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301: Increasing organ availability in heart transplantation with the use of warm blood perfusion for organ preservation
The Journal of Heart and Lung Transplantation Volume 26, Number 2S
anti-fungal therapy post transplant for patients colonized with S.apiospermum can result in a favourable outcome. 299 STENOTROPHOMONAS MALTOPHILIA IN LUNG TRANSPLANTATION K.J. McAnally,1 V.G. Valentine,1 R.W. Bonvillain,2 G.A. Lombard,1 S.G. LaPlace,1 L. Seoane,1 D.E. Taylor,1 1Lung Transplantation, Ochsner Medical Center, New Orleans, LA; 2Medicine and Genetics, LSU Health Sciences Center, New Orleans, LA Purpose: Stenotrophomonas maltophilia (SM), a gram negative rod commonly seen in cystic fibrosis pts, is emerging as a pathogen in transplant recipients. Recovery of SM from the respiratory tract (RT) of pts with distorted lung architecture or recent antibiotic exposure often represents colonization rather than true infection (INF). The incidence and clinical outcome of SM infection in lung transplant recipients have not been well described. This report analyzes the clinical spectrum of SM and its relationship with BOS in lung transplantation (LT). Methods and Materials: We retrospectively analyzed 202 LT pts who underwent LT between 11/90 and 11/05. All cases of SM INF were identified. INF was defined by positive BAL, sputum or blood cultures with appropriate clinical findings. Presence of an infiltrate on chest radiography confirmed lower RT INF. Results: We confirmed 47 SM INFs in 33 LT pts during a median observation period of 2.7 years (range 0-13.6). Sites of INF included: lower RT (45%), upper RT (40%) and blood (15%). SM alone was isolated from 53% and 57% of the RT and blood cultures that grew SM, respectively. The 1-, 3-, 5-, and 7-year cumulative incidences of SM INF after LT were 9%, 15%, 22%, and 28%, respectively. Although, the occurrences of SM RT INFs were evenly distributed pre- and postBOS, the 7-year BOS-free survival was 7% vs 35% in those without SM, (p ⬍ 0.01). Moreover, the 7-year cumulative incidence of SM INF in those with BOS was 37% vs 14% in those without BOS, (p ⫽ 0.05). More SM INFs after BOS were seen in emphysema pts, (0.12 ⫾ 0.37 INFs/pt vs 0.09 ⫾ 0.53 in the non-emphysema pts, [p ⫽ 0.05]). Of note, SM INFs were not more common in cystic fibrosis recipients. Conclusions: SM infections develop in 16.4% of LT recipients. These organisms are commonly isolated in pure culture and represent true pathogens. A relationship between these pathogens and the damaged BOS lung exists. Isolation of SM from LT recipients with and without BOS warrants treatment. Whether SM heralds the onset of BOS requires further study. 300 EX-VIVO EVALUATION OF DONOR HEARTS IN THE BEATING FUNCTIONING STATE IN THE ORGAN CARE SYSTEM (OCS) S. Schulte-Eistrup,1 U. Schulz,1 A. Elbetanony,2 A. El-Banayosy,1 G. Tenderich,1 R. Koerfer,1 1Dept. of Thoracic & Cardiovascular Surgery, Heart Center NRW, Bad Oeynhausen, Germany; 2 TransMedics Inc., Andover, MA Purpose: Maintaining donor hearts on OCS in a beating state, enables ex-vivo evaluation of cardiac & metabolic functions of donor hearts. This analysis investigates the relationship between ex-vivo cardiac and metabolic parameters and post transplant outcomes. Methods and Materials: 10 hearts were maintained on OCS for heart transplantation in our institution.Perfusion Parameters (PP) (CF, AOP, HR, PAP, SvO2) were monitored & recorded on the OCS during preservation.Serial arterial and venous serum lactate samples were analyzed at 10 minutes post instrumentation on OCS,various time points throughout preservation and at time of cardioplegic arrest prior to transplantation.
