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We appreciate the comments from the University of Kentucky Lung Transplant program [1Diaz-Guzman E. Davenport D.L. Zwischenberger J.B. Hoopes C.W. Lung function and ECMO after lung transplantation (letter).Ann Thorac Surg. 2012; 94: 686-687Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar] regarding our article recently published in The Annals of Thoracic Surgery, “Improved survival but marginal allograft function in patients treated with extracorporeal membrane oxygenation after lung transplantation” [2Hartwig M.G. Walczak R. Lin S.S. Davis R.D. Improved survival but marginal allograft function in patients treated with extracorporeal membrane oxygenation after lung transplantation.Ann Thorac Surg. 2012; 93: 366-371Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar]. Their critical review of the literature on extracorporeal membrane oxygenation (ECMO) and specific comments on our article highlight the need to better understand and use venovenous (VV) ECMO in primary graft dysfunction (PGD) after lung transplantation. We agree that early deployment of VV ECMO should be used in the setting of severe PGD after lung transplantation. In fact, the primary conclusion of our experience is that an aggressive ECMO support program will lead to better recipient survival than what was previously published in the literature. Although we prefer VV ECMO to venoarterial ECMO in this setting, others have purported equal survival between the two techniques, albeit with diminished overall survival in their patients [3Bermudez C.A. Adusumilli P.S. McCurry K.R. et al.Extracorporeal membrane oxygenation for primary graft dysfunction after lung transplantation: long-term survival.Ann Thorac Surg. 2009; 87: 854-860Abstract Full Text Full Text PDF PubMed Scopus (104) Google Scholar]. While we saw a survival improvement when using ECMO for PGD, we did not note a difference in bronchiolitis obliterans syndrome. This may have been due to the limited size of our cohort and the limited follow-up period (mean, 719 days in the ECMO group). To further characterize allograft function after ECMO, we chose to evaluate the peak forced expiratory volume in 1 second (FEV1). Our analysis indicates that peak FEV1 appears to be lower in individuals requiring ECMO. There were no differences between the ECMO group and the non-ECMO group in terms of “high-risk organs” or “extrathoracic factors.” It is important to note that our article does not implicate the use of VV ECMO in the diminished lung function of patients with severe PGD. Rather, PGD remains the most likely culprit in a negative impact on peak FEV1 values. As reported elsewhere, PGD has been associated with worse allograft dysfunction, and we hypothesize that the most severely affected recipients who previously would not have survived are now salvaged with VV ECMO [4King R.C. Binns O.A. Rodriguez F. et al.Repferfusion injury significantly impacts clinical outcomes after pulmonary transplantation.Ann Thorac Surg. 2000; 69: 1681-1685Abstract Full Text Full Text PDF PubMed Scopus (308) Google Scholar]. These injured allografts do not emerge unscathed after PGD but rather have permanent detriments to their function, as reflected in their spirometry values. Unfortunately, the United Network for Organ Sharing (UNOS) dataset cited by Diaz-Guzman does not address the question of ECMO for PGD and subsequent allograft dysfunction. The UNOS dataset describes recipients receiving ECMO at the time of transplantation, eg, a “bridge to transplantation.” There is no indication that these recipients in the UNOS dataset suffered from severe PGD after transplantation. Therefore, the impact of PGD on allograft function cannot be determined from this information. In contradistinction to this, our patients all had severe PGD requiring support with ECMO and subsequently had worse peak pulmonary function when compared with our recipients who did not have severe PGD. In conclusion, we believe survival is improved with the use of VV ECMO for PGD. Additionally, we believe that VV ECMO provides the simplest and safest method of supporting patients with severe PGD requiring extracorporeal support. We appreciate the opportunity to further clarify our findings as previously described in The Annals of Thoracic Surgery. Lung Function and ECMO After Lung TransplantationThe Annals of Thoracic SurgeryVol. 94Issue 2PreviewWe read with great interest the article by Hartwig and colleagues in a recent issue of The Annals of Thoracic Surgery [1]. The authors presented their experience with the use of venovenous extracorporeal membrane oxygenation (VV-ECMO) in 28 patients with severe primary graft dysfunction (PGD) after lung transplantation. The authors describe significant improvements in 1-year and 3-year survival compared with previous reports. In addition, the authors found no difference in progression to development of bronchiolitis obliterans syndrome (BOS) between patients on ECMO and the rest of the cohort. Full-Text PDF