Faculty Bibliography

BACKGROUND: The role of posterior papillary muscle anchoring (PPMA) in the management of chronic ischemic mitral regurgitation (CIMR) is controversial. We studied the effect of anchoring point direction and relocation displacement on left ventricular (LV) regional myofiber stress and pump function. METHODS: Previously described finite element models of sheep 16 weeks after posterolateral myocardial infarction (MI) were used. True-sized mitral annuloplasty (MA) ring insertion plus different PPM anchoring techniques were simulated. Anchoring points tested included both commissures and the central anterior mitral annulus; relocation displacement varied from 10% to 40% of baseline diastolic distance from the PPM to the anchor points on the annulus. For each reconstruction scenario, myofiber stress in the MI, border zone, and remote myocardium as well as pump function were calculated. RESULTS: PPMA caused reductions in myofiber stress at end-diastole and end-systole in all regions of the left ventricle that were proportional to the relocation displacement. Although stress reduction was greatest in the MI region, it also occurred in the remote region. The maximum 40% displacement caused a slight reduction in LV pump function. However, with the correction of regurgitation by MA plus PPMA, there was an overall increase in forward stroke volume. Finally, anchoring point direction had no effect on myofiber stress or pump function. CONCLUSIONS: PPMA reduces remote myofiber stress, which is proportional to the absolute distance of relocation and independent of anchoring point. Aggressive use of PPMA techniques to reduce remote myofiber stress may accelerate reverse LV remodeling without impairing LV function.

Primary tumors of the aorta are rare entities. We report the unusual manifestation of an aortic intimal sarcoma that presented as a brain metastasis in a 56-year-old, otherwise healthy woman. After the brain mass had been resected, multiple imaging methods revealed pseudocoarctation and the primary tumor in the aortic arch. To our knowledge, this is the first report of the diagnosis of an aortic intimal sarcoma with use of real-time, 3-dimensional transesophageal echocardiography.

Objective: Calculate changes in leaflet coaptation and stresses on mitral valve (MV) and left ventricle (LV) resulting from MV repair in a patient with posterior leaflet (P2) prolapse degenerative mitral regurgitation (MR). Analyze three mitral annuloplasty (MA) devices, each in four sizes, to assess impact of ring shape and size on leaflet and LV stress. Methods: Magnetic resonance imaging (MRI) was performed before and intra-operative 3D trans-esophageal echocardiogram (TEE) was performed before and after repair of P2 prolapse in a single patient. Repair included triangular resection and placement of a CG Future partial annuloplasty band. MRI and TEE images were co-registered to create a 3D finite-element model. Elements of the P2 region were removed to model leaflet resection, and virtual sutures were used to repair the leaflet and attach the MA ring. The model was optimized to match leaflet coaptation, end-diastolic volume, and end-systolic volume from the imaging data. Two additional rings were digitized using microCT. Simulations were completed in four sizes for each ring. Anterior and posterior leaflet and LV myofiber stress were compared. Results: All three rings abol- ished regurgitation. Repair decreased stress in the anterior leaflet and LV wall during diastole and systole but increased posterior leaflet stress. Compared to a flat ring, saddle-shape increased anterior leaflet stress while decreasing posterior leaflet and myofiber stress at end-diastole. At end-systole, saddle-shape decreased leaflet and myofiber stress modestly. As ring size decreased, leaflet and myofiber stress and orifice area decreased regardless of ring shape. Undersizing the ring by two sizes decreased anterior leaflet stress by 12.4+5.8% and posterior leaflet stress by 14.1+3.0% (averaged across all ring shapes). Conclusions: None of the studied ring shapes was superior in all categories. Undersizing was associated with decreased end-systolic anterior leaflet, posterior leaflet, and myofiber stress and also de!

