Minimal dissection and continuous retrograde cardioplegia for aortic valve replacement in patients with a patent left internal mammary artery bypass graft.

BACKGROUND AND AIM OF THE STUDY: Aortic valve replacement (AVR) in patients with previous coronary artery bypass grafting (CABG) and a patent pedicled internal mammary artery (IMA) is often complicated by a need to dissect and clamp the IMA to achieve optimal myocardial protection. Eliminating this need may simplify and facilitate surgery; hence, a new surgical technique for use in these patients is described.

METHODS: Five patients with previous CABG and functioning IMA who required AVR between January 1998 and October 2002 were studied. In all patients, the IMA was neither dissected nor clamped. Myocardial protection comprised an initial bolus of antegrade cardioplegia, followed by continuous retrograde infusion of tepid non-diluted oxygenated blood, supplemented with cardioplegic drugs to maintain cardiac arrest. The systemic and myocardial temperature was 30-32 degrees C.

RESULTS: All patients underwent surgery as planned, and there was no operative mortality or myocardial infarction. One patient sustained a minor stroke. None of the IMA was injured.

CONCLUSION: In patients requiring AVR, it is both possible and reasonable to leave the IMA undissected and unclamped. Limited experience suggests that this new technique provides adequate myocardial protection, while keeping surgery both simple and safe.