Background: An inferoposterior transseptal puncture (TSP) is generally recommended for percutaneous left atrial appendage (LAA) closure. However, the LAA is a highly variable anatomical structure; this may impact the preferred TSP site.
Aims: This study aimed to determine the most optimal TSP site for percutaneous LAA closure in different LAA morphologies.
Methods: In this prospective study, 182 patients undergoing percutaneous LAA closure were included. The spatial relationship of the LAA to the fossa ovalis and its consequence for TSP was assessed at pre-procedural cardiac computed tomography (CCT).
Results: Based on CCT analysis, it was predicted that co-axial alignment between delivery sheath and LAA would be obtained by an inferoposterior, -central, or -anterior TSP in 75%, 16% and 8% of cases, respectively. This was also confirmed by procedural LAA angiogram in 175 cases (96%) with <30o angle between delivery sheath and LAA central axis. Multivariate logistic regression analysis identified reverse chicken wing LAA (Odds Ratio (OR) 6.36 [1.85-29.3]; P=0.005) and posterior bending of the proximal LAA (OR 17.2 [3.3-96.2]; P<0.001) as independent predictors of a central or anterior TSP – this to increase the chance of obtaining co-axial alignment between delivery sheath and LAA.
Conclusions: An inferoposterior TSP is recommended in a majority of percutaneous LAA closure procedures in order to obtain co-axial alignment between delivery sheath and LAA. An inferior but more central/anterior TSP should be recommended in case of a reverse chicken wing LAA or posterior bending of the proximal LAA, which occurs in 20-25% of cases.