Study Objectives/Specific Aims Overall Goal: To compare between transseptal approach and the conventional left atrial approach for mitral valve procedures.

• Objective 1: Assess the intraoperative approach related criteria in valve exposure, cardiopulmonary bypass time and intraoperative complications.
• Objective 2: Assess the outcomes and postoperative results.

Mitral valve diseases are considered among the most prevalent valvular heart diseases that necessitate surgical intervention.

as the Modern international guidelines substantially recommend mitral valve repair whenever possible there is significant decrease in mitral valve replacement rates.

Cardiothoracic surgeons have to face the problem of Making a decision regarding mitral valve repair, reconstruction or replacement which requires excellent valve exposure for precise anatomical definition and manipulation taking in mind cases with specific anatomical challenges.

Since the beginning of modern cardiac surgery only two basic approaches to the mitral valve have been described by Effler who wrote in 1958 " the actual entry into the left atrium may be accomplished in either of two ways : through the Fossa Ovalis by way of the right atrium or through the posterior interatrial groove " Nowadays median sternotomy is still the most commonly used incision for mitral valve surgery which allows the best exposure for the valve through transseptal incision or through Sandergaard's groove.

Although the latter approach is the preferred method for most surgeons the transseptal approach has been revisited in more recent years in various forms by those seeking better exposure of mitral valve especially in cases with difficult anatomy.

In this paper we try to compare the transseptal approach with the conventional left atrial approach for mitral valve procedures to review previous literatures' results and to clarify the effect of using each of the two approaches in preoperative ,intra and postoperative course .

Inclusion Criteria:

• Patients underwent mitral valve replacement, mitral valve repair, redo mitral valve replacement, combined mitral and tricuspid procedures, combined mitral surgery and coronary arteries bypass graft at cardiothoracic surgery department Assiut University Hospital.

Exclusion Criteria:

• Patients with congenital mitral valve diseases .
• patient refused to sign the informed consent to be a part in the research .

all patients who presented to Cardiothoracic Surgery Department, Assiut University Hospital and who meet the listed inclusion from 2016 to 2019 within the range of 100 eligible case.