Mitral valve repair in a regional quality collaborative: Respect or resect?

Objective

Mitral valve repair is the gold standard for treatment of mitral regurgitation, but the optimal technique remains debated. By using a regional collaborative, we sought to determine the change in repair technique over time.

Methods

We identified all patients undergoing isolated mitral valve repair from 2012 to 2022 for degenerative mitral disease. Those with endocarditis, transcatheter repair, or tricuspid intervention were excluded. Continuous variables were analyzed via Wilcoxon rank sum, and categorical variables were analyzed via chi-square testing.

Results

We identified 1653 patients who underwent mitral valve repair, with 875 (59.2%) undergoing a no resection repair. Over the last decade, there was no significant trend in the proportion of repair techniques across the region (P = .96). Those undergoing no resection repairs were more likely to have undergone prior cardiac surgery (5.0% vs 2.2%, P = .002) or minimally invasive approaches (61.4% vs 24.7%, P < .001) with similar predicted risk of mortality (median 0.6% vs 0.6%, P = .75). Intraoperatively, no resection repairs were associated with longer bypass times (140 [117-167] minutes vs 122 [91-159] minutes, P < .001). Operative mortality was similar between both groups (1.1% vs 1.0%, P = .82), as were other postoperative outcomes. Anterior leaflet prolapse (odds ratio, 11.16 [6.34-19.65], P < .001) and minimally invasive approach (odds ratio, 6.40 [5.06-8.10], P < .001) were most predictive of no resection repair.

Conclusions

Despite minor differences in operative times, statewide over the past decade there remains a diverse mix of both classic "resect" and newer "respect" strategies with comparable short-term outcomes and no major timewise trends. These data may suggest that both approaches are equivocal.

Neochordal Goldilocks: Analyzing the biomechanics of neochord length on papillary muscle forces suggests higher tolerance to shorter neochordae

OBJECTIVE

Estimating neochord lengths during mitral valve repair is challenging, because approximation must be performed largely based on intuition and surgical experience. Little data exist on quantifying the effects of neochord length misestimation. We aimed to evaluate the impact of neochord length on papillary muscle forces and mitral valve hemodynamics, which is especially pertinent because increased forces have been linked to aberrant mitral valve biomechanics.

METHODS

Porcine mitral valves (n = 8) were mounted in an ex vivo heart simulator, and papillary muscles were fixed to high-resolution strain gauges while hemodynamic data were recorded. We used an adjustable system to modulate neochord lengths. Optimal length was qualitatively verified by a single experienced operator, and neochordae were randomly lengthened or shortened in 1-mm increments up to ±5 mm from the optimal length.

RESULTS

Optimal length neochordae resulted in the lowest peak composite papillary muscle forces (6.94 ± 0.29 N), significantly different from all lengths greater than ±1 mm. Both longer and shorter neochordae increased forces linearly according to difference from optimal length. Both peak papillary muscle forces and mitral regurgitation scaled more aggressively for longer versus shorter neochordae by factors of 1.6 and 6.9, respectively.

CONCLUSIONS

Leveraging precision ex vivo heart simulation, we found that millimeter-level neochord length differences can result in significant differences in papillary muscle forces and mitral regurgitation, thereby altering valvular biomechanics. Differences in lengthened versus shortened neochordae scaling of forces and mitral regurgitation may indicate different levels of biomechanical tolerance toward longer and shorter neochordae. Our findings highlight the need for more thorough biomechanical understanding of neochordal mitral valve repair.

Robotic mitral valve surgery

Totally endoscopic robotic mitral valve repair is the least invasive surgical therapy for mitral valve disease. Robotic mitral valve surgery demonstrates faster recovery with shorter hospital stays, less morbidity, and equivalent mortality and mid-term durability compared to sternotomy. In this review, we will explore the advantages and disadvantages of robotic mitral valve surgery and consider important technical details of both operative set-up and mitral valve repair techniques. The number of robotic cardiac surgical procedures being performed globally is expected to continue to rise as experience grows with robotic techniques and increasing numbers of cardiac surgeons become proficient with this innovative technology. This will be facilitated by the introduction of newer robotic systems and increasing patient demand.

