Minimally Invasive Versus Conventional Open …

1 ORIGINALARTICLEM inimally Invasive Versus Conventional open Mitral ValveSurgeryA Meta-Analysis and Systematic ReviewDavy C. H. Cheng, MD,* Janet Martin, PharmD, MSc (HTA&M),* Avtar Lal, MD, PhD,*Anno Diegeler, MD, PhD, Thierry A. Folliguet, MD, L. Wiley Nifong, MD, Patrick Perier, MD, Ehud Raanani, MD, J. Michael Smith, MD,# Joerg Seeburger, MD,** and Volkmar Falk, MD Objective:This meta-analysis sought to determine whether mini-mally Invasive mitral valve surgery (mini-MVS) improves clinicaloutcomes and resource utilization compared with Conventional openmitral valve surgery (conv-MVS) in patients undergoing mitralvalve repair or :A comprehensive search of MEDLINE, CochraneLibrary, EMBASE, CTSnet, and databases of abstracts was under-taken to identify all randomized and nonrandomized studies up toMarch 2010 of mini-MVS through thoracotomy Versus conv-MVSthrough median sternotomy for mitral valve repair or of interest included death, stroke, myocardial infarction,aortic dissection, need for reintervention, and any other reportedclinically relevant outcomes or indicator of resource risk and weighted mean differences and their 95% confi-dence intervals were analyzed as appropriate using the randomeffects model.

2 Heterogeneity was measured using the :Thirty-five studies met the inclusion criteria (two random-ized controlled trials and 33 nonrandomized studies). The mortalityrate after mini-MVS Versus conv-MVS was similar at 30 days ( ), 1 year ( vs ), 3 years ( vs ), and 9years (0% vs ). A number of clinical outcomes were signifi-cantly improved with mini-MVS Versus conv-MVS including atrialfibrillation (18% vs 22%), chest tube drainage (578 vs 871 mL),transfusions, sternal infection ( vs ), time to return tonormal activity, and patient scar satisfaction. However, the 30-dayrisk of stroke ( vs ), aortic dissection/injury ( vs 0%),groin infection (2% vs 0%), and phrenic nerve palsy (3% vs 0%)were significantly increased for mini-MVS Versus conv-MVS. Otherclinical outcomes were similar between groups.

3 Cross-clamp time,cardiopulmonary bypass time, and procedure time were significantlyincreased with mini-MVS; however, ventilation time and length ofstay in intensive care unit and hospital were :Current evidence suggests that mini-MVS maybeassociated with decreased bleeding, blood product transfusion, atrialfibrillation, sternal wound infection, scar dissatisfaction, ventilationtime, intensive care unit stay, hospital length of stay, and reducedtime to return to normal activity, without detected adverse impact onlong-term need for valvular reintervention and survival beyond 1year. However, these potential benefits for mini-MVS may comewith an increased risk of stroke, aortic dissection or aortic injury,phrenic nerve palsy, groin infections/complications, and increasedcross-clamp, cardiopulmonary bypass, and procedure time.

4 Avail-able evidence is largely limited to retrospective comparisons ofsmall cohorts comparing mini-MVS Versus conv-MVS that provideonly short-term outcomes. Given these limitations, randomizedcontrolled trials with adequate power and duration of follow-up tomeasure clinically relevant outcomes are recommended to determinethe balance of benefits and Words:Systematic review, Meta-analysis, Mitral valve sur-gery, Minimally Invasive surgery .(Innovations2011;6:84 103)Accepted for publication December 31, the *Department of Anesthesia & Perioperative Medicine, Evidence-Based Perioperative Clinical Outcomes Research Group (EPiCOR), Lon-don Health Sciences Centre, University of Western Ontario, London, ONCanada; High Impact Technology Evaluation Centre, London HealthSciences Centre, London, ON Canada; Division of CardiothoracicSurgery, Herz-und Gefasse Klinik Bad Neustadt, Bad Neustadt, Ger-many; De partement de Pathologie Cardiaque, L Institut MutualisteMontsouris, Paris, France; Department of Cardiothoracic surgery , EastCarolina University School of Medicine, Greenville, NC USA; ShebaMedical Center, Tel Hashomer, Tel Aviv, Israel; #Cardiac, Vascular &Thoracic Surgeons, Inc.

5 , Cincinnati, OH USA; **Klinik fu r Herzchiru-rgie, Herzzentrum der Universita t Leipzig, Leipzig, Germany; and Klinik fu r Herz- und Gefa sschirurgie, Universita tsspital Zu rich,Zurich, by The International Society for Minimally Invasive Cardiotho-racic surgery (ISMICS), which has received unrestricted educationalgrants from industries that produce surgical technologies; and by theEvidence-Based Perioperative Clinical Outcomes Research Group (EPi-COR), Department of Anesthesia & Perioperative Medicine, Universityof Western Ontario, London, ON :J. Michael Smith, MD, serves as a scientific advisor toIntuitive Surgical, Inc., Sunnyvale, CA USA; AtriCure, West Chester, OHUSA; Edwards LifeSciences, Irvine, CA USA; and Ethicon Endo- surgery ,Inc., Cincinnati, OH USA. He is on the Speakers Bureau of IntuitiveSurgical and Edwards LifeSciences.

