**2.3 Establishment of a cardiopulmonary bypass**

In a robotic mitral valve repair, cardiopulmonary bypass is established either via an antegrade perfusion with a central cannulation or via a retrograde perfusion with a peripheral cannulation. It is a controversy in which perfusion strategy is optimal [12].

Murzi et al. reviewed 1421 patients who underwent antegrade perfusion and 141 patients who underwent retrograde perfusion [13]. They reported that retrograde perfusion was associated with higher incidence of stroke than antegrade perfusion (3.5 vs. 1.1%). In the meantime, LaPietra et al. reviewed 1501 patients, and found that stroke rate was low (about 1.5%) regardless of cannulation technique [14]. Nowadays, several experienced centers routinely apply retrograde femoral perfusion during minimally invasive mitral valve surgery [1, 3, 6].

In establishing the peripheral cannulation, the venous drainage for cardiopulmonary bypass is obtained by a placement of cannula, usually via the right femoral vein and right internal jugular vein. It is essential to introduce cannula under a transesophageal echocardiography to avoid the risk of extravasation, migration of the cannula, or other types of complications [15]. Arterial cannula is usually inserted to the right femoral artery. It is also essential to obtain a preoperative multidetector computed tomography angiography for the assessment of aortoiliac atherosclerosis in order to plan an optimal surgical approach [16].
