Circumflex coronary artery (CCA) injury during mitral valve surgery is a rare but serious complication whit difficult diagnosis. The aim of our study was to describe the elements of diagnosis that could allow prevention of this complication.

From 2006 to 2013 in Rouen University Hospital, 8 patients (1.03%) among 775 undergoing mitral valve surgery (repair or replacement) presented CCA occlusion confirmed by coronary angiography. Sex ratio was 5 men for 3 women with a mean age of 54.2 years. Left main coronary dominance was present in 75%. Mitral valve repair was performed in 5 patients and valve replacement in 3. The diagnosis was suspected by ECG in 7/8 patients: 6 patients (75%) presented ST segment elevation, 1 had permanent AV block while EKG was normal in one. CCA occlusion led to a significant impairment of left ventricular function, median LVEF: decreased from 58 to 43% (p=0.04) although coronary angiography was performed within one hour in 5 patients (62.5%). Five had complete revascularization (4 of those with immediate coronary angiography), while 3 patients were treated medically.

Occlusion, assessed by coronary angiography, was preferentially located on the superolateral quarter of the mitral annulus next to the anterolateral commissure predominantly on its mid portion (75%). As regards to the mechanism of CCA occlusion, 37.5% of patients had a stitch passing through the CCA, 50% had a kinking of the vessel due to a stitch located close to the CCA and one of them had a compressive hematoma

Follow-up at day-7 was uneventful in 7 patients with one in-hospital death one day after the surgery (cardiac tamponade).

CCA injury is a rare but serious complication of mitral valve surgery suspected on ECG, due to a stitch always located at the same point of mitral annulus. An eventual intraoperative angiography in hybrid rooms could be a specific solution for patients at risk (large mitral ring, left main coronary dominance).