Respect Versus Resect Approaches for Mitral Valve Repair: A Meta-Analysis of Reconstructed Time-to-Event Data

Mitral valve repair (MVr) has been associated with superior long-term survival and freedom from valve-related complications compared with mitral valve replacement for primary mitral regurgitation (MR). The 2 main approaches for MVr are chordal replacement ("respect approach") and leaflet resection ("resect approach"). We performed a systematic review and a meta-analysis using 3 search databases to compare the long-term end points between both approaches. The primary end point was long-term survival. The secondary end points were long-term MR recurrence and reoperation. After reconstruction of time-to-event data for the individual survival analysis, pooled Kaplan-Meier curves for the end points were generated. A total of 14 studies (5,565 patients) were included in the analysis. The respect approach was associated with superior survival compared with the resect approach in the overall sample (hazard ratio [HR] 0.73, 95% confidence interval [CI] 0.56 to 0.96, p = 0.024, n = 3,901 patients) but not in the risk-adjusted sample (HR 1.00, 95% CI 0.55 to 1.82, p = 0.991, n = 620 patients). There was no difference between the approaches in the rate of MR recurrence in the overall sample (HR 1.39, 95% CI 0.92 to 2.08, p = 0.116, n = 1,882 patients) or in the risk-adjusted sample (HR 1.62, 95% CI 0.76 to 3.47, p = 0.211, n = 288 patients). The data for reoperation were only available in the overall sample and did not reveal a difference (HR 0.92, 95% CI 0.62 to 1.35, p = 0.663, n = 3,505 patients). In conclusion, the current evidence suggests no difference in long-term mortality, MR recurrence, or reoperation between the resect and respect approaches for MVr after adjusting for patient risk factors. More long-term follow-up data are warranted.

Neochordae implantation versus leaflet resection in mitral valve posterior leaflet prolapse and dilated left ventricle: a propensity score matching comparison with long-term follow-up

OBJECTIVES

Uncorrected severe mitral regurgitation (MR) due to posterior prolapse leads to left ventricular dilatation. At this stage, mitral valve repair becomes mandatory to avoid permanent myocardial injury. However, which technique among neochoardae implantation and leaflet resection provides the best results in this scenario remains unknown.

METHODS

We selected 332 patients with left ventricular dilatation and severe degenerative MR due to posterior leaflet (PL) prolapse who underwent neochoardae implantation (85 patients) or PL resection (247 patients) at our institution between 2008 and 2020. A propensity score matching analysis was carried on to decrease the differences at baseline.

RESULTS

Matching yielded 85 neochordae implantations and 85 PL resections. At 10 years, freedom from cardiac death and freedom from mitral valve reoperation were 92.6 ± 6.1% vs 97.8 ± 2.1% and 97.7 ± 2.2% vs 95 ± 3% in the neochordae group and in the PL resection group, respectively. The MR ≥2+ recurrence rate was 23.9 ± 10% in the neochordae group and 20.8 ± 5.8% in the PL resection group (P = 0.834) at 10 years. At the last follow-up, the neochordae group showed a higher reduction of left ventricular end-diastolic diameter (44 vs 48 mm; P = 0.001) and a better ejection fraction (60% vs 55%; P < 0.001) compared to PL resection group.

CONCLUSIONS

In this subgroup of patients, both neochordae implantation and leaflet resection provide excellent durability of the repair in the long term. Neochordae implantation might have a better effect on dilated left ventricle.

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.

Propensity Matched Outcomes of Minimally Invasive Mitral Surgery: Does a Heart-Team Approach Eliminate Female Gender as an Independent Risk Factor?

BACKGROUND

There is increasing evidence that female gender is an independent risk factor for cardiac surgery. Minimally invasive mitral surgery (MIV) has proven to have excellent long-term results, but little is known about gender-dependent outcomes. The aim of our study was to analyze our heart team's decision-based MIV-specialized cohort.

METHODS

In-hospital and follow-up data were retrospectively collected. The cohort was divided into gender groups and propensity-matched groups.

RESULTS

Between 22 July 2013 and 31 December 2022, 302 consecutive patients underwent MIV. Before matching, the total cohort showed that women were older, had a higher EuroSCORE II, were more symptomatic, and had more complex valve pathology and tricuspid regurgitation resulting in more valve replacements and tricuspid repairs. Intensive and hospital stays were longer. In-hospital deaths (n = 3, all women) were comparable, with more atrial fibrillation in women. The median follow-up time was 3.44 (0.008-8.9) years. The ejection fraction, NYHA, and recurrent regurgitation were low and comparable and atrial fibrillation more frequent in women. The calculated 5-year survival and freedom from re-intervention were comparable (p = 0.9 and p = 0.2). Propensity matching compared 101 well-balanced pairs; women still had fewer resections and more atrial fibrillation. During the follow-up, women had a better ejection fraction. The calculated 5-year survival and freedom from re-intervention were comparable (p = 0.3 and p = 0.3).

