A meta-analysis of robotic vs. conventional mitral valve surgery

Abstract

Objectives: The present study is the first meta-analysis to compare the surgical outcomes of robotic vs. conventional mitral valve surgery in patients with degenerative mitral valve disease.

Methods: A systematic review of the literature was conducted to identify all relevant studies with comparative data on robotic vs. conventional mitral valve surgery. Predefined primary endpoints included mortality, stroke and reoperation for bleeding. Secondary endpoints included cross-clamp time, cardiopulmonary bypass time, length of hospitalization and duration of intensive care unit (ICU) stay. Echocardiographic outcomes were assessed when possible.

Results: Six relevant retrospective studies with comparative data for robotic vs. conventional mitral valve surgery were identified from the existing literature. Meta-analysis demonstrated a superior perioperative survival outcome for patients who underwent robotic surgery. Incidences of stroke and reoperation were not statistically different between the two treatment arms. Patients who underwent robotic surgery required a significantly longer period of cardiopulmonary bypass time and cross-clamp time. However, the lengths of hospitalization and ICU stay were not significantly different. Both surgical techniques appeared to achieve satisfactory echocardiographic outcomes in the majority of patients.

Conclusions: Current evidence on comparative outcomes of robotic vs. conventional mitral surgery is limited, and results of the present meta-analysis should be interpreted with caution due to differing patient characteristics. However, it has been demonstrated that robotic mitral valve surgery can be safely performed by expert surgeons for selected patients. A successful robotic program is dependent on a specially trained team and a sufficient volume of referrals to attain and maintain safety.

Keywords: Mini-mitral; meta-analysis; mitral valve; robotic surgery.

Figure 1

PRISMA chart summarizing the search strategy performed to identify relevant comparative studies on robotic vs. conventional mitral valve surgery.

Figure 2

Forest plot of the relative risk (RR) of perioperative mortality after robotic vs. conventional mitral valve surgery. The estimate of the RR of each trial corresponds to the middle of the squares, and the horizontal line shows the 95% confidence interval (CI). On each line, the numbers of events as a fraction of the total number randomized are shown for both treatment groups. For each subgroup, the sum of the statistics, along with the summary RR, is represented by the middle of the solid diamonds. A test of heterogeneity between the trials is given below the summary statistics.

Figure 3

Forest plot of the relative risk (RR) of perioperative stroke after robotic vs. conventional mitral valve surgery. The estimate of the RR of each trial corresponds to the middle of the squares, and the horizontal line shows the 95% confidence interval (CI). On each line, the numbers of events as a fraction of the total number randomized are shown for both treatment groups. For each subgroup, the sum of the statistics, along with the summary RR, is represented by the middle of the solid diamonds. A test of heterogeneity between the trials is given below the summary statistics.

Figure 4

Forest plot of the relative risk (RR) of re-operation for bleeding after robotic vs. conventional mitral valve surgery. The estimate of the RR of each trial corresponds to the middle of the squares, and the horizontal line shows the 95% confidence interval (CI). On each line, the numbers of events as a fraction of the total number randomized are shown for both treatment groups. For each subgroup, the sum of the statistics, along with the summary RR, is represented by the middle of the solid diamonds. A test of heterogeneity between the trials is given below the summary statistics.

Figure 5

Forest plot of the standardized mean difference (SMD) of duration of cross-clamp time after robotic vs. conventional mitral valve surgery. The estimate of the SMD of each trial corresponds to the middle of the squares, and the horizontal line shows the 95% confidence interval (CI). A test of heterogeneity between the trials is given below the summary statistics.

Figure 6

Forest plot of the standardized mean difference (SMD) of duration of cardiopulmonary bypass time after robotic vs. conventional mitral valve surgery. The estimate of the SMD of each trial corresponds to the middle of the squares, and the horizontal line shows the 95% confidence interval (CI). A test of heterogeneity between the trials is given below the summary statistics.

Figure 7

A summary of echocardiographic findings of the severity of mitral valve regurgitation. (A) Before robotic or conventional mitral valve surgery; and (B), after robotic or conventional mitral valve surgery.