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Results: 6 hearts were transplanted with excellent post transplant outcomes.These hearts exhibited stable PP on OCS throughout preservation (585⫾64ml/min, 51⫾19mmHg, 79⫾15Bpm, 84⫾3%) and downward trend of lactate from initial to end measurements (1.8⫾0.4mg/dl, 1.5⫾0.2mg/dl). 4 hearts showed abnormally high and rising AOP on OCS (79.1⫾24mmHg) with significant increase of serum lactate from initial to end (3.2⫾2mg/dl to 9.2⫾3mg/dl) indicating cardiac ischemia.1 of the 4 was transplanted & suffered primary failure. 3 hearts were rejected for transplantation based on the above PM & lactate parameters.Evaluation of these hearts revealed the following: 1 heart was subjected to large dose of catecholamine during blood collection for OCS resulting in toxic levels in the circulating blood;1 heart showed CAD on histopath that was undetected at donor evaluation; 1 heart was subjected to prolonged hypoperfusion in the donor due to anaphylactic shock with significantly elevated serum creatinine at time of harvest;and 1 heart was found to have toxic doses of catecholamines of undocumented origin in the circulating blood. Conclusions: Ex-vivo assessment of functioning donor organs provides a new and potentially important quality tool for the surgeon.In our experience, serum lactate measurement is a sensitive indicator for the adequacy of perfusion of donor heart on OCS and immediate posttransplant outcomes. 301 INCREASING ORGAN AVAILABILITY IN HEART TRANSPLANTATION WITH THE USE OF WARM BLOOD PERFUSION FOR ORGAN PRESERVATION G. Tenderich,1 U. Schulz,1 T. Khayal,2 S. Schulte-Eistrup,1 R. Koerfer,1 1Thoracic and Cardiovascular Surgery, Heart Center North Rhine-Westphalia, Bad Oeynhausen, Germany; 2 TransMedics, Inc., Andover, MA Purpose: Marginal donors, pulmonary hypertension and transportation time remain limiting factors in cardiac transplantation (HTx). We report on our experience with The Organ Care System (OCS) in such borderline cases. Results: Case 1: A catecholamine dependent (dopamine 3,3/milrinone 0,68 g/kg/min) 54 y. o. female pt. with dilated cardiomyopathy (DCM) received an organ from a 42 y.o. female donor multiply rejected because of status post MOF including ARDS, stomach perforation, peritonitis and MOF. Echo showed RV hypokinesia and norepinephrine (0,02 g/kgBW/min) was needed to maintain stable hemodynamics. OCS perfusion time was 180 min. Weaning from bypass (CPB) with dopamine 4.3 g/kg/min and milrinone 0,34 g/kg/min. Echocardiography on po day 1 demonstrated normal RV function and an LV-EF of 75%. The pt. left the ICU after 24 hrs. & was discharge at pod 27 with good RV function (RV-FS 38%). Case 2: A 55 y.o. female pt. with DCM and sarcoidosis was pretreated with PDE-III inhibitors, iv epoprostenol, inhaled iloprost and bosentan for severe pulmonary hypertension (PVR 6 WE; TPG 18 mmHg). Htx of a 21 y.o. male donor organ was performed after OCS perfusion time of 256 min. Weaning from CPB without epoprostenol, reduced milrinone and slightly increased dopamine. Mechanical ventilation weaned after 5 hrs. The pt. left the ICU after 32 hrs. and was discharged on pod 22 with PVR 2,2 WE and TPG 4 mmHg. Case 3: A 34 y.o from Slovenia was transplanted in a 60 y.o. recipient with DCM after 326 min of OCS perfusion. In contrast to similar cold ischemic times the weaning from CPB was completely uneventful. Dopamine (4.9 g/kg/min) and milrinone (0,11 g/kg/ min) support was needed for 42 hrs. The patient left the ICU after 2 days and was discharged on po day 22 with excellent LV function (EF 76%). Conclusions: OCS perfusion has the potential of ameliorating the course in cases of marginal donor organs and pulmonary hyperten-