BACKGROUND: Recurrent mitral regurgitation after mitral valve (MV) repair for degenerative disease occurs at a rate of 2.6% per year and reoperation rate progressively reaches 20% at 19.5 years. We believe that MV repair durability is related to initial postoperative leaflet and annular geometry with subsequent leaflet remodeling due to stress. We tested the hypothesis that MV leaflet and annular stress is increased after MV repair. METHODS: Magnetic resonance imaging was performed before and intraoperative three-dimensional (3D) transesophageal echocardiography was performed before and after repair of posterior leaflet prolapse in a single patient. The repair consisted of triangular resection and annuloplasty band placement. Images of the heart were manually co-registered. The left ventricle and MV were contoured, surfaced, and a 3D finite element (FE) model was created. Elements of the posterior leaflet region were removed to model leaflet resection and virtual sutures were used to repair the leaflet defect and attach the annuloplasty ring. RESULTS: The principal findings of the current study are the following: (1) FE simulation of MV repair is able to accurately predict changes in MV geometry including changes in annular dimensions and leaflet coaptation; (2) average posterior leaflet stress is increased; and (3) average anterior leaflet and annular stress are reduced after triangular resection and mitral annuloplasty. CONCLUSIONS: We successfully conducted virtual mitral valve prolapse repair using FE modeling methods. Future studies will examine the effects of leaflet resection type as well as annuloplasty ring size and shape.

BACKGROUND: Since the first aortic valve replacement through a right thoracotomy was reported in 1993, upper hemisternotomy and right anterior thoracotomy have become the predominant approaches for minimally invasive aortic valve replacement. Clinical studies have documented equivalent operative mortality, less bleeding, and reduced intensive care/hospital stay compared with conventional sternotomy despite longer procedure times. However, comparative trials face challenges due to patient preference, surgeon bias, and the lack of a standardized minimally invasive surgical approach. METHODS: Twenty cardiothoracic surgeons from 19 institutions across the United States, with a combined experience of nearly 5000 minimally invasive aortic valve replacement operations, formed a working group to develop a basis for a standardized approach to patient evaluation, operative technique, and postoperative care. In addition, a stepwise learning program for surgeons was outlined. RESULTS: Improved cosmesis, less pain and narcotic use, and faster recovery have been reported and generally accepted by patients and by surgeons performing minimally invasive aortic valve replacement. These benefits are more likely to be verified with standardization of the procedure itself, which will greatly facilitate the design and implementation of future clinical studies. CONCLUSIONS: Surgeons interested in learning and performing minimally invasive aortic valve replacement must have expertise in conventional aortic valve replacement at centers with adequate case volumes. A team approach that coordinates efforts of the surgeon, anesthesiologist, perfusionist, and nurses is required to achieve the best clinical outcomes. By first developing fundamental minimally invasive skills using specialized cannulation techniques, neck lines, and long-shafted instruments in the setting of conventional full sternotomy, the safest operative environment is afforded to patients.

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.

OBJECTIVE: A concern with the initiation of totally endoscopic robotic mitral valve repair (TERMR) programs has been the risk for the learning curve. To minimize this risk, we initiated a TERMR program with a defined team and structured learning approach before clinical implementation. METHODS: A dedicated team (two surgeons, one cardiac anesthesiologist, one perfusionist, and two nurses) was trained with clinical scenarios, simulations, wet laboratories, and "expert" observation for 3 months. This team then performed a series of TERMRs of varying complexity. RESULTS: Thirty-two isolated TERMRs were performed during the first programmatic year. All operations included mitral valve repair, left atrial appendage exclusion, and annuloplasty device implantation. Additional procedures included leaflet resection, neochordae insertion, atrial ablation, and papillary muscle shortening. Longer clamp times were associated with number of neochordae (P < 0.01), papillary muscle procedures (P < 0.01), and leaflet resection (P = 0.06). Sequential case number had no impact on cross-clamp time (P = 0.3). Analysis of nonclamp time demonstrated a 71.3% learning percentage (P < 0.01; ie, 28.7% reduction in nonclamp time with each doubling of case number). There were no hospital deaths or incidences of stroke, myocardial infarction, unplanned reoperation, respiratory failure, or renal failure. Median length of stay was 4 days. All patients were discharged home. CONCLUSIONS: Totally endoscopic robotic mitral valve repair can be safely performed after a pretraining regimen with emphasis on experts' current practice and team training. After a pretraining regimen, cross-clamp times were not subject to learning curve phenomena but were dependent on procedural complexity. Nonclamp times were associated with a short learning curve.

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.

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.