Faculty Bibliography

BACKGROUND AND AIM OF THE STUDY: Optimal repair of the mitral valve involves the implantation of an annuloplasty device to geometrically reshape and/or stabilize the annulus and improve long-term durability. It has been reported previously that trigone-to-trigone semi-rigid posterior band (PB) annuloplasty is associated with excellent short-term outcomes, physiologic motion of the anterior mitral annulus and leaflet, and lower postoperative transvalvular gradients compared to complete ring (CR) annuloplasty. The aim of this retrospective study was to compare the long-term effectiveness of PB and CR annuloplasty in patients with degenerative mitral valve regurgitation (MR). METHODS: Between 1993 and 2010, a total of 1,612 patients with degenerative MR underwent mitral valve repair (MVr) with either PB (n = 1,101) or CR (n = 511). Initially, CR was the annuloplasty device of choice, but after 2001 PB was preferred. A retrospective review of clinical and echocardiographic follow up was performed on these patients. The eight-year cumulative freedom from adverse events were determined by life-table analysis. RESULTS: Hospital mortality was 1.9% overall (n = 30/1612), but 1.3% (12/939) for isolated MVr, and 2.7% (18/673) for MVr with concomitant procedures (p = 0.04). Hospital mortality was similar for both PB (1.9%; 21/1101) and CR (1.8%; 9/511) (p = 0.8). The mean MR grade was reduced from 3.9 +/- 0.3 preoperatively to 0.6 +/- 0.9 at follow up using PB (p < 0.01), and from 3.9 +/- 0.4 to 0.9 +/- 0.9 using CR (p < 0.01). PB was associated with a similar long-term freedom from death (77 +/- 0.03% versus 83 +/- 0.02%; p = 0.4), reoperation (95 +/- 0.01% versus 92 +/- 0.01%; p = 0.06), and reoperation or recurrent severe MR (91 +/- 0.02% versus 92 +/- 0.01%; p = 0.7), and slightly greater freedom from valve-related complications compared to CR (91 +/- 0.02% versus 87 +/- 0.02%; p = 0.02). CONCLUSION: The long-term outcome of mitral valve annuloplasty with PB was comparable to that with CR for degenerative disease. Anterior annuloplasty was found to be unnecessary in this patient population.

BACKGROUND: There are limited data in the literature concerning the effect of a blood conservation strategy (BCS) on aortic valve replacement (AVR) patients. METHODS: From 2007 to 2011, 778 patients underwent AVR at a single institution. During this period, a multidisciplinary BCS was initiated with emphasis on limiting intraoperative hemodilution, tolerance of perioperative anemia, and blood management education for the cardiac surgery care providers. RESULTS: Mortality was 3.0% (23 of 778) overall and 1.7% (9 of 522) for isolated first-time AVR. There was no difference in rates of mortality (p = 0.5) or major complications (p = 0.4) between the pre-BCS and post-BCS groups; however, the BCS was associated with a lower risk of major complications (odds ratio, 1.7; p = 0.046) by multivariable analysis. The incidence of red blood cell (RBC) transfusion decreased from 82.9% (324 of 391) to 68.0% (263 of 387; p < 0.01). Of those patients who did not receive any day-of-operation RBC transfusions, 64.5% (191 of 296) did not receive any postoperative RBC transfusions. Lower risk of RBC transfusion was associated with isolated AVR (p < 0.01), a minimally invasive approach (p < 0.01), and BCS (p < 0.01), whereas a greater risk of RBC transfusion was associated with older age (p < 0.01), prior cardiac operation (p = 0.01), female sex (p < 0.01), and smaller body surface area (p < 0.01). Day-of-operation RBC transfusion of 2 units or more was associated with increased deaths (p = 0.01), prolonged intubation (p < 0.01), postoperative renal failure (p = 0.01), and increased incidence of any complication (p < 0.01). CONCLUSIONS: Perioperative BCS reduced RBC transfusion in AVR patients without an increase in mortality or morbidity. Guidelines for BCS in routine cardiac operations should be extended to AVR patients.

