3D Transesophageal Echocardiography and Pseudo Pulmonary Artery Stenosis in Lung Transplantation

A woman in her 40s with idiopathic pulmonary fibrosis presented for bilateral orthotopic lung transplantation. Postimplantation, 2-dimensional (2D) echocardiography color-flow Doppler and pulse wave Doppler flow measurement showed turbulent flow and elevated peak gradient in the right pulmonary artery. Associated increased left pulmonary vein flow and relatively decreased right pulmonary vein flow without sign of anatomic stenosis were suggestive of disproportionate flow through the left lung (Supplemental Figures 1 and 2, available online at http://www.mayoclinicproceedings.org). Three-dimensional (3D) echocardiography identified focal narrowing of elliptical geometry in the right pulmonary artery suggestive of external compression vs normal circular geometry, acute angulation of anastomotic stenosis, or vascular kinking, respectively. Upon inspection, external pericardial tissue wrap for bronchial anastomosis protection was found to be causing focal arterial compression. Postcorrection, the right pulmonary arterial dimensions returned to normal. Subsequent equalization of bilateral pulmonary vein flow was noted postcorrection with significantly improved forward right pulmonary venous flow and relative reduction of left pulmonary venous flow (Figures 1 and 2).Figure 2Right pulmonary artery (ˆ) after external compression removed.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Vascular anastomotic complications in lung transplantation include both pulmonary venous and pulmonary arterial anastomoses.1Abrams B.A. Melnyk V. Allen W.L. et al.TEE for lung transplantation: a case series and discussion of vascular complications.J Cardiothorac Vasc Anesth. 2020; 34: 733-740Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar The diagnosis is most often delayed into the postoperative period, using a combination of echocardiography and pulmonary angiogram, with an overwhelming majority of patients requiring emergency corrective surgery (76%), resulting in a mortality of 23%.2Kumar N. Hussain N. Kumar J. et al.Evaluating the impact of pulmonary artery obstruction after lung transplant surgery: a systematic review and meta-analysis.Transplantation. 2021; 105: 711-722Crossref Scopus (6) Google Scholar Accuracy of anatomic diameter and vascular flow is reliant on the echocardiographer evaluating intraoperative images postimplantation and postseparation from extracorporeal life support.3Martin A.K. Harrison B.A. Fritz A.V. et al.Intraoperative management of a hybrid extracorporeal membrane oxygenation circuit for lung transplantation.J Card Surg. 2020; 35: 3560-3563Crossref PubMed Scopus (11) Google Scholar The use of 3D echocardiography to examine pulmonary arterial anatomy, in conjunction with differential pulmonary venous velocity measurement, allowed for an immediate intraoperative solution to an otherwise potential postoperative challenge. The authors report no competing interests. Dr Martin is a consultant and on the Scientific Advisory Board for Attgeno AB, with all compensation to Mayo Clinic. Supplemental Figure 2A, 3D echocardiography image showing the external compression (arrows) by peribronchial tissue (∗) of the right pulmonary artery (ˆ) precorrection. B, 2D echocardiography image of the right pulmonary artery (ˆ) with and without turbulent color flow Doppler precorrection. C, Continuous wave Doppler of the right pulmonary artery and the associated flow patterns showing increased velocity precorrection. D, Postcorrection right pulmonary artery (ˆ). E, Postcorrection color flow Doppler of the right pulmonary artery (ˆ) showing decrease in turbulent flow compared with precorrection. F, Continuous wave Doppler of the right pulmonary artery and associated flow patterns showing decreased velocities postcorrection.View Large Image Figure ViewerDownload Hi-res image Download (PPT)