Challenges of management and therapy in patients with a functionally single ventricle after Fontan operation.

Forty years ago, Fontan and Baudet performed the first life-saving operation on a patient with a functionally single ventricle. This multi-stage procedure established the connection between systemic venous circulation and pulmonary arteries. As a consequence, the pulmonary circulation is supplied in a passive way, whereas the single ventricle pumps the blood into the systemic circulation only. Over the years, the technique of creating the abovementioned vascular connections has undergone several modifications. Due to the fundamental non-physiological hemodynamic relations between arterial pulmonary and systemic venous pressures, numerous complications can be observed in these patients including: supraventricular arrhythmias, thromboemboli, hepatic dysfunction, protein-losing enteropathy, heart failure, worsening cyanosis, systemic venous collateralization, and pulmonary arteriovenous malformations, as well as connective tissue lesions in bronchi. Although based on an ingenious concept, the operation remains of a palliative character. Occasionally, heart transplantation is the ultimate resolution. Pharmacological therapy, and surgical conversion, often appear to be ineffective. However, this procedure has enabled many patients to reach adulthood and enjoy their lives to the full. This fact poses a great challenge for cardiologists wishing to become more knowledgeable and experienced as regards such patients, if we are not to waste such fabulous surgical achievements.