In the 1990s, the success of 'minimally invasive' laparoscopic operations in other surgical subspecialties sparked an interest in minimally-invasive approaches for cardiac surgery, specifically for mitral valve repair. In 1996 at New York University (NYU) we began our experience with minimally invasive mitral valve repair performed through a small right anterior mini-thoracotomy incision using the Port-Access system in a phase I clinical trial. This was the beginning of our extensive right mini-thoracotomy experience for mitral valve repair at NYU. Currently at our institution the preferred approach for the right mini-thoracotomy mitral valve surgery is through the 3rd or 4th interspace mini-thoracotomy incision. Perfusion is accomplished with direct aortic or femoral cannulation, long femoral venous cannula drainage, and a retrograde cardioplegia catheter placed trans-atrialy in the coronary sinus under TEE guidance. An antegrade cardioplegia and venting needle is placed in the ascending aorta and direct external aortic clamping is achieved with one of several specialized crossclamps. With over four decades of experience, more than 4,000 patients have undergone mitral valve repair at NYU including 1,922 performed through a right mini-thoracotomy. We have reported an overall operative mortality of 1.3%, 8-year freedom from reoperation of 95%, freedom from reoperation or severe recurrent mitral regurgitation of 93%, and freedom from all valve-related complications of 90% for our initial series of 1,071 right mini-thoracotomy mitral valve repair. Based on our extensive experience we believe that mitral valve repair through a right mini-thoracotomy provides a durable and safe alternative to a traditional sternotomy with the benefits of improved cosmesis, reduced post-operative pain, less blood loss with fewer blood transfusions, fewer infections, shorter length of stay, and faster return to activity. It is our standard of care approach for mitral valve surgery.

BACKGROUND: Minimally invasive mitral valve surgery (MIMVS) has become a standard technique to perform mitral valve surgery in many cardiac centers. However, there remains a question regarding when MIMVS should not be performed due to an increased surgical risk. Consequently, expert surgeons were surveyed regarding their opinions on patient factors, mitral valve pathology and surgical skills in MIMVS. METHODS: Surgeons experienced in MIMVS were identified through an electronic search of the literature. A link to an online survey platform was sent to all surgeons, as well as two follow-up reminders. Survey responses were then submitted to a central database and analyzed. RESULTS: The survey was completed by 20 surgeons. Overall results were not uniform with regard to contraindications to performing MIMVS. Some respondents do not consider left atrial enlargement (95% of surgeons), complexity of surgery (75%), age (70%), aortic calcification (70%), EuroSCORE (60%), left ventricular ejection fraction (55%), or obesity (50%) to be contraindication to surgery. Ninety percent of respondents believe more than 20 cases are required to gain familiarity with the procedure, while 85% believe at least one MIMVS case needs to be performed per week to maintain proficiency. Eighty percent recommend establishment of multi-institutional databases and standardized surgical mentoring courses, while 75% believe MIMVS should be incorporated into current training programs for trainees. CONCLUSIONS: These results suggest that MIMVS has been accepted as a treatment option for patients with mitral valve pathologies according the expert panel. Initial training and continuing practice is recommended to maintain proficiency, as well as further research and formalization of training programs.

OBJECTIVE: Recent Society of Thoracic Surgeons and Society of Cardiovascular Anesthesiologists (STS/SCA) guidelines highlight the safety of blood conservation strategies in routine cardiac surgery. We evaluated the feasibility and impact of such a program in complex aortic surgery. METHODS: Between March 2010 and October 2011, 63 consecutive aortic replacement procedures were performed: aortic root (n = 17; 27%), ascending aorta (n = 15; 23.8%), aortic arch (n = 19; 30.2%), descending aorta (n = 8; 12.7%), and thoracoabdominal aorta (n = 4; 6.3%). Aortic dissections were present in 32 patients. A multidisciplinary approach to blood conservation included minimal perioperative crystalloid, small priming circuits, hemoconcentration, meticulous hemostasis, and tolerance of postoperative anemia (hemoglobin of >/= 7mg/dL). RESULTS: Operative mortality was 11.1%. Multivariate predictors of mortality were low preoperative hematocrit (HCT, P = 0.05) and endocarditis (P = 0.021). Seventy-four percent of patients required no intraoperative packed red blood cell (pRBC) transfusion. For nondissection patients, 80.6% required /= 2 U (P = 0.001). CONCLUSIONS: These findings demonstrate that a perioperative blood conservation management strategy can be extended to complex aortic surgery and is associated with better clinical outcomes.

