Establishing an Anatomical Proximity Between the Coronary Circumflex Artery and the Mitral Valve Annulus: Implications for Mitral Valve Surgery

Abstract

The coronary circumflex artery (CX) lies in the left atrioventricular groove, running intimately parallel to the mitral valve annulus. Thus, unintentional damage to the CX can occur via a fixation suture during mitral valve surgery, typically reported in hearts with a left dominant or co‐dominant circulation. This study aims to elucidate the anatomical relationship between the CX and annulus, and evaluate damage to the CX following three different mitral valve surgical repairs. It is predicted that left dominant or co‐dominant hearts should exhibit the closest anatomical relationship between the CX and annulus and experience a greater incidence of damage despite the chosen mitral valve surgery. Using fixed (n=18) and fresh‐frozen (n=9) cadaveric hearts, coronary circulation was dissected and dominance determined. After opening the left atrial wall, a clock face was overlaid on the mitral valve (12:00 position at the A2 leaflet midline) and the distance between the annulus and the CX was measured at each hour. The CX was closest to the annulus in fresh‐frozen, left dominant hearts. All left dominant and co‐dominant hearts had CXs that hugged the posterior length of the annulus, diving deep at 3:00 (before the posterior commissure), a finding previously unreported. Preliminary results from the ongoing surgical repairs advocate for cautionary suture placement in areas formerly considered to be at low risk for damage.