Mitral valve repair for secondary mitral regurgitation
Is there room yet for repair in these patients?
Patients who develop secondary mitral regurgitation (Carpentier type IIIb) have a very controversial indication for intervention and to make the scenario even more challenging, the type of intervention has several peculiarities. In international guidelines, in case of intervention in regurgitation mitral valve of functional etiology, correction with valve replacement utilizing prosthesis seems to be a better indication. Perhaps because it is heart muscle disease, the need to preserve the subvalvar at all costs is not as a priority, but rather, to guarantee the patency of the proposed correction.
However, there are those who argue that repair should be the method of choice, since less manipulation of left ventricular geometry and preservation of native leaflets to the detriment of pericardial leaflets/mobile prosthetic elements would be the least harmful in long-term monitoring.
Given this fact, some researchers invest in the long-term results of several mitral annular repair techniques, as was the case of a German group that published on Heart, in 2018, a comparison of the subannular repair technique with the traditional repair model using a semi-rigid ring. They saw that in patients who underwent a combined procedure of surgical revascularization and MR correction, patients who had semi-rigid ring and some additional subannular technique such as neochords, re-approximation of the papillaries and even stretching of leaflets, showed better results than using isolated from the ring. In any case, the degree of MR recurrence in a degree greater than 2+ occurred in approximately 10% of the individuals, which demonstrates that the surgery still needs technical improvement.
- We know the adequate correction of functional MR, when properly indicated, brings about reverse remodeling of the left ventricle and this has a direct impact on patient survival.
- There is a clear improvement in the surgical technique of mitral repair with the association of subannular correction and this makes the perspective more optimistic, since if a repair achieves the same prevalence of patency as a valve replacement, it can become the procedure of choice.
- The approach with subannular technique may bring benefits, but others such as cutting of strings and excessive manipulation proved to be harmful by worsening the ventricular geometry, with the papillary muscles approximation (PMA) being the most used technique.
- Thus far, the indication is for valve replacement, but in certain cases, there is the possibility of successful repair.
1 – Harmel EK, Reichenspurner H, Girdauskas E. Subannular reconstruction in secondary mitral regurgitation: a meta-analysis. Heart. 2018 Nov;104(21):1783-1790.
2 – Goldstein D, Moskowitz AJ, Gelijns AC, et al. Two-Year Outcomes of Surgical Treatment of Severe Ischemic Mitral Regurgitation. N Engl J Med. 2016 Jan 28;374(4):344-53.