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sion. Extended transportation times also appear possible without impact on clinical outcomes. 302 FEMALE GENDER IS ASSOCIATED WITH CARDIAC DYSFUNCTION IN BRAIN DEAD ORGAN DONORS K.K. Khush,1 R.L. Menza,2 W.D. Babcock,2 C.W. Hoopes,3 J.G. Zaroff,1 1Medicine/Cardiology, University of California, San Francisco, CA; 2California Transplant Donor Network, Oakland, CA; 3Surgery, University of California, San Francisco, CA Purpose: In the setting of acute subarachnoid hemorrhage, female gender is associated with left ventricular (LV) systolic dysfunction and regional wall motion abnormalities (RWMA). This form of neurocardiogenic injury, which is often reversible, is likely due to excessive myocardial catecholamine release. We studied the association between female gender and LV dysfunction in a diverse population brain dead patients evaluated for organ donation. Methods and Materials: All potential cardiac organ donors managed by the California Transplant Donor Network between 2002-03, aged 14-60 years and without coronary artery disease, were included in this analysis. Univariate predictors of LV dysfunction were identified and multiple regression analysis was used to assess the relative independent contribution of each predictor. Results: 197 potential donors (122 male, 75 female, mean age 38 ⫾ 14 years) were studied. The cause of brain death was trauma in 64 potential organ donors, and non-traumatic (cerebrovascular death, anoxia, or other) in 133 potential donors. 12% had LV systolic dysfunction (LV ejection fraction⬍50%) and 15% had RWMA by echocardiography. Univariate analyses revealed that female gender, smaller donor size (weight, height, and body-mass index), and higher heart rate were independent predictors of LV systolic dysfunction and RWMA. Donor cause of death, cardiopulmonary resuscitation, and history of cocaine or methamphetamine use, smoking, and hypertension did not predict LV dysfunction or RWMA. In a multivariable model, after adjusting for donor age, size, and heart rate, female gender remained a strong independent predictor of LV systolic dysfunction (OR 5.75, 95% CI 1.76-18.76, p⫽0.004) and RWMA (OR 5.73, 95% CI 2.02-16.20, p⫽0.001). Conclusions: Female gender is associated with the presence of LV systolic dysfunction and RWMA in brain dead organ donors. Further studies assessing the reversibility of LV dysfunction and suitability of these organs for transplantation are required. 303 OXYGENATED PERFUSION OF DONOR HEARTS REDUCES ISCHEMIC DAMAGE DURING PRESERVATION A. Halldorsson,1 H.A. Goolsby,2 M.D. Tomison,2 S.D. Prien,2 1 Surgery, Texas Tech University Health Sciences Center, Lubbock, TX; 2Obstetrics and Gynecology, Texas Tech University Health Sciences Center, Lubbock, TX Purpose: It is well documented that ischemic cold storage of hearts during transplantation procedures can cause damage to the organ at the cellular level. The damage manifests itself as structural changes in both the tissue and subcellular organelles, and limits the time the heart can be stored to a few short hours. Recently, a number of groups have proposed perfusion of the hearts during storage to supply oxygen and other nutrient during the storage process as a means of combating ischemic damage. However, concerns have been raised that the use of crystalloid solutions will lead to edema of the organ and further damage to tissue and cells. The objective of the present study was to compare heart tissue at the cellular and subcellular levels from cadaver hearts that had been stored using a
The Journal of Heart and Lung Transplantation February 2007
traditional cold, static method verses a new organ preservation system (LifeCradle™, Organ Transport Systems; Frisco, TX) which perfuses an oxygenated solution through the organ while maintaining the temperature at 5° C. Methods and Materials: Twenty-six cadaver hearts were extracted from swine donors within 5 minutes of euthanasia in a slaughter facility. The hearts were flushed with heparinized cardioplegic solution and weighed prior to storage. The hearts were then stored in using either the standard ice-slurry methodology (n⫽9; SIS) for 4-8 hrs or in the new preservation device (n⫽17; LC) for times of 4-14 hrs. At the end of the storage time the hearts were weighed again to establish weight gain and tissue samples collected for ultrastructural analysis using TEM. Results: Results indicated no significant increased weight gain in the LC as compared to SIS (12.9 gm vs. 12.3 gm respectively; p⫽.954) even after 3X longer is storage. Further, ultrastructural damage was minimal in hearts from the LC as compared to the control as assessed by a pathologist blinded to tissue source. Conclusions: These data suggest the LC may be a superior storage environment over SIS and suggest further transplant studies are warranted. Grant support and supply of experimental instrument; Organ Transplant Systems. 