Minimally invasive mitral valve surgery: a systematic safety analysis

Pushing boundaries in cardiac surgery: minimally invasive mitral valve repair combined with tricuspid valve repair and/or other concomitant procedures

Introduction

Minimally invasive mitral valve repair/replacement has emerged as a widely accepted surgical approach for managing mitral valve disorders. Continuous technological progress has contributed to the refinement of this procedure, leading to improved safety, decreased surgical trauma, and faster recovery times. Despite these advancements, there remains a scarcity of data concerning minimally invasive complex mitral valve repair surgeries when combined with additional procedures.

Methods

Between November 2008 and December 2022, 153 patients underwent an operation using a minimally invasive technique. All patients underwent mitral valve surgery for severe mitral valve insufficiency/stenosis in combination with at least one additional procedure for tricuspid valve repair (n = 52, 34%), patent foramen ovale or atrial septal defect closure (n = 34, 22.2%), left atrial appendage occlusion (n = 25, 16.3%), or electrophysiological procedure (n = 101, 66.0%). Two concomitant procedures were conducted in 98 patients (64.1%), three concomitant procedures in 49 patients (32%), and four concomitant procedures in 6 patients (3.9%).

Results

Surgical success was achieved in 99.3% of the patients (n = 152), one patient required a revision of the mitral valve repair on the first postoperative day due to systolic anterior motion phenomenon. Mitral valve repair was performed in 136 patients (88.9%), while 15 patients (9.8%) received a mitral valve replacement as per a preoperative decision due to severe mitral valve stenosis, and two patients (1.3%) underwent other mitral valve procedures. Therapeutic success in treating atrial fibrillation was achieved in 86 patients (85.1%) of the 101 who received an additional maze-procedure. The 30-day mortality rate was 0.7%, with one patient succumbing to respiratory failure. Neurological complications occurred in 7 patients (4.6%). Freedom from reoperation was calculated as 98% at 5-year follow-up and 96.5% at 10-year follow-up.

Conclusion

Minimally invasive mitral valve surgery, even when performed alongside concomitant procedures, stands out as a reproducible and safe technique with outstanding outcomes. It is imperative to advance towards the next frontier in minimally invasive surgery, encouraging experienced surgeons to undertake more complex procedures using minimally invasive approaches. These results help envision extending the boundaries of minimally invasive surgery by performing complex mitral valve procedures and associated interventions entirely through endoscopic means in suitable patients.

Minimally Invasive Strategy to Repair Mitral Valve after Repeated Coronary Revascularization: A Case Report and Literature Review

Redo cardiac surgery after Coronary Artery Bypass Grafting (CABG) is burdened by high morbidity and mortality, either intraoperatively and postoperatively, with the repeated sternotomy playing a crucial role as risk factor. The right minithoracotomy approach guarantees a safer control on conduits integrity and the right ventricular wall and a low impact on the respiratory mechanics. Herein, we report a patient who previously underwent two CABG (coronary artery bypass grafting) procedures and who was admitted to the hospital with a picture of heart failure caused by a severe mitral regurgitation. He was successfully submitted to a mitral valve repair on a beating heart via the right minithoracotomy approach.

Mid-term results of endoscopic mitral valve repair and insights in surgical techniques for isolated posterior prolapse

BACKGROUND

The adoption of minimally invasive techniques to perform mitral valve repair surgery is increasing. This is enhanced by the compelling evidence of satisfactory short-term results and lower major morbidity. We analyzed mid-term follow-up results of our experience, and further compared two techniques: isolated leaflet resection and neochord implantation for posterior leaflet prolapse.

METHODS

Data for all consecutive endoscopic mitral valve repairs via video-assisted right anterior mini-thoracotomy were analyzed between December 2012 and September 2021. The early and mid-term follow-up results were ascertained. The main outcome was the incidence of mortality and the recurrence of significant mitral regurgitation during follow-up which were summarized by the Kaplan-Meier estimator and compared between treatment arms using the stratified log-rank test. Secondary outcomes were the early-postoperative results including 30-days mortality and the occurrence of major complications.

