Joerg Seeburger

Minimal invasive mitral valve repair for mitral regurgitation: results of 1339 consecutive patients

OBJECTIVE Some have expressed concern that minimal invasive mitral valve (MV) repair may not meet the standard of open surgical techniques. We therefore reviewed our results for minimal invasive MV repair for mitral regurgitation (MR). MATERIAL AND METHODS Between March 1999 and February 2007, a total of 1536 consecutive patients underwent minimal invasive MV surgery for MR at our institution using a right lateral mini-thoracotomy and femoral cannulation for cardiopulmonary bypass. Of these, a total of 1339 (87.2%) patients underwent MV repair and these form the focus of this study. The mean grade of preoperative MR was 3.3+/-0.6, age was 60.3+/-12.7 years, ejection fraction was 59.2+/-15.1% and 819 patients (61.2%) were male. RESULTS The procedure was successfully performed in all but four patients (0.3%) who required intraoperative conversion to full sternotomy. MV repair techniques consisted of ring annuloplasty with or without chordae-replacement or Carpentier-type leaflet resection. Concomitant procedures consisted of atrial fibrillation ablation in 351 patients (26.2%), tricuspid valve surgery in 80 patients (6.0%), and patent foramen ovale/atrial septal defect closure in 88 patients (6.6%). Mean duration of CPB was 121+/-38min and mean aortic cross-clamp time was 70+/-32min. Thirty-day mortality was 2.4%. Follow-up was performed in 99% of patients at an average of 28.1+/-23.9 months postoperatively. The Kaplan-Meier estimate for survival at 5 years was 82.6% (95% CI: 78.9-85.7%) and for freedom from MV reoperation was 96.3% (95% CI: 94.6-97.4%). CONCLUSIONS Minimal invasive MV repair, along with certain concomitant procedures, can be performed in the vast majority of patients with MR. Our large series demonstrates that these procedures can be performed with low perioperative complication rates and very good durability.

How does the use of polytetrafluoroethylene neochordae for posterior mitral valve prolapse (loop technique) compare with leaflet resection? A prospective randomized trial

OBJECTIVE Mitral valve surgery for posterior mitral leaflet prolapse consists mostly of leaflet resection, but implantation of premeasured polytetrafluoroethylene neochordae (ie, loops) is another option. The aim of this prospectively randomized trial was to determine how preservation of leaflet structure in combination with premeasured neochordae compares with the widely adopted technique of leaflet resection. METHODS A total of 129 patients with severe mitral regurgitation, with a mean mitral regurgitation grade of 3.6 +/- 0.6, underwent minimal invasive mitral valve surgery through a right lateral mini-thoracotomy. The mean age was 59.5 +/- 12 years, 90 patients were male, the mean preoperative ejection fraction was 65% +/- 8%, and the mean New York Heart Association functional class was 2.1 +/- 0.7. Posterior mitral leaflet prolapse was diagnosed in all patients. Randomization was performed preoperatively, and crossover was allowed if the surgeon deemed it medically necessary. Crossover from resection to loops occurred in 9 patients, and crossover from loops to resection occurred in 3 patients. RESULTS Mitral valve repair was accomplished in all patients (n = 129, 100%), and all patients received an annuloplasty ring. The mean number of loops implanted on the posterior mitral leaflet was 3.2 +/- 0.9, with a mean length of 13.3 +/- 2.2 mm. The mean duration of cardiopulmonary bypass was 135 +/- 37 minutes and the mean aortic crossclamp time was 82 +/- 26 minutes in all patients, with no significant difference between groups. Intraoperative transesophageal echocardiography showed a significantly longer line of mitral valve leaflet coaptation after implantation of loops (7.6 +/- 3.6 mm) than after resection (5.9 +/- 2.6 mm; P = .03). Thirty-day mortality was 1.6% for the entire group (2/129), with both deaths occurring in the loop group. Cause of death was massive pulmonary embolism in 1 patient and acute right heart failure in 1 patient. Early and mid-term echocardiographic follow-up revealed excellent valve function in the majority of patients, with no significant difference in mitral orifice area (3.6 +/- 1.0 cm(2) vs 3.7 +/- 1.1 cm(2), P = .4). CONCLUSION Both repair techniques for posterior mitral leaflet prolapse are associated with excellent results and appear comparable in the early postoperative course. The loop technique, however, results in a significantly longer line of leaflet coaptation and may therefore be more durable. Longer follow-up is required.