OBJECTIVES: Simulated mitral valve replacement may aid in the assessment of technical skills required for adequate performance in the operating room. We sought to design and assess a mitral valve replacement training station that is low-cost, nonperishable, portable, and reproducible as a first step in developing a mitral valve surgical skills curriculum. METHODS: Nineteen physicians (7 general surgery residents, 8 cardiothoracic surgery residents, and 4 attending cardiothoracic surgeons) underwent simulated mitral valve replacement testing. Simulated mitral valve replacement was performed on a training station consisting of a replaceable "mitral annulus" inside a restrictive "left atrium." Eight components of performance were graded on a 5-point scale. A composite score (100 point maximum) was calculated by weighting the grades by procedural time. The effect of training level was evaluated using analysis of variance and post hoc Tukey honestly significant difference. RESULTS: The speed of simulated mitral valve replacement varied among general surgery residents, cardiothoracic surgery residents, and attending cardiothoracic surgeons (52.9 +/- 9.0 vs 32.8 +/- 4.7 vs 28.0 +/- 3.5 minutes, respectively; F = 25.3; P < .001). Level of training significantly affected all 8 evaluation components (P < .001). Composite scores increased with level of training (general surgery residents 32.9 +/- 11.4, cardiothoracic surgery residents 65.1 +/- 11.5, and attending cardiothoracic surgeons 88.3 +/- 7.8 of a possible 100 points; F = 35.7; P < .001). Cardiothoracic surgery residents who reported having performed 10 to 50 mitral valve replacements as the primary surgeon had a composite score of 65.0 +/- 2.8 (P < .01 compared with attending cardiothoracic surgeons). CONCLUSIONS: Simulated mitral valve replacement can be performed using this simple, affordable, portable setup. Performance scores correlate with level of training and experience, but residents who performed 10 to 50 mitral valve replacements still failed to reach attending-level proficiency. This training simulator may facilitate skills practice and evaluation of competency in cardiac surgery trainees.

BACKGROUND: While it is known that band annuloplasty for functional mitral regurgitation (FMR) improves leaflet coaptation, the effect on regional coaptation geometry has not previously been well defined. We used three-dimensional transesophageal echocardiography (3D-TEE) to analyze the regional effects of semirigid band annuloplasty on annular geometry and leaflet coaptation zones of patients with FMR. METHODS: Sixteen patients with severe FMR underwent a semirigid band annuloplasty. Intraoperative full volume 3D-TEE datasets were acquired pre valve and post valve repair. Offline analysis assessed annular dimensions and regional coaptation zone geometry. The regions were defined as R1 (A1-P1), R2 (A2-P2), and R3 (A3-P3); coaptation distance, coaptation depth, and coaptation length were measured in each region. Differences were analyzed with repeated measures within a general linear model. RESULTS: Band annuloplasty decreased mitral regurgitation grade from 3.7 to 0.1 (scale 0 to 4). Annular septolateral dimension (p < 0.01) and coaptation distance (p < 0.01) decreased significantly in all regions. Likewise, anterior and posterior leaflet coaptation lengths increased in all regions (p < 0.01 and p = 0.05, respectively), with region 2 showing the greatest increase (p = 0.01). Changes in coaptation depth were not significant. CONCLUSIONS: Semirigid band annuloplasty for FMR produces significant regional remodeling of leaflet coaptation zones, with region 2 showing the greatest increase in leaflet coaptation length. This regional analysis of annular geometry and leaflet coaptation creates a framework to better understand the mechanisms of surgical success or failure of annuloplasty for FMR.

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.