304 INTERMITTENT ANTEGRADE CARDIOPLEGIA: IMPLICATIONS FOR DONOR HEART PRESERVATION A.L. Rivard,1,3 C.M. Swingen,4 F.D. Kamdar,5 Z. Demorest,5 E.J. Cordova,5 J.E. Foker,2 M. Jerosch-Herold,,6 R.W. Bianco,3 R. John,3 1Radiology, University of Florida, Gainesville, FL; 2 Surgery, Division of Cardiovascular and Thoracic, University of Minnesota, Minneapolis, MN; 3Surgery, University of Minnesota, Minneapolis, MN; 4Radiology, University of Minnesota, Minneapolis, MN; 5Medical School, University of Minnesota, Minneapolis, MN; 6Radiology, Oregon Health Sciences Center, Portland, OR Purpose: The scarcity of donor hearts limits the growth of heart transplantation. Currently, donor heart preservation techniques allow for only 4-6 hours of ischemia. Prolongation of this time would allow procurement at greater distances, thus reducing wastage. Because pH is directly related to the degree of ischemia, we hypothesized that administration of cardioplegia to the isolated heart would improve microvascular perfusion. Methods and Materials: Porcine hearts were excised, flushed with a ribose based cardioplegic solution and stored at 9.2 °C for 6.1 ⫾ 0.6 hours. Control hearts (Group 1, n ⫽ 9) were stored without receiving any additional perfusion, whereas experimental hearts (Group 2, n ⫽ 8) received an intermittent antegrade bolus (150 ml, q30 min, 150 ml/min). Ph probes were placed into the LV and RV myocardium for continuous measurement. At the end of the preservation, contrast enhanced, T-1 weighted MR imaging was performed in the short axis view. Peak contrast enhancement was used as a measurement of viable microvasculature. Wet/dry weight was then measured. Results: In both groups, myocardial LV pH decreased exponentially in all hearts immediately following flushing. In Group 1 hearts, pH decreased to 6.2 ⫾0.2. As opposed to Group 2 hearts; pH at the end of 6 hours was 6.7 ⫾0.3. The mean pH difference was of 0.55 (p ⬍ .005). Ph measurements of the RV had a similar response to perfusion (p ⫽ .02). MR contrast imaging showed no differences in peak contrast enhancement in the 2 groups, Group 1 ⫽ 62%, Group 2 ⫽ 40% (p ⫽ .08). There was also no difference of the wet/dry weights. Conclusions: Although microvascular perfusion was not significantly different between the two groups in this study; we demonstrated that intermittent perfusion maintains a significantly higher
anti-fungal therapy post transplant for patients colonized with S.apiospermum can result in a favourable outcome. 299 STENOTROPHOMONAS MALTOPHILIA IN LUNG TRANSPLANTATION K.J. McAnally,1 V.G. Valentine,1 R.W. Bonvillain,2 G.A. Lombard,1 S.G. LaPlace,1 L. Seoane,1 D.E. Taylor,1 1Lung Transplantation, Ochsner Medical Center, New Orleans, LA; 2Medicine and Genetics, LSU Health Sciences Center, New Orleans, LA Purpose: Stenotrophomonas maltophilia (SM), a gram negative rod commonly seen in cystic fibrosis pts, is emerging as a pathogen in transplant recipients. Recovery of SM from the respiratory tract (RT) of pts with distorted lung architecture or recent antibiotic exposure often represents colonization rather than true infection (INF). The incidence and clinical outcome of SM infection in lung transplant recipients have not been well described. This report analyzes the clinical spectrum of SM and its relationship with BOS in lung transplantation (LT). Methods and Materials: We retrospectively analyzed 202 LT pts who underwent LT between 11/90 and 11/05. All cases of SM INF were identified. INF was defined by positive BAL, sputum or blood cultures with appropriate clinical findings. Presence of an infiltrate on chest radiography confirmed lower RT INF. Results: We confirmed 47 SM INFs in 33 LT pts during a median observation period of 2.7 years (range 0-13.6). Sites of INF included: lower RT (45%), upper RT (40%) and blood (15%). SM alone was isolated from 53% and 57% of the RT and blood cultures that grew SM, respectively. The 1-, 3-, 5-, and 7-year cumulative incidences of SM INF after LT were 9%, 15%, 22%, and 28%, respectively. Although, the occurrences of SM RT INFs were evenly distributed