Pulmonary Artery Size and Late Functional Outcome After Fontan Operation

Background. Pulmonary artery (PA) growth after a Fontan procedure tends to be suboptimal to somatic growth. This study aimed to investigate whether the PA size affects the late outcomes of the Fontan procedure. Methods. This study enrolled 120 Fontan patients. Their mean age was 19.3 +/- 5.6 years. PA size was measured from computed tomographic images. Patients were divided into three groups according to the PA index (PAI) (Nakada index): PAI < 180 mm(2)/m(2) (group I: n = 37); 180 mm(2)/m(2) <= PAI < 250 mm(2)/m(2) (group II: n = 56); and PAI >= 250 mm(2)/m(2) (group III: n = 26). Data on hemodynamics, biochemical test, B-type natriuretic peptide, and cardiopulmonary exercise performance were analyzed. Results. The three groups showed no differences in occurrence of adverse outcomes such as protein losing enteropathy, arrhythmia, and hepatic changes. No differences were observed after cardiac catheterization. Various parameters of exercise tolerance test were not different between the three groups. However, B-type natriuretic peptide level was significantly higher in group III than in the other groups (p = 0.010); there was no difference between groups I and II. Ventricular volume unloading in group III was later than that in group I (4.6 +/- 3.7 vs 2.6 +/- 2.7 years, respectively; p < 0.05). Conclusions. PA size does not affect late outcomes or functional status in the survivors of the Fontan operation. Hence, a pre-Fontan palliative procedure to augment the PA size, at the expense of ventricular overload, is not recommended. (Ann Thorac Surg 2011;91:1240-7) (C) 2011 by The Society of Thoracic Surgeons