RESULTS

A total of 309 patients were included. Along with ring annuloplasty, 136 (44.4%) patients received posterior leaflet resection (122 isolated) whereas 97 (31.1%) underwent posterior leaflet chords implantation (88 isolated). Forty-nine patients had annuloplasty alone. In-hospital mortality was 1.0%. Mean follow-up was 28.8 ± 22.0 months (maximum 8.3 years). Kaplan-Meier survival rate at 5 years was 97.3 ± 1.0%, mitral regurgitation ([Formula: see text]3+) or valve reoperation free-survival at 5 years was estimated as 94.5 ± 2.3%. Subgroup time-to-event analysis for the indexed outcomes showed no statistical significance between the techniques.

CONCLUSIONS

Endoscopic mitral valve repair is safe and associated with excellent short- and mid-term outcomes. No differences were found between leaflet resection and gore-tex chords implantation for posterior leaflet prolapse.

The evolution of technical prerequisites and local boundary conditions for optimization of mitral valve interventions-Emphasis on skills development and institutional risk performance

This viewpoint report describes how the evolution of transcatheter mitral valve intervention (TMVI) is influenced by lessons learned from three evolutionary tracks: (1) the development of treatment from mitral valve surgery (MVS) to transcutaneous procedures; (2) the evolution of biomedical engineering for research and development resulting in predictable and safe clinical use; (3) the adaptation to local conditions, impact of transcatheter aortic valve replacement (TAVR) experience and creation of infrastructure for skills development and risk management. Thanks to developments in computer science and biostatistics, an increasing number of reports regarding clinical safety and effectiveness is generated. A full toolbox of techniques, devices and support technology is now available, especially in surgery. There is no doubt that the injury associated with a minimally invasive access reduces perioperative risks, but it may affect the effectiveness of the treatment due to incomplete correction. Based on literature, solutions and performance standards are formulated with an emphasis in technology and positive outcome. Despite references to Heart Team decision making, boundary conditions such as hospital infrastructure, caseload, skills training and perioperative risk management remain underexposed. The role of Biomedical Engineering is exclusively defined by the Research and Development (R&D) cycle including the impact of human factor engineering (HFE). Feasibility studies generate estimations of strengths and safety limitations. Usability testing reveals user friendliness and safety margins of clinical use. Apart from a certification requirement, this information should have an impact on the definition of necessary skills levels and consequent required training. Physicians Preference Testing (PPT) and use of a biosimulator are recommended. The example of the interaction between two Amsterdam heart centers describes the evolution of a professional ecosystem that can facilitate innovation. Adaptation to local conditions in terms of infrastructure, referrals and reimbursement, appears essential for the evolution of a complete mitral valve disease management program. Efficacy of institutional risk management performance (IRMP) and sufficient team skills should be embedded in an appropriate infrastructure that enables scale and offers complete and safe solutions for mitral valve disease. The longstanding evolution of mitral valve therapies is the result of working devices embedded in an ecosystem focused on developing skills and effective risk management actions.

A qualitative improvement program for minimally invasive mitral surgery: technical advancements ameliorate outcome and operative times

OBJECTIVES

Minimally invasive mitral valve surgery (MIMVS) has evolved over the last 2 decades. The aim of the study was to identify the impact of era and technical improvements on perioperative outcome after MIMVS.

METHODS

A tota of 1000 patients (mean age: 60.8 ± 12.7 years, 60.3% male) underwent video-assisted or totally endoscopic MIMVS between 2001 and 2020 in a single institution. Three technical modalities were introduced during the observed period: (i) 3D visualization, (ii) use of premeasured artificial chordae (PTFE loops) and (iii) preoperative CT scans. Comparisons were made before and after the introduction of technical improvements.

