EFFECTS OF INHALED NITRIC-OXIDE IN SINGLE-LUNG TRANSPLANTATION IN RATS WITH MONOCROTALINE-INDUCED PULMONARY-HYPERTENSION

Background: The edema of grafted lungs during the early postoperative period is one of the serious complications of single lung transplantat ion for primary pulmonary hypertension. Methods: The effectiveness of inhaled nitric oxide in single lung transplantation far primary pulmon ary hypertension during the early postoperative period was evaluated w ith the use of rats with monocrotaline-induced pulmonary hypertension. In the inhaled nitric oxide group, rats were given 60 parts par milli on of nitric oxide for 24 hours just after left lung transplantation; in the no inhaled nitric oxide group, rats were kept without nitric ox ide inhalation; in the control group, normal rats received left isogra fts. Results: Three hours after transplantation, the mean pulmonary ar tery pressure of the no inhaled nitric oxide group (28.0 +/- 4.6) was significantly higher than that of the control group (23.3 +/- 0.9, p < 0.05) and the inhaled nitric oxide group (72.7 +/- 1.7, p < 0.05). On the first postoperative day, the mean left-to-right pulmonary blood f low ratio in the inhaled nitric oxide group was 0.34 +/- 0.03; it show ed no significant difference to those of the other two groups, whereas that of the no inhaled nitric oxide group (0.42 +/- 0.14) was signifi cantly elevated compared with that of the control group (0.14 +/- 0.03 , p < 0.05). Histopathologically, the edema of the grafted lungs 24 ho urs after operation in the inhaled nitric oxide group was less severe than that in the no inhaled nitric oxide group. Conclusions: The posto perative use of inhaled nitric oxide is effective to reduce the pulmon ary edema of the grafts in single lung transplantation for pulmonary h ypertension by reducing acute pulmonary blood flow shift toward grafts after transplantation.