A valuable echocardiographic indicator for the optimal tightness of bilateral pulmonary artery banding

The optimal tightness of bilateral pulmonary artery banding (BPAB) is considered to balance not only systemic-to-pulmonary blood flow but also each pulmonary blood flow, which is still challenging. To achieve them, we adopt the end-diastolic velocity (EDV) to the peak systolic velocity (PSV) ratio at BPAB with intraoperative epicardial echocardiography. We evaluated the usefulness of the EDV to PSV ratio and the patient outcomes.

34 patients underwent BPAB with this indicator and using a looped polytetrafluoroethylene suture. The PSV and the EDV to PSV ratio with echocardiography were measured in the intraoperative, early postoperative and late postoperative period. Lung perfusion scintigraphy was performed to quantify flow to each lung.

There were 3 early deaths (< 30 days). Two patients required re-BPAB due to hypoxia. The intraoperative EDV to PSV ratios in the right and left were almost equal (0.50 ± 0.07 versus 0.51 ± 0.06, P = 0.73). There was no significant difference in the right and left EDV to PSV ratios throughout the postoperative course. The right PSV was smaller than the left PSV due to the Doppler angle intraoperatively (2.78 ± 0.57 versus 3.02 ± 0.50, P = 0.030). In addition, the PSV changed significantly until the late postoperative period (P < 0.001). Lung perfusion scintigraphy revealed only two patients had perfusion abnormalities.

Our clinical outcomes are satisfactory with low early mortality and a low rate of re-BPAB. The EDV to PSV ratio can be a reliable indicator to assess flow distribution to each lung and may be a valuable adjunct to achieve balanced systemic to pulmonary flow.