Learning Minimally Invasive Mitral Valve Surgery A Cumulative Sum Sequential Probability Analysis of 3895 Operations From a Single High-Volume Center

Background— Learning curves are vigorously discussed and viewed as a negative aspect of adopting new procedures. However, very few publications have methodically examined learning curves in cardiac surgery, which could lead to a better understanding and a more meaningful discussion of their consequences. The purpose of this study was to assess the learning process involved in the performance of minimally invasive surgery of the mitral valve using data from a large, single-center experience. Methods and Results— All mitral (including tricuspid, or atrial fibrillation ablation) operations performed over a 17-year period through a right lateral mini-thoracotomy with peripheral cannulation for cardiopulmonary bypass (n=3907) were analyzed. Data were obtained from a prospective database. Individual learning curves for operation time and complication rates (using sequential probability cumulative sum failure analysis) and average results were calculated. A total of 3895 operations by 17 surgeons performing their first minimally invasive surgery of the mitral valve operation at our institution could be evaluated. The typical number of operations to overcome the learning curve was between 75 and 125. Furthermore, >1 such operation per week was necessary to maintain good results. Individual learning curves varied markedly, proving the need for good monitoring or mentoring in the initial phase. Conclusions— A true learning curve exists for minimally invasive surgery of the mitral valve. Although the number of operations required to overcome the learning curve is substantial, marked variation exists between individual surgeons. Such information could be very helpful in structuring future training and maintenance of competence programs for this kind of surgery. # Clinical Perspective {#article-title-25}Background— Learning curves are vigorously discussed and viewed as a negative aspect of adopting new procedures. However, very few publications have methodically examined learning curves in cardiac surgery, which could lead to a better understanding and a more meaningful discussion of their consequences. The purpose of this study was to assess the learning process involved in the performance of minimally invasive surgery of the mitral valve using data from a large, single-center experience. Methods and Results— All mitral (including tricuspid, or atrial fibrillation ablation) operations performed over a 17-year period through a right lateral mini-thoracotomy with peripheral cannulation for cardiopulmonary bypass (n=3907) were analyzed. Data were obtained from a prospective database. Individual learning curves for operation time and complication rates (using sequential probability cumulative sum failure analysis) and average results were calculated. A total of 3895 operations by 17 surgeons performing their first minimally invasive surgery of the mitral valve operation at our institution could be evaluated. The typical number of operations to overcome the learning curve was between 75 and 125. Furthermore, >1 such operation per week was necessary to maintain good results. Individual learning curves varied markedly, proving the need for good monitoring or mentoring in the initial phase. Conclusions— A true learning curve exists for minimally invasive surgery of the mitral valve. Although the number of operations required to overcome the learning curve is substantial, marked variation exists between individual surgeons. Such information could be very helpful in structuring future training and maintenance of competence programs for this kind of surgery.

Chordae Replacement Versus Resection for Repair of Isolated Posterior Mitral Leaflet Prolapse: À Ègalité

