P951 Intraprocedural echocardiographic technique to locate the insertion points of artificial chordae during transventricular beating heart mitral valve repair: ultrasound ""starry sky""

BACKGROUND Mitral valve repair is the preferred surgical treatment for severe mitral regurgitation due to degenerative leaflet prolapse. Within the growing era of transcatheter treatments for valvular heart disease, an innovative micro-invasive trans-ventricular beating-heart procedure was developed. Three-dimensional transoesophageal echocardiographic guidance is crucial to assist the operator in instrument navigation and chords positioning. Indeed, it is important an equidistant chords placement on the leaflet to ensure a uniform force distribution on the prolapsing segment and to avoid damaging of the previously inserted chords. PURPOSE To propose an intraoperative three-dimensional echocardiographic technique that allows operators to see the exact location of the polytetrafluoroethylene (ePTFE) chords used for the mitral repair. METHODS The procedure is performed using a device that is introduced through a posterolateral ventriculotomy and it is advanced towards the mitral valve under real-time 3D transoesophageal guidance. The prolapsing segments are grasped with the jaw of the instrument and the chords are implanted to achieve the proper distribution of forces and then tensioned and secured outside the ventricle. The proposed technique exploits the greater echogenicity of the artificial chord loop compared to native chords and leaflets. By lowering of the gains, remaining in the three-dimensional mitral valve surgical view, the signals of the native structures are attenuated, the underlying ventricular cavity appears black and the insertion points are visible as an intense signal on the virtual free edge of the leaflet treated. Figure 1 shows the intraoperative sequence of images of a case performed at our centre. The images were acquired using real time single beat three-dimensional reconstruction. Figure 1A shows the surgical view of the native valve with prolapse of the P2-P3 scallops. Image 1B reveals the prolapsing leaflet grasping and device location. After gain lowering, it’s possible to see the intense signal of the positioned artificial chord (Figure 1C). It can also be noted how this position matches with the position of the device at the time of grasping. Image 1D shows the partial disappearance of the prolapse during the tensioning test after the positioning of a second chord in a more medial position. Figure 1E shows the correct position of the ePTFE chords. We can notice the second chord placed in a medial position from the first one. This view, with dark ventricular chamber and intense signals of chordae loops, looks like a "STARRY SKY". RESULTS This technique allows to locate the correct insertion points of the artificial chords during the procedure. CONCLUSIONS This is a simple technique to guide operators during trans-ventricular beating heart mitral valve repair with ePTFE chords. Abstract P951 Figure 1

Three-dimensional echocardiography

The advent of fully-sampled matrix array transthoracic transducers has enabled advanced digital processing and improved image formation algorithms and brought three-dimensional echocardiography (3DE) technology into clinical practice. Currently, 3DE is recognized as an important echocardiographic technique, demonstrated to be superior to two-dimensional echocardiography in various clinical scenarios. This chapter focuses on the technology of 3DE matrix transducers, physics of 3D imaging, data set acquisition (multiplane, real-time, full-volume, zoom, and colour), and display (volume rendering, surface rendering and multislice) modalities. The chapter also addresses the issues of training in 3DE, and main clinical indications and reporting of transthoracic and transoesophageal 3DE.

Intracardiac and intravascular echocardiography

Intracardiac echocardiography is a relatively new echocardiographic technique, essentially used for monitoring of percutaneous atrial septal defect closure procedures and for electrophysiological catheter-based ablations. It is still limited to a few experienced centres, but presents with several advantages, including the safe guidance of percutaneous interventional treatments, avoidance of general anaesthesia, and reduction in radiation exposure. Intracardiac echocardiography is likely to be more and more used, with the development of new catheter interventional procedures. This chapter discusses the principles, methods, and main indications for intracardiac echocardiography in monitoring and guidance of interventional procedures as well as new developments and its cost-benefit ratio.

Transoesophageal echocardiography

Transoesophageal echocardiography (TOE) is a standard echocardiographic technique which uses the oesophagus and upper stomach as echo windows on the heart and thoracic vessels via an endoscopic probe. It is indicated when transthoracic echocardiography is unable or unlikely to answer the clinical question. Typical indications where TOE has a proven superiority include diagnosis of left atrial thrombi, especially in the appendage, morphological evaluation of atrial septal defect, infective endocarditis, mitral valve disease, aortic and prosthetic valves, aortic diseases, and intraoperative monitoring of cardiac surgery or interventions. Indications, technique, typical views, and information to obtain in specific scenarios are presented.