PERCUTANEOUS PULMONARY ENDOARTERIAL BIOPSY IN AN EXPERIMENTAL-MODEL OF PULMONARY-HYPERTENSION

Study objectives: The aims of this study were: to evaluate the perform ance of a novel arterial biopsy catheter in obtaining pulmonary endova scular samples in hypertensive dogs; to compare the results of pulmona ry endoarterial biopsy in hypertensive vs normotensive dogs; and to as sess the histologic changes in the hypertensive model, Design and inte rventions: Thirty-four dogs (27 with normal pulmonary arterial pressur es and seven with pulmonary hypertension) were catheterized through an external jugular vein to obtain endovascular biopsy samples from dist al pulmonary arteries 2 to 3 mm in luminal diameter. To induce pulmona ry hypertension, seven dogs were given repeated infusions of 0.6- to 0 .9-mm ceramic microspheres into the superior vena cava, Endoarterial s amples were obtained at pulmonary systolic arterial pressures ranging from 10 to 110 mm Hg. Measurements and results: Sixty-two biopsy cathe terization procedures were performed in the 34 dogs. After 12 initial procedures of technique refinement, endoarterial samples were obtained in each of the last 50 procedures (21 in normotensive dogs and 29 in hypertensive dogs). The average number of endovascular biopsy samples retrieved was 7.1 (range, 2 to 12) from a mean of 8.6 (range, 2 to 15) biopsy attempts per catheterization (success rate=83%). The average b iopsy piece measured 1.13 mm in length, 0.33 mm in depth, and up to 1. 0 mm in width. The biopsy success rates and endoarterial sample sizes were similar in normotensive and hypertensive dogs. Smooth muscle cell s and endothelial cells were grown fi om the biopsy samples, There wer e no significant procedural complications, except for one self-limited hemorrhage. Histologically, samples obtained from dogs with pulmonary hypertension showed characteristic changes when compared with biopsie s from normotensive dogs. Conclusion: This new endoarterial biopsy cat heter was safe and effective when used to obtain pulmonary endoarteria l samples in dogs with normal and experimentally elevated pulmonary ar terial pressures. The quality and quantity of the biopsy samples allow ed identification of pathologic changes.