BACKGROUND Mitral valve (MV) repair for posterior mitral leaflet (PML) prolapse has proven excellent results. The loop technique, which involves insertion of polytetrafluoroethylene neochordae while preserving the native PML tissue, was developed to facilitate MV repair through a minimally invasive approach. The aim of this study was to assess the medium-term results of the loop technique in comparison with the widely adopted leaflet resection technique for repair of isolated PML prolapse. METHODS Between March 1999 and January 2008, a total of 1,708 patients underwent minimally invasive MV repair. Six hundred and seventy patients (39.2%) had isolated PML prolapse and were treated with either the loop technique (n = 317) or the leaflet resection (n = 353) technique, according to surgeon preference. Mean follow-up time was 2.8 +/- 2.2 years, and follow-up was 99% complete. RESULTS Early postoperative echocardiography showed a significantly larger mitral orifice area (3.3 +/- 0.3 cm(2) versus 3.0 +/- 0.8 cm(2), p < 0.001) and lower mean pressure gradient (2.7 +/- 1.7 mm Hg versus 3.1 +/- 1.7 mm Hg, p = 0.03) after implantation of loops. Other perioperative outcomes were similar for the two groups of patients. Freedom from reoperation at 5 years was significantly higher after the loop technique (98.7%, 95% confidence interval [CI]: 96.7% to 99.5%) when compared with leaflet resection (93.9%, 95% CI: 90.7% to 96.1%, log-rank p = 0.005). Cox regression analysis revealed that implantation of a flexible, incomplete band was an independent predictor of reoperation (hazard ratio 6.2, 95% CI: 1.3 to 110.7), whereas use of leaflet resection had a nonsignificant trend toward an increased reoperation rate (hazard ratio 2.6, 95% CI: 0.9 to 9.1). Reoperation for excessive systolic anterior motion did not occur in any loop patient. CONCLUSIONS Both the loop technique and conventional leaflet resection yield excellent results for repair of isolated PML prolapse. The technical ease of performing the loop technique through a minimally invasive approach, however, makes this method a particularly valuable alternative for MV repair surgery.

A propensity score-adjusted retrospective comparison of early and mid-term results of mitral valve repair versus replacement in octogenarians

AIMS Feasibility and efficacy of mitral repair in the elderly remain controversial. This study aims to compare outcomes of mitral repair and replacement in octogenarians. METHODS AND RESULTS We compared the outcomes of 322 consecutive octogenarian patients (mean age 82.6 ± 2.2 years) who underwent mitral repair (n = 227, 70%) or replacement (n = 95, 30%) at Mount Sinai Medical Center and Leipzig Herzzentrum between 1998 and 2008 using propensity score adjustment and univariate and multivariate analyses. Patients undergoing aortic valve replacement were excluded. Coronary bypass was performed in 47.5% (n = 153), and 31.1% (n = 100) required tricuspid repair. Propensity score adjustment yielded comparable groups. Thirty-day mortality in patients undergoing primary elective mitral repair for degenerative disease was 5.1% (2/39). Overall 90-day mortality was 18.9% (43/227) for repair compared with 31.6% (30/95) for replacement (P = 0.014). Pre-discharge echocardiography revealed less than moderate residual regurgitation in 99% of patients (231/232). Adjusted 1-, 3-, and 5-year survival for patients undergoing mitral repair was 71 ± 3, 61 ± 4, and 59 ± 4%, respectively, compared with 56 ± 5, 50 ± 6, and 45 ± 6% for patients undergoing mitral replacement (P = 0.046). Multivariate analysis demonstrated emergency surgery, previous myocardial infarction, concomitant coronary artery bypass surgery, and mitral replacement to be strong independent predictors of early mortality; mitral valve replacement was an independent predictor of reduced survival in degenerative patients. CONCLUSION Elective mitral repair can be performed with low operative mortality and good long-term outcomes in selected octogenarians with degenerative mitral disease, and is associated with better long-term survival than mitral replacement. The survival benefit associated with surgery for non-degenerative disease is more questionable.

Comparison of outcomes of minimally invasive mitral valve surgery for posterior, anterior and bileaflet prolapse

