Mitral Valve Repair Should Be the Preferred Technique When Durable Results Are Expected
Mitral valve repair is strongly preferred over replacement for primary mitral regurgitation (MR) when anatomically feasible, as it provides superior long-term survival, fewer thromboembolic and hemorrhagic complications, and better preservation of left ventricular function 1, 2.
Primary (Degenerative) Mitral Regurgitation
When Repair is Strongly Indicated:
- Single segment flail of the posterior leaflet due to fibroelastic deficiency without calcification represents the ideal scenario for repair and should never undergo replacement unless repair fails 1
- Thin, pliable leaflets with isolated posterior leaflet prolapse (especially P2 scallop) have the highest likelihood of durable repair 1
- Repair demonstrates lower early mortality (0.96% vs 2.2%), fewer thromboembolic events, and better quality of life compared to replacement 3, 4
When Repair is Possible but More Complex:
- Bileaflet prolapse with multiple scallop involvement requires referral to experienced surgeons at high-volume centers 1
- Anterior leaflet prolapse can be addressed with artificial chordae (PTFE) techniques 1
- Barlow's disease with diffuse myxomatous changes may require sliding leaflet valvuloplasty 1
When Replacement May Be Preferred:
- Prior cardiac surgery or chest radiation where reoperation for failed repair carries substantially increased risk 1
- Extensive calcification, severe fibrosis, or mixed disease requiring highly complex reconstruction 3
- Rheumatic mitral disease shows significantly higher reoperation rates after repair (HR 3.30) and may favor replacement 5
Critical caveat: The most important predictor of long-term failure is moderate or greater residual MR at the index operation 1. If repair cannot achieve trivial/mild residual MR, replacement should be performed.
Secondary (Functional) Mitral Regurgitation
The decision-making differs substantially from primary MR:
Repair Approach:
- Restrictive remodeling with rigid annuloplasty ring for annular dilatation mechanism 1
- Should be avoided as sole therapy when severe leaflet tethering (>10 mm tenting height) or inferobasal aneurysm is present 1
Replacement Approach:
- Chord-sparing mitral valve replacement is reasonable to consider in preference to repair for severe ischemic MR with significant tethering 1
- No significant survival advantage for repair over replacement in secondary MR, unlike degenerative disease 4
Concomitant Aortic Valve Surgery
When performing simultaneous aortic valve replacement:
- Mitral valve repair plus AVR shows superior long-term survival compared to double valve replacement in unselected patients 5
- Lower early mortality (RR 0.67), fewer thromboembolic events (RR 0.81), and fewer hemorrhagic events (RR 0.87) 5
- Exception: Rheumatic heart disease patients have 3-fold higher reoperation rates with repair, favoring replacement 5
Reoperation Risk Trade-off
While repair has higher reoperation rates (7-19% vs <2% for replacement) 3, the composite outcome of death or reoperation does not differ significantly 4. The survival benefit of repair outweighs the reoperation risk in appropriate candidates.
Technical Feasibility Assessment
Evaluate these factors to determine repair feasibility:
- Leaflet mobility and thickness (thin/pliable favors repair)
- Extent of prolapse (single segment vs multisegment)
- Presence of calcification (extensive calcification favors replacement)
- Mechanism of regurgitation (Carpentier classification)
- Surgeon experience and institutional volume 1
Postoperative surveillance: Transthoracic echocardiography is required either before discharge or within 1-3 months to assess repair durability 1.