Abstract

Objective: To determine the incidence of right ventricular outflow tract (RVOT) aneurysm after TOF correction, identify risk factors for aneurysm formation, evaluate regression of right ventricular (RV) dysfunction after reoperation with valved conduit implantation.

Material and Methods: Retrospective study of 441 patients (pt.) with potential risk of RVOT aneurysm formation after total correction of TOF between 1977--1997. Patients were divided in two groups: TAN patch reconstruction - 184 pt. (group A) and RVOT patch reconstruction - 257 pt. (group B). Thirty-two pt. developed RVOT aneurysm 23 pt. in group A and 9 pt. in group B respectively. Out of 32 pt. with RVOT aneurysm 23 pt. (71.8%) was indicated for reoperation. Indication for reoperation was 1) right ventricular hypertension with RV/LV pressure ratio higher than 0.75 2) grade III. of tricuspid regurgitation 3) increasing size of RVOT aneurysm. Out of 19 of reoperated pt. in group A fresh autologous pericardial patch was used in 17 pt., Polystan pericardial monocusp patch in 1 and homograft monocusp in one patient. Out of 4 of reoperated pt. in group B fresh autologous pericardial patch was used in 3 and dacron patch in one patient. Mean time interval from original repair to reoperation was 61 month (6--183 m.). Mean follow up was 62 month (1--97 m.) postreoperatively.

Results: The incidence of RVOT aneurysm formation was significantly higher in TAN patch group (p < 0.001) as well as the usage of fresh autologous pericardial patch in combination with TAN technique (p < 0.001). After valved conduit implantation RV/LV pressure ratio decreased below 0.6 in all survivors. Four out of 23 pt. (17%) died early postreoperatively due to irreversible RV failure.

Conclusion: Major risk factors for RVOT aneurysm formation are transanular approach, fresh autologous pericardial patch reconstruction with residual RV hypertension due to residual pulmonary artery branches stenoses. Selected patients following TOF repair with RVOT aneurysm formation do benefit from valved conduit implantation, which is the only prevention of development of irreversible right ventricular failure.