In order to evaluate the effects of pulsatile flow in the pulmonary artery of patients undergoing bidirectional cavopulmonary shunts (BCS), we reviewed the data of 36 patients operated upon from October 1990 to July 1994. Age at operation ranged from 11 months to 14 years (mean 4.4 ± 3.4 years) and diagnoses were as follows: tricuspid atresia (18), single ventricle (16), mitral atresia (1) and pulmonary atresia with intact ventricular septum (1). A total of 19 (52.8%) patients had a prior palliative operation done. Cardiopulmonary bypass was used in every case, with mild hypothermia in 11 cases and profound hypothermia and circulatory arrest in the remaining. The surgical technique was an anastomosis between the superior vena cava and the ipsilateral pulmonary artery in an end-to-side fashion. The main pulmonary artery was ligated only if the mean pressure taken at the site of the anastomosis was higher than 15 mmHg but in 2 recent cases with a very high mean pulmonary pressure, the main pulmonary artery was banded, adjusting the pressure to the desirable levels. The overall hospital survival was 91.7% (33 patients). One patient required a systemic to pulmonary shunt due to persistent low arterial oxygen saturation, 7 days after the BCS. Twenty-eight patients were followed for a mean of 1.8 ± 1.2 years (3 months to 4.1 years) and were divided in 2 groups: A-18 patients without pulsatile flow in the pulmonary artery, and B-10 patients with pulsatile flow. In Group B, the mean arterial saturation has ranged from 80% to 90% (mean 86 ± 3.8%) and is significantly higher than in Group A (68 to 85%, mean, 77.6 ± 5.5) (p<0.001). Two patients of Group A are in NYHA functional class III, whereas all patients of Group B are in class I or II (p=0.05). There was one late death and one patient required a subsequent Fontan procedure, both of Group A. Thus, the presence of pulsatile flow in the pulmonary artery improved the arterial oxigen saturation and exercise tolerance in patients submitted to a cavopulmonary shunt, without adverse effects on pulmonary circulation.
Glenn operation; Pulmonary artery