922-55 Transesophageal Echocardiography in Assessing Pulmonary Venous Anastomosis and Flow After Single Lung Transplantation

Abstract

Single lung transplantation (SLT) is a viable treatment option in end-stage pulmonary disease. The post-operative period following SLT may be complicated by hemodynamic and gas exchange abnormalities which may be related to vascular complications of the left atrial/pulmonary venous anastomosis. After successful SLT, the pulmonary flow into the transplanted lung is higher, creating a blood flow differential between the transplanted and the non-transplanted lungs. Biplane transesophageal echocardiography (TEE) can visualize the anatomic characteristics of the pulmonary venous anastomosis and measure the pulmonary venous flow selectively from each lung. By applying the formula: Q = A· FVI, where Q is flow, A is cross-sectional pulmonary vein area, and FVI is flow velocity integral, the pulmonary venous flow can be estimated and the flow differential between the two lungs calculated. In a blinded fashion, we calculated the TEE-derived right and left pulmonary vein flow in 26 patients, 15 pts pre-SLT and 11 pts post-SLT. We compared the TEE data with the percentage pulmonary flow derived by nuclear medicine perfusion scans (Technectium 99). Both techniques were expressed as percent blood flow to each lung. The correlation between both techniques was excellent r = 0.87, SEE = 7.94, p < 0.001. Figure illustrates results for differential lung flow. In all 11 post-op pts, the pulmonary venous/left atrial anastomosis was clearly visualized. In 1 patient a large thrombus was seen in the right pulmonary veins. TEE is an excellent alternative to estimate differential lung perfusion in SLT. In addition, visualization of the pulmonary veins can help exclude complications at the pulmonary vein anastomosis