Aortic valve replacement in post-op mitral valve surgery after 28 years
A 50-year-old male, known post-operative mitral valve replacement, was admitted with shortness of breath. He was on meticulous anticoagulation, even though he worked at a desert farm. On evaluation, he was diagnosed to have severe aortic stenosis. Previous mitral valve replacement was done 28 years prior with On-x valve by the same surgeon. At that time, aortic valve did not have significant gradient. The mitral prosthetic valve was functioning well with minimal gradient. It was decided to proceed with aortic valve replacement.
After induction, left femoral vessels were exposed and isolated for emergency cannulation and to go on cardiopulmonary bypass. Sternotomy was uneventful. Patient underwent aortic valve replacement with 21 mm Sorin Carbomedics Supra-annular top hat valve. Transfusion was minimized by the use of cell-saver, antifibrinolytics and meticulous attention to hemostasis.
Patients who need cardiac surgery have become increasingly more complex, and an increasing proportion of them require reoperative cardiac surgery. Surgical techniques have significantly improved in recent times. However redo cardiac surgery has several inherent challenges that can increase mortality and also morbidity to the patient. With the use of imaging, the risk of sternal opening is now better assessed. Preparedness, in case of an injury induced emergency, increases in intensity from having the perfusionist in the room (for the lowest-risk patients), to exposing the axillary artery or groin vessels, to establishing cardiopulmonary bypass (CPB) before opening, to performing hypothermic circulatory arrest (for the highest-risk patients). Early CPB results in a longer pump run, increased risk of bleeding due to coagulopathy, and higher risk of end-organ dysfunction. For these reasons, we believe that CPB or circulatory arrest (or both) should be established before opening only in patients who are at the highest risk of injury upon opening.
Reoperation does present increased risk in selected patients. However, systematic protocol-based approach, and use of checklists help in decreasing the risks of redo surgery.