CONCLUSIONS

Despite women being older and sicker, with more complex valve pathology and subsequent replacement, early and mid-term mortality and the need for reoperation were low and comparable before and after propensity matching, which might be the result of the MIV setting combined with our patient-tailored decision-making. We believe that a multidisciplinary heart team approach is crucial to optimize patient outcomes in MIV, and it might also reduce the widely reported increased surgical risk in female patients. Further studies are needed to prove our findings.

An Image-Based Computational Fluid Dynamics Study of Mitral Regurgitation in Presence of Prolapse

PURPOSE

In this work we performed an imaged-based computational study of the systolic fluid dynamics in presence of mitral valve regurgitation (MVR). In particular, we compared healthy and different regurgitant scenarios with the aim of quantifying different hemodynamic quantities.

METHODS

We performed computational fluid dynamic (CFD) simulations in the left ventricle, left atrium and aortic root, with a resistive immersed method, a turbulence model, and with imposed systolic wall motion reconstructed from Cine-MRI images, which allowed us to segment also the mitral valve. For the regurgitant scenarios we considered an increase of the heart rate and a dilation of the left ventricle.

RESULTS

Our results highlighted that MVR gave rise to regurgitant jets through the mitral orifice impinging against the atrial walls and scratching against the mitral valve leading to high values of wall shear stresses (WSSs) with respect to the healthy case.

CONCLUSION

CFD with prescribed wall motion and immersed mitral valve revealed to be an effective tool to quantitatively describe hemodynamics in case of MVR and to compare different regurgitant scenarios. Our findings highlighted in particular the presence of transition to turbulence in the atrium and allowed us to quantify some important cardiac indices such as cardiac output and WSS.

Microinvasive mitral valve surgery: Current status and status quo

Surgical mitral valve repair, performed either through median sternotomy or minimal invasive approach, presents the gold standard treatment for degenerative mitral valve disease. In dedicated centres, high repair and low complication rates have been established with excellent valve repair durability. Recently, new techniques have been introduced, that allow mitral valve repair to be performed through small surgical incisions and while avoiding cardio-pulmonary bypass. These new techniques, however, conceptually differ significantly when compared to surgical repair and it remains questionable whether they are capable of reproducing the results of surgical treatment.

Building a successful minimally invasive mitral valve repair program before introducing the robotic approach: The Massachusetts General Hospital experience

Background

Patients with mitral valve prolapse (MVP) requiring surgical repair (MVr) are increasingly operated using minimally invasive strategies. Skill acquisition may be facilitated by a dedicated MVr program. We present here our institutional experience in establishing minimally invasive MVr (starting in 2014), laying the foundation to introduce robotic MVr.

Methods

We reviewed all patients that had undergone MVr for MVP via sternotomy or mini-thoracotomy between January 2013 and December 2020 at our institution. In addition, all cases of robotic MVr between January 2021 and August 2022 were analyzed. Case complexity, repair techniques, and outcomes are presented for the conventional sternotomy, right mini-thoracotomy and robotic approaches. A subgroup analysis comparing only isolated MVr cases via sternotomy vs. right mini-thoracotomy was conducted using propensity score matching.

Results

Between 2013 and 2020, 799 patients were operated for native MVP at our institution, of which 761 (95.2%) received planned MVr (263 [34.6%] via mini-thoracotomy) and 38 (4.8%) received planned MV replacement. With increasing proportions of minimally invasive procedures (2014: 14.8%, 2020: 46.5%), we observed a continuous growth in overall institutional volume of MVP (n = 69 in 2013; n = 127 in 2020) and markedly improved institutional rates of successful MVr, with 95.4% in 2013 vs. 99.2% in 2020. Over this period, a higher complexity of cases were treated minimally-invasively and increased use of neochord implantation ± limited leaflet resection was observed. Patients operated minimally invasively had longer aortic cross-clamp times (94 vs. 88 min, p = 0.001) but shorter ventilation times (4.4 vs. 4.8 h, p = 0.002) and hospital stays (5 vs. 6 days, p < 0.001) than those operated via sternotomy, with no significant differences in other outcome variables. A total of 16 patients underwent robotically assisted MVr with successful repair in all cases.

