Left circumflex coronary artery injury – this arterial branch off the left main coronary artery runs in the atrioventricular groove.
It can be injured if the sutures used during the valve replacement are placed too far radially, particularly on the left lateral edge of the annulus.
If a suture is placed through this artery, it is sometimes recognized immediately by bleeding from the posterior heart. It can also present with poor left ventricular wall motion on intraoperative echocardiogram, decreased cardiac output or ischemic changes on ECG in V5 and V6. Correction of this error involves removing the stitch and sometimes a saphenous vein graft to bypass the injured area.
Perivalvular leak – this condition can occur either early or late. It presents as mitral regurgitation and is seen in patients with friable tissue, mitral valve endocarditis, and extensive valvular calcification. The risk of this complication can be lessened by using pledgeted sutures in patients with fragile or minimal annular tissue.
The diagnosis is made by detecting a new holosystolic murmur, on echocardiogram, or a prominent V wave suggesting a rise in left atrial pressure. Small perivalvular leaks may be observed closely. Large leaks require an urgent return to the operating room with replacement of the valve.
Prosthetic valve thrombosis – this occurs when clot forms on any part of the valve. it is diagnosed by a low cardiac output and is often associated with less than full anticoagulation or the use of vitamin K. Confirmation by echocardiogram shows restricted leaflet motion.
Treatment options include thrombolytic therapy if the patient is clinically stable or immediate reoperation. The valve is inspected and if there is an obvious technical problem such as an impinging suture, the clot is removed and then the valve is irrigated. If it does not appear that a technical problem exists or a thrombectomy will be sufficient, the valve is removed and a new one is inserted.
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