DEPT. OF CARDIAC SURGERY, SHAHEED RAJAEI CARDIOVASCULAR AND MEDICAL CENTER, TEHRAN, IRAN
Background- Pulmonary regurgitation (PR) is the most important residual lesion remaining after the repair of Tetralogy of Fallot (TOF). Through a thorough review of the data, statistics of patients undergoing pulmonary valve replacement following total correction for TOF and analyzing these data, the following study was performed and presented below.
Methods- Database search for medical records of patients undergoing pulmonary valve replacement following total correction for TOF was performed and the data gathered, analyzed, and presented.
Results- The age of the patients (22.21±6.98 years old), time elapsed between the two operations, right ventricular ejection fraction ( mildly decreased, 18.6%; moderately decreased, 67.9%; and severely decreased, 12.2% of cases), aneurysm in the outflow tract of the right ventricle (20.8%), tricuspid regurgitation (56.6%), tricuspid steno sis (1 case), valve type used for pulmonary valve replacement (biologic, 86.6%; metallic, 11.2%; and homograft, 1.9%), pulmonary artery pressure [<25mmHg, 34 cases (64.2%); 25mmHg - 50mmHg, 7 cases (13.2%); 50mmHg-75mmHg, 1 case (1.9%), and > 75mmHg, 1 case] were evaluated.
Conclusions- Although right ventricular volume overload due to severe pulmonary regurgitation after repair of TOF can be tolerated for years, there is now evidence that the compensatory mechanisms of the right ventricular myocardium ultimately fail and that if the volume overload is not eliminated or reduced, this dysfunction may be irreversible. In light of those data and with better understanding of risk factors for adverse outcomes late after TOF repair, many centers are now recommending early pulmonary valve replacement before symptoms of heart failure develop.