Controversy in mitral valve repair, resection or chordal replacement?

Mitral valve plasty has superseded valve replacement as the standard technique for treating degenerative mitral valve prolapse. Quadrangular resection is considered the gold standard for posterior leaflet prolapse. Chordal replacement was first developed to treat the anterior leaflet and subsequently became widely used for the posterior leaflet, after which a new version of posterior leaflet resection was developed that did not involve local annular plication. In the era of the mini-thoracotomy, the premeasured loop technique is simple to adopt and is as durable as quadrangular resection. However, there is controversy surrounding whether resection or chordal replacement is the optimal technique. The resection technique is curative because it removes the main pathologic lesion. The disadvantage of the resection is that it can be complicated and often requires advanced surgical skills. In contrast, chordal replacement is not pathologically curative because it leaves behind a redundant leaflet. However, the long-term results appear to be equivalent in many reports. Functionally, chordal replacement retains greater posterior leaflet motion with a lower trans-mitral pressure gradient than quadrangular resection. Moreover, chordal replacement is simple and yields uniform results. The optimal technique depends on whether the anterior leaflet or posterior leaflet is involved, the Barlow or non-Barlow disease state, and whether a mini-thoracotomy or standard sternotomy approach is used. For mitral valve repair, the most superior and reliable technique for the posterior leaflet is resection using the newer resection technique with a sternotomy approach, which requires a skilled surgeon.