ORIGINAL ARTICLE Heart, Lung and Vessels. 2015; 7(3): 246-255 246 Innovative cold storage of donor organs using the Paragonix Sherpa PakTM devices S.G. Michel1,2, G.M. LaMuraglia II1, M.L.L Madariaga1, Lisa M. Anderson3,4 1Transplantation Biology Research Center, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; 2Department of Cardiac Surgery, Ludwig-Maximilians-University, Munich, Germany; 3Paragonix Technologies, Inc., Braintree, MA, USA; 4Corresponding author: Lisa M. Anderson Heart, Lung and Vessels. 2015; 7(3): 246-255 ABSTRACT Introduction: Currently, the gold standard for donor organ preservation in clinical organ transplantation consists of 3 plastic bags and an ice box. The first plastic bag includes the organ itself immersed in preservation solution (e.g. Celsior). This bag is put in a second bag filled with saline, and then these two are put in a third bag filled with saline which is then put in the ice box. The disadvantage of this method is that the organ usually gets too cold. It has been shown that the theoretical perfect temperature for organ preservation is 4°C - 8°C. While higher temperatures lead to hypoxic injury of the organ because the metabolism is not decreased efficiently, lower temperatures than 4°C increase the risk of cold injury with protein denaturation. In the current study, we investigated a device that keeps the organ temperature consistently in the desired range of 4°C - 8°C and can potentially decrease cold injury to donor organs. Methods: Three different ex vivo studies were performed with the Paragonix Sherpa Pak™ devices: 1) the temperature of the fluid-filled device was measured for up to 30 hours at an outside temperature set at 22°C; 2) the temperature of the fluid-filled device was measured for up to 30 hours at extreme outside temperatures set at -8°C and 31°C; 3) the temperature of a pig heart attached to the device was measured up to 12 hours. Results: All studies showed that the Paragonix Sherpa Pak™ can keep the temperature of the heart consistently between 4° and 8°C. Conclusions: The Paragonix Sherpa Pak™ device may decrease cold injury of donor organs by maintaining the temperature consistently between 4°C and 8°C and therefore may decrease primary graft failure after organ transplantation. Keywords: hypothermic cold storage, heart transplantation, kidney transplantation, organ preservation. INTRODUCTION Successful organ preservation is an important component of transplantation and ensures the maintenance of organ viability until implantation into the recipient. Currently, heart preservation for transplantation is limited to 4 to 6 hours of cold ischemic storage, and longer  periods of isch- Corresponding author: Lisa M. Anderson Paragonix Technologies, Inc. 639 Granite Street, Suite 408 Braintree, MA 02184 e-mail: lisa@paragonixtechnologies.com emia are known to adversely affect survival (1-3). This is in contrast to preservation of the liver, kidney, and  pancreas, which have been successfully preserved for 24 to 36  hours although graft function may be transiently compromised. Following procurement of an organ, ischemia represents the immediate cause of injury. Ischemia initiates a complex injury process that is characterized by the loss of high energy phosphates, the accumulation of intracellular inosine and hypoxanthine, cessation of the Na+-K+ pump, followed by cell swelling, cytosolic calcium increase, Heart, Lung and Vessels. 2015, Vol.7 Innovative cold storage of donor hearts and enzymatic degradation (4-6). In general, lower organ temperatures (0°C to 4°C) maintain high energy phosphates more effectively (7-10). However, temperatures below 2°C significantly increase the risk of cold injury with some proteins denaturing below 0°C. At higher temperatures (8°C to 12°C), organ function is maintained to a greater extent (11, 12). However, at temperatures above 12°C the higher metabolic demand for oxygen leads to irreversible hypoxic injury and thus significantly impairs organ function. Ideally, there should be a temperature range at which these two tendencies can be balanced. The instructions for use of organ preservation solutions state a temperature range between 2-8°C or 4-8°C. Hence, the balance seemingly forms the cornerstone of