title: Problems in the modified Fontan operation for univentricular heart of the right ventricular type.
abstract: Thirteen patients (ages 4 to 16 years) with univentricular heart of right ventricular type, nine with double-inlet right ventricle (DIRV), and four with mitral atresia who underwent a modified Fontan operation were reviewed. Among those with DIRV, right isomerism with a common atrioventricular (AV) valve was found in eight and situs inversus in one; among those with mitral atresia, AV discordance was found in two and concordance in two. Intra-atrial routing using a baffle with atriopulmonary anastomosis was the main procedure (11 patients). There were two operative deaths (one DIRV, one mitral atresia) and three hospital deaths, with an early mortality of 38.5% overall (DIRV 44%, mitral atresia 25%). Low cardiac output was the main cause of death, with relatively high right atrial pressure and with tachyarrhythmias in most of the patients. Mortality was 75% for patients with DIRV who had total anomalous pulmonary venous drainage (n = 4) and 20% for those without (n = 5). Preoperative ventricular volume and ejection fraction were not different between those with severely low cardiac output (n = 4, three deaths) and the others, whereas ventricular mass/volume ratio was significantly lower in the former group. Two late deaths (one DIRV, one mitral atresia) related to the AV valve regurgitation. These results may indicate a relatively poor outcome after the modified Fontan operation for patients with univentricular heart of right ventricular type as a result of basic anatomic and hemodynamic problems.
mesh_terms: D001166:Arteriovenous Shunt, Surgical; D001807:Blood Vessel Prosthesis; D002303:Cardiac Output, Low / Q000401:mortality; D002648:Child; D004310:Double Outlet Right Ventricle / Q000601:surgery*; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000601:surgery*; D006352:Heart Ventricles / Q000002:abnormalities; D006801:Humans; D008943:Mitral Valve / Q000002:abnormalities*; D011183:Postoperative Complications / Q000401:mortality*; D013997:Time Factors