Three-dimensional Transesophageal Echocardiography for Transcatheter Patent Foramen Ovale Closure: Standardizing Anatomic Nomenclature and Novel Sizing Concepts.

• Terminology for PFO tunnel sizing remains unstandardized. • Device size selection for transcatheter PFO closure is highly variable. • Tunnel width measurements may be a better descriptor of PFO size. • Wire sizing may be a useful technique for assessment of PFO dimensions. • PFO sizing strategies based on tunnel width need to be better studied.