cold ischemic storage which is hypothermia at 4°C to 8°C with an appropriate cold storage solution. Hypothermia decelerates metabolism and the ionic constituents of the storage solution facilitate rapid cessation of electrical activity. The formulation of the preservation solution is based on three principles: a) hypothermic arrest of metabolism; b) provision of a physical and biochemical environment that maintains viability of the structural components of the tissue during hypothermic metabolic arrest; c) minimization of the effects of reperfusion injury. Hypothermia does not stop metabolism but it slows down biochemical  reaction rates and decreases the rate at which intracellular enzymes degrade essential cellular components necessary for organ viability (13). Most enzymes of hypothermic animals show a 1.5 to 2.0-fold decrease in activity for every 10°C decrease  in temperature. Hypothermia also retards lysis of organelles like lysosomes that, in turn, release autolytic enzymes that cause cell death. Hypothermia remains one of the most important tools used to  preserve organs today. The current gold standard for transporting a donor organ to a recipient for transplant involves storing the organ in organ preservation fluid within sequential plastic bags A B Figure 1 - (A) Full assembly of Paragonix Sherpa Pak™ prototype used in studies. (B) Innermost container that holds the organ. Heart, Lung and Vessels. 2015, Vol.7 247 S.G. Michel, et al. 248 that are placed on ice and transported in a cooler. Some of the potential issues associ- A ated with this method of storage include: a) variability of packaging materials used; b) bioincompatibility of the material that touches the organ; c) tissue injury due to movement/vibration; d) potential uneven cooling of the organ tissue. In a multicenter study of 186 organs, recommended packaging guidelines were tested for their ability to maintain organ temperatures at acceptable temperatures (14). The results showed that all packaging protocols maintained organ temperatures below ±0°C. Paragonix Technologies, Inc. has developed a series of medical devices intended for transport of donor hearts and kidneys to recipients for implant: the Sherpa Pak™ Cardiac Transport System (CTS) and the Sherpa Pak™ Kidney Transport System (KTS). The Sherpa Pak™ System (Figures 1 and 2) is intended to provide a safe, consistent method for cold ischemic storage and transport of donor organs. The Systems are designed to overcome many of the potential issues associated with the current systems used for transport. The Sherpa Pak’s cooling mechanism is based on phase-change material (PCM), which is a substance with a high heat of fusion which is capable of storing and releasing large amounts of energy. The Sherpa Pak’s PCM panels are designed to hold 5°C longer than conventional phase change material cold packs (which undergo phase change at 0°C, and have little heat capacity at 5°C). In addition, the PCM can be placed in direct contact with temperature sensitive products because there is no risk of freezing (please note, however, that the cold panels do not come in direct contact with the donor organ). B C Figure 2 - (A, B,C) Future product design of Sherpa Pak™ CTS and KTS. Heart, Lung and Vessels. 2015, Vol.7 Innovative cold storage of donor hearts The entire System is single-use and does not require power during operation. Management of preservation in the Sherpa Pak™ System is the same for both kidneys and hearts other than that the heart is connect- ed to a connector in the inner hard shell assembly and the kidney is not. We have performed multiple temperature profile studies for varying periods of time, from 4 hours up to 30 hours of storage (Tables 1 and 2). Table 1 - Preconditioning protocol for components of the Sherpa Pak Systems. Component Environment Set Point °C +/-2 Minimum Time to Stabilization (h) Sherpa Pak/Sherpa Pak Shell 4°C 24 Shipper and Packaging Material, 22°C PH5 Blankets 24 PH5 Cold Pack Panels -23°C 24 *PH5, Phase 5 Change material (undergoes phase change at 5°C). Table 2 - Performance data for static hypothermic storage between 4 and 8°C for up to 30 hours using the Sherpa Pak technology at ambient temperature. Sample sizes reflect the number of data