Conclusion

A focused approach towards minimally invasive MVr has transformed the overall MVr strategy (incision; repair techniques) at our institution, leading to a growth in MVr volume and improved repair rates without significant complications. On this foundation, robotic MVr was first introduced at our institution in 2021 with excellent outcomes. This emphasizes the importance of building a competent team to perform these challenging operations, especially during the initial learning curve.

Mitral valve repair with artificial chords: Tips and tricks

Mitral valve regurgitation (MR) is a common valvular disorder occurring in up to 10% of the general population. Mitral valve reconstructive strategies may address any of the components, annulus, leaflets, and chords, involved in the valvular competence. The classical repair technique involves the resection of the prolapsing tissue. Chordal replacement was introduced already in the '60, but in the mid '80, some surgeons started to use expanded polytetrafluoroethylene (ePTFE) Gore-Tex sutures. In the last years, artificial chords have been used also using transcatheter approach such as NeoChord DS 1000 (Neochord) and Harpoon TSD-5. The first step is to achieve a good exposure of the papillary muscles that before approaching the implant of the artificial chords. Then, the chords are attached to the papillary muscle, with or without the use of supportive pledgets. The techniques to correctly implant artificial chords are many and might vary considerably from one center to another, but they can be summarized into three big families of suturing techniques: single, running or loop. Regardless of how to anchor to the mitral leaflet, the real challenge that many surgeons have taken on, giving rise to some very creative solutions, has been to establish an adequate length of the chords. It can be established based on anatomically healthy chords, but it is important to bear in mind that surgeons work on the mitral valve when the heart is arrested in diastole, so this length could fail to replicate the required length in the full, beating heart. Hence, some surgeons suggested techniques to overcome this problem. Herein, we aimed to describe the current use of artificial chords in real-world surgery, summarizing all the tips and tricks.

Midterm results after seamless patch mitral reconstruction

Objectives

Some pathologies, including infective endocarditis or sclerotic changes of the mitral leaflet, make the conventional mitral valve repair challenging. Our previously described technique for reconstruction with a seamless pericardial patch makes the repair feasible in some of such difficult pathologies. However, the extent of mitral leaflet segments that could be safely repaired using this technique remains unknown. We investigated the association between the midterm outcome and the extent of mitral leaflet segments replaced by a pericardial patch.

Methods

From January 2009 to January 2022, patients who underwent mitral valve repair with the seamless 1-patch reconstruction technique were included. The glutaraldehyde-treated pericardium was trimmed and anchored at the papillary muscle. The edge was sewn to the leaflet and the annulus.

Results

A total of 49 patients (aged 60 ± 15 years) underwent mitral valve repair with this technique. The totally endoscopic approach was used in 27 patients (55%). No patient's repair was converted to valve replacement. No operative mortality or disabling stroke was observed during the early postoperative period. In the midterm follow-up, redo surgery was required in 9 patients (18%). Freedom from mitral valve reintervention rates at 1, 5, and 10 years were 84%, 82%, and 82% for all patients, respectively. Freedom from reoperation at 5 years was 100%, 92%, and 46% for commissural lesion, 1- to 2-segment involvement, and 3-segment involvement, respectively. There was a significant difference among the 3 groups with regard to mitral valve reoperation rate (P = .002).

Conclusions

Mitral valve seamless patch reconstruction provides excellent midterm results if applied to commissural lesions or lesions involving up to 2 segments.

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.

Simplifying Mitral Valve Repair: A Guide to Neochordae Reconstruction

Mitral valve reconstruction techniques using polytetrafluoroethylene sutures are associated with high repair rates and excellent durability but are dependent on accurate neochordae length estimates. Current strategies to determine the appropriate length of artificial neochordae commonly rely on nonphysiologic saline testing on the arrested heart, with erroneous lengths resulting in residual mitral regurgitation. We present a guide for reproducible and accurate neochordae reconstruction based upon transesophageal echocardiographic measurements, which simplifies mitral repair for most patients with degenerative mitral regurgitation and can be used in conventional or minimally invasive approaches.