RESULTS

A total of 741 patients underwent isolated mitral valve (MV) procedure, whereas 259 received concomitant procedures. These consisted of tricuspid valve repair (208), left atrium ablation (145) and persistent foramen ovale or atrial septum defect (ASD) closure (172). The aetiology was degenerative in 738 (73.8%) patients and functional in 101 patients (10.1%). A total of 900 patients received MV repair (90%), and 100 patients (10%) underwent MV replacement. Perioperative survival was 99.1%, and periprocedural success 93.5% with a periprocedural safety of 96.3%. Improvement in periprocedural safety attributed to the lower rates of postoperative low output (P = 0.025) and less reoperations for bleeding (P < 0.001). 3D visualization improved cross-clamp (P = 0.001) but not cardiopulmonary bypass times. The use of loops and preoperative CT scan both had no impact on periprocedural success or safety but improved cardiopulmonary bypass and cross-clamp times (both P < 0.001).

CONCLUSIONS

Increased surgical experience improves safety in MIMVS. Technical improvements are related to increased operative success and decreased operative times in patients undergoing MIMVS.

Robotic and endoscopic mitral valve repair for degenerative disease

BACKGROUND

Minimally invasive mitral valve repair has been proven to be a safe alternative to open sternotomy and may be accomplished through classic endoscopic and robotic endoscopic approaches. Outcomes across different minimally invasive techniques have been insufficiently described. We compare early and late clinical outcomes across matched patients undergoing robotic endoscopic and classic endoscopic repair.

METHODS

From 2011 to 2020, 786 patients underwent minimally invasive mitral surgery, from which we were able to generate 124 matched patients (62 patients in each cohort). Clinical results were then compared between the two matched populations. Survival analysis was used to compare freedom from mortality to 10 years among matched classic endoscopic and robotic endoscopic mitral valve repair cohorts and to calculate freedom from moderate or severe mitral insufficiency at latest follow-up. Histograms of cardiopulmonary bypass (CPB) and aortic cross-clamp times were constructed, and mean bypass and cross-clamp times were compared between classic endoscopic and robotic endoscopic cohorts.

RESULTS

There was no difference in early or late mortality at 10 years in either cohort. Freedom from moderate or severe mitral regurgitation or mitral valve replacement at last echocardiogram was 86.4% vs. 73.5% at 10 years, P=0.97. Patients undergoing robotic endoscopic mitral repair had a significantly longer CPB run when compared to the classic endoscopic cohort, with 148 min of CPB in the robotic endoscopic cohort compared to 133 min in the classic endoscopic group, P=0.03. Overall post-operative length of stay was not statistically significant between the robotic endoscopic and classic endoscopic groups, 6.3±0.5 and 6.0±0.3 days, respectively. No patients in either cohort developed renal failure or wound infection. The classic endoscopic group had a slightly higher risk of prolonged ventilation when compared to the robotic endoscopic group, with three classic endoscopic patients remaining intubated >8 hours post-operatively, compared to a single patient in the robotic endoscopic group. There were no unplanned reoperations in either group. Rates of postoperative stroke were comparable between groups (three in the classic endoscopic cohort, and two in the robotic endoscopic cohort).

CONCLUSIONS

Index mitral valve surgery via a classic endoscopic approach yields similar clinical outcomes when compared to robotic endoscopic surgery. We demonstrate that both classic endoscopic and robotic endoscopic approaches allow repair of degenerative mitral valves with excellent short- and medium-term outcomes in a tertiary referral center.

Decision Making during the Learning Curve of Minimally Invasive Mitral Valve Surgery: A Focused Review for the Starting Minimally Invasive Surgeon

Minimally invasive mitral valve surgery is evolving rapidly since the early 1990’s and is now increasingly adopted as the standard approach for mitral valve surgery. It has a long and challenging learning curve and there are many considerations regarding technique, planning and patient selection when starting a minimally invasive program. In the current review, we provide an overview of all considerations and the decision-making process during the learning curve.

