Minimally invasive mitral valve repair through right minithoracotomy in the setting of degenerative mitral regurgitation: early outcomes and long-term follow-up

Minimally invasive mitral valve repair for functional mitral regurgitation

Systolic heart failure is frequently accompanied by a relevant functional mitral valve regurgitation (FMR) which develops as a direct sequela of the ongoing left ventricular remodelling. The severity of mitral regurgitation is further aggravated by progressive left ventricular enlargement causing leaflet tethering and reduced systolic leaflet movement. The prognosis of such patients is obviously limited by an underlying left ventricular disease, and the correction of secondary FMR has been previously suggested as predominantly ‘cosmetic’ surgery in the setting of ongoing cardiomyopathy. Inferior results of an isolated annuloplasty in type IIIb FMR supported the philosophy of malignant course of progressive cardiomyopathy and resulted in increasingly restricted indications for mitral valve surgery for FMR in the guidelines. The lack of a standardized pathophysiological approach to correct type IIIb FMR led to the development of valve replacement strategy and edge-to-edge catheter-based mitral valve procedures, which became the most frequent procedures in the FMR setting in Europe. Modern mitral valve surgery combines the advantages of 3-dimensional endoscopic minimally invasive surgical approach with standardized subannular repair to address the pathophysiological background of type IIIb FMR. The perioperative results have been significantly improved, and there is a growing evidence of improved long-term stability of subannular repair procedures as compared to isolated annuloplasty. This review article aims to present the current state-of-the-art of the modern mitral valve surgery in FMR and provides suggestions for future trials analysing the potential advantages in these patients.

Plasma exosomes characterization reveals a perioperative protein signature in older patients undergoing different types of on-pump cardiac surgery

Although exosomes are extracellular nanovesicles mainly involved in cardioprotection, it is not known whether plasma exosomes of older patients undergoing different types of on-pump cardiac surgery protect cardiomyocytes from apoptosis. Since different exosomal proteins confer pro-survival effects, we have analyzed the protein cargo of exosomes circulating early after aortic unclamping. Plasma exosomes and serum cardiac troponin I levels were measured in older cardiac surgery patients (NYHA II-III) who underwent first-time on-pump coronary artery bypass graft (CABG; n = 15) or minimally invasive heart valve surgery (mitral valve repair, n = 15; aortic valve replacement, n = 15) at induction of anesthesia (T0, baseline), 3 h (T1) and 72 h (T2) after aortic unclamping. Anti-apoptotic role of exosomes was assessed in HL-1 cardiomyocytes exposed to hypoxia/re-oxygenation (H/R) by TUNEL assay. Protein exosomal cargo was characterized by mass spectrometry approach. Exosome levels increased at T1 (P < 0.01) in accord with troponin values in all groups. In CABG group, plasma exosomes further increased at T2 (P < 0.01) whereas troponin levels decreased. In vitro, all T1-exosomes prevented H/R-induced apoptosis. A total of 340 exosomal proteins were identified in all groups, yet 10% of those proteins were unique for each surgery type. In particular, 22 and 12 pro-survival proteins were detected in T1-exosomes of heart valve surgery and CABG patients, respectively. Our results suggest that endogenous intraoperative cardioprotection in older cardiac surgery patients is early mediated by distinct exosomal proteins regardless of surgery type.

Retrospective Comparison of Endoscopic Versus Open Procedure for Mitral Valve Disease

OBJECTIVES

We investigated whether the totally video-assisted thoracoscopic mitral valve surgery provides superior clinical outcomes and less inflammatory injury reaction compared with conventional sternotomy.

METHODS

A total of 504 consecutive patients admitted for mitral valve surgery from May 2014 through May 2019 in a single center were retrospectively analyzed according to two distinct procedure approach: the totally video-assisted thoracoscopic approach (group A, n = 127) and standard median sternotomy (group B, n = 377). The primary end point was the durations of cardiopulmonary bypass, aortic cross-clamping, the ventilation time and intensive care unit of stay; the secondary endpoints included inflammation indexes like high sensitivity C-reactive protein, neutrophil-lymphocyte ratio and metabolic injury parameters cardiac Troponin and lactate.

RESULTS

There was only one in-hospital death due to diffuse intravascular coagulation in group A, but similar complications such as repair failure, re-thoracotomy and stroke in both groups. The durations of cardiopulmonary bypass and aortic cross-clamping were significantly longer in group A. In contrast, ventilation time and intensive care unit of stay were shortened compared with these in group B. In addition, postoperative equivalent lactate clearance but lower high sensitivity C-reactive protein, neutrophil-lymphocyte ratio and cardiac Troponin level was in group A than those in group B within postoperative 24 hours(P < 0.05).

