Virtual Reality Computed Tomography Evaluation　― Anatomy and Clinical Implications for Valve-Sparing Aortic Root Replacement ―

Abstract

Background: Three-dimensional aortic root evaluation using virtual reality (VR) techniques for valve-sparing aortic root replacement (VSARR) preparation has not yet been implemented, so we demonstrated VR computed tomography (VR-CT) and assessed its utility for VSARR. Methods and Results:We enrolled 72 patients who underwent multidetector CT before elective VSARR for annuloaortic ectasia with tricuspid aortic valve. The geometries of their aortic roots were measured with a VR-CT workstation. The mean values of geometric height (GH), free margin length (FML), and commissural height (CH) were 17.2±2.4 mm, 36.0±5.2 mm, and 24.0±4.3 mm, respectively. The right coronary/noncoronary CH was significantly greater than the left coronary/right coronary and left coronary/ noncoronary CH. The left coronary cusp had the shortest FML, intercommissural distances (ICD), and smallest central angle. Although the right coronary cusp had the largest values for FML, ICD, and central angle, the right coronary cusp had the lowest GH and EH. The VR-CT measurements strongly correlated with intraoperative alternatives, especially with mean GH (R 2 =0.75) and left coronary/noncoronary CH (R 2 =0.79). Furthermore, mean GH was observed to be significantly different among the selected graft size groups; therefore, the preoperative mean GH could play a significant role in graft sizing.Conclusions: VR-CT evaluation allows a thorough understanding of aortic root anatomy, which could facilitate VSAAR.