Three-Dimensional (3D) Printing for Left Atrial Appendage Occlusion Device Sizing: A Systematic Review and Comparative Analysis.

In recent years, the clinical application of three-dimensional (3D) printing technology has shown great potential in surgical planning. The left atrial appendage (LAA) is a key site for thrombus formation in nonvalvular atrial fibrillation (NVAF), increasing the risk of stroke. One recent application of this technology is for LAA occlusion, a procedure used to seal the LAA and prevent the formation of systemic thromboembolism associated with NVAF in patients with contraindications for oral anticoagulation therapy.  In this systematic review, the use of 3D printing for device sizing during the planning of LAA occlusion procedures was evaluated through a literature search using the following keywords: ("Left atrial appendage" OR "LAA" or "intra-atrial mass" OR "left atrial mass" ) AND ("3D printing" OR "additive manufacturing" OR "rapid prototyping" OR "computer-aided design" OR "CAD" OR "bioprinting") AND ("occlusion" OR "closure" OR "device sizing" OR "atrial fibrillation").  After data extraction, 16 studies reported using 3D printing, prospectively or retrospectively, to estimate the accuracy of LAA device sizing and/or deployment. These studies demonstrated that 3D-printed models can improve anatomical measurements and allow for improved device sizing and implantation compared to standard-of-care imaging-assisted procedural planning.  Of the articles included in this review, two articles found a significant reduction in devices used per procedure (from 1.7 to 1.1 and 1.20 to 1.05, respectively), with shorter procedure times in the 3D-printed groups. Additionally, the 3D-printed models showed fewer devices deployed per procedure, perivascular leaks, and residual shunts. Additionally, one article found fewer perivascular leaks in the 3D group (one vs. four in controls), and one article showed no residual shunts in the 3D group compared to 14.29% in controls.  Although the 16 studies included in this review demonstrate the value of 3D printing in LAA occlusion procedures, the findings underscore the need for larger, multicenter studies to further quantify its clinical benefits, particularly in improving procedural planning and reducing complications in the intravascular treatment of LAA thrombosis in NVAF. Future research should focus on multicenter trials, larger cohorts, and testing 3D-printed occlusion devices for personalized treatments.