The hemi-Fontan operation.

In hearts with a functional single ventricle, cavity volume and myocardial muscle mass increase as a consequence of the excessive volume load associated with parallel pulmonary and systemic circulations. The hemi-Fontan operation was conceived as a means of accomplishing early reduction of the volume work of the single ventricle, in anticipation of eventual completion of a modified Fontan procedure. The hemi-Fontan procedure includes association of the superior vena(e) cava(e) (SVC) with the branch pulmonary arteries, augmentation of the central pulmonary arteries, occlusion of the inflow of the SVC into the right atrium, and elimination of other sources of pulmonary blood flow. Because it is preparatory to an eventual completion Fontan procedure, concomitant procedures are conveniently performed in conjunction with the hemi-Fontan. These may include atrial septectomy, relief of aortic arch obstruction, proximal main pulmonary artery to ascending aortic anastomosis, repair or revision of anomalous pulmonary venous connection, atrioventricular valvuloplasty, or other procedures.