P5129Left atrial appendage closure guided by 3D printed patient-specific models

Abstract

Background: Percutaneous left atrial appendage (LAA) occlusion has emerged as an alternative therapeutic approach to medical therapy for stroke prevention in patients affected by atrial fibrillation. Thanks to 3D printing is nowadays possible to manufacture patient-specific models of any given anatomical portion of the heart reconstructed by medical images such as Computed Tomography Angiography (CTA). Purpose: The present study aims at assessing whether the sizing of the implanted occluder device, based on the sole medical image analysis, is in accordance with the sizing obtained using the 3D printing models Methods: We report our experience in using 3D printing to create patient-specific LAA models, reconstructed by CTA, as supporting tool of the pre-operative stage of the LAA occlusion procedure with endovascular devices, such as the Wave Crest device (Coherex Medical, Inc, USA) and the Amplatzer Amulet device (St Jude Medical, St Paul, MN). In particular, we retrospectively analysed our database to identify 13 cases of LAA occlusion. For each case, we segmented the pre-operative CTA scan by ITK-snap [2] creating a LAA 3D model (Caretronik, Prato, Italy), that after smoothing, refining, and improvement of the mesh quality was considered suitable for 3D stereolithography printing (SLA) technique (Form 2 Desktop, Formlabs Inc., MA, USA). Two independent observers measured the LAA landing zone, major and minor axis using a digital caliper. The measurements were used for sizing. A rehearse occlusion was then accomplished using the 3D printed LAA and the occluder device models; the resulting values were subsequently compared with the size of the implanted device to assess agreement, over or underestimation and its correlation with post-operative drawbacks. Results: Thirteen patients, undergoing percutaneous LAA occlusion, were retrospectively analyzed; for each of them a patient-specific 3D LAA printed model was manufactured using pre-operative CTA images. The comparison between the 3D printed model sizing and the actual sizing revealed that: i) in 54% of the cases (n=7) the actual sizing was underestimated when compared to the 3D printed model; ii)in 38% of the cases (n=5) the two sizing approaches matched; iii) only in 1 case (8%) an overestimation of the actual size compared to the 3D printed model was detected. It is worth noticing that in all underestimated cases a drawback, such as leakage or device migration was observed; consequently, the results suggest that the use of 3D printing models help in finding the correct size of the device, potentially avoiding the negative outcome of the surgery. Conclusions: This report demonstrates that 3D printing LAA model may contribute in sizing the device, finding its correct position and guiding the choice of the device, providing additional data to angiography and TEE.