OBJECTIVE We sought to compare the outcomes of minimally invasive mitral valve (MV) surgery for anterior (anterior mitral leaflet, AML), posterior (posterior mitral leaflet, PML) or bileaflet (BL) MV prolapse. METHODS Between August 1999 and December 2007, 1230 patients who presented with isolated AML (n=156, 12.7%), isolated PML (n=672, 54.6%) or BL (n=402, 32.7%) MV prolapse underwent minimally invasive MV surgery. The preoperative mitral regurgitation (MR) grade was 3.3+/-0.8, left ventricular ejection fraction (LVEF) was 62+/-12% and mean age was 58.9+/-13.0 years; 836 patients (68.0%) were male. Mean follow-up time was 2.7+/-2.1 years, and the follow-up was 100% complete. RESULTS Overall, the MV repair rate was 94.0% (1156 patients). Seventy-four patients (6.0%) received MV replacement. MV repair for PML prolapse was accomplished in 651 patients (96.9%), for AML in 142 patients (91%) and for BL in 363 patients (90.3%). Repair techniques consisted predominantly of leaflet resection and/or implantation of neochordae, combined with ring annuloplasty. Concomitant procedures were tricuspid valve surgery (n=56), atrial fibrillation ablation (n=286) and closure of an atrial septal defect or patent foramen ovale (PFO) (n=89). The overall duration of cardiopulmonary bypass was 127+/-40 min and aortic cross-clamp time was 78+/-33 min. The mean postoperative hospital stay was 11.6+/-9.7 days for the overall group. Early echocardiographic follow-up revealed excellent valve function in the vast majority of patients, regardless of the repair technique, with a mean MR grade of 0.3+/-0.5. For the overall group, 5-year survival rate was 87.3% (95% CI: 83.9-90.1) and 5-year freedom from cardiac reoperation rate was 95.6% (95% CI: 94.1-96.7). The log-rank test revealed no significant difference between the three groups regarding long-term survival or freedom from reoperation. CONCLUSIONS Minimally invasive MV repair can be achieved with excellent results. Long-term outcomes and reoperation rates for AML prolapse are not significantly different from PML or BL prolapse.

Minimally Invasive Versus Sternotomy Approach for Mitral Valve Surgery in Patients Greater Than 70 Years Old: A Propensity-Matched Comparison

BACKGROUND The goal of this study was to compare the outcome after mitral valve surgery through either standard sternotomy or right lateral minithoracotomy in elderly patients with higher perioperative risk. METHODS All 1,027 elderly patients (>70 years) who received isolated mitral valve surgery (± tricuspid valve repair) between August 1999 and July 2009 were analyzed for outcome differences due to surgical approach using propensity score matching. The etiology of mitral valve disease was degenerative (83%), endocarditis (6%), rheumatic (10%), and acute ischemic (<1%). Isolated stenosis was rare (3%); most patients had mitral valve regurgitation (72%) or combined mitral valve disease (25%). RESULTS The minimally invasive approach led to longer duration of surgery (186 ± 61 vs 169 ± 59 minutes, p = 0.01), cardiopulmonary bypass time (142 ± 54 vs 102 ± 45 minutes, p = 0.0001), and cross-clamp time (74 ± 44 vs 64 ± 28 minutes, p = 0.015). There were no differences between the matched groups in 30-day mortality (7.7% vs 6.3%, p = 0.82), combined major adverse cardiac and cerebrovascular events (11.2% vs 12.6%, p = 0.86), or other postoperative outcome. Only the number of postoperative arrhythmias and pacemaker implants was higher in the sternotomy group (65.7% vs 50.3%, p = 0.023 and 18.9% vs 10.5%, p = 0.059). Long-term survival was 66% ± 5.6% vs 56 ± 5.5% at 5 years and 35% ± 12% vs 40% ± 7.9% at 8 years, and did not show significant differences. CONCLUSIONS Minimally invasive mitral valve surgery through a right lateral minithoracotomy is at least as good and safe as the standard sternotomy approach in elderly patients.

Minimally invasive mitral valve surgery after previous sternotomy: experience in 181 patients.