6 He receives no royalties or stipendsfrom any company. Volkmar Falk, MD, is a speaker and receives consult-ing fees for Medtronic, Inc., Minneapolis, MN USA; St. Jude Medical, , MN USA; Symetis, Lausanne, Switzerland; and Valtech Cardio, OrYehuda, correspondence and reprint requests to Davy C. H. Cheng, MD,LHSC-University Hospital, 339 Windermere Road, C3-172, London, ONCanada N6A 5A5. E-mail: 2011 by the International Society for Minimally InvasiveCardiothoracic SurgeryISSN: 1556-9845/11/0602-0084 Innovations Volume 6, Number 2, March/April 201184 RATIONALEI nterest in Minimally Invasive cardiac surgery continues togrow rapidly. Although conventionally mitral valve surgery hasbeen performed via a full incision through the sternum, a varietyof technologies and techniques have enabled Minimally invasivemitral valve surgery (mini-MVS) to be performed through oneor more small incisions in the thorax with assisted vision usingcameras.

7 In some cases, robotic surgery may be used for mini-MVS. The goal of mini-MVS is to reduce the surgical trauma tothe patient (presumably to reduce pain, scarring, and inflamma-tory response) while maintaining the proven surgical efficacy ofthe Conventional open , but not all, studies suggest that favorable out-comes are achieved using the Minimally Invasive approach tomitral valve surgery . A comprehensive meta-analysis ofavailable comparative studies (randomized and nonrandom-ized) is needed to better assess the risks Versus benefits ofmini-MVS Versus Conventional open mitral valve surgery (conv-MVS) through median sternotomy. One previousmeta-analysis of mini-MVS by Modi et al1has been pub-lished. However, a number of relevant studies were notidentified, and only some outcomes of interest were analyzedin the article.

8 Therefore, we conducted a systematic reviewwith meta-analysis to address the available evidence to datewhich compares mini-MVS via thoracotomy or parasternalapproach with conv-MVS through median objective of this systematic review with meta-analysis was to determine whether, in patients undergoingmitral valve surgery , mini-MVS improves postoperativecomplications and provides comparable or improved long-term clinical outcomes, quality of life, and cost-effectivenesscompared with answer this primary objective, the following sub-questions were prespecified to guide the systematic review:1. Does mini-MVS reduce risk of death compared withconv-MVS?2. Does mini-MVS reduce perioperative complicationscompared with conv-MVS?3. Does mini-MVS improve quality of life, functionality,or other patient-reported outcomes?

9 4. Does mini-MVS reduce total costs, intensive care unit(ICU) and hospital length of stay, need for repeatcardiac surgery , readmissions, and is it cost-effective?METHODSThis systematic review with meta-analysis of comparativestudies was performed in accordance with state-of-the-art meth-odological recommendations for randomized and observationalstudies (ie, as per the Quality of Reports of Meta-Analyses and Meta-Analysis of Observational Studies of Epidemiology, QUOROM and MOOSE guidelines, respectively)2,3and accord-ing to a protocol that prespecified outcomes, search strategies,inclusion criteria, and statistical endpoints of interest included postoperativeall-cause mortality, stroke, myocardial infarction, atrial fibril-lation, low cardiac output syndrome, need for antiarrhythmicdrugs, need for pacemaker, reexploration for bleeding, majorbleeding, transfusions, renal failure, heart failure, New YorkHeart Association (NYHA)

10 Class, reintervention for bleeding,reintervention for valvular repair or replacement, patientsatisfaction, functionality, quality of life, cross-clamp time,duration of surgery , ICU length of stay, total hospital lengthof stay, costs, and SearchA comprehensive literature search of MEDLINE,EMBASE, Cochrane CENTRAL, CTSnet, and databases ofconference abstracts using keywords and variants was per-formed from the earliest available date to March 2010. Searchterms included variants of surgical procedures, minimallyinvasive, mitral valve, thoracoscopic, and robotic. No limitswere placed on date, study design, or language. This was supple-mented with hand search from the selected articles and reviewarticles. Experts were contacted to solicit additional reports ofpublished or unpublished clinical studies of CriteriaTo be eligible for inclusion in the systematic reviewand meta-analysis, studies had to be randomized or nonran-domized comparative studies comparing mini-MVS (per-formed via thoracotomy through port-access or keyhole, witheither direct visualization or with camera or robotic assistancethrough lateral, parasternal, or xiphoid approaches) versusconv-MVS (performed via median sternotomy or parasternalapproach).