HEMODYNAMIC-EFFECTS OF BIDIRECTIONAL CAVOPULMONARY SHUNT WITH PULSATILE PULMONARY FLOW

The effects of "pulsatile" bidirectional cavopulmonary shunt (BCPS) produced by the flow from the ventricle or Blalock-Taussig (B-T) shunt on ventricular function and pulmonary circulation were evaluated in 10 patients with univentricular heart from 3 to 37 months (mean, 16.6 +/- 9.5 months) after surgery. Age at operation ranged from 7 months to 15 years (mean, 5.5 +/- 4.5 years). In addition to the BCPS, pulmonary flow was supplied from a B-T shunt on the contralateral side of the BCPS in five patients, from the ventricle through the stenotic pulmonary valve in four patients, and from both the ventricle and a B-T shunt in one patient. There were no operative deaths; however, there were two late deaths from acute respiratory infection 10 and 13 months after operation. Mean pulmonary arterial pressure measured the first day after operation ranged from 10 to 19 mm Hg (mean, 14 +/- 3 mm Hg). Mean pulmonary arterial pressure at postoperative cardiac catheterization was less than 15 mm Hg (mean, 12 +/- 4 mm Hg). Pulse pressure ranged from 3 to 12 mm Hg (mean, 7 +/- 4 mm Hg). Arterial oxygen saturation increased significantly from 77 +/- 5% before BCPS to 86 +/- 4% immediately after discharge from the intensive care unit (p < 0.005) and 85 +/- 3% (p < 0.025) at late cardiac catheterization. Pulmonary arteriovenous fistula was not detected in contrast echocardiography and pulmonary arteriography. Systemic ventricular end-diastolic volume index decreased significantly (p < 0.01) from 141 +/- 54 ml/m2 before BCPS to 98 +/- 35 ml/m2 1 month after BCPS by echocardiography. There was no significant change in systemic ventricular ejection fraction (from 47 +/- 11% to 45 +/- 13%). Systemic atrioventricular valve regurgitation was improved in five patients and not changed in five other patients. There was no significant change in pulmonary vascular resistance and pulmonary arterial size. Angiography showed that the superior vena caval flow went into both pulmonary arteries even when the pulmonary arterial flow was pulsatile. Thus, BCPS with pulmonary flow from the ventricle or the B-T shunt showed favorable hemodynamic results without adverse effects on pulmonary circulation.