At the Crossroads of Minimally Invasive Mitral Valve Surgery—Benching Single Hospital Experience to a National Registry: A Plea for Risk Management Technology

Almost 30 years after the first endoscopic mitral valve repair, Minimally Invasive Mitral Valve Surgery (MIMVS) has become the standard at many institutions due to optimal clinical results and fast recovery. The question that arises is can already good results be further improved by an Institutional Risk Management Performance (IRMP) system in decreasing risks in minimally invasive mitral valve surgery (MIMVS)? As of yet, there are no reports on IRMP and learning systems in the literature. (2) Methods: We described and appraised our five-year single institutional experience with MIMVS in isolated valve surgery included in the Netherlands Heart Registry (NHR) and investigated root causes of high-impact complications. (3) Results: The 120-day and 12-month mortality were 1.1% and 1.9%, respectively, compared to the average of 4.3% and 5.3% reported in the NHR. The regurgitation rate was 1.4% compared to 5.2% nationwide. The few high-impact complications appeared not to be preventable. (4) Discussion: In MIMVS, freedom from major and minor complications is a strong indicator of an effective IRMP but remains concealed from physicians and patients, despite its relevance to shared decision making. Innovation adds to the complexity of MIMVS and challenges surgical competence. An IRMP system may detect and control new risks earlier. (5) Conclusion: An IRMP system contributes to an effective reduction of risks, pain and discomfort; provides relevant input for shared decision making; and warrants the safe introduction of new technology. Crossroads conclusions: investment in machine learning and AI for an effective IRMP system is recommended and the roles for commanding and operating surgeons should be considered.

State-of-the-Art Review: Technical and Imaging Considerations in Novel Transapical and Port-Access Mitral Valve Chordal Repair for Degenerative Mitral Regurgitation

Degenerative mitral regurgitation (DMR) based on posterior leaflet prolapse is the most frequent type of organic mitral valve disease and has proven to be durably repairable in most cases by chordal repair techniques either by conventional median sternotomy or by less invasive approaches both utilizing extracorporeal circulation and cardioplegic myocardial arrest. Recently, several novel transapical chordal repair techniques specifically targeting the posterior leaflet have been developed as a far less invasive and beating heart (off-pump) alternative to port-access mitral repair. In order to perform a safe and effective minimally invasive mitral chordal repair, thorough knowledge of the anatomy of the mitral valve apparatus and adequate use of multimodality imaging both pre- and intraoperatively are fundamental. In addition, comprehensive understanding of the available novel devices, their delivery systems and the individual procedural steps are required.

Predictors of safety and success in minimally invasive surgery for degenerative mitral disease

OBJECTIVES

The aim of this study was to identify predictors of periprocedural success and safety in minimally invasive mitral valve surgery and to determine the impact of pathology localization and repair technique on reoperation-free survival.

METHODS

We isolated 686 patients (mean age 60.5, standard deviation 12.3 years, 69.4% male) who underwent surgery for mitral valve prolapse between 2002 and 2020 in a single institution. Patients with concomitant disease, redo or mitral pathology other than degenerative mitral disease were excluded from the analysis. Periprocedural safety was defined as: freedom from perioperative death, myocardial infarction, stroke, use of extracorporeal membrane oxygenation or reoperation for bleeding. Operative success was defined as: successful primary mitral repair without conversion to replacement or to larger thoracic incisions, without residual mitral regurgitation > mild at discharge or reoperation within 30 days. Predictors for perioperative success and safety were identified using univariable and multivariable analyses. The impact of prolapse localization and repair technique on reoperation-free survival was assessed by Cox regression.

