Faculty Bibliography

OBJECTIVE: Perfusion strategies and operative techniques for minimally invasive mitral valve repair have evolved over time. During the past decade, our institution's approach has progressed from a port access platform with femoral perfusion to predominantly a central aortic cannulation through a right anterior minithoracotomy incision. We analyzed this institutional experience to evaluate the impact of approach on patient outcomes. METHODS: Between 1995 and 2007, 1282 patients (mean age, 59.3 years; range, 18-99 years) underwent first-time, isolated mitral valve repair using a minimally invasive technique. Patient demographics included peripheral vascular disease (3.2%), chronic obstructive pulmonary disease (8.3%), atherosclerotic aorta (6.5%), cerebrovascular disease (4.3%), and ejection fraction less than 30% (4.3%). Retrograde perfusion was performed in 394 (30.7%) of all patients and endoaortic balloon occlusion in 373 (29.1%); the operative technique was a right anterior minithoracotomy in 1264 (98.6%) and left posterior minithoracotomy in 18 (1.4%). The etiology of mitral disease was degenerative in 73.2%, functional in 20.6%, and rheumatic in 2.4%. Data were collected prospectively using the New York State Cardiac Surgery Report System and a customized minimally invasive surgery data form. Logistic analysis was used to evaluate risk factors and outcomes; operative experience was divided into tertiles. RESULTS: Overall hospital mortality was 2.0% (25/1282). Mortality was 1.1% (10/939) for patients with degenerative etiology and 0.4% (3/693) for patients younger than 70 years of age with degenerative valve disease. Risk factors for death were advanced age (P = .007), functional etiology (P = .010; odds ratio [OR] = 3.3), chronic obstructive pulmonary disease (P = .013; OR = 3.4), peripheral vascular disease (P = .014; OR = 4.2), and atherosclerotic aorta (P = .03; OR = 2.8). Logistic risk factors for neurologic events were advanced age (P = .02), retrograde perfusion (P = .001; OR = 3.8), and emergency procedure (P = .01; OR = 66.6). Interaction modeling revealed that the only significant risk factor for neurologic event was the use of retrograde perfusion in high-risk patients with aortic disease (P = .04; OR = 8.5). Analysis of successive tertiles during this 12-year experience revealed a significant decrease in the use of retrograde arterial perfusion (89.6%, 10.4%, and 0.0%; P < .001) and endoaortic balloon occlusion (89.3%, 10.7%, and 0%; P < .001). The overall frequency of postoperative neurologic events was 2.3% (30/1282) and decreased from 4.7% in the first tertile to 1.2% in the second and third tertiles (P < .001). CONCLUSIONS: Central aortic cannulation through a right anterior minithoracotomy for mitral valve repair allows excellent outcomes in patients with a broad spectrum of comorbidities and has become our preferred approach for most patients undergoing mitral valve repair. Retrograde arterial perfusion is associated with an increased risk of stroke in patients with severe peripheral vascular disease and should be reserved for select patients without significant atherosclerosis.

BACKGROUND: A Society of Thoracic Surgeons' publication recently associated 'minimally invasive' approaches with increased neurologic complications; this proposed association was questionable due to imprecise definitions. To critically reevaluate this issue, we reviewed a large minimally invasive valve experience with robust definitions. METHODS: From November 1995 to January 2007, 3,180 isolated, non-reoperative valve operations were performed; 1,452 (45.7%) were aortic replacements and 1,728 (54.3%) were mitral valve procedures. Surgical approach was standard sternotomy (28%) or minimally invasive technique (72%). Antegrade arterial perfusion was used in 2,646 (83.2%) patients and retrograde perfusion in 534 (16.8%). Aortic clamping was direct in 83.4%, with endoclamp in 16.4% and no clamp in 0.2%. Patients were prospectively followed in a proprietary database and the New York State Cardiac Surgery Reporting System (mandatory, government audited). A neurologic event was defined as a permanent deficit, a transient deficit greater than 24 hours, or a new lesion on cerebral imaging. RESULTS: Hospital mortality for aortic valve replacement was 4.0% (sternotomy [5.1%] versus minimally invasive [3.4%] p = 0.13); for mitral procedures it was 2.4% (sternotomy [4.8%] versus minimally invasive [1.8%] p = 0.001). Multivariate analysis revealed that age, female gender, renal disease, ejection fraction less than 0.30, chronic obstructive pulmonary disease, and emergent operation were risk factors for mortality. Stroke occurred in 71 patients (2.2%) (sternotomy [2.1%] versus minimally invasive [2.3%] p = 0.82). Multivariate analysis of neurologic events revealed that cerebrovascular disease, emergency procedure, no-clamp, and retrograde perfusion were risk factors. In patients 50 years old or younger (n = 662), retrograde perfusion had no significant impact on neurologic events (1.6% vs 1.1%, p = 0.57). CONCLUSIONS: A minimally invasive approach with antegrade perfusion does not result in increased neurologic complications. Retrograde perfusion, however, is associated with increased neurologic risk in older patients

