CIRCULATING MICROEMBOLI IN PATIENTS AFTER AORTIC-VALVE REPLACEMENT WITH PULMONARY AUTOGRAFTS AND MECHANICAL VALVE PROSTHESES

Background The pulmonary autograft procedure (Ross) is now considered the gold standard for aortic valve replacement. One of its advantages is the freedom from macroemboli without anticoagulation. Whether this holds true for circulating microemboli, detectable as high-intensity t ransient Doppler signals (HITS), has not yet been verified. Methods an d Results We investigated 8 patients (2 women, 6 men; mean age, 50.6 /- 17.9 years) after the Ross procedure, 9 patients (3 women, 6 men; m ean age, 67.2 +/- 9.46 years) after aortic valve replacement with a me chanical valve prosthesis, and 12 young healthy volunteers by unilater al 1 hour recording of the middle cerebral artery on digital audio tap e. Patients with extracranial carotid artery disease were excluded by color duplex sonography. During the off-line evaluation, the investiga tor was not aware of any patient details. No HITS were detected in hea lthy volunteers (95% confidence interval [CI], 0% to 26.46%). After th e Ross procedure, 1 patient had 11 and 1 patient had 1 HITS (95% CI, 3 .19% to 65.09%). All recipients of mechanical valves had HITS, ranging from 2 to 84 per hour (95% CI, 66.7% to 100%). Significantly more rec ipients of mechanical valves exhibited HITS than recipients of pulmona ry autografts (P<.O5) or control subjects (P<.05). Conclusions In cont rast to mechanical valves, pulmonary autografts are seldom the source of microemboli, confirming the pulmonary autograft as the superior sub stitute for aortic valve replacement.