We would like to thank Dr. Ren and colleagues for their much appreciated interest in our paper (1), particularly because they are such long-standing experts in the field of intracardiac echocardiography (ICE). In the following response, we will attempt to address the points made in their letter.
Left atrial appendage (LAA) closure procedures should be carefully planned in the pre-operation phase. Not all data can be obtained from a single imaging technique, and we recommend using different imaging sources to perform a safe and effective procedure.
1. We agree that, in case of enlarged left atrium, the right atrium/coronary sinus view of the LAA could be suboptimal. However, in our experience, the combined use of fluoroscopy and ICE was adequate for delivery system positioning, device placement, and release. The final aim is to perform the procedure avoiding general anesthesia.
2. In Figure 1 (Figure 2A from our paper  without superimposed drawings), all of the anatomical structures are clearly visible. In Figure 2B of our paper (1), the probe is advanced in the deep coronary sinus. From this view, the interatrial septum is not already visible; furthermore, the image was magnified and cut for editorial reasons.
3. We agree that placing the probe in the right ventricular outflow tract and/or in the pulmonary artery provides optimal LAA views, and this is a useful suggestion for operators; unfortunately, this approach is challenging and time consuming.
4. We also agree with the limitation of ICE from the right atrium and coronary sinus in the evaluation/elimination of peridevice leaks due to sampling difficulty for parallel flow. We have already indicated that ICE alone is not the correct method to rule out any peridevice leaks; we recommend the integrated use of angiography and ICE.
5. As for the peridevice leak evaluation, we rely on angiography combined with ICE. We consider small peridevice leaks to be benign, as it has been shown that they are common, tend to disappear during the follow-up, and have little clinical relevance (2).
6. We agree that ICE and transesophageal echocardiography (TEE) measurements might be discordant; in our paper, the 21.6% of disagreement supports the argument of Ren and colleagues. However, the detected differences were not so important as to cause selection of a different device. The significant correlation between the angiographic and ICE measurements corroborates the effectiveness of our strategy (pre-procedural TEE evaluation followed by ICE and angiographic confirmation). We are aware that a careful pre-procedural evaluation with TEE could represent a bias in the ICE intraprocedural evaluation.
7. In response to the comments by Ren and colleagues about Figure 6 of our paper (1), we suggest that, using TEE and ICE, it is possible to obtain similar results. In particular, as in Figure 6 of our paper (1), we measure the ostium of the LAA and the landing zone 1 cm inside according to the Instructions for Use of the Amplatzer Cardiac Plug device.
The intracardiac echocardiography (ICE) view of the left atrium (LA) and left atrial appendage (LAA) as seen from the right atrium (RA). We can see the long axis of the LAA, the interatrial septum (IAS) (yellow arrow), and the circumflex artery (CX) (green arrow).
On the basis of the above considerations, although we are aware of ICE’s technical limitations, we maintain the convictions expressed in our paper (1).