Exercise performance of rats after isogenic left or right lung transplantation followed by contralateral pulmonary artery ligation.

BACKGROUND

After single lung transplantation for pulmonary hypertension, large mismatches in ventilation/perfusion distribution persist late after transplantation. The larger graft volume of the transplanted lung after transplantation, the better the exercise performance. Because the right lung is larger in volume than the left, we compared the left single lung transplant with the right single lung transplant regarding exercise performance with an animal model.

METHODS

To simulate significant ventilation/perfusion imbalance observed after single lung transplantation for pulmonary hypertension, we transplanted isogenic left or right pulmonary grafts to normal rats, and the contralateral pulmonary artery was ligated 2 weeks after transplantation. The treadmill test was performed weekly until 6 weeks after transplantation to measure maximum tolerated running speed and maximum oxygen uptake.

RESULTS

Graft vital capacity of left and right pulmonary grafts were 4.5 +/- 0.43 ml (37% +/- 3.7% of recipient's predicted vital capacity) and 7.8 +/- 0.34 ml (63% +/- 2.4%), respectively (p < 0.01). Maximum tolerated speeds of left and right single lung transplants were 8 +/- 7.6 and 29 +/- 2.2 m/min, respectively, at 6 weeks after transplantation (p < 0.01). Maximal oxygen uptake values of left and right single lung transplants were 34 +/- 12.0 and 65 +/- 3.8 ml/kg/min, respectively (p < 0.01).

CONCLUSIONS

Results suggest that right lung transplantation is superior to left lung transplantation for pulmonary hypertension in terms of exercise performance in this animal model.