Update on Lung Transplantation using Donation after Cardiac Death in NSW

Abstract

P< 0.05) with hydraulic permeability and burst pressure equal to autologous conduits (HP: IMA 0ml/min/cm2, EC 0 P=ns; BP: IMA 2267 mmHg, EC 1922 P=ns). Fluorescence microscopy confirmed endothelial proliferation on electrospun fibres, and thrombogenicity studies demonstrated reducedplatelet attachment on rHE scaffolds. Discussion: Synthetic coronary conduits constructed using rHE/PCL fibres match the mechanical properties of the IMA. In addition, these scaffolds exhibit reduced thrombogenicity and the ability to support endothelialisation. The elastic conduits will be implanted as carotid artery interposition grafts in rabbits for assessment in vivo before ultimate study as coronary bypass graft candidates. These novel conduits show great potential as a synthetic internal mammary artery, the “Holy Grail” of coronary revascularisation surgery. doi:10.1016/j.hlc.2010.10.034 Update on Lung Transplantation using Donation after Cardiac Death in NSW E. Granger ∗, P. Spratt, M. Harkess, P. Jansz, K. Dhital, P. Macdonald, M. Malouf, A. Glanville The Lung TransplantUnit, St. Vincent’s Hospital, Darlinghurst, ever it will probably augment transplant numbers by only 15%. Current results are excellent despite “warm ischaemia”. Donors with longer warm ischaemic times and more “marginal” gas exchange may now be considered. doi:10.1016/j.hlc.2010.10.035 Beating Heart Preservation of Donor Hearts for Transplantation—A Working Heart Perfusion System for Pig Hearts to Extend Organ Preservation Time P. Pritzwald-Stegmann1,∗, J. Passage1,2, T. Muller 2, A. Muhle2, S. Krabbes1,2, S. Dhein2, F.-W. Mohr2 1Monash Medical Centre, Clayton, Australia Q4 2 Heart Centre Leipzig, Leipzig, Germany Introduction:Donor heart ischaemic time places significant geographic constraints on organ retrieval. Constant pressure perfusion systems can double current time limits in a pig model of heart transplantation from 4 to 8h, but the yield of successfully preserved hearts is low. The aim of this studywas to develop aworking heart perfusion system that would extend donor heart preservation time and allow the subsequent assessment of organ function post reperfusion. Methods: Beating hearts were harvested from 61± 3 kg pigs (n= 6) andperfused via a double lumen cannula using Sydney, NSW, Australia Introduction: Donation after cardiac death (DCD) from Maastrict category 3 donors consists of approximately 12% of lung transplant activity in New South Wales. We review the results of DCD lung transplants and discuss the future direction of the program at St. Vincent’s Hospital. Methodology: Since commencing in November 2007 there have been 25 referrals for DCD, leading to 11 attempted retrievals. Only 9 retrievals resulted in lung donation. Elective withdrawal of life-sustaining support and certification of death (limit of 60min fromwithdrawal) occurred in the Intensive Care Unit or Operating Theatre. Results: Average recipient age was 35 years (range 15–61) and aetiology of respiratory failure included cystic fibrosis (2), bronchiectasis (1), bronchiolitis obliterans (1), emphysema (3), interstitial lung disease (1) and pulmonary hypertension (1). The donor group average age was 37 years (range 14–56) and average PaO2/FiO2 ratio 412 (±51). Causes of death included subarachnoid haemorrhage (2), Traumatic head injury (2), hypoxic brain injury (3) and embolic CVA (2). Mean time to asystole after withdrawal of treatment was 27min (range 9–57), mean warm ischaemic time 19min (range 10–31) and mean cold ischaemic time (left lung) 279min (range 241–320). Early gas exchange was excellent: an average PaO2/FiO2 of 324 (141–503). Average intensive care stay was 5 days (3–10) and length of stay 23 days (12–36). All patients are still alive. Conclusion: Organ donation remains at a challenging low level in Australia. Donation after cardiac death may increase the “donor organ pool”, howaLangendorff-basedperfusioncircuit.Workingheart conditionswere created, at physiological perfusion pressures. After 7 hours, the hearts were arrested with cold HTK cardioplegia solution and underwent 1 hour of warm ischaemia. The hearts were subsequently reperfused in a non-working state at constant pressure for 1 hour and then weaned to again perform under the original working heart conditions. Pmax, max dp/dt, min dp/dt were monitored throughout. Tissue adenosine triphosphate (ATP) and malondialdehyde (MDA) were measured to assess myocardial energy content and oxidative stress respectively. Induction of apoptosis was assessed by staining for AIF. Results: All 6 hearts were successfully harvested, preserved and weaned following reperfusion. Pmax achieved during the working heart mode was higher than in the donor animal (142 vs 86mmHg, p= 0.002). There was no significant overall deterioration in systolic (max dp/dt 2030 vs 1812mmHg/s, p= 0.521) or diastolic (min dp/dt 1200 vs 1225mmHg/s, p= 0.902) function throughout preservation. ATP stores recovered to pre harvest levels (23.6 vs 22.1 pmol/ g, p= 0.57) and oxidative stress was well controlled (1.6 vs 1.8 mol/g, p= 0.926). Apoptosis levels were comparable to hearts that underwent conventional 4 h hypothermic arrest prior to transplantation (15.7 vs 12.7/hpf, p= 0.741). Discussion: A working heart perfusion system can be utilised to successfully increase donor heart preservation times. The system allows the real-time monitoring of donor organ function and canmimic the ischaemia and reperfusion events that occur during transplantation. It permits the specific modification of preservation parame-