To the Editor,
I read the report by Kuzmin et. al.1 that describes a
circumflex lesion occurring following mitral valve (MV) repair,
tricuspid valve (TV) repair, and left atrial appendage (LAA) closure.
Although the patient’s atrial fibrillation was left untreated, the
surgeon did close the LAA with an AtriClip. Postoperatively, there are
two significant complications, myocardial infarction and permanent
pacemaker requirement. The report focuses on the infarction. Permanent
pacemaker requirement is a known complication of double valve
repair2. Although one cannot say conclusively which
ring implantation caused heart block, it is reported more frequently
with tricuspid repair as a consequence of violating the Triangle of Koch
or impinging on the Bundle of His as it travels along the posterior rim
of the Membranous Septum.
Circumflex coronary artery occlusion or impingement during MV repair is
well described in the literature3. The cause of
coronary obstruction in the reported case is at least , if not more
likely due to the MV repair. On two-dimensional cine the ring appears
somewhat remote but that is not conclusive, and 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 appendage without due attention to distortion of the adjacent
circumflex might be capable of creating compression or accordioning of
the vessel. At Franciscan Health Heart Center, we have implanted more
than 2,400 AtriClips of various models, in a variety of open and
minimally invasive cardiac operations over six years, with no such
complication.
I would point out that the version of the clip and delivery system
reported by Kuzmin et. al.1 is designed for minimally
invasive procedures and is not the clip they implanted. A standard non-V
clip was implanted and can be seen on the fluoroscopic pictures.
Furthermore, a 50mm clip is rarely implanted, making up <5%
of our practice managing appendages of all sizes and anatomies. If the
authors are concerned about the possibility of adjacent structure
injury, I would encourage gaining familiarity with the different
versions of the device, and the prescribed methods of implantation,
including sizing. The clip should be placed at the true base of the
appendage. In open cases, there is advantage of dissecting certain
attachments to ensure safe closure. 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.
Whereas it is possible in an open case under direct visualization to
create circumflex coronary obstruction with an AtriClip, it is more
likely due to a mitral stitch; the path of which is not directly
visualized after it breaches the endocardium. If there were no clip seen
on the postoperative images, one would assume the circumflex lesion was
a consequence of mitral ring implantation. It is simply impossible to
determine the mechanism for the case report.
1. Kuzmin B, Staack T, Wippermann J and Wacker M. Left atrial appendage
occlusion device causing coronary obstruction: A word of caution.J Card Surg . 2021;36:723-725.
2. Moskowitz G, Hong KN, Giustino G, Gillinov AM, Ailawadi G, DeRose JJ,
Jr., Iribarne A, Moskowitz AJ, Gelijns AC and Egorova NN. Incidence and
Risk Factors for Permanent Pacemaker Implantation Following Mitral or
Aortic Valve Surgery. J Am Coll Cardiol . 2019;74:2607-2620.
3. Coutinho GF, Leite F and Antunes MJ. Circumflex artery injury during
mitral valve repair: Not well known, perhaps not so infrequent-lessons
learned from a 6-case experience. J Thorac Cardiovasc Surg .
2017;154:1613-1620.