Use of grafts with extended ischemic time (above 4 hours or more): analysis of the experience of the largest Brazilian heart transplant center, from 2013 to 2022
Ronaldo Honorato Santos1, Fabio A Gaiotto1, Samuel P Steffen1, Domingos D L Filho1, Shirlyne FD Gaspar1, Fernando Bacal1, Fabio B Jatene1.
1Cardiothoracic Department - Cardiovascular Surgery Division - Heat Transplant Nucleus , Heart Institute - University of São Paulo Medical School , São Paulo, Brazil
Introduction: The use of grafts harvested over a long distance, with ischemia time above 4 hours, is a routine in our center, the Institute of the Heart of São Paulo, the largest transplant center in Brazil. The shortage of donors, the large number of recipients (90% in national priority) and the high mortality rate on the waiting list, pushes and encourages us to use these hearts.
Objective: We evaluated transplants performed from January 2013 to March 2022, with hearts harvested at long distance, using static preservation (hypothermic) and with ischemic time greater than 4 hours, some longer than 5 hours. We evaluated survival rates, the main causes of mortality and the PGD rate, in this extended ischemic time group.
Material and methods: From January 2013 to March 2022, 396 heart transplants were performed. All grafts were preserved using static hypothermic method and the solution used was Custodiol. Preservation routine was: cardiac arrest in the donor, one the new infusion in the back-table and the grafts were brought immersed in the protection solution. The "no ice touch" technique was also used for additional protection of grafts. A total of 68 transplants (17.17% of the total) used grafts with more than 4 hours of ischemia. Of the long-distance transplants, 58 (85.29%) were with grafts with ischemic time up to 5 hours and 10 (14.70%) were performed with ischemic time greater than 5 hours.
Results: Of the 68 transplants performed with hearts with ischemic time equal to or greater than 4 hours, 58 (85.29% of this group and 14.64% of the general total) were with a time between 4 and 5 hours and 10 (14.70% of the long ischemia group and 2.53% of the overall total) were with more than 5 hours. There were 16 deaths (23.52%) in this extended ischemia time group: 13 deaths (22.41%) in the group of 4 to up to 5 hours and 3 deaths (30%) in the group with ischemia greater than 5 hours. Of the 13 deaths (19.11% of the total group with extended ischemia time) 6 deaths were due to infection (46.15%), 3 deaths were due to PGD (23.07%), 2 deaths were stroke (15.38%), 1 death was of undetermined cause (in the 63 POD) 1 death was due to ABO mismatch. Of the 3 deaths in the group with ischemia time of more than 5 hours, 2 deaths were due to infection (20%) and 1 death was due to PGD (10%).
Conclusions: Despite the risks and difficulties imposed by this modality (logistics mainly), the scarcity of organs, high mortality rate on the waiting list and the large number of patients prioritized in our institution, we believe that this routine contributed with a significant number of transplants (about 17.17% of all transplants). The main cause of mortality was infectious and the PGD rate was 6.77%. These results in this special group (ischemic time equal to or greater than 4 hours - or even longer) motivates us to continue this model. Access to new preservation technologies, especially the dynamics, can optimize this modality in our country even more.
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