Introduction : Major cyanosis and elevated hematocrit significantly increase morbidity after surgical repair of Tetralogy of Fallot (ToF). Diastolic dysfunction is mainly observed in patients with severe hematological disturbances.
Methodology : All patients (57 pts) operated for a ToF between March 1999 and February 2004 with an hematocrit above 60 % were reviewed. Group 1 (n = 30) had a complete repair and group 2 (n =27) had a two stage repair : an aorto-pulmonary shunt was performed around 15 days before a total corrective procedure.
Results : Both groups were similar in age (63 ± 51 in group 1 vs 96 95 months in group 2; ns), in preoperative pulse oxymetry (65 ± 13% vs 66 ± 9%;ns), in hematocrit, in aortic cross clamp time, CPB duration and surgical technique. No hospital mortality was observed in the two groups but 4 patients in group 1 required ECMO assistance. Morbidity was significantly lower in group 2: shorter length of stay in PICU (12 ± 11 days vs 6 ± 6 days; p= 0.002), shorter ino-tropic support (7.3 ± 6.5 days vs 3.7 ± 3.4 days, p= 0.01), less acute pulmonary edema (12 pts vs 3 pts, p= 0.002). These results could be attributed to a better pulmonary flow improving left ventricular compliance associated with a better preoperative myocardial oxygenation.
Conclusions : An aorto-pulmonary shunt implanted 15 days before a complete repair of ToF reduces the risk of myocardial dysfunction after surgery in patients with an hematocrit above 60 %.