RESULTS

The mitral repair rate and the need for concomitant tricuspid repair were 94.6% and 16.5%, respectively. Perioperative mortality occurred in 5 patients (0.7%). The criteria for perioperative safety and success were met in 646/686 (94.2%) and 648/686 (94.5%) patients, respectively. The absence of tricuspid disease requiring repair was the only independent predictor of safety in this cohort [hazard ratio (HR) 0.460 (0.225-0.941), P = 0.033]. The only independent predictor of operative success was the use of chordal replacement [0.27 (0.09-0.83), P = 0.022]. Reoperation-free survival was 98.5%, 94.5% and 86.9% at 1, 5 and 10 years, respectively. Posterior leaflet pathology demonstrated a higher reoperation-free survival as compared to other localizations (log-rank P = 0.002). The localization of leaflet pathology but not the repair method was an independent predictor for reoperation-free survival (HR 1.455, 95% confidence interval 1.098-1.930; P = 0.009).

CONCLUSIONS

In minimally invasive mitral surgery for degenerative disease, chordal replacement yields higher rates of periprocedural success than leaflet resection. Posterior leaflet pathology is an independent predictor of reoperation-free survival.

The Impact of Biomedical Engineering on the Development of Minimally Invasive Cardio-Thoracic Surgery

(1) We describe the boundary conditions for minimally invasive cardiac surgery (MICS) with the aim to reduce procedure-related patient injury and discomfort. (2) The analysis of the MICS work process and its demand for improved tools and devices is followed by a description of the relevant sub-specialties of bio-medical engineering: electronics, biomechanics, and materials sciences. (3) Innovations can represent a desired adaptation of an existing work process or a radical redesign of procedure and devices such as in transcutaneous procedures. Focused interaction between engineers, industry, and surgeons is always mandatory (i.e., a therapeutic alliance for addressing 'unmet patient or professional needs'. (4) Novel techniques in MICS lean heavily on usability and safe and effective use in dedicated hands. Therefore, the use of training and simulation models should enable skills selection, a safe learning curve, and maintenance of proficiency. (5) The critical technical steps and cost-benefit trade-offs during the journey from invention to application will be explained. Business considerations such as time-to-market and returns on investment do shape the cost-benefit room for commercial use of technology. Proof of clinical safety and effectiveness by physicians remains important, but establishing the technical reliability of MICS tools and warranting appropriate surgical skills come first.

Reoperative Mitral Valve Surgery Through Port Access

Minimally invasive mitral valve surgery (MIMVS) has become the standard approach for mitral valve pathology in many centres. The anterolateral mini thoracotomy access is beneficial in reoperative surgery by avoiding repeat sternotomy associated risks. The aim of this study is to analyse the safety of this technique. All patients undergoing reoperative MIMVS between 2008 and 2019 were studied retrospectively. Primary endpoint was 30-day major complications and mortality; secondary outcome was long term survival, reoperation rate and rate of more than moderate recurrent regurgitation. 146 Patients underwent reoperative MIMVS with a mean age of 68 ± 8 years. The composite outcome of 30-day major complication and mortality was 29.5%. 30-Day mortality was 6.2% and stroke rate 3.4%. Survival for the whole cohort was 89.7 ± 2.5% at 1-year, 71.6 ± 4.3% at 5 year and 50.9 ± 5.9% at 8-year follow up. Cox regression analysis revealed reduced left ventricular function (HR 2.8; 95%CI 1.5 - 5.0), GFR < 60 (HR 2.1; 95%CI 1.2 - 3.7) and active endocarditis (HR 6.4; 95%CI 2.7 - 15.4) as variables associated with reduced long-term survival. The cumulative incidence of re-operation after mitral valve replacement was 11.3 ± 3.2% at 5-year and for repair 16.2 ± 7.5% at 5-year. The cumulative incidence of more than moderate recurrent regurgitation after mitral valve repair was 25.4 ± 9.0% at 3-year. Minimally invasive access in reoperative mitral valve surgery in the current study showed similar 30-day mortality and stroke rate compared to repeat sternotomy results reported in literature.

