Suture obliteration of the circumflex coronary artery in three patients undergoing mitral valve operation. Role of left dominant or codominant coronary artery.

Three patients, two undergoing mitral valve replacement and one a mitral valve annuloplasty with a Carpentier-Edwards ring, had suture obliteration of the circumflex coronary artery. Examination of the distance of the circumflex artery from the mitral anulus in 15 specimens showed a direct correlation to the type of coronary dominance. That is, left dominance (4.1 mm, range 3 to 6.5) or codominance (5.5 mm, range 4.5 to 7.5), where the posterior descending artery arises from the circumflex, was associated with greater proximity to the mitral anulus than right dominance (8.4 mm, range 6 to 11.5). Two of our patients had left dominance and one codominance, predisposing them to circumflex injury. Factors that identify patients at high risk for such injury are therefore left dominance and codominance. Surgeons forewarned with this information can now focus on the proximal third of the circumflex--the area most predisposed to injury.