Establishing a brain-death donor model in pigs.

INTRODUCTION: An animal model that imitates human conditions might be useful not only to monitor pathomechanisms of brain death and biochemical cascades but also to investigate novel strategies to ameliorate organ quality and functionality after multiorgan donation. METHODS: Brain death was induced in 15 pigs by inserting a catheter into the intracranial space after trephination of the skull and augmenting intracranial pressure until brain stem herniation. Intracranial pressure was monitored continuously; after 60 minutes, brain death diagnostics were performed by a neurologist including electroencephalogram (EEG) and clinical examinations. Clinical examinations included testing of brain stem reflexes as well as apnoe testing; then intensive donor care was performed according to standard guidelines until 24 hours after confirmation of brain death. Intensive donor care was performed according to standard guidelines for 24 hours after brain death. RESULTS: Sixty minutes after brain-death induction, neurological examination and EEG examination confirmed brain death. Intracranial pressure increased continuously, remaining stable after the occurrence of brain death. All 15 animals showed typical signs of brain death such as diabetes insipidus, hypertensive and hypotensive periods, as well as tachycardia. All symptoms were treated with standard medications. After 24 hours of brain death we performed successful multiorgan retrieval. DISCUSSION: Brain death can be induced in a pig model by inserting a catheter after trephination of the skull. According to standard guidelines the brain-death diagnosis was established by a flat-line EEG, which occurred in all animals at 60 minutes after induction.

Establishing a donation after cardiac death model in pigs.

INTRODUCTION: Due to the lack of human donors, several strategies have sought to expand the organ pool. Efforts to characterize donation after cardiac death (DCD) have included studies of cell viability, histological and immunohistochemical changes, and oxidative stress, which is known to negatively impact graft survival. A large animal model would be useful for these inquiries. Therefore, we sought to establish a DCD animal model in pigs. METHODS: We simulated non-heart-beating donation Maastricht II and III conditions in 24 pigs. Cardiac fibrillation was induced using 9-V direct current. After various times of ventricular fibrillation (1-10 minutes) with no mechanical and/or medical treatment to achieve cardiac output, reanimation was performed for 30 minutes prior to multiorgan donation. Then, a neurological status was performed. Blood samples were obtained at defined times tissue samples were stored in liquid nitrogen and subsequently embedded in paraffin and subjected to further analysis. RESULTS: We established a DCD pig model in our laboratory by inducing cardiac fibrillation. Up to now, only DCD donation according to the Maastricht criteria II and III has been performed, but establishing all Maastricht criteria of DCDs seems to be feasible. CONCLUSION: A DCD model in pigs enables us to characterize organ quality more precisely as well as evaluate amelioration of storage conditions and donor treatments in a large-animal model.