the perfusate reservoir. The thermal control is based on thermal measurements made for example by thermistor probes in the perfusate solution or '. inside the organ or by sensors in the TED.
The automatic control is preferably effected by ah interactive control program using easily operated menu icons and displays. The parameters may be prestored for selection by a user or programmed by the user during operation of the system. The control program is preferably implemented on a programmed general purpose computer. However, the controller can also be implemented on a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an ASIC or other integrated circuit, a digital signal processor, a hardwired electronic or logic circuit such as a discrete element circuit, a programmable logic devicesuchasaPLD,PLA,FPGAorPAL,orthelike. In general, any device capable of implementing a finite state machine that is in turn capable of implementing the control process described herein may be used. The control program is preferably implemented using a ROM. However, it may also be implemented using a PROM, an EPROM, an EEPROM, an optical ROM disk, such as a CD-ROM or DVD-ROM, and disk drive or the like. However, if desired, the control program may be employed using static or dynamic RAM. It may also be implemented using a floppy disk and disk drive, a writable optical disk and disk drive, a hard drive, flash memory or the tike.
In operation, as seen in Fig. 15, the basic steps of operation to control perfusion of one or more organs include first inputting organ data. The organ, data includes at least the type of organ and the mass. Then, the program will prompt the user to select one or more types of perfusion modes. The types of perfusion modes, discussed above, include hypothermia perfusion, normothermic perfusion, and sequential perfusion using both normothermic and hypothermic perfusion. When both normothermic and hypothermic perfusion are employed, the .user can select between
medical fluids at different temperatures. Of course, the system includes default values based on previously stored values appropriate for the particular organ. The user may also select intermittent perfusion, single pass perfusion, and recirculation perfusion. Depending on the type of perfusion selected, aerobic or anaerobic medical fluids may be specified.
Next, the type of flow control for each selected perfusion mode is set. The flow control selector selects flow control based on at least one of perrasate flow rate, perfusate pH, organ inlet pressure and timed sequences. In the preferred embodiment, the flow control is based on detected pressure at the perfusion inlet to the organ. The flow of the medical fluid is then based on the selected perfusion mode and flow control.
During operation the conditions experienced by the system, in particular by the organ and the perfusate, are detected and monitored. The detected operating . conditions are compared with prestored operating conditions. A signal can men be generated indicative of organ viability based on the comparison. The various detectors, sensors and monitoring devices are described above, but include at least a pressure sensor, a pH detector, an oxygen sensor and a flow meter.
. The control system may also include a thermal controller for controlling temperature of at least one of the perfusate and the organ. The thermal controller can control the temperature of the medical fluid reservoirs and the organ container by controlling the TEDs. As noted above, temperature sensors are connected to the controller to facilitate monitoring and control.
The above described apparatus and method may be used for child or small organs as well as for large or adult organs with modification as needed of the cassettes and or of the pressures and flow rates accordingly. As previously discussed, the organ cassette(s) can be configured to the shapes and sizes of specific organs or organ sizes.
The apparatus and method can also be used to provide an artificial blood supply to, such, for example, artificial placentas cell cultures, for growing/cloning organ(s).
While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations may be apparent to those skilled in the art Accordingly, the preferred embodiments of the invention as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.
1 . An ex vivo mcthod of determining cffects of at lcast onc tcst substancc or a bioactive
(i) perfusing at least one ex vivo organ that has been determined to be
unsuitable for transplantation with a first medical fluid selected from
the group comprising of blood; blood optionally containing an
antioxidant and/or the test substance; a synthetic fluid; a synthctic fluid
optionally containing an oxygen carrier, the test substance, and/or an
antioxidant; a crystalloid solution; and a crystalloid solution optionally
containing an oxygcn carrier, the test substance, and/or an antioxidant,
to prcscrve the at least one organ;
(ii) exposing the at least one organ to thc at lcast one tcst substancc
sclccted from a group comprising of a chemical compound, at lcast
one of natural and modified antibodies and an immunotoxin; and
(iii) gathering data regarding at least one of the organ, the at least one test
substance, and interaction between the at least one organ and thc at
least one test substance.
2. The mcthod as clairncd in claim I, wherein the exposing step (ii) is carried out by
pcrfusing thc organ with a second medical fluid sclcctcd from thc group
comprised of blood comprising the test substancc and optionally containing an
antioxidant; a synthetic fluid comprising the test substance and optionally
containing an oxygen carricr, and/or an antioxidant; and a crystalloid solution
comprising the test substance and optionally containing an oxygen carrier, and/or
an antioxidant, wherein the second medical fluid contains thc tcst substance.
3. l'he method as claimcd in claim 2, wherein the first and second medical fluids are
the samc or different.
4. The method as claimed in claim I , whercin optionally at lcast one of the at lcast
one organ and an cffluent from thc organ is monitorcd by a sensor that scnscs
characteristics of at least one of the effluent and the at lcast one organ.
5. 'I'he method as claimed in claim 4, which involves generating data comprised of
the sensed characteristics.
6. 'I'he method as claimed in claim 5, wherein the data is generated and displayed in
real time, storcd, transmitted to a remote site, transferred to a rccording medium,
or relayed to a microprocessor for asscssmcnt.
7. The method as claimed in claim 1 or 2, which involves collecting the second
medical fluid that has passed through the at lcast onc organ from an organ bath
and sensing characteristics of the collected medical fluid indicative of the
interaction between the at least one organ and the test substance.
8. 'I'he method as claimed in claim 2, wherein the second medical fluid is blood.