OBJECTIVE This study evaluated the results for minimally invasive mitral valve (MV) surgery in patients who had undergone previous cardiac operations through a sternotomy. METHODS From March 1, 1999 to January 2008, minimally invasive MV reoperations were performed in 181 consecutive patients (110 men) with a mean age of 64.5 +/- 12 years. A right-sided lateral minithoracotomy with femoral cannulation for cardiopulmonary bypass (CPB) was used. The principal indication was symptomatic severe mitral regurgitation (mean grade, 3.0 +/- 0.8). Previous procedures were isolated coronary bypass grafting (CABG) in 76 (42%), isolated valve operation, 55 (30%); combined CABG and valve, 16 (9%); and other cardiac operations, 34 (19%). MV replacement was previously performed in 19 patients and MV repair in 31. Mean preoperative left ventricular ejection fraction was 0.54 +/- 0.16. RESULTS MV repair, including repeat repair, was performed in 109 patients (60%) and MV replacement in 72 (40%). Operations were performed during ventricular fibrillation in 140 (77%), and a transthoracic aortic cross-clamp was used in 31 (17%). Ten patients (6%) underwent beating heart operations with CPB support. Mean total operating time was 176 +/- 50 min. Mean CPB time was 135 +/- 40 min. Thirty-day mortality was 6.6%. Early echocardiographic follow-up revealed excellent valve function in most patients. CONCLUSION A minimally invasive approach is a useful alternative for patients requiring a MV procedure after a previous cardiac operation, particularly in patients with patent coronary bypass grafts or previous aortic valve replacement. Very good perioperative results can be achieved with this method.

Crimping May Affect the Durability of Transcatheter Valves: An Experimental Analysis

BACKGROUND Transcatheter aortic valve implantation has gained widespread acceptance to treat elderly high-risk patients with aortic stenosis. We used a subcutaneous rat model to evaluate whether crimping may affect valve long-term durability. METHODS Standard Sapien transcatheter valves (Edwards Lifesciences, Irvine, CA) were crimped for different durations (1 hour, 1 day, 1 month) and uncrimped, and leaflet pieces as well as control tissue (Perimount Magna, Edwards) were then implanted subcutaneously in 15 male weanling Sprague-Dawley rats for 12 weeks. Grade of calcification was measured by freeze-dried mass and van Kossa staining. Histologic and electron microscopic examination were performed to investigate potential leaflet-fragmentation caused by crimping. RESULTS There were no differences in calcification among the groups. The calcium carbonate concentrations in all samples ranged from 0.1 to 100 mg/g dry weight. Leaflet morphology, however, differed from no fragmentation (control group) to highly fragmented tissue (1-month crimped). These differences reached statistical significance between crimped and non-crimped leaflets (p<0.003). CONCLUSIONS Transcatheter valve crimping does not necessarily affect leaflet calcification. However, the structural changes of the leaflets that were caused by crimping may have clinical significance. Duration of crimping should be as short as possible, and very tight crimping to small diameters should be avoided.

An integrated framework for finite-element modeling of mitral valve biomechanics from medical images: Application to MitralClip intervention planning

Treatment of mitral valve (MV) diseases requires comprehensive clinical evaluation and therapy personalization to optimize outcomes. Finite-element models (FEMs) of MV physiology have been proposed to study the biomechanical impact of MV repair, but their translation into the clinics remains challenging. As a step towards this goal, we present an integrated framework for finite-element modeling of the MV closure based on patient-specific anatomies and boundary conditions. Starting from temporal medical images, we estimate a comprehensive model of the MV apparatus dynamics, including papillary tips, using a machine-learning approach. A detailed model of the open MV at end-diastole is then computed, which is finally closed according to a FEM of MV biomechanics. The motion of the mitral annulus and papillary tips are constrained from the image data for increased accuracy. A sensitivity analysis of our system shows that chordae rest length and boundary conditions have a significant influence upon the simulation results. We quantitatively test the generalization of our framework on 25 consecutive patients. Comparisons between the simulated closed valve and ground truth show encouraging results (average point-to-mesh distance: 1.49 ± 0.62 mm) but also the need for personalization of tissue properties, as illustrated in three patients. Finally, the predictive power of our model is tested on one patient who underwent MitralClip by comparing the simulated intervention with the real outcome in terms of MV closure, yielding promising prediction. By providing an integrated way to perform MV simulation, our framework may constitute a surrogate tool for model validation and therapy planning.