Approach to severe mitral annular calcification using ultrasonic aspiration

Abstract

Severe mitral annular calcification (MAC) is perhaps the greatest challenge faced in mitral valve surgery. Valve replacement in the setting of severe MAC carries with it the risk of numerous surgical complications and modes of technical failure, including catastrophic atrioventricular (AV) groove disruption. In the face of these challenges, a variety of surgical approaches to severe MAC have been described but without clear consensus. We describe an approach using the Cavitron Ultrasonic Surgical Aspirator (CUSA) emphasizing minimal, focal disruption of annular calcium. Ultrasonic aspiration is applied only when needed and only at the precise site of valve suture placement to aspirate away or merely soften dense calcium such that sutures can be placed through or around the calcified annulus. Our approach is simple and eliminates the need for complete annular decalcification which risks avoidable AV groove destabilization and requires complex annular reconstruction. In our experience of 55 cases of high-risk mitral replacement in the setting of very severe MAC, we report two cases of AV groove disruption (4%), two cases of coronary injury (4%), and two cases of stroke (4%), with no cases of paravalvular leak worse than mild. In-hospital mortality was 16%, due largely to significant underlying cardiac and non-cardiac comorbidity and underscoring the often underestimated non-technical risks inherent in these cases. While no single approach may be optimal in every case of severe MAC, we feel our technique of limited ultrasonic aspiration is an important tool in the mitral surgeon's armamentarium.