Influence of graft ischemic time and donor age on survival after lung transplantation

Increased graft ischemic time and donor age are risk factors for early death after heart transplantation, but the effect of these variables on survival after lung transplantation has not been determined in a large, multinational study.

All recipients of cadaveric lung transplantations performed between October 1, 1987 and June 30, 1997 which were reported to the United Network for Organ Sharing/International Society for Heart and Lung Transplantation (UNOS/ISHLT) Registry were analyzed. Patient survival rates were estimated using Kaplan-Meier methods. Multivariate logistic regression was used to determine the impact of donor and recipient characteristics on patient survival after transplantation. To examine whether the impact of donor age varied with ischemic time, interactions between the 2 terms were examined in a separate multivariate logistic regression model.

Kaplan-Meier survival did not differ according to the total lung graft ischemia time, but recipient survival was significantly adversely affected by young (-10 years) or old (-51 years) donor age (p = 0.01). On multivariate analysis, neither donor age nor lung graft ischemic time per se were independent predictors of early survival after transplantation, except if quadratic terms of these variables were included in the model. The interaction between donor age and graft ischemia time, however, predicted 1 year mortality after lung transplantation (p = 0.005), especially if donor age was greater than 55 years and ischemic time was greater than 6 to 7 hours.

Graft ischemia time alone is not a risk factor for early death after lung transplantation. Very young or old donor age was associated with decreased early survival, whereas the interaction between donor age and ischemic time was a significant predictor of 1 year mortality after transplantation. Cautious expansion of donor acceptance criteria (especially as regards ischemic time) is advisable, given the critical shortage of donor lung grafts.