RECONSIDERATION OF CRITERIA FOR THE FONTAN OPERATION - INFLUENCE OF PULMONARY-ARTERY SIZE ON POSTOPERATIVE HEMODYNAMICS OF THE FONTAN OPERATION

Background The outcome of the Fontan operation largely depends on pati ent selection because this procedure is a physiological correction. Am ong the several selection criteria for the Fontan operation, the impor tance of adequate size of the pulmonary artery remains controversial. To clarify whether or not pulmonary artery size is indispensable as on e of the selection criteria for the Fontan operation, we considered th e physiological importance of pulmonary artery size and investigated h ow pulmonary artery size influenced postoperative hemodynamics of the Fontan operation. Methods and Results In congenital heart disease of d ecreasing pulmonary blood flow, 40 patients were examined for this ana lysis. Pulmonary artery indexes (cross-sectional area of the right and left pulmonary arteries divided by body surface area) were measured a s the expression of pulmonary artery size, and the relations of pulmon ary artery index (PAI) to pulmonary vascular resistance (Rp) and compl iance (Cp) were studied. There was no significant correlation between PAI and Rp, whereas a significant correlation was found between PAI an d Cp (r=.71, P=.001). Furthermore, Cp influenced postoperative hemodyn amics of the Fontan operation by affecting peak central venous pressur e and total impedance, which was the afterload to the ventricle. Imped ance increased abruptly when PAI was less than approximate to 100 mm(2 )/m(2). Conclusions The smaller pulmonary artery size is hemodynamical ly disadvantageous after the Fontan operation, with resultant rise in peak centrol venous pressure and increased afterload to the single ven tricle.