points collected at regular interval. Study I.a I.b Device Sherpa Pak CTS Sherpa Pak CTS Study purpose Homogenous cooling between 4-8°C Homogenous cooling between 4-8°C Animal/Organ None None Storage (h) 12 24-30 Individual Test Run Data Center 1 Center 2 Wall Top Inner Bottom Inner Run#1 12 h 12 h 12 h 24 h 30 h 24 h 30 h Sample Size 145 145 145 288 361 288 361 Range (°C) 4.16 – 4.99 4.13 – 4.92 4.20 – 5.12 4.46-5.96 4.46-7.40 4.29-6.42 4.29-6.72 Mean ± St. dev. 4.38±0.26 4.3±0.2 4.42±0.25 4.99±0.71 5.31±0.8 4.78±0.39 5.03±0.63 Run#2 Sample Size 145 145 145 288 361 288 361 Range (°C) 4.4-4.25 4.33-5.25 4.39–5.20 4.27-5.62 4.27-6.6 4.02-5.37 4.02-6.32 Mean ± St. dev. 4.63±0.25 4.58±0.25 4.58±0.23 4.8±0.38 5.1±0.62 4.6±0.38 4.84±0.6 Run#3 Sample Size 145 145 145 288 361 288 361 Range (°C) 4.4-5.17 4.33-4.89 4.27-5.03 4.68-6.97 4.68-7.11 4.48-7.37 4.48-7.37 Mean ± St. dev. 4.68±0.22 4.54±0.15 4.48±0.21 5.03± 0.32 5.3±0.63 4.97±0.38 5.22±0.59 Major Finding Maintenance of temperatures within a Maintenance of temperatures within a range of 4°C range of 4°C-6°C for 12 hours. - 8°C for 30 hours. *Thermocouple locations are designed as follows: Center 1 = One probe (n=1) located in the center of the fluid filled Sherpa Pak. Center 2 = One probe (n=1) located in the center of the fluid filled Sherpa Pak. Wall = one probe (n=1) located at the wall of the inner organ container. Top Inner = One probe (n=1) located at the top of the fluid filled Sherpa Pak. Bottom Inner = One (n=1) probe placed at the bottom of the fluid filled Sherpa Pak. Sherpa Pak CTS, Sherpa Pak Cardiac Transport System. St. dev. = standard deviation. Heart, Lung and Vessels. 2015, Vol.7 249 S.G. Michel, et al. 250 METHODS Once conditioned, the systems were assem- bled in accordance with the instructions for Sherpa PakTM storage. All protocols were in use with the exception that additional ther- conformity with the Guide for the Care and mocouples were placed to monitor tempera- Use of Laboratory Animals published by the ture at various locations within the system. National Institutes of Health 86-23, revised These thermocouples were connected to an in 1985. A total of 14 pig hearts were used external display (the presence of the ther- in this study. Anesthesia was induced with mocouples did not alter the closure of the 4.4 mg/kg Telazol, 2.2 mg/kg xylazine and device). Temperature readings were moni- 0.04 mg/kg atropine intramuscularly and tored and recorded at regular intervals for maintained with isoflurane after endotra- the period of the experiment. Temperature cheal intubation. Median sternotomy was measurements were taken every 5 min in performed and heparin (300 units/kg) was Studies I.a, I.b and III.a, and every 10 s in given intravenously. An aortic root cannula studies II and III.b. When not otherwise in- was inserted and, after cross-clamping the dicated, the storage solution was saline or ascending aorta, 1 L of Celsior® (Genzyme, water. Cambridge, MA, USA) cardioplegia was ad- In order to capture any variations in tem- ministered through the cannula. The heart perature within the device, thermocouples was vented through the left atrial append- were placed in various locations of the de- age, and superior and inferior vena cava, vice. Thermocouple locations are designat- and donor cardiectomy was performed. ed as follows: Center1 = One Probe (n=1) Complete Sherpa Pak™ Cardiac Transport located in the center of the fluid filled Sher- Systems (CTS) and Sherpa Pak™ Kidney pa Pak. Wetted probe = One Probe (n=1) Transport Systems (KTS) were utilized for located at the top of the fluid filled Sherpa the thermal qualification test. Prior to ini- Pak (within fluid). tiating the testing, the components of the Conventional ice storage. The organ was im- Sherpa Pak™ Systems were preconditioned mersed in solution and packaged in a first according to the instructions for use pro- plastic bag. This first bag was then placed vided with the device (Table 1). into a second bag filled with solution. This The Sherpa Pak™ System consists of mul- assembly was then placed into a third so- tiple components: lution-filled bag and placed onto crushed 1) an outer transport shipper which con- ice in an ice chest. When not otherwise in- tains various non-ice-based temperature dicated, the storage solution was saline or controlled packaging elements; water. 