Retrograde femoral arterial perfusion and stroke risk during minimally invasive mitral valve surgery: is there cause for concern?

Recent data have suggested that retrograde arterial perfusion (RAP) during minimally invasive mitral valve surgery (MIMVS) is associated with a higher stroke rate than sternotomy approaches. To assess whether there is genuine cause for concern, we examine the strengths and weaknesses of this data. A multitude of confounding factors obfuscate interpretation of the data including imprecise definitions of MIMVS, the effect of the substantial learning curve, retrospective comparisons of small historic cohorts with baseline differences and differing risk profiles for atherosclerosis, different methods of aortic occlusion and lack of reporting of peripheral vascular disease (PVD)/aortic assessment in patient populations. In patients with severe (grades IV and V) aortic arch/ascending aortic atherosclerosis, RAP has clearly been shown to be associated with an increase in risk of cerebral embolic complications. It would be reasonable to assume that grades IV/V atheroma anywhere along the aorto-iliac axis (from femoral cannulation site to carotid arteries) may also increase the risk of stroke. Hence those at risk of severe atherosclerotic vascular disease should be screened to fully assess the aortoiliac axis. Apart from this patient group, there is no convincing evidence (without confounding variables) that retrograde perfusion per se during minimally invasive mitral surgery increases the risk of stroke. This may be due to the largely differing aetiologies of vascular and mitral degenerative disease.