179 POST-OPERATIVE ASSESSMENT OF FONTAN OPERATION

Abstract

From 1975 to 1980, 10 patients (pts.) age 2.5-24 years (y)(mean 13.6±6y) had modified Fontan operation for tricuspid atresia (7), univentricular heart (2), and transposed great vessels (1). Six had right atrial (RA) to pulmonary artery (PA) anastomosis (ANS), 4 with valved conduit and 2 direct ANS. Four had RA to right ventricular (RV) ANS, 1 with a non-valved conduit and 3 direct ANS. Eight pts. also had Glenn shunts. All 9 survivors are in normal sinus rhythm. Seven pts. had cardiac catheterization 2-60 months (m) post-operatively (post-op)(median 8m). RA mean pressures (p) were 3-19mmHg with RA ‘a’ waves of 10-25mmHg. Pts. with RA-PA ANS had narrow PA pulse p of 2-3mmHg, while pts. with RA-RV ANS had wider, biphasic PA pulse p due to RV contractions. No RA-PA p gradients were present. Aortic saturation was 79%±9 pre-operatively (pre-op) and 95%±3 post-op; left ventricular (LV) end diastolic p was 7.0±5.8mmHg pre-op and 6.7±1.9 post-op. RA regurgitation into hepatic veins and coronary sinus was more marked in pts. with RA-PA ANS. Post-op LV contractility was decreased in all (average LV ejection fraction 53.2%±12) except the youngest pt. While all pts. had improved exercise tolerance post-op, treadmill testing in 5 was impaired with average duration of 6.9 minutes, and maximal endurance index of 238±49 (normal 344±65). These data suggest that RA-RV ANS results in better forward flow and less regurgitation than RA-PA ANS. Exercise tolerance and oxygenation improved post-op but most pts. have clinical and angiographic evidence of decreased cardiac function.