2) an inner and outer hard shell assembly Study design. Three different ex-vivo stud- (i.e. Sherpa Pak™/Sherpa Pak™ Shell) ies have been performed with the Parago- which provides a double, rigid barrier nix Sherpa Pak™ devices: shipper in which the organ is immersed 1. Study I: The temperature of the fluid and suspended in a cold storage fluid filled device was measured for up to 30 cleared for use in storing and transport- h at an outside temperature set at 22°C ing donor organs; (Study I.a and Study I.b, Table 2). 3) an off-the-shelf temperature data logger 2. Study II: The temperature of the fluid that monitors and displays the tempera- filled device was measured for up to 30 ture of the organ during transport; h at extreme outside temperatures set at 4) an off-the-shelf timer that displays -8°C and 31°C (Study II, Table 3). elapsed time during transport. 3. Study III: The temperature of pig hearts Heart, Lung and Vessels. 2015, Vol.7 Innovative cold storage of donor hearts attached to the device was measured for up to 12 h (study III.a and III.b; Table 4). RESULTS Sherpa Pak™ can keep the temperature of the preservation solution between 4-8°C for a period of up to 30 hours.The first part of study I (Table 2) demonstrated in three separate test runs that all temperatures recorded from the individually placed temperature probes remained below the 8°C upper limit of the design specification through four hours. Temperatures were recorded every 5 min, providing 145 readings. Moreover, all recorded temperatures from all individually placed temperature probes remained below the 8°C upper limit through 12 hours of Table 3 - Performance data for static hypothermic storage between 4 and 8°C for up to 30 hours using the Sherpa Pak technology with two 1 hour excursions to extreme hot and cold temperatures. Study II Device Sherpa Pak KTS Study purpose Homogenous cooling between 4-8°C Animal/Organ None Storage (h) 24-30 Testing Conditions Temperature profile “Hot” run: 1h @ 22°C, 1h @ 31°C, 15h @ 22°C, 1h @ 31°C, then 22°C until 30h “Cold” run: 1h @ 22°C, 1h @ -8°C, 15h @ 22°C, 1h @ -8°C, then 22°C until 30h Individual Test Run Data Wetted probe Run#1 “Hot” Run #1 24 h 26 h 28 h 30 h Sample Size 8641 9361 10081 10801 Range (°C) 4.2-5.7 4.2-5.9 4.2-6.5 4.2-7.2 Mean ± St. dev. 4.65±0.41 4.74±0.49 4.84±0.60 4.97±0.77 Run#2 “Hot” Run #2 Sample Size 2881 121 3361 3601 Range (°C) 6.6-7.5 6.6-8.0 6.6-8.6 6.6-9.2 Mean ± St. dev. 6.96±0.29 7.02±0.35 7.11±0.47 7.23±0.64 Run#3 “Cold” Run #1 Sample Size 8641 9361 10081 10801 Range (°C) 4.6-6.2 4.6-6.6 4.6-7.2 4.6-7.8 Mean ± St. dev. 5.53±0.33 5.59±0.39 5.68±0.50 5.80±0.66 “Cold” Run #2 Sample Size 2881 3121 3361 3601 Range (°C) 4.6-6.7 4.6-7.3 4.6-7.8 4.6-8.6 Mean ± St. dev. 5.93±0.33 6.01±0.43 6.12±0.57 6.26±0.76 Major Finding Maintenance of temperatures within a range of 4°C - 8°C for 24 h *Thermocouple locations are designed as follows: Center 1 = One Probe (n=1) located in the center of the fluid filled Sherpa Pak. Wetted probe = One Probe (n=1) located at the top of the fluid filled Sherpa Pak (within fluid). Sherpa Pak CTS, Sherpa Pak Cardiac Transport System. St. dev. = standard deviation. Heart, Lung and Vessels. 2015, Vol.7 251 S.G. Michel, et al. 252 Table 4 - Summary of animal studies of static hypothermic storage between 4 and 8°C using the Sherpa Pak technology. Study III.a III.b Device Sherpa Pak CTS Sherpa Pak CTS Study purpose Homogenous cooling between 4-8°C; comparison to con- Homogenous cooling between 4-8°C ventional ice storage method when the pig heart is stored in Celsior® solution. Animal/Organ Pig/Heart Pig/Heart Storage (h) 4, 12 4, 6, 8, 12 Sample size per group N=1 N=3 (4h); N=1 (6h); N=1 (8h); N=7 (12h) Ambient temperature 22°C 18-22°C Individual Test Run Data Run Sherpa 4h (12 h) Ice 4 h (12 h) 4 h 6 h 8 h 12 h Thermocouple Left ven- Heart apex Left ven- Heart apex Fluid location tricle tricle Fluid Fluid Fluid Run #1 Sample Size 49 (145) 49 (145) 49 (145) 49 (145) 2775 2114 2846 8513 Range (°C) 6.94-8.1 6.71-6.98 0.98-8.1 0.24-2.29 3.8-4.8 (6.32-8.1) (6.54-6.98) (0.23-8.1) (-0.09-2.29) 3.4-4.9 3.8-5.1 5.2-6.5 Mean (°C) ± St. dev. Run #2 Sample Size Range (°C) Mean (°C) ± St. dev. Run #3 Sample Size Range (°C) Mean (°C) ± St. dev. Run #4 Sample Size Range (°C) Mean (°C) ± St. dev. Run #5 Sample Size 7.27±0.23 6.81±0.13 3.08±1.95 0.97±0.59 4.69±0.17 4.74±0.28 4.93±0.19 6.10±0.25 (6.80±0.39) (6.54±0.23) (1.29±1.71) (0.33±0.57) 2815 6.0-7.3 7.15±0.26 8291 3.2-5.3 5.21±0.19 2783 4.8-6.2 5.99±0.30 8474 4.0-5.7 5.54±0.23 8518 3.7-6.2 5.84±0.21 4268 Heart, Lung and Vessels. 