Surgical mitral valve repair technique considerations based on the available evidence

Mitral valve regurgitation is the second most common valve disease in the western world. Surgery is currently the best tool for generating a long-lasting elimination of mitral valve regurgitation. However, the mitral valve apparatus is a complex anatomical and functional structure, and repair results and durability show substantial heterogeneity. This is not only due to differences in the underlying mitral valve regurgitation pathophysiology but also due to differences in repair techniques. Repair philosophies differ substantially from one surgeon to the other, and consensus for the technically best repair strategy has not been reached yet. We had previously addressed this topic by suggesting that ring sizing is "voodoo". We now review the available evidence regarding the various repair techniques described for structural and functional mitral valve regurgitation. Herein, we illustrate that for structural mitral valve regurgitation, resuspension of prolapsing valve segments or torn chordae with polytetrafluoroethylene sutures and annuloplasty can generate the most durable results paired with the best achievable hemodynamics. For functional mitral valve regurgitation, the evidence suggests that annuloplasty alone is insufficient in most cases to generate durable results, and additional subvalvular strategies are associated with improved durability and possibly improved clinical outcomes. This review addresses current strategies but also implausibilities in mitral valve repair and informs the mitral valve surgeon about the current evidence. We believe that this information may help improve outcomes in mitral valve repair as the heterogeneity of mitral valve regurgitation pathophysiology does not allow a one-size-fits-all concept.

Outcomes of loop technique with ring annuloplasty: a > 10-year experience

OBJECTIVE

We assessed the long-term outcomes of the loop technique with ring annuloplasty for mitral regurgitation from our > 10-year experience.

METHODS

We retrospectively reviewed 362 patients who underwent the loop technique with ring annuloplasty via median sternotomy or right mini-thoracotomy for mitral regurgitation. The median follow-up duration was 4.1 years (interquartile range 2.3-5.8 years).

RESULTS

This study involved 147 women and 215 men (median age, 66.5 years). Mitral regurgitation was caused by Barlow's disease in 27 patients. Seven patients required reoperations (recurrent regurgitation caused by technical issues, n = 3; progression of degenerative disease, n = 4). The 5- and 10-year cumulative incidences of reoperation considering death as the competing event were 1.4% and 5.4%, respectively. The 5- and 10-year postoperative cumulative incidences of moderate-to-severe recurrent mitral regurgitation were 4.7% and 13.0%, respectively. Residual regurgitation ≥ mild (hazard ratio, 6.99; 95% confidence interval, 1.520-32.12; P = .012) was an independent risk factor for reoperation. The independent risk factors for moderate-to-severe recurrent regurgitation were residual regurgitation ≥ mild (hazard ratio, 9.60; 95% confidence interval, 3.042-30.31; P < .001) and the loop-in-loop technique (hazard ratio, 3.40; 95% confidence interval, 1.058-10.90; P = .040). The median mean pressure gradient was sustained at almost 3.5 mmHg for > 7 years.

CONCLUSIONS

The loop technique with ring annuloplasty provided excellent results with good hemodynamics beyond the mid-term. Residual regurgitation ≥ mild and the loop-in-loop technique may not be preferable for durable outcomes.

Respect versus resect approaches for mitral valve repair: a study-level meta-analysis

Mitral valve repair (MVr) restores leaflets coaptation while preserving the patient's own valve. The two main techniques are: (a) chordal replacement ("respect approach"), whereby artificial neochordae are used to resuspend prolapsed segments of the affected leaflet - and (b) leaflet resection ("resect approach"), whereby diseased leaflet segment is resected, and the remaining segments are sutured together. Both techniques of MVr are associated with better long-term results, fewer valve-related complications and lower mortality when compared with mitral valve replacement (MVR). They also restore quality of life and improve survival to rates equivalent to those of the general population. We performed a meta-analysis to pool data of clinical studies that compared outcomes of MVr stratified by the surgical technique. Seventeen studies accounting for 6,046 patients fulfilled our eligibility criteria. The "respect approach" outperformed the "resect approach" with lower permanent pacemaker implantation rates and lower mean gradients. Despite any possible advantages of one technique over the other, which approach is best for each patient must be decided on a case-by-case basis and more long-term follow-up data are warranted.