CONCLUSIONS

The analysis of present study indicated despite relatively longer cardiopulmonary bypass time, the totally thoracoscopic mitral valve procedure seemed to be favorable with regard to the extent of inflammatory reaction, cardiac injury and postoperative recovery compared with conventional median sternotomy.

Failed MitraClip therapy: surgical revision in high-risk patients

Background

MitraClip implantation is a valid interventional option that offers acceptable short-term results. Surgery after failed MitraClip procedures remains challenging in high-risk patients. The data on these cases are limited by the small sample numbers.

Aim

The aim of our study is to show, that mitral valve surgery could be possible and more advantageous, even in high-risk patients.

Methods

Between 2010 and 2016, nine patients underwent mitral valve surgery after failed MitraClip therapy at our institution.

Results

The patients’ ages ranged from 19 to 75 years (mean: 61.2 ± 19.6 years). The median interval between the MitraClip intervention and surgical revision was 45 days (range: 0 to 1087 days). In eight of nine patients, the MitraClip intervention was initially successful and the  mitral regurgitation was reduced. Only one patient had undergone cardiac surgery previously.

Intra-operatively, leaflet perforation or rupture, MitraClip detachment, and chordal or papillary muscle rupture were potentially the causes of recurrent mitral regurgitation.

There were three early deaths. One year after surgery, the six remaining patients were alive.

Conclusions

Mitral valve surgery can be successfully performed after failed MitraClip therapy in high-risk patients. The initial indication for MitraClip therapy should be considered carefully for possible surgical repair.

Feasibility, safety, and short-term outcome of totally thoracoscopic mitral valve procedure

Background

The totally thoracoscopic procedure for mitral valve (MV) disease is a minimally invasive method. We investigated the procedure’s feasibility, safety and effectiveness when it was performed by an experienced operator.

Methods

We retrospectively analysed 53 consecutive patients with MV disease treated between December 2014 and April 2017 by minimally invasive procedures. The procedures were performed on femoral artery-vein bypass through three 2–4 cm incisions, with one additional penetrating point on the right chest wall under totally thoracoscopic visual guidance and surveillance of transoesophageal echocardiography.

Results

Two patients who underwent intraoperative conversion to sternotomy were excluded due to indivisible pleural cavity adhesion. Of the others (38 female patients, average age, 49 ± 14 years, left ventricular ejection fraction, 59 ± 7%), 34 received MV replacement for rheumatic mitral lesions, which was redone for one patient after the discovery of serious paravalvular leakage, 17 received MV repair for mitral regurgitation (with 4 secondary to atrial septum defect, 2 diagnosed with left atrial myxoma, and 2 redone for mitral valve replacement due to repair failure), 28 received additional tricuspid valvuloplasty, and one patient received a Warden procedure. The cardiopulmonary bypass and aortic cross clamp times were 144 ± 39 min and 80 ± 22 min, respectively. Postoperational chest tube drainage in the first 48 h was 346 ± 316 ml. The ventilation time and intensive care unit stay length were 11 ± 11 h and 23 ± 2 h, respectively. One patient died of disseminated intravascular coagulation and prosthesis thrombosis with fear of anticoagulation-related bleeding.

Conclusions

The totally thoracoscopic procedure on mitral valves by an experienced surgeon is technically feasible, safe, effective and worthy of widespread adoption in clinical practice.

Early and long-term results of minimally invasive mitral valve surgery through a right mini-thoracotomy approach: a retrospective propensity-score matched analysis

Background

Minimally invasive mitral valve surgery (MVS) via right mini-thoracotomy has recently attracted a lot of attention. Minimally invasive MVS shows postoperative results that are comparable to those of conventional MVS through the median sternotomy as per various earlier studies.

Methods

Between 2000 and 2016, a total of 669 isolated mitral valve procedures for isolated mitral valve regurgitation were performed. A propensity score-matched analysis was generated for the elimination of the differences in relevant preoperative risk factors between the cohorts and included 227 patient pairs. Only degenerative mitral valve regurgitation was included. The aim of our study was to examine if the minimally MVS is superior to the conventional approach through sternotomy based on a retrospective propensity-matched analysis. The primary endpoints were early mortality and long-term survival. The secondary endpoints included postoperative complications.