2015, Vol.7 Innovative cold storage of donor hearts Range (°C) 5.5-6.7 Mean (°C) ± St. dev. Run #6 6.40±.19 Sample Size 4232 Range (°C) 6.2-7.1 Mean (°C) ± St. dev. Run #7 6.64±0.32 Sample Size 4250 Range (°C) 4.9-6.0 Mean (°C) ± St. dev. 5.65±0.19 Major finding Maintenance of temperatures within a range of 4°C Maintenance of temperatures within a range of - 8°C for 12 hours when system is loaded with a pig 4°C - 8°C for up to 12 hours when system is heart loaded with a pig heart *Sherpa Pak CTS, Sherpa Pak Cardiac Transport System. St. dev. = standard deviation. experimentation. Most importantly, the experiment verified that the fluid within the Sherpa Pak™ (in which the donor heart is immersed) was maintained between 4°C and 6°C (as measured by the three probes placed within the fluid; two at center of the container, one against the side wall) which is within the accepted 4°C - 8°C. The second part of study I (Table 2) demonstrated that all temperatures recorded from the individually placed temperature probes remained below the 8°C upper limit through 30 hours. Temperatures were recorded every 5 min, providing up to 361 readings. Most importantly, the experiment verified that the fluid within the Sherpa Pak™ (in which the donor organ is immersed) was maintained between 4°C and 8°C (as measured by the temperature probes placed within the fluid). Sherpa Pak™ consistently maintains fluid temperature at 4-8°C despite extreme fluctuations in ambient temperature. Results of the four separate test runs (two test runs each at cold or hot temperatures) of the ex- periment (study II: Table 3) demonstrated that the storage solution remained below the 8°C upper limit of the design specification through 24 hours. Temperatures were recorded every 10 s, providing up to 10801 readings. Interestingly, in the second warm temperature test run, the cold storage solution wasn’t preconditioned according to its instructions for use and the starting temperature of the fluid was 7ºC (versus 6ºC according to manufacturer IFUs). Even with this slightly elevated temperature, the Sherpa Pak™ system was capable of maintaining temperature throughout the 24 hour period. Sherpa Pak™ can maintain the temperature at 4-8°C when the system is loaded with a pig heart. Both the Sherpa Pak™ CTS as well as the conventional ice storage demonstrated their ability to cool and maintain temperature throughout the experimental period. However, the “ice system” cooled the heart based on the two thermocouples to temperatures as low as 0°C at the apex closest to the ice, and <1°C inside the left ventricle Heart, Lung and Vessels. 2015, Vol.7 253 S.G. Michel, et al. 254 of the pig heart. The experiment verified range of 4°C - 8°C throughout 30 hours of that the fluid within the Sherpa Pak™ (in monitoring. Based upon the results of the which the donor organ is immersed) was testing, we conclude that the Sherpa Pak™ maintained between 4°C and 8°C (study devices are designed such that they can re- III, table 4). Temperatures were recorded liably maintain a clinically acceptable stor- every 5 min, providing up to 145 readings age temperature for the donor organ. in study III.a, and every 10 s, providing up It is commonly accepted that the 4°C - to 10801 readings in study III.b 8°C temperature range is the best balance Results of 12 temperature test runs dur- for preservation of high energy phosphate ing pig heart storage demonstrated that the stores, minimization of cold injury, and Sherpa Pak™ CTS was able to maintain fluid preservation of post-transplant function temperatures within a range of 4-8°C when (15). Although temperatures below 4°C fully loaded with a pig heart (Table 4). offer superior maintenance of high energy phosphates, temperatures below 2°C sig- DISCUSSION nificantly increase the risk of