Mitral valve surgery: current status and future prospects of the minimally invasive approach

Alternative minimally invasive surgical explantation techniques for failed transcatheter mitral valve repair devices

Objective

The use of transcatheter mitral valve repair (TMVr) devices is increasing in elderly and high-risk patients. However, the increasing number of patients with recurrent mitral regurgitation (MR) has confronted surgeons with the issue of how to explant the devices and whether the mitral valve should be repaired or replaced. The aim of the study is to summarize our clinical experience with the explantation of different TMVr devices and to provide alternative surgical techniques that can be performed in different clinical scenarios.

Methods

A simulator system including a dummy valve representing native valves was used to create video documentation and to develop alternative surgical methods for clip explantation. Moreover, the clip explantation techniques were shown in 2 patients undergoing minimally-invasive mitral valve repair after a failed TMVr.

Results

Alternative explantation techniques were described for each TMVr device; 2 techniques for MitraClip and 3 techniques for PASCAL (Precision Transcatheter Valve Repair System), which may be adjusted for each individual according to the underlying valve pathology and the degree of device encapsulation. The patients were discharged without residual MR and remained MR free at the follow-up.

Conclusions

Transcatheter edge-to-edge repair devices can be surgically explanted without damaging the MV leaflets. Removal of each device may require a different technique tailored to the degree of device encapsulation and valve pathology. Increasing experience may facilitate repair in patients with recurrent MR after TMVr.

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.

Minimally Invasive Extirpation of Benign Atrial Cardiac Tumors: Clinical Follow-Up and Survival

OBJECTIVE

Evidence determining the optimal treatment for cardiac tumors is rare. We report our midterm clinical outcome and patient characteristics of our series undergoing atrial tumor removal through a right lateral minithoracotomy (RLMT).

METHODS

From 2015 to 2021, 51 patients underwent RLMT for atrial tumor extirpation. Patients receiving concomitant atrioventricular valvular, cryoablation, and/or patent foramen ovale closure surgery were included. Follow-up was performed using standardized questionnaires (mean: 1,041 ± 666 days). Follow-up involved any tumor recurrence, clinical symptoms, and any recurrent arterial embolization. Survival analysis was successfully achieved in all patients.

RESULTS

Successful surgical resection was achieved in all patients. Mean cardiopulmonary bypass and cross-clamping times were 75 ± 36 and 41 ± 22 min, respectively. The most common tumor location was the left atrium (n = 42, 82.4%). Mean ventilation time was 12.74 ± 17.23 h, intensive care unit stay ranged from 1 to 1.9 days (median: 1 day). Nineteen patients (37.3%) received concomitant surgery. Histopathological analysis showed 38 myxoma (74.5%), 9 papillary fibroelastoma (17.6%), and 4 thrombus (7.8%). Thirty-day mortality was observed in 1 case (2%). One patient (2%) suffered a stroke postoperatively. No patient had a relapse of cardiac tumor. Three patients (9.7%) showed arterial embolization during follow-up. Thirteen follow-up patients (25.5%) were in New York Heart Association class ≤II. Overall survival was 90.2% at 2 years.

CONCLUSIONS

A minimally invasive approach for benign atrial tumor resection is effective, safe, and reproducible. Of the atrial tumors, 74.5% were myxoma and 82% were located in the left atrium. A low 30-day mortality rate with no manifestation of recurrent intracardiac tumor was observed.

Totally endoscopic aortic valve replacement: Techniques and early results

Objective

To demonstrate the technical details of total endoscopic aortic valve replacement using a standard prosthesis, compare the clinical effect and safety of endoscopic aortic valve replacement and traditional aortic valve replacement.

Methods

From 2020 to 2021, 60 consecutive patients underwent elective isolated aortic valve replacement (AVR). They were divided into two groups: the total endoscopic AVR group (TE-AVR group, 29 patients, nine women, aged 51.65 ± 11.79 years), and the traditional full-sternotomy group (AVR group, 31 patients, 13 women, aged 54.23 ± 12.06 years). Three working ports were adopted in the TE-AVR procedure.

Results

No patient died in either group. The cardiopulmonary bypass (CPB) time and aortic cross-clamp (ACC) time in the TE-AVR group were longer than those in the AVR group (CPB time: 177.6 ± 43.2 vs. 112.1 ± 18.1 min, p < 0.001; ACC time: 118.3 ± 29.7 vs. 67.0 ± 13.2 min, p < 0.001). However, the mechanical ventilation duration (14.2 ± 9.3 vs. 24.0 ± 18.9 h, p = 0.015) and postoperative hospital stay (6.0 ± 1.7 vs. 8.0 ± 4.5 days, p = 0.025) were shorter in patients of TE-AVR group than those of AVR group. Although the ICU stay (55.1 ± 26.9 vs. 61.5 ± 44.8 h, p = 0.509) and post-operative chest drainage of the first 24 h (229.8 ± 125.0 vs. 273.2 ± 103.2 ml, p = 0.146) revealed no statistical difference, there was a decreasing trend in the TE-AVR group. Among the patients of the TE-AVR group, two patients were converted to thoracotomy because of mild to moderate paravalvular leakage identified by intraoperative transesophageal echocardiography.

Conclusion

Total endoscopic aortic valve replacement is safe and feasible, with less trauma and quicker recovery.