OBJECTIVE: Current video-assisted thoracoscopic surgery training models rely on animals or mannequins to teach procedural skills. These approaches lack inherent teaching/testing capability and are limited by cost, anatomic variations, and single use. In response, we hypothesized that video-assisted thoracoscopic surgery right upper lobe resection could be simulated in a virtual reality environment with commercial software. METHODS: An anatomy explorer (Maya [Autodesk Inc, San Rafael, Calif] models of the chest and hilar structures) and simulation engine were adapted. Design goals included freedom of port placement, incorporation of well-known anatomic variants, teaching and testing modes, haptic feedback for the dissection, ability to perform the anatomic divisions, and a portable platform. RESULTS: Preexisting commercial models did not provide sufficient surgical detail, and extensive modeling modifications were required. Video-assisted thoracoscopic surgery right upper lobe resection simulation is initiated with a random vein and artery variation. The trainee proceeds in a teaching or testing mode. A knowledge database currently includes 13 anatomic identifications and 20 high-yield lung cancer learning points. The 'patient' is presented in the left lateral decubitus position. After initial camera port placement, the endoscopic view is displayed and the thoracoscope is manipulated via the haptic device. The thoracoscope port can be relocated; additional ports are placed using an external 'operating room' view. Unrestricted endoscopic exploration of the thorax is allowed. An endo-dissector tool allows for hilar dissection, and a virtual stapling device divides structures. The trainee's performance is reported. CONCLUSIONS: A virtual reality cognitive task simulation can overcome the deficiencies of existing training models. Performance scoring is being validated as we assess this simulator for cognitive and technical surgical education

OBJECTIVE: Functional ischemic mitral regurgitation is a complication of ventricular remodeling; standard therapy is reduction annuloplasty and coronary artery bypass grafting. Unfortunately, outcomes are retrospective and contradictory. We report a multicenter study that documents the outcomes of reduction annuloplasty for functional ischemic mitral regurgitation. METHODS: Twenty-one centers randomized 75 patients to the coronary artery bypass grafting + reduction annuloplasty subgroup that was the control arm of the Randomized Evaluation of a Surgical Treatment for Off-pump Repair of the Mitral Valve trial. Entry criteria included patients requiring revascularization, patients with severe or symptomatic moderate functional ischemic mitral regurgitation, an ejection fraction 25% or greater, a left ventricular end-diastolic dimension 7.0 cm or less, and more than 30 days since acute myocardial infarction. All echocardiograms were independently scored by a core laboratory. Reduction annuloplasty was achieved by device annuloplasty. Two patients underwent immediate intraoperative conversion to a valve replacement because reduction annuloplasty was unable to correct mitral regurgitation; as-treated results are presented. RESULTS: Thirty-day mortality was 4.1% (3/73). Patients received an average of 2.8 bypass grafts. Mean follow-up was 24.6 months. Mitral regurgitation was reduced from 2.6 +/- 0.8 preoperatively to 0.3 +/- 0.6 at 2 years. Freedom from death or valve reoperation was 78% +/- 5% at 2 years. There was significant improvement in ejection fraction and New York Heart Association class with reduction of left ventricular end-diastolic dimension. Cox regression analyses suggested that increasing age (P = .001; hazard ratio, 1.16 per year; 95% confidence interval, 1.06-1.26) and renal disease (P = .018; hazard ratio, 3.48; 95% confidence interval, 1.25-9.72) were associated with decreased survival. CONCLUSIONS: Coronary artery bypass grafting + reduction annuloplasty for functional ischemic mitral regurgitation predictably reduces mitral regurgitation and relieves symptoms. This treatment of moderate to severe mitral regurgitation is associated with improved indices of ventricular function, improved New York Heart Association class, and excellent freedom from recurrent mitral insufficiency. Although long-term prognosis remains guarded, this multicenter study delineates the intermediate-term benefits of such an approach