cold injury and frostbite (8, 9). The results of the stud- The purpose of this study was to verify ies demonstrated that the Paragonix Sherpa whether the Paragonix Sherpa Pak™ de- Pak™ device was capable of maintaining a vice was capable of maintaining the de- very consistent temperature within the 4°C sired temperature for organ storage which - 8°C temperature range through twelve lies between 4 and 8°C. Several studies hours. The conventional ice storage was were performed during which all system also very effective at cooling and maintain- components including the cold storage so- ing temperature of the heart through six lution were preconditioned according to hours; however, the data show that tem- the instructions for use. In certain studies, peratures encountered with this system exterior conditions remained constant as approached 0°C for the last few hours of the System will always be under the direct the experiment, thus increasing the poten- supervision of medical personnel during tial for issues with the donor heart. These transport and not anticipated to be exposed data compared well to a multicenter study to uncontrolled temperatures or environ- on transport temperature of organs (14). mental conditions. The purpose of study II, Studying 186 organs, the average organ in which exterior conditions were changed temperature during transportation was to either high temperatures (31°C) or low below 2°C, and after 6 hours below 0°C. temperatures (-8°C) for 1 hour twice dur- Based upon these test results, it appears ing 30 hours of monitoring, was to chal- that the Paragonix Sherpa Pak™ Transport lenge the system at two extreme tempera- System is effective at maintaining the tem- tures. perature of the organ in the optimal tem- The results of the testing verified that the perature range. design of the Sherpa System was able to While the study investigated ambient tem- maintain the fluid in which the donor organ peratures that might be expected in a clini- is contained within the clinically accept- cal situation and temperature excursion able range of 4°C - 8°C through 24 hours, that may occur during organ transport, even when challenged to high and low tem- a limitation of the study is that measure- peratures. When ambient temperatures ments were taken in a research setting, were kept constant (at 22°C) the System which may not entirely reflect the clinical was able to maintain temperatures within a setting. Heart, Lung and Vessels. 2015, Vol.7 Innovative cold storage of donor hearts CONCLUSION The Paragonix Sherpa Pak™ device may decrease cold injury of donor organs by maintaining the temperature consistently between 4°C and 8°C and therefore may decrease primary graft failure after organ transplantation. REFERENCES 1. Keck BM, White R, Breen TJ, Daily OP, Hosenpud JD. Thoracic organ transplants in the United States: a report from the UNOS/ISHLT Scientific Registry for Organ Transplants. United Network for Organ Sharing. International Society for Heart and Lung Transplantation. Clin Transpl. 1994; 37-46. 2. Stehlik J, Edwards LB, Kucheryavaya AY, Benden C, Christie JD, Dipchand AI, et al. 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The importance of temperature. J Thorac Cardiovasc Surg 1992; 104: 1618-1624. 13. Buckberg GD. Myocardial temperature management during aortic clamping for cardiac surgery. Protection, preoccupation, and perspective. J Thorac Cardiovasc Surg. 1991; 102: 895-903. 14. Horch DF, Mehlitz T, Laurich O, Abel A, Reuter S, Pratschke H, et al. Organ transport temperature box: multicenter study on transport temperature of organs. Transplant Proc. 2002; 34: 2320. 15. Jahania MS, Sanchez JA, Narayan P, Lasley RD, Mentzer RM Jr. Heart preservation for transplantation: principles and strategies. Ann Thorac Surg. 1999; 68: 983. 255 Cite this article as: Michel SG, LaMuraglia II GM, Madariaga MLL, Anderson LM. Innovative cold storage of donor organs using the Paragonix Sherpa PakTM devices. Heart, Lung and Vessels. 2015; 7(3): 246-255. Source of Support: This work was in supported by a Phase I SBIR grant (1R43HL115852-01) awarded to Paragonix Technologies Inc. Disclosures: L.M. Anderson is an employee of Paragonix Technologies, Inc. Heart, Lung and Vessels. 2015, Vol.7