The utility of aortic blood flow measurements in the prediction of pulmonary artery banding outcome

Background The purpose of this study was to evaluate the clinical utility of intraoperative aortic blood flow measurements on clinical outcome in patients undergoing pulmonary artery banding (PAB). Methods We reviewed 12 patients who underwent a PAB between September 2008 and March 2013 who also had intraoperative aortic blood flow measurements. Diagnosis included biventricular physiology in 6, single-ventricle physiology in 4, and inadequate systemic ventricle in 2 patients. Aortic blood flow was measured at the time of surgery by Transonic flow probe (Transonic Systems Inc, Ithaca, NY). Aortic flow, intraoperative hemodynamics, and clinical outcomes were analyzed to determine the potential predictive utility of intraoperative variables on postoperative outcomes. Results The aortic flow increased after PAB from 1.56 ± 0.73 to 2.20 ± 1.10 L · min^-1 · m^-2 (41.0% increase; p = 0.001). The efficacy of the PAB procedure was found to be directly related to the percentage increase in aortic blood flow measured intraoperatively. Three patients with less than 20% increase in aortic blood flow died, required re-PAB, or developed ventricular dysfunction, while patients with successful PAB had more than 40% increase in aortic blood flow. The percentage increase in aortic blood flow was not predictable based on pre-band or post-band absolute aortic blood flow measurements. The percentage increase in aortic blood flow was inversely correlated to the tightness of the PAB as defined relative to that predicted by the Trusler formula (r = 0.67; p = 0.01). Conclusions This study identifies the change in the aortic blood flow as a new, physiologically based parameter to help predict PAB outcome.