title: Value of augmented reality-enhanced transesophageal echocardiography (TEE) for determining optimal annuloplasty ring size during mitral valve repair.
abstract: BACKGROUND
  Mitral valve (MV) annuloplasty is an integral part of MV repair, but sizing under direct vision is occasionally challenging. Furthermore, traditional sizing is not possible for percutaneous MV repair techniques. This study compared augmented reality-enhanced three-dimensional (3D) transesophageal echocardiography (TEE) for determining MV annuloplasty size with conventional surgical sizing.
  
  
  METHODS
  In patients undergoing elective MV repair, a 3D MV reconstruction was performed using TEE. Modified 4D valve assessment software was used to create 3D computer-aided design models of standard annuloplasty rings (28 to 36 mm), which were stored in a digital database. These virtual 3D annuloplasty ring templates were superimposed on the preoperative 3D TEE reconstructions of the MV, and results were compared with conventional sizing under direct vision. A post hoc validation of the 3D models was performed using the implanted rings as a control. The echocardiographer was blinded to the implanted ring size.
  
  
  RESULTS
  The study included 50 patients. The correlation between the selected 3D annuloplasty ring template and the implanted annuloplasty ring size was 0.83. Thirty ring templates (60%) were the same size as the implanted annuloplasty ring, 19 templates (38%) differed by +/-2 mm in size, and 1 template differed by +4 mm. Postoperatively, the validation protocol revealed a correlation of 0.94 between the size of the ring templates and the implanted annuloplasty prostheses.
  
  
  CONCLUSIONS
  Augmented reality-enhanced TEE for determining optimal annuloplasty ring size during MV repair correlates well with conventional surgical sizing and may facilitate future percutaneous MV repair techniques.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine II, Leipzig Heart Center, University of Leipzig, Leipzig, Germany. joerg.ender@medizin.uni-leipzig.de
authors.forename: Joerg
authors.initials: J
authors.lastname: Ender
authors.forename: Jasmina
authors.initials: J
authors.lastname: Koncar-Zeh
authors.forename: Chirojit
authors.initials: C
authors.lastname: Mukherjee
authors.forename: Stephan
authors.initials: S
authors.lastname: Jacobs
authors.forename: Michael A
authors.initials: MA
authors.lastname: Borger
authors.forename: Christoph
authors.initials: C
authors.lastname: Viola
authors.forename: Michael
authors.initials: M
authors.lastname: Gessat
authors.forename: Jens
authors.initials: J
authors.lastname: Fassl
authors.forename: Friedrich W
authors.initials: FW
authors.lastname: Mohr
authors.forename: Volkmar
authors.initials: V
authors.lastname: Falk
mesh_terms: D000328:Adult; D000465:Algorithms; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000601:surgery*; D016343:Monitoring, Intraoperative; D011474:Prosthesis Design; D017755:Prosthesis Fitting / Q000379:methods*