pre- and postBOS, the 7-year BOS-free survival was 7% vs 35% in those without SM, (p ⬍ 0.01). Moreover, the 7-year cumulative incidence of SM INF in those with BOS was 37% vs 14% in those without BOS, (p ⫽ 0.05). More SM INFs after BOS were seen in emphysema pts, (0.12 ⫾ 0.37 INFs/pt vs 0.09 ⫾ 0.53 in the non-emphysema pts, [p ⫽ 0.05]). Of note, SM INFs were not more common in cystic fibrosis recipients. Conclusions: SM infections develop in 16.4% of LT recipients. These organisms are commonly isolated in pure culture and represent true pathogens. A relationship between these pathogens and the damaged BOS lung exists. Isolation of SM from LT recipients with and without BOS warrants treatment. Whether SM heralds the onset of BOS requires further study. 300 EX-VIVO EVALUATION OF DONOR HEARTS IN THE BEATING FUNCTIONING STATE IN THE ORGAN CARE SYSTEM (OCS) S. Schulte-Eistrup,1 U. Schulz,1 A. Elbetanony,2 A. El-Banayosy,1 G. Tenderich,1 R. Koerfer,1 1Dept. of Thoracic & Cardiovascular Surgery, Heart Center NRW, Bad Oeynhausen, Germany; 2 TransMedics Inc., Andover, MA Purpose: Maintaining donor hearts on OCS in a beating state, enables ex-vivo evaluation of cardiac & metabolic functions of donor hearts. This analysis investigates the relationship between ex-vivo cardiac and metabolic parameters and post transplant outcomes. Methods and Materials: 10 hearts were maintained on OCS for heart transplantation in our institution.Perfusion Parameters (PP) (CF, AOP, HR, PAP, SvO2) were monitored & recorded on the OCS during preservation.Serial arterial and venous serum lactate samples were analyzed at 10 minutes post instrumentation on OCS,various time points throughout preservation and at time of cardioplegic arrest prior to transplantation.
Abstracts
S167
Results: 6 hearts were transplanted with excellent post transplant outcomes.These hearts exhibited stable PP on OCS throughout preservation (585⫾64ml/min, 51⫾19mmHg, 79⫾15Bpm, 84⫾3%) and downward trend of lactate from initial to end measurements (1.8⫾0.4mg/dl, 1.5⫾0.2mg/dl). 4 hearts showed abnormally high and rising AOP on OCS (79.1⫾24mmHg) with significant increase of serum lactate from initial to end (3.2⫾2mg/dl to 9.2⫾3mg/dl) indicating cardiac ischemia.1 of the 4 was transplanted & suffered primary failure. 3 hearts were rejected for transplantation based on the above PM & lactate parameters.Evaluation of these hearts revealed the following: 1 heart was subjected to large dose of catecholamine during blood collection for OCS resulting in toxic levels in the circulating blood;1 heart showed CAD on histopath that was undetected at donor evaluation; 1 heart was subjected to prolonged hypoperfusion in the donor due to anaphylactic shock with significantly elevated serum creatinine at time of harvest;and 1 heart was found to have toxic doses of catecholamines of undocumented origin in the circulating blood. Conclusions: Ex-vivo assessment of functioning donor organs provides a new and potentially important quality tool for the surgeon.In our experience, serum lactate measurement is a sensitive indicator for the adequacy of perfusion of donor heart on OCS and immediate posttransplant outcomes. 301 INCREASING ORGAN AVAILABILITY IN HEART TRANSPLANTATION WITH THE USE OF WARM BLOOD PERFUSION FOR ORGAN PRESERVATION G. Tenderich,1 U. Schulz,1 T. Khayal,2 S. Schulte-Eistrup,1 R. Koerfer,1 1Thoracic and Cardiovascular Surgery, Heart Center North Rhine-Westphalia, Bad Oeynhausen, Germany; 2 TransMedics, Inc., Andover, MA Purpose: Marginal donors, pulmonary hypertension and transportation time remain limiting factors in cardiac transplantation (HTx). We report on our experience with The Organ Care System (OCS) in such borderline cases. Results: Case 1: A catecholamine dependent (dopamine 3,3/milrinone 0,68 g/kg/min) 54 y. o. female pt. with dilated cardiomyopathy (DCM) received an organ from a 42 y.o. female donor multiply rejected because of status post MOF including ARDS, stomach perforation, peritonitis and MOF. Echo showed RV hypokinesia and norepinephrine (0,02 g/kgBW/min) was needed to maintain stable hemodynamics. OCS perfusion time was 180 min. Weaning from bypass (CPB) with dopamine 4.3 g/kg/min and milrinone 0,34 g/kg/min. Echocardiography on po day 1 