UNILATERAL PULMONARY-ARTERY THROMBOTIC OCCLUSION - IS DISTAL ARTERIOPATHY A CONSEQUENCE

The characteristics and postoperative outcomes of a unique group of el even patients with total unilateral pulmonary artery (PA) thromboembol ic occlusion were compared with those of some 400 patients who underwe nt bilateral thromboendarterectomies,during the same time period. Preo perative historical, physical, and laboratory features and postoperati ve outcomes of these two groups were analyzed. The unilateral group ha d no distinct historical features. However, they were younger (32 +/- 10 yr) than the bilateral group (51 +/- 15 yr), dominantly female (10 of 11) versus a male predominance (62%) in the bilateral group; had si gnificantly lower preoperative PA mean pressures (30 +/- 12 versus 46 +/- 12 mm tig) and calculated pulmonary vascular resistance (360 +/- 2 93 versus 901 +/- 467 dynes/s/cm(-5)); and small lung by chest radiogr aph was common (8 of 11). Postoperatively, four unilateral patients de veloped unilateral rethrombosis (two immediate; two late, at several y ears postsurgery); this occurred in only one bilateral patient. Furthe rmore, of six patients with unilateral occlusion present more than 1 y r, reperfusion was poor in four despite an adequate thromboendarterect omy in all. Postoperative pulmonary angiograms in two of these disclos ed apparent atrophy of central and distal pulmonary arteries. Prior an imal investigation models indicate that unilateral PA occlusion is fol lowed by development of a postobstructive arteriopathy in the resistan ce arteries of the occluded lung. The unusual outcomes in these 11 pat ients suggest that they may develop a similar arteriopathy which requi res special management considerations at surgery and postoperatively.