title: Minimally invasive mitral valve surgery expands the surgical options for high-risks patients.
abstract: BACKGROUND
  A simplified minimally invasive mitral valve surgery (MIMVS) approach avoiding cross-clamping and cardioplegic myocardial arrest using a small (5 cm) right antero-lateral incision was developed. We hypothesized that, in high-risk patients and in patients with prior sternotomy, this approach would yield superior results compared to those predicted by the Society of Thoracic Surgeons (STS) algorithm for standard median sternotomy mitral valve surgery.
  
  
  METHODS
  Five hundred and four consecutive patients (249 males/255 females), median age 65 years (range 20-92 years) underwent MIMVS between 1/06 and 8/09. Median preoperative New York Heart Association function class was 3 (range 1-4). Eighty-two (16%) patients had an ejection fraction ≤35%. Forty-seven (9%) had a STS predicted mortality ≥10%. Under cold fibrillatory arrest (median temperature 28°C) without aortic cross-clamp, mitral valve repair (224/504, 44%) or replacement (280/504, 56%) was performed.
  
  
  RESULTS
  Thirty-day mortality for the entire cohort was 2.2% (11/504). In patients with a STS predicted mortality ≥ 10% (range 10%-67%), the observed 30-day mortality was 4% (2/47), lower than the mean STS predicted mortality of 20%. Morbidity in this high-risk group was equally low: 1 of 47 (2%) patients underwent reexploration for bleeding, 1 of 47 (2%) patients suffered a permanent neurologic deficit, none had wound infection. The median length of stay was 8 days (range 1-68 days).
  
  
  CONCLUSIONS
  This study demonstrates that MIMVS without aortic cross-clamp is reproducible with low mortality and morbidity rates. This approach expands the surgical options for high-risk patients and yields to superior results than the conventional median sternotomy approach.
authors.affiliation: Vanderbilt Heart and Vascular Institute, Nashville, TN, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Petracek
authors.forename: Marzia
authors.initials: M
authors.lastname: Leacche
authors.forename: Natalia
authors.initials: N
authors.lastname: Solenkova
authors.forename: Ramanan
authors.initials: R
authors.lastname: Umakanthan
authors.forename: Rashid M
authors.initials: RM
authors.lastname: Ahmad
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Ball
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Hoff
authors.forename: Tarek S
authors.initials: TS
authors.lastname: Absi
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Balaguer
authors.forename: John G
authors.initials: JG
authors.lastname: Byrne
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures / Q000379:methods; D005260:Female; D006349:Heart Valve Diseases / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D008943:Mitral Valve / Q000601:surgery*; D012307:Risk Factors; D055815:Young Adult