Mitro annular disjunction
Mitro annular disjunction is an entity on its own which combines:
1) symmetrical end systolic regurgitation,
2) excess tissue of both anterior and posterior leaflets,
3) end systolic excursion of P2 out of the plane of the annulus, and
4) a very specific kink of the base of the Left Ventricle (LV) due to a lack of ventricular muscle reaching the MV annulus.
This entity is more frequently identified as before, and the two main features are, 1)the kink of the base of the LV just below the PL in end systole, and 2) the features of the regurgitant jet which is all along the closure line and centrally directed. Surgery is sometimes required despite mild to moderate regurgitation. Its syndrome can also be accompanied by malignant ventricular arrythmias which may explain sudden deaths in relation with ventricular fibrillation. Such patients in their work up should undergo a Gadolinium MRI, searching for a ventricular scar despite normal coronary anatomy and even more specifically a papillary muscle scar. Surgery may eliminate the arrhythmic episodes but not in all cases. Some have suggested cryoablation of the papillary muscle and in other patients a permanent AICD implantation may be indicated.
In some cases, but not all, a simple annuloplasty may be sufficient as it suppresses end systolic motion and the kink of the base of the LV, which in turn eradicates the regurgitation, by bringing back both leaflets into the LV cavity in systole. In some cases, a true repair is required in order to reduce P2 height and avoid a post-operative SAM
Alfieri is currently using in such cases a modified Alfieri stitch, which is a complete running suture between A2and P2 in the body of the leaflets, leaving 2 orifices at the level of A1-P1 and A3-P3, always associated to a complete ring annuloplasty.