Propensity-matched comparison of right mini-thoracotomy versus median sternotomy for isolated mitral valve repair

BACKGROUND

A right mini-thoracotomy (RT) versus median sternotomy (MS) approach for isolated mitral valve (MV) repair has been associated with less postoperative morbidity, shorter hospital stay, and faster functional recovery, but with consistently longer cross-clamp time and higher operative costs.

METHODS

We assessed the impact of a modified operative technique on outcomes in 158 RT versus 129 MS patients treated with myxomatous MV repair from 2016 through 2021. Propensity matching based upon the Society of Thoracic Surgeons Risk Score was used to compare 108 patients in each cohort.

RESULTS

Propensity-matched RT patients had reductions in total ventilation time (P=0.025), postoperative atrial fibrillation (P=0.019), and hospital length of stay (P<0.001). RT and MS patients had similar cross-clamp times (66.4±13.7 vs 64.8±16.0 minutes, P=0.414), with less overall leaflet resection (32.4% vs 57.4%, P<0.001) and fewer Gore-Tex NeoChords implanted per patient (1.7±0.7 vs 2.1±1.0, P=0.028) in the RT group. The two cohorts did not differ with respect to 30-day major surgical complications. No patient died and there was no difference between the two groups with respect to freedom from re-operation (98.2% vs 98.2%, P=0.800) at a mean follow-up of 21.4±18.5 months. Direct total hospital costs were lower for the RT group (P=0.018), with reductions in postoperative charges offsetting increased operating room costs.

CONCLUSIONS

In this single-center study, the RT compared to the MS approach for myxomatous MV repair resulted in less postoperative morbidity and shorter hospital length of stay, with similar cross-clamp time, reduced total hospital costs, and comparable intermediate outcomes.

Factors associated with an unsuccessful Fast-Track course following Minimally Invasive Surgical Mitral Valve Repair

OBJECTIVES

Analyses of fast-track processes demonstrated that low-risk cardiac surgical patients require minimal intensive care, with a low incidence of mortality or morbidity. We investigated perioperative factors and their association with fast-track failure in a retrospective cohort study of patients undergoing minimally invasive mitral valve surgery.

METHODS

Patients undergoing minimally invasive surgical mitral valve repair for Carpentier type I or type II mitral regurgitation between 2014 and 2020 were included in the study. The definition of fast-track failure consisted of > 10 hours mechanical ventilation, >24 hours intensive care unit stay, re-intubation after extubation and re-admission to the intensive care unit. Multivariable logistic regression analysis enabled the identification of factors associated with fast-track failure.

RESULTS

In total, 491 patients were included in the study and were analysed. Two-hundred and thirty-seven patients (48.3%) failed the fast-track protocol. Multivariable logistic regression analysis showed that a New York Heart Association classification ≥3 (OR 2.05; CI 1.38-3.08; p < 0.001, pre-existing chronic kidney disease (OR 2.03; CI 1.14-3.70; p = 0.018), coronary artery disease (OR 1.90; CI 1.13-3.23; p = 0.016), postoperative bleeding requiring surgical revision (OR 8.36; CI 2.81-36.01; p < 0.001) and procedure time (OR 1.01; CI 1.01-1.01; p < 0.001) were independently associated with fast-track failure.

CONCLUSIONS

Factors associated with fast-track failure in patients with Carpentier type I and II pathologies undergoing minimally invasive mitral valve repair are a New York Heart Association classification III-IV at baseline, pre-existing chronic kidney disease and coronary artery disease. Postoperative bleeding requiring rethoracotomy and procedure time were also identified as important factors associated with failed fast-track.

CLINICAL REGISTRATION NUMBER

The corresponding local ethics committee (Charité Medical School, Berlin, Germany) approved the present study which complies with the Declaration of Helsinki (ethics approval number: EA2/175/20).

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.

A system for real-time multivariate feature combination of endoscopic mitral valve simulator training data

Purpose

For an in-depth analysis of the learning benefits that a stereoscopic view presents during endoscopic training, surgeons required a custom surgical evaluation system enabling simulator independent evaluation of endoscopic skills. Automated surgical skill assessment is in dire need since supervised training sessions and video analysis of recorded endoscope data are very time-consuming. This paper presents a first step towards a multimodal training evaluation system, which is not restricted to certain training setups and fixed evaluation metrics.

Methods

With our system we performed data fusion of motion and muscle-action measurements during multiple endoscopic exercises. The exercises were performed by medical experts with different surgical skill levels, using either two or three-dimensional endoscopic imaging. Based on the multi-modal measurements, training features were calculated and their significance assessed by distance and variance analysis. Finally, the features were used automatic classification of the used endoscope modes.

Results

During the study, 324 datasets from 12 participating volunteers were recorded, consisting of spatial information from the participants’ joint and right forearm electromyographic information. Feature significance analysis showed distinctive significance differences, with amplitude-related muscle information and velocity information from hand and wrist being among the most significant ones. The analyzed and generated classification models exceeded a correct prediction rate of used endoscope type accuracy rate of 90%.

Conclusion

The results support the validity of our setup and feature calculation, while their analysis shows significant distinctions and can be used to identify the used endoscopic view mode, something not apparent when analyzing time tables of each exercise attempt. The presented work is therefore a first step toward future developments, with which multivariate feature vectors can be classified automatically in real-time to evaluate endoscopic training and track learning progress.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11548-022-02588-1.