title: Higher-risk mitral valve operations after previous sternotomy: endoscopic, minimally invasive approach improves patient outcomes.
abstract: BACKGROUND
  Reoperative mitral valve (MV) surgery is associated with significant morbidity and mortality; however, endoscopic minimally invasive surgical techniques may preserve the surgical benefits of conventional mitral operations while potentially reducing perioperative risk and length of stay (LOS) in hospital.
  
  
  METHODS
  We compared the outcomes of consecutive patients who underwent reoperative MV surgery between 2000 and 2014 using a minimally invasive endoscopic approach (MINI) with those of patients who underwent a conventional sternotomy (STERN). The primary outcome was in-hospital/30-day mortality. Secondary outcomes included blood product transfusion, LOS in hospital and in the intensive care unit (ICU), and postoperative complications.
  
  
  RESULTS
  We included 132 patients in our study: 40 (mean age 68 ± 14 yr, 70% men) underwent MINI and 92 (62 ± 13 yr, 40% men) underwent STERN. The MINI group had significantly more comorbidities than the STERN group. While there were no significant differences in complications, all point estimates suggested lower mortality and morbidity in the MINI than the STERN group (in-hospital/ 30-day mortality 5% v. 11%,p= 0.35; composite any of 10 complications 28% v. 41%,p= 0.13). Individual complication rates were similar between the MINI and STERN groups, except for intra-aortic balloon pump requirement (IABP; 0% v. 12%,p= 0.034). MINI significantly reduced the need for any blood transfusion (68% v. 84%,p= 0.036) or packed red blood cells (63% v. 79%,p= 0.042), fresh frozen plasma (35% v. 59%,p= 0.012) and platelets (20% v. 40%,p= 0.024). It also significantly reduced median hospital LOS (8 v. 12 d,p= 0.014). An exploratory propensity score analysis similarly demonstrated a significantly reduced need for IABP (p< 0.001) and a shorter mean LOS in the ICU (p= 0.046) and in hospital (p= 0.047) in the MINI group.
  
  
  CONCLUSIONS
  A MINI approach for reoperative MV surgery reduces blood product utilization and hospital LOS. Possible clinically relevant differences in perioperative complications require assessment in randomized clinical trials.
authors.affiliation: From the Division of Cardiac Surgery, Department of Surgery, Western University, Lawson Health Research Institute, London, Ont., (Losenno, Valdis, Fox, Kiaii, Chu); and the Department of Anesthesia & Perioperative Medicine and Epidemiology & Biostatistics, Western University, London, Ont., (Jones).
authors.forename: Katie L
authors.initials: KL
authors.lastname: Losenno
authors.affiliation: From the Division of Cardiac Surgery, Department of Surgery, Western University, Lawson Health Research Institute, London, Ont., (Losenno, Valdis, Fox, Kiaii, Chu); and the Department of Anesthesia & Perioperative Medicine and Epidemiology & Biostatistics, Western University, London, Ont., (Jones).
authors.forename: Philip M
authors.initials: PM
authors.lastname: Jones
authors.affiliation: From the Division of Cardiac Surgery, Department of Surgery, Western University, Lawson Health Research Institute, London, Ont., (Losenno, Valdis, Fox, Kiaii, Chu); and the Department of Anesthesia & Perioperative Medicine and Epidemiology & Biostatistics, Western University, London, Ont., (Jones).
authors.forename: Matthew
authors.initials: M
authors.lastname: Valdis
authors.affiliation: From the Division of Cardiac Surgery, Department of Surgery, Western University, Lawson Health Research Institute, London, Ont., (Losenno, Valdis, Fox, Kiaii, Chu); and the Department of Anesthesia & Perioperative Medicine and Epidemiology & Biostatistics, Western University, London, Ont., (Jones).
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Fox
authors.affiliation: From the Division of Cardiac Surgery, Department of Surgery, Western University, Lawson Health Research Institute, London, Ont., (Losenno, Valdis, Fox, Kiaii, Chu); and the Department of Anesthesia & Perioperative Medicine and Epidemiology & Biostatistics, Western University, London, Ont., (Jones).
authors.forename: Bob
authors.initials: B
authors.lastname: Kiaii
authors.affiliation: From the Division of Cardiac Surgery, Department of Surgery, Western University, Lawson Health Research Institute, London, Ont., (Losenno, Valdis, Fox, Kiaii, Chu); and the Department of Anesthesia & Perioperative Medicine and Epidemiology & Biostatistics, Western University, London, Ont., (Jones).
authors.forename: Michael W A
authors.initials: MW
authors.lastname: Chu
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058386:Mitral Valve Annuloplasty / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D010043:Outcome and Process Assessment, Health Care; D011183:Postoperative Complications; D012086:Reoperation / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D012189:Retrospective Studies; D056346:Sternotomy / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D013906:Thoracoscopy / Q000009:adverse effects / Q000379:methods* / Q000401:mortality