Results

The in-hospital mortality rate was significantly higher within the conventional sternotomy cohort (3.1%, n = 7 vs 0.4%, n = 1 for the minimally invasive cohort; p = 0.032). The incidence of stroke and exploration for bleeding was comparable. In contrast, the necessity for dialysis was significantly lower in the minimally invasive cohort (p = 0.044). Postoperative pain was not significantly lower in the minimally invasive MVS cohort (p = 0.862). While patients who underwent minimally invasive MVS experienced longer bypass and cross-clamp times, their lengths of stay in the intensive care unit and in the hospital, did not differ from the conventionally operated collective (p = 0.779 and p = 0.516), respectively. The mitral valve repair rate of 81.1% in the minimally invasive cohort was significantly superior to that of the conventional approach, which was 46.3% (p < 0.0001). The one-, five-, and 10-year survival rates were significantly higher in the minimally invasive cohort compared to the conventional approach (96%, 90%, and 84% vs. 89%, 85%, and 70%; log rank p = 0.004).

Conclusion

Despite prolonged cardiopulmonary bypass and cross-clamping times, the minimally invasive MVS may be considered a safe approach that is equivalent to standard median sternotomy with lower early mortality and superior long-term survival.

Predictors of survival in octogenarians after mitral valve surgery for degenerative disease: The Mitral Surgery in Octogenarians study

OBJECTIVES

An increasing number of octogenarians are referred to undergo mitral valve surgery for degenerative disease, and percutaneous approaches are being increasingly used in this subgroup of patients. We sought to determine the survival and its predictors after Mitral Valve Surgery in Octogenarians (MiSO) in a multicenter UK study of high-volume specialized centers.

METHODS

Pooled data from 3 centers were collected retrospectively. To identify the predictors of short-term composite outcome of 30 days mortality, acute kidney injury, and cerebrovascular accident, a multivariable logistic regression model was developed. Multiple Cox regression analysis was performed for late mortality. Kaplan-Meier curves were generated for long-term survival in various subsets of patients. Receiver operating characteristic analysis was done to determine the predictive power of the logistic European System for Cardiac Operative Risk Evaluation.

RESULTS

A total of 247 patients were included in the study. The median follow-up was 2.9 years (minimum 0, maximum 14 years). A total of 150 patients (60.7%) underwent mitral valve repair, and 97 patients (39.3%) underwent mitral valve replacement. Apart from redo cardiac surgery (mitral valve repair 6 [4%] vs mitral valve replacement 11 [11.3%], P = .04) and preoperative atrial fibrillation (mitral valve repair 79 [52.6%] vs mitral valve replacement 34 [35.1%], P < .01), there was no significant difference in terms of any other preoperative characteristics between the 2 groups. Patient operative risk, as estimated by logistic European System for Cardiac Operative Risk Evaluation, was lower in the mitral valve repair group (10.2 ± 11.8 vs 13.7 ± 15.2 in mitral valve replacement; P = .07). No difference was found between groups for duration of cardiopulmonary bypass and aortic crossclamp times. The 30-day mortality for the whole cohort was 13.8% (mitral valve repair 4.7% vs mitral valve replacement 18.6%; P < .01). No differences were found in terms of postoperative cerebrovascular accident (2% vs 3.1%; P = .9), acute kidney injury requiring dialysis (6.7% vs 13.4%; P = .12), and superficial or deep sternal wound infection (10% vs 16.5%, P = .17; 2% vs 3.1%, P = .67, respectively). The final multiple regression model for short-term composite outcome included previous cardiac surgery (odds ratio [OR], 4.47; 95% confidence interval [CI], 1.37-17.46; P = .02), intra-aortic balloon pump use (OR, 4.77; 95% CI, 1.67-15.79; P < .01), and mitral valve replacement (OR, 7.7; 95% CI, 4.04-14.9; P < .01). Overall survival for the entire cohort at 1, 5, and 10 years was 82.4%, 63.7%, and 45.5% (mitral valve repair vs mitral valve replacement: 89.9% vs 70.7% at 1 year, 69.6% vs 54% at 5 years, and 51.8% vs 35.5% at 10 years; P = .0005). Cox proportional hazard model results showed mitral valve replacement (hazard ratio, 1.88; 95% CI, 1.22-2.89; P < .01) and intra-aortic balloon pump use (hazard ratio, 2.54; 95% CI, 1.26-5.13; P < .01) to be independent predictor factors affecting long-term survival. Logistic European System for Cardiac Operative Risk Evaluation did not perform well in predicting early mortality (area under the curve, 0.57%).

CONCLUSIONS

In octogenarians, mitral valve repair for degenerative disease is associated with good survival and remains the gold standard, whereas mitral valve replacement is still associated with significant mortality. Logistic European System for Cardiac Operative Risk Evaluation was unable to predict early mortality in our cohort of patients. Larger international multicenter registries are required to optimize the decision-making process in such a high-risk subgroup.