Improved management of systemic venous anomalies in a single ventricle: New rationale

Objectives: Two innovative surgical approaches addressing systemic venous anomalies in single-ventricle patients are evaluated. Methods: Between 2003 and 2007, 7 patients underwent a unifocal bilateral bidirectional cavopulmonary anastomosis, and 5 patients underwent a hepatoazygos venous connection associated with a previous (n = 4) or concomitant (n = 1) Kawashima operation. Computational fluid dynamics simulations allowed investigation of 2 sets of comparative models: (1) bifocal versus unifocal bilateral bidirectional cavopulmonary anastomosis and (2) classic hepatic vein-pulmonary artery channel versus hepatoazygos direct anastomosis for Fontan completion after or combined with the Kawashima operation. Results: There was 1 hospital death in the unifocal bilateral bidirectional cavopulmonary anastomosis group. At a mean follow-up of 15.6 +/- 7.40 months after a unifocal bilateral bidirectional cavopulmonary anastomosis and of 38.7 +/- 13.2 months after direct hepatoazygos venous connection, respectively, all 11 survivors are in New York Heart Association class I with functional anastomoses. Computational assessment of bifocal bilateral bidirectional cavopulmonary anastomosis demonstrated weak perfusion between caval veins against symmetric and steady bilateral flow fields in the unifocal arrangement. In the classic post-Kawashima Fontan completion model, the hepatic venous flow to the pulmonary artery was held back by means of preponderant opposite flow, whereas in the direct hepatoazygos venous connection model, the hepatic venous flow merged smoothly into the azygos vein. Power-loss calculation showed no significant difference between bifocal and unifocal bilateral bidirectional cavopulmonary anastomosis topology, whereas the hepatoazygos connection clearly had better energy preservation than the classical connection. Conclusions: This limited clinical and computational fluid dynamics assessment suggests the efficacy of this new rationale to reduce the additional thrombotic risks produced by systemic venous anomalies in single-ventricle patients.