demonstrated normal RV function and an LV-EF of 75%. The pt. left the ICU after 24 hrs. & was discharge at pod 27 with good RV function (RV-FS 38%). Case 2: A 55 y.o. female pt. with DCM and sarcoidosis was pretreated with PDE-III inhibitors, iv epoprostenol, inhaled iloprost and bosentan for severe pulmonary hypertension (PVR 6 WE; TPG 18 mmHg). Htx of a 21 y.o. male donor organ was performed after OCS perfusion time of 256 min. Weaning from CPB without epoprostenol, reduced milrinone and slightly increased dopamine. Mechanical ventilation weaned after 5 hrs. The pt. left the ICU after 32 hrs. and was discharged on pod 22 with PVR 2,2 WE and TPG 4 mmHg. Case 3: A 34 y.o from Slovenia was transplanted in a 60 y.o. recipient with DCM after 326 min of OCS perfusion. In contrast to similar cold ischemic times the weaning from CPB was completely uneventful. Dopamine (4.9 g/kg/min) and milrinone (0,11 g/kg/ min) support was needed for 42 hrs. The patient left the ICU after 2 days and was discharged on po day 22 with excellent LV function (EF 76%). Conclusions: OCS perfusion has the potential of ameliorating the course in cases of marginal donor organs and pulmonary hyperten-
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sion. Extended transportation times also appear possible without impact on clinical outcomes. 302 FEMALE GENDER IS ASSOCIATED WITH CARDIAC DYSFUNCTION IN BRAIN DEAD ORGAN DONORS K.K. Khush,1 R.L. Menza,2 W.D. Babcock,2 C.W. Hoopes,3 J.G. Zaroff,1 1Medicine/Cardiology, University of California, San Francisco, CA; 2California Transplant Donor Network, Oakland, CA; 3Surgery, University of California, San Francisco, CA Purpose: In the setting of acute subarachnoid hemorrhage, female gender is associated with left ventricular (LV) systolic dysfunction and regional wall motion abnormalities (RWMA). This form of neurocardiogenic injury, which is often reversible, is likely due to excessive myocardial catecholamine release. We studied the association between female gender and LV dysfunction in a diverse population brain dead patients evaluated for organ donation. Methods and Materials: All potential cardiac organ donors managed by the California Transplant Donor Network between 2002-03, aged 14-60 years and without coronary artery disease, were included in this analysis. Univariate predictors of LV dysfunction were identified and multiple regression analysis was used to assess the relative independent contribution of each predictor. Results: 197 potential donors (122 male, 75 female, mean age 38 ⫾ 14 years) were studied. The cause of brain death was trauma in 64 potential organ donors, and non-traumatic (cerebrovascular death, anoxia, or other) in 133 potential donors. 12% had LV systolic dysfunction (LV ejection fraction⬍50%) and 15% had RWMA by echocardiography. Univariate analyses revealed that female gender, smaller donor size (weight, height, and body-mass index), and higher heart rate were independent predictors of LV systolic dysfunction and RWMA. Donor cause of death, cardiopulmonary resuscitation, and history of cocaine or methamphetamine use, smoking, and hypertension did not predict LV dysfunction or RWMA. In a multivariable model, after adjusting for donor age, size, and heart rate, female gender remained a strong independent predictor of LV systolic dysfunction (OR 5.75, 95% CI 1.76-18.76, p⫽0.004) and RWMA (OR 5.73, 95% CI 2.02-16.20, p⫽0.001). Conclusions: Female gender is associated with the presence of LV systolic dysfunction and RWMA in brain dead organ donors. Further studies assessing the reversibility of LV dysfunction and suitability of these organs for transplantation are required. 303 OXYGENATED PERFUSION OF DONOR HEARTS REDUCES ISCHEMIC DAMAGE DURING PRESERVATION A. Halldorsson,1 H.A. Goolsby,2 M.D. Tomison,2 S.D. Prien,2 1 Surgery, Texas Tech University Health Sciences Center, Lubbock, TX; 2Obstetrics and Gynecology, Texas Tech University Health Sciences Center, Lubbock, TX Purpose: It is well documented that ischemic cold storage of hearts during transplantation procedures can cause damage to the organ at the cellular level. The damage manifests itself as structural changes in both the tissue and subcellular organelles, and limits the time the heart can be stored to a few short hours. Recently, a number of groups have proposed perfusion of the hearts during storage to supply oxygen and other nutrient during the storage process as a means of combating ischemic damage. However, concerns have been raised that the use of crystalloid solutions will lead to edema of the organ and further damage to tissue and cells. The objective of the present study was to compare heart tissue at the cellular and subcellular levels from cadaver hearts that had been stored using a
