Transesophageal Echocardiography, Computed Tomography, or Both when Assessing the Efficacy of Different Left Atrial Appendage Closure Techniques?

We read with great interest the article by Petersen and colleagues.1Petersen J. Böning H. Yildirim S. et al.Efficacy of four different left atrial appendage closure techniques during cardiac surgery—a transesophageal echocardiography follow-up study.J Thorac Cardiovasc Surg Tech. 2024; XX: XXhttps://doi.org/10.1016/j.xjtc.2024.05.007Abstract Full Text Full Text PDF Scopus (0) Google Scholar Despite their excellent results, questions remain. Of particular interest is whether transesophageal echocardiography (TEE) or computed tomography (CT) is the best assessment tool for this issue. Over the past 2 years, we have routinely used TEE and CT both preoperatively and postoperatively in patients undergoing concomitant atrial fibrillation radiofrequency ablation and left atrial appendage (LAA) closure in our institution. Although our data have not been published yet, a brief analysis (Figure 1) shows that CT appears to have superior sensitivity for detecting preoperative LAA thrombus compared with TEE. Prior studies similarly reported high diagnostic accuracy of CT for LAA thrombus detection, with sensitivity ranging from 92% to 100% when delayed imaging was used.2Yu S. Zhang H. Li H. Cardiac computed tomography versus transesophageal echocardiography for the detection of left atrial appendage thrombus: a systemic review and meta-analysis.J Am Heart Assoc. 2021; 10e022505https://doi.org/10.1161/JAHA.121.022505Crossref Scopus (28) Google Scholar A possible explanation for this is that the high spatial resolution and 3-dimensional structural depiction of cardiac CT offer unique imaging planes of the left atrium and LAA, not appreciated with TEE, which has been the conventional preimaging modality of choice for LAA closure. Another possible explanation is that TEE accuracy is highly dependent on the operator's experience and skill. Due to the complex morphology of the LAA, TEE does not always provide a satisfactory display of the LAA and may miss thrombi smaller than 2 mm. In contrast, CT's noninvasive nature and non-fasting requirements limit patients discomfort. Petersen and colleagues1Petersen J. Böning H. Yildirim S. et al.Efficacy of four different left atrial appendage closure techniques during cardiac surgery—a transesophageal echocardiography follow-up study.J Thorac Cardiovasc Surg Tech. 2024; XX: XXhttps://doi.org/10.1016/j.xjtc.2024.05.007Abstract Full Text Full Text PDF Scopus (0) Google Scholar reported a high success rate of LAA clipping and surgical excision (98.4% vs 93.1%); however, this does not rule out events such as the incidence of acute thrombosis after surgical LAA closure that often goes undetected by TEE3Inoue T. Takahashi H. Kurahashi K. Yoshimoto A. Suematsu Y. Incidence of acute thrombosis after surgical left atrial appendage occlusion for atrial fibrillation.Ann Thorac Surg. 2024; 117: 1172-1176https://doi.org/10.1016/j.athoracsur.2024.02.012Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar or the presence of a trabeculated LAA stump and residual LAA stump detected by CT. Recent studies by Caliskan and colleagues4Caliskan E. Eberhard M. Falk V. Alkadhi H. Emmert M.Y. Incidence and characteristics of left atrial appendage stumps after device-enabled epicardial closure.Interact Cardiovasc Thorac Surg. 2019; 29: 663-669https://doi.org/10.1093/icvts/ivz176Crossref PubMed Scopus (17) Google Scholar and Lim and colleagues5Lim S.K. Kim C.H. Choi K.H. et al.A comparative study of thoracoscopic left atrial appendage clipping vs stapled resection.Ann Thorac Surg. 2024; 117: 1230-1236https://doi.org/10.1016/j.athoracsur.2023.09.010Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar similarly found an incidence of residual stump formation after LAA closure. Caliskan and colleagues4Caliskan E. Eberhard M. Falk V. Alkadhi H. Emmert M.Y. Incidence and characteristics of left atrial appendage stumps after device-enabled epicardial closure.Interact Cardiovasc Thorac Surg. 2019; 29: 663-669https://doi.org/10.1093/icvts/ivz176Crossref PubMed Scopus (17) Google Scholar documented successful LAA occlusion in 43 patients (100%), as confirmed by intraoperative TEE and CT imaging. However, CT revealed residual LAA stumps in 11 out of 43 patients (26%) with a length <10 mm and a significant residual stump with a depth of >10 mm (12 mm) in 1 patient (2%).4Caliskan E. Eberhard M. Falk V. Alkadhi H. Emmert M.Y. Incidence and characteristics of left atrial appendage stumps after device-enabled epicardial closure.Interact Cardiovasc Thorac Surg. 2019; 29: 663-669https://doi.org/10.1093/icvts/ivz176Crossref PubMed Scopus (17) Google Scholar A significant limitation of the study is its lack of an intraoperative TEE protocol, specifically the absence of serial TEE measurements, as mentioned by the authors. This may prevent a precise assessment of when the failure occurred in all of the study's patients. Notwithstanding its limitations, Petersen and colleagues'1Petersen J. Böning H. Yildirim S. et al.Efficacy of four different left atrial appendage closure techniques during cardiac surgery—a transesophageal echocardiography follow-up study.J Thorac Cardiovasc Surg Tech. 2024; XX: XXhttps://doi.org/10.1016/j.xjtc.2024.05.007Abstract Full Text Full Text PDF Scopus (0) Google Scholar study makes a valuable contribution to our understanding of the efficacy of LAA closure techniques. We believe that both TEE and CT are indispensable in the context of a comparative analysis of different LAA closure techniques, and CT should be used as a complementary tool alongside TEE to provide more comprehensive evidence. Future research should aim to overcome this study's limitations by including both CT and TEE in assessing the efficacy of these closure techniques. The authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.