Bosentan was applied within 7 days after Fontan surgery as follows : at the first month , 7.8125 mg Bid for patients with body weight 10 kg ; 15.625 mg Bid for patients with body weight between 10-20 kg ; 31.25 mg Bid for patients with body weight 20-30 kg and 62.5 mg Bid for patients with body weight > 30 kg .