Clinical outcome of the Fontan operation in patients with impaired ventricular function

Objective: Although a staged Fontan strategy allows for an excellent outcome in high-risk patients, an impaired ventricular function remains a significant factor of early/late mortality and morbidity. This study evaluated the clinical outcome of the Fontan operation in patients with impaired ventricular function. Methods: A retrospective review was performed on 217 patients who had undergone the Fontan operation between 1991 and 2007. Results: Twenty-nine (13%) of the 217 patients had an impaired ventricular function (ejection fraction (EF) <50%). The median age at the time of the operation was 3 (range: 1-31 years) years. There were five adult patients. The ventricular morphology was right in 20 patients (including five hypoplastic left heart syndrome (HLHS)) and others (left and two-ventricle) in nine patients. Heterotaxy syndrome was present in eight patients. Previous surgical interventions included bidirectional Glenn anastomoses in 24, modified Blalock-Taussig shunts in two and pulmonary artery banding in two. The preoperative EF was 43 ± 6%. Significant (moderate or severe) atrioventricular valve regurgitation was noted in four patients. The percutaneous oxygen saturation (SpO₂) was 82 ± 5%. The pulmonary artery pressure and pulmonary artery index were 11 ± 3 mmHg and 296 ± 102 mm² m^-2, respectively. All 29 patients underwent the Fontan operation without any early mortality. There were two late mortalities and two re-operations. EF was maintained at 59 ± 15% at a median follow-up of 7.5 (range: 1-19) years. The percent normal systemic ventricular end-diastolic volume decreased from 174 ± 95% to 124 ± 39% (p < 0.05). The SpO₂ increased to 92 ± 2%. The mean cardiothoracic ratio in chest X-ray and B-type natriuretic peptide were 51% (range: 35-68%) and 22 pg ml^-1 (range: 9-382 pg ml^-1), respectively. Three patients developed congestive heart failure, seven had arrhythmia and two developed protein-losing enteropathy. The New York Heart Association (NYHA) class functional class is I in 21 patients, II in five and III in one. Conclusions: Acceptable clinical outcomes were observed at an intermediate follow-up of the Fontan operation in patients with an impaired ventricular function.