Evaluation of: Chikwe J, Goldstone AB, Passage J et al.: A propensity score-adjusted retrospective comparison of early- and mid-term results of mitral-valve repair versus replacement in octogenarians. Eur. Heart J. 32(5), 618-626 (2011). Mitral regurgitation (MR) is common in the elderly, increasing in prevalence with age. Common causes of MR include: degenerative disease of the valve and subvalvular apparatus; ischemic MR due to annular dilatation, papillary muscle displacement and left ventricular remodeling; rheumatic mitral valve disease and infectious endocarditis. The optimal treatment of severe mitral insufficiency in the elderly remains unknown. Mitral-valve repair or replacement have historically been considered high risk in older patients and, for this reason, many elderly patients are not offered surgery. Yet with recent advances in surgical techniques and outcomes, mitral-valve surgery is being increasingly utilized in elderly patients. A recent study by Chikwe et al. in the European Heart Journal examines overall and comparative outcomes of mitral-valve repair and mitral-valve replacement in an elderly cohort. This study finds that mitral-valve repair confers a survival benefit relative to mitral-valve replacement in octogenarians, particularly in patients undergoing surgery for degenerative disease. 2011 Future Medicine Ltd

OBJECTIVES: We sought to determine whether patients with functional mitral regurgitation (FMR) would benefit from ventricular reshaping by the Coapsys device (Myocor, Inc., Maple Grove, Minnesota). BACKGROUND: FMR occurs when ventricular remodeling impairs valve function. Coapsys is a ventricular shape change device placed without cardiopulmonary bypass to reduce FMR. It compresses the mitral annulus and reshapes the ventricle. We hypothesized that Coapsys for FMR would improve clinical outcomes compared with standard therapies. METHODS: RESTOR-MV (Randomized Evaluation of a Surgical Treatment for Off-Pump Repair of the Mitral Valve) was a randomized, prospective, multicenter study of patients with FMR and coronary disease with core laboratory analysis. After enrollment, patients were stratified to the standard indicated surgery: either coronary artery bypass graft alone or coronary artery bypass graft with mitral valve repair. In each stratum, randomization was to either control (indicated surgery) or treatment (coronary artery bypass graft with Coapsys ventricular reshaping). RESULTS: The study was terminated when the sponsor failed to secure ongoing funding; 165 patients were randomized. Control and Coapsys both produced decreases in left ventricular (LV) end-diastolic dimension and MR at 2 years (p < 0.001); Coapsys provided a greater decrease in LV end-diastolic dimension (p = 0.021). Control had lower MR grades during follow-up (p = 0.01). Coapsys showed a survival advantage compared with control at 2 years (87% vs. 77%) (hazard ratio: 0.421; 95% confidence interval: 0.200 to 0.886; stratified log-rank test; p = 0.038). Complication-free survival (including death, stroke, myocardial infarction, and valve reoperation) was significantly greater with Coapsys at 2 years (85% vs. 71%) (hazard ratio: 0.372; 95% confidence interval: 0.185 to 0.749; adjusted log-rank test; p = 0.019). CONCLUSIONS: Analysis of RESTOR-MV indicates that patients with FMR requiring revascularization treated with ventricular reshaping rather than standard surgery had improved survival and a significant decrease in major adverse outcomes. This trial validates the concept of the ventricular reshaping strategy in this subset of patients with heart failure. (Randomized Evaluation of a Surgical Treatment for Off-Pump Repair of the Mitral Valve [RESTOR-MV]; NCT00120276)

BACKGROUND: Elderly patients requiring reoperative cardiac surgery for valve disease are considered high risk for immediate outcomes, but little is known about their long-term survival. It is often conjectured that medical therapy provides equivalent late survival in this population, which may dissuade both patient and surgeon from considering reoperation. We analyzed a cohort of such patients undergoing reoperative valve surgery to determine their long-term survival. METHODS: From 1992 through 2007, 363 patients aged 75 years or more underwent reoperative isolated valve surgery; 211 (58%) had aortic valve replacement and 152 (42%) had mitral valve surgery. Mean age was 80.5 years. Hospital outcomes were prospectively recorded. Survival from all-cause death was determined from the Social Security Death Index. RESULTS: Hospital mortality was 13.8% (12.8% for aortic and 15.1% for mitral valve operations; p = 0.52). Multivariable predictors of hospital death were New York Heart Association functional class III or IV heart failure (odds ratio = 3.19, p = 0.012), dialysis (odds ratio = 15.63, p = 0.003), and more than one reoperation (odds ratio = 2.59, p = 0.058). At 5 years, overall survival was 62% +/- 3% for all patients (66% +/- 4% for aortic and 56% +/- 4% for mitral valve patients). For aortic valve patients aged 80 years or more, 5-year survival was 60% +/- 0.6%. Life expectancy table analysis predicted a 5-year survival of 57% for an age-matched and sex-matched comparison group. CONCLUSIONS: Reoperative surgery for elderly patients with isolated aortic or mitral valve pathology is associated with excellent long-term survival, particularly when treating aortic valve disease. While in-hospital mortality is higher among the elderly than among younger patients, specific predictors of poor outcome can be identified preoperatively to risk stratify these patients