Enhancement of ventricular mechanics following bidirectional superior cavopulmonary anastomosis in patients with single ventricle.

Seventeen consecutive patients undergoing bidirectional cavopulmonary anastomosis (BDCPA) using normothermic, noncardioplegic, cardiopulmonary bypass were studied preoperatively and early postoperatively (12.2 days) using transthoracic echocardiographic techniques. The purpose of the study was to assess the changes in left ventricular mechanics associated with the change in blood flow related to the BDCPA. Of the 17 patients, pulmonary atresia and tricuspid stenosis was present in 7, tricuspid atresia in 6, double inlet left ventricle in 3, and severe pulmonic stenosis with straddling of the tricuspid valve in 1. All other forms of single ventricle type anatomy and other patients undergoing BDCPA were excluded for the purposes of this study. The mean left ventricular end-diastolic volume index fell from 120 mL/m2 to 91.1 mL/m2 (p < 0.05). Similarly the left ventricular end-systolic volume index fell from 55.8 mL/m2 to 42.3 mL/m2, respectively (p < 0.05). The stroke volume index also fell from 64.5 mL/m2 to 48.8 mL/m2. Left ventricular ejection fraction was preserved and was unchanged in every patient. It was concluded that BDCPA, performed as described above, preserves left ventricular function and that the systolic and diastolic volumes as well as the stroke volume are significantly decreased as evidence of improvement of left ventricular mechanics. The continued use of the BDCPA either as a definitive procedure or as a staged procedure in preparation for total cavopulmonary connection is therefore endorsed.