Background: We routinely use aortic root enlargement (ARE) as part of one strategy to avoid prosthesis-patient mismatch in patients with relatively small aortic roots who are undergoing aortic valve replacement (AVR).
Methods: We performed a retrospective review of 657 consecutive stented AVR patients at a single institution between 1995 to 2001. Of these, 114 (17%) patients underwent ARE. Root enlargement was selectively performed in patients at risk for prosthesis-patient mismatch, defined as calculated projected indexed effective orifice area (iEOA) less than 0.85 cm2/m2. This involved extension of the aortotomy between the left and noncoronary cusps, valve implantation, and Dacron patch closure of the aorta, thus permitting replacement with a valve size appropriate to body surface area.
Results: The mean age of ARE patients was 72.5 +/- 11.0 years, with 32% aged 80 years or more. Of the patients, 61% were female and 27% had undergone previous cardiac operations. Combined procedures included coronary bypass in 57 patients and mitral repair or replacement in 24. The prevalence of mismatch was less than 3%. The ARE required an average of 19 minutes of additional aortic clamp time. The 30-day mortality was 0.9%. Logistic regression showed perfusion time to be the only independent predictor of mortality.
Conclusions: Our results show that ARE can be performed readily and with minimal added risk relative to standard AVR. We also present a preventive strategy to minimize mismatch predicted at time of operation from the reference value of effective orifice area for a given prosthesis and the patient's size. This includes use of ARE to enhance the potential benefit of AVR.