Is limited anterior mitral valve resection advisable?

Limited Anterior Mitral Valve Resection: Advisability

Limited triangular resection of the anterior mitral valve leaflet is advisable and effective for focal anterior leaflet prolapse, though it should be used selectively—reserved primarily for focal defects rather than extensive myxomatous disease, where neochordal reconstruction is generally preferred. 1

Guideline-Based Framework

The 2020 ACC/AHA guidelines explicitly acknowledge that focal triangular resection may be used for focal anterior leaflet defects, though they note this is done "rarely" 1. This cautious endorsement reflects the technical complexity and the availability of alternative techniques. The guidelines prioritize:

• Non-resection techniques (PTFE neochordal reconstruction or chordal transfer) as the primary approach for isolated anterior leaflet prolapse 1
• Focal triangular resection as an acceptable alternative specifically for focal defects 1
• The overarching principle that mitral valve repair should restore leaflet coaptation depth to >5 mm, stabilize the annulus, restore normal leaflet motion, and eliminate mitral regurgitation 1

When Limited Anterior Resection Works Best

The technique is most appropriate when:

• Focal, segmental prolapse is present rather than diffuse myxomatous degeneration 2
• The lesion is well-demarcated and involves less than extensive portions of the anterior leaflet
• The surgeon has specific experience with this technique, as anterior leaflet pathology represents higher complexity than posterior leaflet disease 1

Supporting Evidence for Effectiveness

Recent data from 2026 demonstrates that triangular resection for extensive anterior mitral leaflet prolapse can achieve excellent outcomes when properly executed 3. In a series of 24 patients with myxomatous extensive anterior leaflet prolapse:

• All patients were successfully repaired
• Only 1 patient (with Barlow disease) required re-repair at 8 years
• The remaining 23 patients had no more than mild mitral regurgitation over 1-21 years of follow-up 3

A 2004 review of 25 years of experience confirmed that anterior leaflet triangular resection is "safe and reproducible," with low rates of recurrent MR, low reoperation rates, and decreased likelihood of systolic anterior motion after repair 2.

The "Respect vs. Resect" Debate

Contemporary evidence (2026) from minimally invasive mitral surgery shows that both leaflet preservation ("Respect") and resection ("Resect") techniques yield equally favorable long-term outcomes 4. At 5-year follow-up:

• Freedom from mitral valve-related reoperation was 93.3% with no significant differences between techniques
• Durable mitral valve competence (MR grade ≤ I) was present in 88.4% of patients
• This held true even for anatomically complex pathologies including anterior leaflet prolapse 4

However, the functional differences matter: chordal replacement retains greater posterior leaflet motion with lower trans-mitral pressure gradients compared to resection 5.

Critical Technical Considerations

Common pitfall: Attempting resection for diffuse myxomatous disease or Barlow's syndrome. These conditions are better managed with neochordal techniques because resection removes redundant tissue but may not address the underlying pathology adequately 1, 5.

Key technical point: The 2026 study describes using a "marking stitch" technique—placing sutures on both sides of the lesion, tying them, performing a leakage test, and only proceeding with triangular resection if no leakage is found 3. This systematic approach optimizes outcomes.

Algorithm for Decision-Making

1. Assess anterior leaflet pathology extent:

   • Focal, segmental defect → Consider limited triangular resection
   • Diffuse myxomatous/Barlow's → Prefer neochordal reconstruction

2. Evaluate surgeon experience:

   • Anterior leaflet pathology requires more specific mitral repair expertise than isolated posterior leaflet disease 1
   • If limited experience, neochordal techniques may be more reproducible

3. Consider anatomic factors:

   • Presence of annular or leaflet calcium → Increases complexity
   • Risk factors for systolic anterior motion → Resection may reduce this risk 2

4. Intraoperative assessment:

   • Use marking stitch technique with leakage testing before committing to resection 3
   • Ensure coaptation depth >5 mm after repair 1

The bottom line: Limited anterior mitral valve resection is advisable for focal anterior leaflet defects when performed by experienced surgeons, offering durable results comparable to neochordal techniques, with the specific advantage of potentially reducing systolic anterior motion risk.