Coronary artery obstruction during mitral valve surgery and concomitant
left atrial appendage exclusion; choosing a culprit.
This letter is in response to the case report by Kuzmin et al. entitled
“Left atrial appendage occlusion device causing coronary obstruction: A
word of caution” , published in November 2020 issue of Journal of
Cardiac Surgery. The report describes a circumflex lesion occurring
following mitral valve (MV) repair, tricuspid valve repair, and left
atrial appendage closure (LAAO) using AtriClip device. The authors
concluded that LAAO is a safe procedure, but in the setting of a
concomitant MV surgery LAAO may be a contributor to the reported event.
Circumflex coronary artery occlusion or impingement during MV repair is
well described in the literature. On the reported two-dimensional cine,
the position of the stenosis is typical of mitral repair induced injury.
A ring suture can gather and compress tissue adjacent to the coronary
creating stenosis without a discrete ligation. It is also true that
vigorous traction on the LAA without due attention to distortion of the
adjacent circumflex might be capable of creating compression or
accordioning of the vessel. To mitigate this, the clip should be placed
at the true base of the appendage. A residual pouch carries as much or
more risk as not attempting to close the appendage at all. The authors’
recommendation to place the clip more distally will inevitably lead to
incomplete closures. In conclusion, the reported event was more likely
due to a mitral stitch, the path of which is not directly visualized
after it breaches the endocardium.