A new transseptal solution for enabling left atrial access of large delivery sheaths

Background Transseptal access for large sheaths may be encumbered by tissue resistance against the sheath–dilator stepped interface. The ExpanSure Large Access Transseptal Dilator (Baylis Medical) is designed as a single introducer and dilation device with a smooth sheath–dilator transition to support transseptal puncture. It may facilitate ease and efficiency of interatrial crossing. Methods This study experimentally evaluated the crossing force of ExpanSure relative to a conventional 8.5 F Swartz SL1 transseptal sheath and dilator in a benchtop septum model. Its ability to reduce the subsequent crossing force of a 14 F WATCHMAN delivery sheath was also tested. The clinical use of ExpanSure, including procedure time, was then validated in a series of left atrial appendage closure (LAAC) procedures. Results In a benchtop septum model (N = 12), less peak force (1.90 ± 0.08 N vs. 2.36 ± 0.09 N; p