The traditional approach to repair of tetralogy of Fallot involves a right ventriculotomy for closure of ventricular septal defect. During the past two decades, reports of progressive right ventricular dilation and dysfunction, and late occurrence of ventricular arrhythmias, have led investigators to re-evaluate this approach and advocate instead the transatrial-transpulmonary approach, hoping to preserve global right ventricular function. We studied the short term effects on right ventricular function of either of the two approaches through a prospective randomised study, involving two comparable groups of patients operated in the same time frame.
Between June 1993 and February 1994, 40 patients having tetralogy of Fallot with comparable preoperative characteristics, were assigned randomly to each of two groups for surgical correction.
In 20 patients, correction was achieved via the transatrial-transpulmonary route. In the other 20 patients, transventricular correction was the chosen option. Six months after surgery, patients were evaluated clinically, by Doppler echocardiography, cardiac catheterisation, first pass radionuclide angiography and by 24 hours ambulatory electrocardiographic monitoring, taking note of hemodynamics, abnormalities in rhythm, and global right ventricular function.
There were no early deaths or morbidity in either group. Mean immediate postoperative ratio between peak right ventricular and systemic pressures was 0.62 ± 0.22 after transatrial and 0.70 ± 0.007 after transventricular correction. All patients were in functional class I. Six months after surgery the mean ratio between peak ventricular pressures was similar in the two groups (transatrial group: 0.37 ± 0.02, transventricular group: 0.38 ( 0.01), but significantly lower than that measured in the operating room. There were no significant arrythmias in either group. Mean right ventricular ejection fraction was nearly the same in both groups (transatrial group versus transventricular group; 44.83 ± 5.65% versus 42.37 ± 8.70%). Significant global hypokinesia of the right ventricle was documented in three patients, and mild hypokinesia in another three, undergoing repair through the transventricular route while in the group undergoing transatrial repair only one patient had mild hypokinesia.
We conclude that comparable hemodynamic results are obtained on short term follow-up after repair of tetralogy of Fallot by either the transatrial or transventricular route. Although more patients in the transventricular group were found to have global hypokinesia of the right ventricle, longer follow-up is necessary to establish the clinical relevence of these findings.