Biomechanical Analysis of Neochordal Repair Error from Diastolic Phase Inversion of Static Left Ventricular Pressurization

Objective

Neochordal implantation is a common form of surgical mitral valve (MV) repair. However, neochord length is assessed using static left ventricular pressurization, leading surgeons to evaluate leaflet coaptation and valve competency when the left ventricle is dilating instead of contracting physiologically, referred to as diastolic phase inversion (DPI). We hypothesize that the difference in papillary muscle (PM) positioning between DPI and physiologic systole results in miscalculated neochord lengths, which might affect repair performance.

Methods

Porcine MVs (n = 6) were mounted in an ex vivo heart simulator and PMs were affixed to robots that accurately simulate PM motion. Baseline hemodynamic and chordal strain data were collected, after which P2 chordae were severed to simulate posterior leaflet prolapse from chordal rupture and subsequent mitral regurgitation. Neochord implantation was performed in the physiologic and DPI static configurations.

Results

Although both repairs successfully reduced mitral regurgitation, the DPI repair resulted in longer neochordae (2.19 ± 0.4 mm; P < .01). Furthermore, the hemodynamic performance was reduced for the DPI repair resulting in higher leakage volume (P = .01) and regurgitant fraction (P < .01). Peak chordal forces were reduced in the physiologic repair (0.57 ± 0.11 N) versus the DPI repair (0.68 ± 0.12 N; P < .01).

Conclusions

By leveraging advanced ex vivo technologies, we were able to quantify the effects of static pressurization on neochordal length determination. Our findings suggest that this post-repair assessment might slightly overestimate the neochordal length and that additional marginal shortening of neochordae might positively affect MV repair performance and durability by reducing load on surrounding native chordae.

Biomechanical engineering analysis of commonly utilized mitral neochordae

Objective

To evaluate the suture rupture forces of commonly clinically utilized neochord repair techniques to identify the most biomechanically resistant most biomechanically resistant technique.

Methods

Several types of neochord techniques (standard interrupted neochordae, continuous running neochordae, and loop technique), numbers of neochordae, and suture calibers (polytetrafluoroethylene CV-3 to CV-6) were compared. To perform the tests, both ends of the neochordae were loaded in a tensile force analysis machine. During the test, the machine applied tension to the neochord until rupture was achieved. The tests were performed 3 times for each variation, and the rupture forces were averaged for statistical analysis.

Results

Rupture force was significantly higher for running neochordae relative to interrupted neochordae (P < .01). However, a single rupture in the running technique resulted in failure of the complete neochord system. For both running and interrupted neochordae, a greater number of neochordae as well as a thicker suture caliber significantly increased the neochord rupture force (P < .01). The loop technique ruptured at significantly lower forces compared with the other 2 techniques (P < .01). A greater number of loops did not significantly increase the rupture force of loop neochordae. Observed rupture forces for all techniques were higher than those normally observed in physiologic conditions.

Conclusions

Under experimental conditions, the running neochord technique has the best mechanical performance due to an increased rupture force. If using running neochordae, more than 1 independent set of multiple running neochordae are advised (ie, >2 independent sets of multiple running neochordae in each set).

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.

Cardiac Surgery 2020 Reviewed

In 2020, nearly 30,000 published references appeared in the PubMed for the search term "cardiac surgery." While SARS-CoV-2 affected the number of surgical procedures, it did not affect outcomes reporting. Using the PRISMA approach, we selected relevant publications and prepared a results-oriented summary. We reviewed primarily the fields of coronary and conventional valve surgery and their overlap with interventional alternatives. The coronary field started with a discussion on trial data value and their interpretation. Registry comparisons of coronary artery bypass surgery (CABG) and percutaneous coronary intervention confirmed outcomes for severe coronary artery disease and advanced comorbidities with CABG. Multiple arterial grafting was best. In aortic valve surgery, meta-analyses of randomized trials report that transcatheter aortic valve implantation may provide a short-term advantage but long-term survival may be better with classic aortic valve replacement (AVR). Minimally invasive AVR and decellularized homografts emerged as hopeful techniques. In mitral and tricuspid valve surgery, excellent perioperative and long-term outcomes were presented for structural mitral regurgitation. For both, coronary and valve surgery, outcomes are strongly dependent on surgeon expertise. Kidney disease increases perioperative risk, but does not limit the surgical treatment effect. Finally, a cursory look is thrown on aortic, transplant, and assist-device surgery with a glimpse into the current stand of xenotransplantation. As in recent years, this article summarizes publications perceived as important by us. It does not expect to be complete and cannot be free of individual interpretation. We aimed to provide up-to-date information for decision-making and patient information.