The Journal of Heart and Lung Transplantation February 2007
traditional cold, static method verses a new organ preservation system (LifeCradle™, Organ Transport Systems; Frisco, TX) which perfuses an oxygenated solution through the organ while maintaining the temperature at 5° C. Methods and Materials: Twenty-six cadaver hearts were extracted from swine donors within 5 minutes of euthanasia in a slaughter facility. The hearts were flushed with heparinized cardioplegic solution and weighed prior to storage. The hearts were then stored in using either the standard ice-slurry methodology (n⫽9; SIS) for 4-8 hrs or in the new preservation device (n⫽17; LC) for times of 4-14 hrs. At the end of the storage time the hearts were weighed again to establish weight gain and tissue samples collected for ultrastructural analysis using TEM. Results: Results indicated no significant increased weight gain in the LC as compared to SIS (12.9 gm vs. 12.3 gm respectively; p⫽.954) even after 3X longer is storage. Further, ultrastructural damage was minimal in hearts from the LC as compared to the control as assessed by a pathologist blinded to tissue source. Conclusions: These data suggest the LC may be a superior storage environment over SIS and suggest further transplant studies are warranted. Grant support and supply of experimental instrument; Organ Transplant Systems. 304 INTERMITTENT ANTEGRADE CARDIOPLEGIA: IMPLICATIONS FOR DONOR HEART PRESERVATION A.L. Rivard,1,3 C.M. Swingen,4 F.D. Kamdar,5 Z. Demorest,5 E.J. Cordova,5 J.E. Foker,2 M. Jerosch-Herold,,6 R.W. Bianco,3 R. John,3 1Radiology, University of Florida, Gainesville, FL; 2 Surgery, Division of Cardiovascular and Thoracic, University of Minnesota, Minneapolis, MN; 3Surgery, University of Minnesota, Minneapolis, MN; 4Radiology, University of Minnesota, Minneapolis, MN; 5Medical School, University of Minnesota, Minneapolis, MN; 6Radiology, Oregon Health Sciences Center, Portland, OR Purpose: The scarcity of donor hearts limits the growth of heart transplantation. Currently, donor heart preservation techniques allow for only 4-6 hours of ischemia. Prolongation of this time would allow procurement at greater distances, thus reducing wastage. Because pH is directly related to the degree of ischemia, we hypothesized that administration of cardioplegia to the isolated heart would improve microvascular perfusion. Methods and Materials: Porcine hearts were excised, flushed with a ribose based cardioplegic solution and stored at 9.2 °C for 6.1 ⫾ 0.6 hours. Control hearts (Group 1, n ⫽ 9) were stored without receiving any additional perfusion, whereas experimental hearts (Group 2, n ⫽ 8) received an intermittent antegrade bolus (150 ml, q30 min, 150 ml/min). Ph probes were placed into the LV and RV myocardium for continuous measurement. At the end of the preservation, contrast enhanced, T-1 weighted MR imaging was performed in the short axis view. Peak contrast enhancement was used as a measurement of viable microvasculature. Wet/dry weight was then measured. Results: In both groups, myocardial LV pH decreased exponentially in all hearts immediately following flushing. In Group 1 hearts, pH decreased to 6.2 ⫾0.2. As opposed to Group 2 hearts; pH at the end of 6 hours was 6.7 ⫾0.3. The mean pH difference was of 0.55 (p ⬍ .005). Ph measurements of the RV had a similar response to perfusion (p ⫽ .02). MR contrast imaging showed no differences in peak contrast enhancement in the 2 groups, Group 1 ⫽ 62%, Group 2 ⫽ 40% (p ⫽ .08). There was also no difference of the wet/dry weights. Conclusions: Although microvascular perfusion was not significantly different between the two groups in this study; we demonstrated that intermittent perfusion maintains a significantly higher