The purpose of this study is to evaluate the outcomes of complete (preservation of both anterior and posterior leaflets) versus partial (preservation of posterior leaflet only) preservation of subvalvular apparatus in cases of mitral valve replacement

After mitral valve replacement (MVR), sudden increases in afterload and disruption of the annular-chordal-papillary-left-ventricular wall causes left ventricular (LV) dysfunction in the early postoperative period.

patients with LV dysfunction after MVR have a significantly lower 8-year survival rate compares with patients who did not have LV dysfunction Papillary muscles play an important role in the left ventricular contraction by drawing the mitral ring toward the apex, thereby causing shortening of the long axis and spherity of the chamber contribute for better ejection of blood.

preservation of papillary muscles and chordae tendineae in MVR reduces postoperative mortality, low cardiac output syndrome and improves haemodynamic function.

Partial preservation of the mitral apparatus through preservation of the posterior leaflet (MVR-P) has been proven to significantly reduce perioperative mortality.

The importance of complete preservation of the mitral apparatus remains controversial, but it is hypothesized that complete preservation with preservation of both the anterior and posterior leaflets may contribute to superior postoperative hemodynamic function as compared to partial preservation.

Due to the increased technical complexity of preserving both leaflets, concerns about longer bypass and cross-clamp times, the need to undersize prostheses, and the possibility of left ventricular outflow tract (LVOT) obstruction, the majority of cardiac surgeons currently prefer to preserve the posterior leaflet alone.

Inclusion Criteria:

• - Age between 18 and 60 years
• Rheumatic mitral disease indicated for mitral valve replacement
• Concomitant other valve disease

Exclusion Criteria:

• - Patients who have undergone previous mitral valve surgery or other heart surgery.
• Patients with ischemic mitral disease.
• emergency operation.
• patients with significant comorbidities (severe pulmonary disease or end stage renal disease).