Left Atrial Appendage Morphology and Course of the Circumflex Artery: Anatomical Implications for Left Atrial Appendage Occlusion Procedures

Abstract

Objective: The aim of this study was to evaluate the anatomic topography of the circumflex artery (Cx) and left atrial appendage (LAA) and to determine the safety zones for epicardial LAA closure and LAA occlusion procedures. Methods: The left coronary artery was segmented and visualized from 116 computed tomography angiography scans. Four points were located on the Cx portion periappendicularly, starting from the entry point. The landing zone plane was defined as parallel to the LAA orifice at the level of the beginning of the periappendicular course of the Cx, and the plane of the neck bend was located at the end of the LAA neck. A distance smaller than 2 mm was considered a dangerous distance. Results: The distance between the Cx and the LAA landing zone was 4.3 ± 2 mm. The distance between the Cx and the LAA neck bend was 5.1 ± 2.2 mm. The distance between the Cx and the LAA bottom surface was 5.8 ± 2.9 mm. In 38.8% of patients, at least 1 distance between Cx and LAA was smaller than 2 mm in at least 1 dimension. These distances occurred in 30.2% of the LAA landing zone dimensions, 19.8% of LAA neck bend dimensions, and 11.2% of the LAA bottom surface distances. Conclusions: The study showed that most dangerous distances (30.2%) occurred in the LAA landing zone dimension. The data showed that landing zones more distal from the orifice of the LAA are safer in terms of Cx damage. Therefore, LAA closure should always be performed with caution, to avoid iatrogenic complications.

Definition and anatomical description of the left atrial appendage neck

“…Our study is the first to define the LAA neck precisely and deliver data on its morphological features and subdivision into potentially clinically essential surfaces. The anatomic definition of the LAA neck provided in the current study incorporates the region defined by clinicians as the LAA landing zone—a crucial region of the heart for all LAA exclusion procedures (Batko et al, 2022; Grygier et al, 2018; Hindricks et al, 2021; Naksuk et al, 2016; Wang et al, 2010). Greater knowledge of the LAA anatomy may contribute to more efficient and safer performance of various procedures in this essential cardiac area.…”

“…Other closure methods may be more appropriate for patients with shorter central axis of the LAA neck (Lee & Hanke, 2022; Litwinowicz et al, 2021; Litwinowicz, Bartus, Kapelak, et al, 2019; Toale et al, 2019). One of the most dangerous complications associated with LAA exclusion procedures is damage or occlusion of the left circumflex coronary artery (Batko et al, 2022; Kuzmin et al, 2021). Some of the specific arrangements of coronary vessels within the LAA isthmus, localized inferiorly to the arterial surface, may predispose to severe vascular injury (Batko et al, 2022; Hołda, Hołda, et al, 2018; Hołda, Koziej, et al, 2018).…”

“…One of the most dangerous complications associated with LAA exclusion procedures is damage or occlusion of the left circumflex coronary artery (Batko et al, 2022; Kuzmin et al, 2021). Some of the specific arrangements of coronary vessels within the LAA isthmus, localized inferiorly to the arterial surface, may predispose to severe vascular injury (Batko et al, 2022; Hołda, Hołda, et al, 2018; Hołda, Koziej, et al, 2018). Additionally, the studied region is of great interest to electrophysiologists, as the mitral isthmus and LAA isthmus, where ablations are performed, are adjacent to the LAA ostium and neck (Hołda et al, 2017).…”

“…All the above procedures are performed in the LAA neck region, whose morphological feature is significant for percutaneously implanted devices. Therefore, the anatomy of the LAA neck and its surrounding area may influence the safety and efficacy of LAA closure procedures (Batko et al, 2022).…”

“…Other closure methods may be more appropriate for patients with shorter central axis of the LAA neck (Lee & Hanke, 2022;Litwinowicz et al, 2021;Toale et al, 2019). One of the most dangerous complications associated with LAA exclusion procedures is damage or occlusion of the left circumflex coronary artery (Batko et al, 2022;Kuzmin et al, 2021). Some of the specific arrangements of coronary vessels within the LAA isthmus, localized inferiorly to the arterial surface, may predispose to severe vascular injury (Batko et al, 2022;.…”