Robotic assistance allows performance of mitral valve operations with a truly minimally invasive and totally thoracoscopic approach, with significant advantages for patients compared to sternotomy-based surgery. Nonetheless, its diffusion has been limited by: 1) significant learning curve and technical requirements; 2) increased immediate financial costs due to dedicated equipment and materials. The aim of the present study is to perform a prospective data collection and evaluation of the in-hospital and follow-up clinical results of mitral valve repair using the last generation DaVinci X robotic platform. A cost-effectiveness analysis of this approach will be also conducted, under a global healthcare system perspective (including the overall patients' pathway starting from diagnosis of mitral valve disease until the completion of the 1st postoperative year). Since the 'competitor' surgical technique is not represented by sternotomy-based mitral surgery, but instead by minimally invasive, video-assisted mitral surgery, patients operated on using such technique will serve as controls.

In an observational, prospective, case-control investigation, the clinical data of all adult (18 years-old or more) patients undergoing robotic-assisted mitral surgery in the Sponsor hospital during the study period will be collected, including preoperative, intraoperative and early postoperative variables. Patients need to be affected by severe mitral regurgitation due to degenerative lesions and be eligible to robotic-assisted surgery. An informed consent for inclusion in the study and management of personal data will be asked from all participants. A total of 30 Baseline variables, 9 intraoperative variables, 26 early postoperative variables and 55 follow-up variables will be collected. Systematic in-house follow-up (clinical and echocardiographic) will be performed at the 3rd, 6th and 12th postoperative months. The database will be managed by research assistants under the supervision of the surgical team. Operations will be performed according to the Institutional protocol using the DaVinci X robotic platform by a trained multidisciplinary team including cardiac surgeons, anesthesiologists, cardiologists, perfusionists and scrub nurses.

The same data will be obtained for all patients undergoing minimally invasive, video-assisted non-robotic-assisted mitral repair during the study period. These patients will serve as controls.

Study Endpoints will include procedural success, early postoperative complications, postoperative functional recovery (both immediate and at follow-up), echocardiographic results of mitral repair.

Such data will be compared with those from control patients undergoing minimally invasive, non-robotic-assisted mitral surgery in our Department during the study period.

In cooperation with Hospital Administration Team, all direct and indirect costs (Euros) associated with the in-hospital pathway of each individual patient will be quantified (17 variables per patient within a separate database). Data collection will be expanded to any hospitalisation occurring during the 1st postoperative year. Such data collection will include patients undergoing both the robotic-assisted and the minimally invasive video-assisted non-robotic-assisted strategy.

Data will be analysed using intergoup comparison statistical tests.

Inclusion Criteria:

• Aged at least 18, willing to complete the study follow-up, having signed the informed consent for participation and data management.
• Severe mitral regurgitation due to degenerative disease with indication to mitral repair surgery.
• If of female gender, being neither pregnant nor lactating.

Exclusion Criteria:

• Previous right chest surgery or severe right intrapleural adhesions.
• Diameter of femoral arteries equal or lesser than 6 mm.
• Left ventricular systolic dysfunction (LVEF <60%).
• Severe right ventricular dysfunction.
• Aortic valve regurgitation >1+/4+.
• Pulmonary artery hypertension (PASP >50 mmHg).
• Chest deformities preventing either robotic-assisted or minimally invasive video-assisted surgery.

Patients affected by severe mitral regurgitation due to degenerative disease (Leaflet prolapse/flail) with indication to surgical mitral repair using either a robotic-assisted approach or a minimally invasive video-assisted non-robotic-assisted approach. Includes patients referred to a tertiary cardiac surgical centre.