Respect or Resect in mitral valve repair: identical durability at 5 years

"Respect" vs "Resect": Which strategy for minimally invasive mitral valve surgery?

Mitral valve repair (MVr) has established itself as the therapeutic standard for degenerative mitral regurgitation (DMR), supplanting valve replacement due to superior long-term outcomes. However, the debate persists in the operating room: should leaflet preservation via neocord implantation be prioritized ("Respect" approach) or should tissue resection be chosen ("Resect" approach)? This question is even more significant in the context of minimally invasive surgery, where complex anatomy — such as in Barlow's disease or bileaflet prolapse — challenges the durability of the techniques.

This study aims to evaluate and compare the 5-year outcomes of these different strategies ("Respect", "Resect", or a combination of both) within a cohort of 447 patients operated on via right mini-thoracotomy. The central objective is to determine if one technique outperforms the others in terms of reintervention, recurrence of mitral regurgitation, or major adverse cardiovascular events (MACCE) over the long term.

The hypothesis tested is based on the idea that an individualized approach, guided by the patient's specific valvular morphology rather than a single technical dogma, ensures durable valvular competence and equivalent clinical safety, even when faced with the most complex degenerative pathologies.

Study design and population

This single-center retrospective cohort study included 447 consecutive patients who underwent isolated mitral valve repair (MVr) between 2006 and 2014. The cohort presented complex degenerative pathologies, including Barlow's disease, bileaflet involvement, and anterior valve prolapse.

Surgical protocol and stratification

All procedures were performed via a minimally invasive surgical approach using a right lateral mini-thoracotomy. Patients were stratified into three groups according to the technical strategy employed:

• "Respect" Group (n = 293, 65.5%): preservation of the leaflets with or without implantation of neocords.
• "Resect" group (n = 109, 24.4%): tissue resection of the layers.
• "Both" group (n = 45, 10.1%): combined use of resection and preservation techniques.

Evaluation criteria and statistical analysis

The mean follow-up was 5 years. The primary endpoints focused on valvular performance: freedom from mitral valve-related reintervention and severity of residual mitral regurgitation (MR). Secondary endpoints included all-cause mortality and major adverse cardiovascular and cerebrovascular events (MACCE). Durability analysis was performed using a Fine–Gray competing risk regression model to account for death as a competing event.

Perioperative safety and overall survival

L'analyse des résultats immédiats met en évidence une morbi-mortalité hospitalière particulièrement faible : le taux de mortalité globale s'établit à 0,7 %, tandis que les événements cérébrovasculaires n'ont concerné que 0,9 % des patients. À 5 ans, la survie globale atteint 94,0 %, confirmant la robustesse de l'approche mini-invasive.

Durability of the repair and valvular performance

The success of mitral repair proves to be sustainable over the long term. After a mean follow-up of 5 years, durable valvular competence (defined as mitral regurgitation grade ≤ I) is observed in 88.4% of patients. The overall rate of freedom from mitral valve-related reoperation stands at 93.3% at 5 years.

Freedom from major adverse cardiac and cerebrovascular events (MACCE) is 96.8% at 5 years. The study shows no statistically significant difference between the three surgical strategies for all endpoints.

Equivalence of techniques according to anatomical complexity

Competing risk analysis (Fine-Gray model), accounting for death, confirms the absence of superiority of one technique over the other (p = 0.647 for reoperations). The three approaches — leaflet preservation with neocords (“Respect”), resection (“Resect”), or combined technique (“Both”) — offer equivalent clinical and echocardiographic results. This stability of results is observed even in complex degenerative pathologies, such as Barlow's disease, bileaflet involvement, or anterior valve prolapse.

Clinical analysis of results

The data from this single-center study confirm equivalent surgical efficacy between preservation ("Respect"), resection ("Resect"), or combined ("Both") approaches. The key finding lies in the stability of the results at 5 years: with 88.4% of patients presenting residual mitral regurgitation grade ≤ I and a survival rate of 94.0%, the minimally invasive approach demonstrates its robustness. The lack of statistical difference (p = 0.647) regarding the risk of reintervention suggests that the technical choice is not the primary driver of medium-term failure, but rather that adequate anatomical correction is paramount.

Limits and perspective

The retrospective and monocentric nature of the study constitutes its main limitation. However, the application of a Fine-Gray regression model to integrate death as a competing risk strengthens the reliability of the reported reoperation rates. Contrary to certain theoretical debates systematically favoring "Respect" to preserve annular physiology, these "real-life" results show that resection remains an equally durable therapeutic weapon when indicated by valvular morphology.

Implications for practice

For the surgeon, these results validate a tailored surgical strategy ("morphology-guided"). The excellence of the clinical results, even in complex pathologies such as Barlow's disease or bileaflet involvement, indicates that technical mastery of minimally invasive access takes precedence over the dogma of a single repair technique. Perioperative safety (0.7% hospital mortality) confirms the viability of this approach for a large cohort of patients.

Summary of results

At 5-year follow-up, the "Respect", "Resect" techniques or the combined approach show equivalent efficacy: 93.3% absence of reoperation and 88.4% durable valvular competence (grade ≤ I). Data show no significant difference (p = 0.647) in overall survival (94%) or the rate of major cardiovascular events (96.8%), validating these approaches even for complex pathologies such as Barlow's disease.

In concrete terms, for the practitioner:

• Morphology-dependence: Prioritise an individualised strategy guided by anatomy; the study demonstrates that preservation (neochordae) or resection of the leaflets offers identical long-term results.
• Validation of the minimally invasive approach: Right mini-thoracotomy is confirmed as a safe (0.7% hospital mortality) and effective surgical approach for degenerative mitral repair.
• Clinical objective: Focus your efforts on the complete correction of the insufficiency intraoperatively, as the choice of specific technique does not statistically influence the risk of reintervention at 5 years.

Technical Lexicon

DMR (Degenerative Mitral Regurgitation): Degenerative mitral regurgitation characterized by an alteration of the valvular structures leading to a coaptation defect.

'Respect' Technique: Surgical approach aiming to preserve the integrity of the mitral leaflets, generally using artificial neochordae to correct prolapse.

'Resect' technique: Classic method consisting of the resection of the prolapsed or excess part of the valve leaflet to restore an adequate coaptation surface.

Barlow's disease: Severe form of myxomatous degeneration of the mitral valve, involving significant tissue excess, thickened leaflets and often multi-segmental involvement.

MACCE (Major Adverse Cardiac and Cerebrovascular Events): Composite endpoint grouping major complications such as death, myocardial infarction, or stroke.

Fine-Gray model: Statistical method for competing risks regression used to estimate the probability of an event (e.g., reoperation) while accounting for mutually exclusive events (e.g., death).

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