title: Augmented reality image guidance improves navigation for beating heart mitral valve repair.
abstract: OBJECTIVE
  Emerging off-pump beating heart valve repair techniques offer patients less invasive alternatives for mitral valve (MV) repair. However, most of these techniques rely on the limited spatial and temporal resolution of transesophageal echocardiography (TEE) alone, which can make tool visualization and guidance challenging.
  
  
  METHODS
  Using a magnetic tracking system and integrated sensors, we created an augmented reality (AR) environment displaying virtual representations of important intracardiac landmarks registered to biplane TEE imaging. In a porcine model, we evaluated the AR guidance system versus TEE alone using the transapically delivered NeoChord DS1000 system to perform MV repair with chordal reconstruction.
  
  
  RESULTS
  Successful tool navigation from left ventricular apex to MV leaflet was achieved in 12 of 12 and 9 of 12 (P = 0.2) attempts with AR imaging and TEE alone, respectively. The distance errors of the tracked tool tip from the intended midline trajectory (5.2 ± 2.4 mm vs 16.8 ± 10.9 mm, P = 0.003), navigation times (16.7 ± 8.0 seconds vs 92.0 ± 84.5 seconds, P = 0.004), and total path lengths (225.2 ± 120.3 mm vs 1128.9 ± 931.1 mm, P = 0.003) were significantly shorter in the AR-guided trials compared with navigation with TEE alone. Furthermore, the potential for injury to other intracardiac structures was nearly 40-fold lower when using the AR imaging for tool navigation. The AR guidance also seemed to shorten the learning curve for novice surgeons.
  
  
  CONCLUSIONS
  Augmented reality-enhanced TEE facilitates more direct and safe intracardiac navigation of the NeoChord DS tool from left ventricular apex to MV leaflet. Tracked tool path results demonstrate fourfold improved accuracy, fivefold shorter navigation times, and overall improved safety with AR imaging guidance.
authors.affiliation: Division of Cardiac Surgery, Department of Surgery, Western University, London, ON Canada. michael.chu@lhsc.on.ca
authors.forename: Michael W A
authors.initials: MW
authors.lastname: Chu
authors.forename: John
authors.initials: J
authors.lastname: Moore
authors.forename: Terry
authors.initials: T
authors.lastname: Peters
authors.forename: Daniel
authors.initials: D
authors.lastname: Bainbridge
authors.forename: David
authors.initials: D
authors.lastname: McCarty
authors.forename: Gerard M
authors.initials: GM
authors.lastname: Guiraudon
authors.forename: Chris
authors.initials: C
authors.lastname: Wedlake
authors.forename: Pencilla
authors.initials: P
authors.lastname: Lang
authors.forename: Martin
authors.initials: M
authors.lastname: Rajchl
authors.forename: Maria E
authors.initials: ME
authors.lastname: Currie
authors.forename: Richard C
authors.initials: RC
authors.lastname: Daly
authors.forename: Bob
authors.initials: B
authors.lastname: Kiaii
mesh_terms: D000818:Animals; D006348:Cardiac Surgical Procedures / Q000379:methods; D047549:Coronary Artery Bypass, Off-Pump; D004195:Disease Models, Animal; D017548:Echocardiography, Transesophageal / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000601:surgery*; D034421:Sus scrofa; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000295:instrumentation / Q000379:methods