A Novel Plug-Based Vascular Closure Device for Percutaneous Femoral Artery Closure in Patients Undergoing Minimally-Invasive Valve Surgery

Objectives: Surgical exposure of groin vessels to establish cardiopulmonary bypass (CPB) for minimally-invasive valve surgery (MIS) is standard of care but may result in postoperative wound healing disorders or seroma formation. Therefore, adaption of transcatheter techniques for fully percutaneous insertion of CPB cannulae may improve clinical results. We herein analyze a single center experience with a novel plug-based vascular closure device for MIS.

Methods: Between 03/2020 and 02/2021 MIS using the MANTA™ (Teleflex Medical Inc., Wayne, PA, USA) vascular closure device was performed in 28 consecutive patients (58.8 ± 10.6 years, 60.3% male, logEuroSCORE II 1.1 ± 0.8%) receiving mitral and/or tricuspid valve repair/replacement. Concomitant procedures were left atrial appendage occlusion and cryoablation for atrial fibrillation in 21.4% (6/28) and 10.7% (3/28) of patients, respectively. Data were retrospectively analyzed in accordance with standardized M-VARC definitions. MANTA™ device success and early safety was defined as absence of any access site or access related vascular injury and major and life-threatening bleeding complications.

Results: MANTA™ device success with immediate hemostasis and early safety were 96.4% (27/28). In one case, device failure necessitated surgical cut down without further complications. Mean aortic cross clamp time and cardiopulmonary bypass were 96.5 ± 24.2 min and 150.2 ± 33.6 min. Stroke, renal failure or myocardial infarction were not observed. Intensive care unit and total hospital stay were 1.7 ± 0.8 days and 10.1 ± 5.7 days. Overall 30-day mortality was 0%. Post-procedure echocardiography presented one case of residual moderate tricuspid regurgitation and competent valves in all other cases.

Conclusions: The MANTA™ device is safe and effective in MIS. Its ease of use and effectiveness to achieve immediate hemostasis have further simplified MIS.

Minimally invasive versus conventional sternotomy for Mitral valve repair: protocol for a multicentre randomised controlled trial (UK Mini Mitral)

INTRODUCTION

Numbers of patients undergoing mitral valve repair (MVr) surgery for severe mitral regurgitation have grown and will continue to rise. MVr is routinely performed via median sternotomy; however, there is a move towards less invasive surgical approaches.There is debate within the clinical and National Health Service (NHS) commissioning community about widespread adoption of minimally invasive MVr surgery in the absence of robust research evidence; implementation requires investment in staff and infrastructure.The UK Mini Mitral trial will provide definitive evidence comparing patient, NHS and clinical outcomes in adult patients undergoing MVr surgery. It will establish the best surgical approach for MVr, setting a standard against which emerging percutaneous techniques can be measured. Findings will inform optimisation of cost-effective practice.

METHODS AND ANALYSIS

UK Mini Mitral is a multicentre, expertise based randomised controlled trial of minimally invasive thoracoscopically guided right minithoracotomy versus conventional sternotomy for MVr. The trial is taking place in NHS cardiothoracic centres in the UK with established minimally invasive mitral valve surgery programmes. In each centre, consenting and eligible patients are randomised to receive surgery performed by consultant surgeons who meet protocol-defined surgical expertise criteria. Patients are followed for 1 year, and consent to longer term follow-up.Primary outcome is physical functioning 12 weeks following surgery, measured by change in Short Form Health Survey (SF-36v2) physical functioning scale. Early and 1 year echo data will be reported by a core laboratory. Estimates of key clinical and health economic outcomes will be reported up to 5 years.The primary economic outcome is cost effectiveness, measured as incremental cost per quality-adjusted life year gained over 52 weeks following index surgery.

ETHICS AND DISSEMINATION

A favourable opinion was given by Wales REC 6 (16/WA/0156). Trial findings will be disseminated to patients, clinicians, commissioning groups and through peer reviewed publication.

TRIAL REGISTRATION NUMBER

ISRCTN13930454.