9. 'I'he method as claimed in claim 4, wherein the sensed characteristics relate to at
least one of absorption, distribution, metabolism and excretion.
10. The method as claimed in claim 4, wherein the sensed characteristics relate to at
least one of pharmacokinetics, pharmacokinetics and toxicity.
1 1 . The method as claimed in claim 4, wherein the sensed characteristics relate to at
least one of determining what the substance is doing to the at least one organ and
what the at least one organ is doing to the substance.
12. The method as claimed in claim 1, wherein method of determining effects of a
bioactive agent involves carrying out before performing the step (i) of claim 1, a
step of determining that at least one ex viva organ is unsuitable for transplantation,
and based on a determination that the organ is unsuitable for transplantation,
(i) perfusing said at least one organ with a first medical fluid to preserve
the at least one organ;
(ii) exposing the at least one organ to at least one bioactive agent selected
from antioxidants, tissue protecting substances, drugs, hormones,
vitamins, nutrients, antibodies etc., such as herein described; and
(iii) gathering data regarding at least one of the at least one organ, the at
least one bioactive agent, and interaction between the at least one
organ and the at least one bioactive agent,
13. 'I'he method as claimed in claim 13, which involves the steps of:
(i) perfusing the at least one organ with a first medical fluid; and
(ii) sensing fluid characteristics indicative of organ viability.
14. The method as claimed in claim 1 and 13, which involves, optionally, before the
perfusing step that preserves the at least one organ, the steps of:
(i) restoring and/or maintaining organ viability of the at least one organ,
wherein the restoring and/or maintaining of the organ viability
includes perfusing the at least one organ with at least one medical fluid
such as herein described during at least one perfusion mode to restore
andlor maintain pre-ischemia energy and enzyme levels of the organ;
(ii) sensing tissue and/or fluid characteristics indicative of organ viability
by a scnsor to obtain data; and
(iii) analyzing the data to determine that the at least one organ is unsuitable
15. 'The method as claimed in claim 1 and 13, wherein thc pcrfusing step involvcs
restoring and/or maintaining pre-isehemia energy and enzyme levels of the at
least one organ.
16. The method as claimed in claim 13, wherein the determining step optionally
compriscs:
(i) perfusing the at least one organ with the first medical fluid;
by a sensor to obtain data; and
(iii) analyzing the data to determine that the at least one organ will not be
17. The method as claimed in claim 1, 5 or 13, which optionally involves the steps of:
(i) generating measurement data based on the sensed characteristics or on
the gathered data; and
(ii) comparing the measurement data to characteristics of the at least one
test substance or characteristics of a normal organ.
4711-DELNP-2006-Abstract-(16-04-2009).pdf
4711-DELNP-2006-Abstract-(26-07-2010).pdf
4711-delnp-2006-abstract.pdf
4711-delnp-2006-assignment.pdf
4711-delnp-2006-Claims-(06-03-2013).pdf
4711-DELNP-2006-Claims-(16-04-2009).pdf
4711-DELNP-2006-Claims-(26-07-2010).pdf
4711-delnp-2006-claims.pdf
4711-delnp-2006-Correspondence-Others-(06-03-2013).pdf
4711-DELNP-2006-Correspondence-Others-(07-05-2010).pdf
4711-DELNP-2006-Correspondence-Others-(16-04-2009).pdf
4711-DELNP-2006-Correspondence-Others-(26-07-2010).pdf
4711-delnp-2006-correspondence-others.pdf
4711-delnp-2006-description (complete).pdf
4711-delnp-2006-drawings.pdf
4711-DELNP-2006-Form-1-(16-04-2009).pdf
4711-DELNP-2006-Form-1-(26-07-2010).pdf
4711-delnp-2006-form-1.pdf
4711-delnp-2006-form-18.pdf
4711-delnp-2006-Form-2-(06-03-2013).pdf
4711-DELNP-2006-Form-2-(16-04-2009).pdf
4711-DELNP-2006-Form-2-(26-07-2010).pdf
4711-delnp-2006-form-2.pdf
4711-DELNP-2006-Form-26-(16-04-2009).pdf
4711-delnp-2006-Form-3-(06-03-2013).pdf
4711-DELNP-2006-Form-3-(07-05-2010).pdf
4711-DELNP-2006-Form-3-(16-04-2009).pdf
4711-delnp-2006-form-3.pdf
4711-DELNP-2006-Form-5-(16-04-2009).pdf
4711-delnp-2006-form-5.pdf
4711-DELNP-2006-Others-Document-(16-04-2009).pdf
4711-delnp-2006-pct-101.pdf
4711-delnp-2006-pct-210.pdf
4711-delnp-2006-pct-220.pdf
4711-delnp-2006-pct-237.pdf
4711-delnp-2006-pct-301.pdf
4711-delnp-2006-pct-304.pdf
4711-DELNP-2006-Petition 137-(26-07-2010)-1.pdf
4711-DELNP-2006-Petition 137-(26-07-2010).pdf
4711/DELNP/2006
2570 E. DEVON AVENUE, DES PLAINES, ILLINOIS 60018, U.S.A.
1 BRASSIL, JOHN 1810 MAPLE AVENUE, NORTHBROOK, ILLINOIS 60062, U.S.A.
2 SCHEIN, DOUGLAS 415 WHITEHALL DRIVE, ARLINGTON HEIGHTS, ILLINOIS 60004, U.S.A.
3 CURTIS, CHRISTOPHER G 2 SOUTHCOURT ROAD, PENYLON, CARDIFF, WALES CF23 9DA, UK.
PCT/US2005/003008
1 10/768,167 2004-02-02 U.S.A.