title: Minimally invasive versus conventional mitral valve surgery: a propensity-matched comparison.
abstract: OBJECTIVE
  Less invasive approaches to mitral valve surgery are increasingly used for improved cosmesis; however, few studies have investigated their effect on outcome. We sought to compare these minimally invasive approaches fairly with conventional full sternotomy by using propensity-matching methods.
  
  
  METHODS
  From January 1995 to January 2004, 2124 patients underwent isolated mitral valve surgery through a minimally invasive approach, and 1047 underwent isolated mitral valve surgery through a conventional sternotomy. Because there were important differences in patient characteristics, a propensity score based on 42 factors was used to obtain 590 well-matched patient pairs (56% of cases).
  
  
  RESULTS
  In-hospital mortality was similar for propensity-matched patients: 0.17% (1/590) for those undergoing minimally invasive surgery and 0.85% (5/590) for those undergoing conventional surgery (P = .2). Occurrences of stroke (P = .8), renal failure (P > .9), myocardial infarction (P = .7), and infection (P = .8) were also similar. However, 24-hour mediastinal drainage was less after minimally invasive surgery (median, 250 vs 350 mL; P < .0001), and fewer patients received transfusions (30% vs 37%, P = .01). More patients undergoing minimally invasive surgery were extubated in the operating room (18% vs 5.7%, P < .0001), and postoperative forced expiratory volume in 1 second was higher. Early after operation, pain scores were lower (P < .0001) after minimally invasive surgery.
  
  
  CONCLUSIONS
  Within that portion of the spectrum of mitral valve surgery in which propensity matching was possible, minimally invasive mitral valve surgery had cosmetic, blood product use, respiratory, and pain advantages over conventional surgery, and no apparent detriments. Mortality and morbidity for robotic and percutaneous procedures should be compared with these minimally invasive outcomes.
authors: Center for Aortic Surgery and Marfan and Connective Tissue Disorder Clinic, the Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute, 9500 Euclid Ave/Mail Stop J4-1, Cleveland, OH 44195, USA. svenssl@ccf.org
authors: Lars G
authors: LG
authors: Svensson
authors: Fernando A
authors: FA
authors: Atik
authors: Delos M
authors: DM
authors: Cosgrove
authors: Eugene H
authors: EH
authors: Blackstone
authors: Jeevanantham
authors: J
authors: Rajeswaran
authors: Gita
authors: G
authors: Krishnaswamy
authors: Ung
authors: U
authors: Jin
authors: A Marc
authors: AM
authors: Gillinov
authors: Brian
authors: B
authors: Griffin
authors: José L
authors: JL
authors: Navia
authors: Tomislav
authors: T
authors: Mihaljevic
authors: Bruce W
authors: BW
authors: Lytle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; 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*; D057216:Propensity Score; D012042:Registries; D012189:Retrospective Studies; D013249:Sternum; D013908:Thoracotomy; D016896:Treatment Outcome; D055815:Young Adult