Enlargement of the small aortic root during aortic valve replacement: is there a benefit?

BACKGROUND: Aortic root enlargement (ARE) at the time of aortic valve replacement (AVR) is an often proposed but still unproven technique to prevent prosthesis-patient mismatch. To evaluate the risks and benefits of ARE, we examined the outcomes of patients with small aortic roots who underwent AVR with or without the use of ARE.
METHODS: Patients (n = 712) with small aortic roots who underwent AVR were prospectively followed (follow-up, 3,730 patient-years; mean, 5.2 +/- 4.1 years). All patients had a small aortic annulus that would have led to the insertion of an aortic prosthesis of 21 or less in size. Multivariate techniques were used to compare outcomes between patients who underwent AVR alone (n = 540) versus AVR plus ARE (n = 172).
RESULTS: Aortic cross-clamp times were 9.9 minutes longer in the AVR+ARE group (p = 0.0002). There were no differences in reopening or stroke rates or perioperative mortality (all p = not significant). All patients in the AVR-alone group received size 19 to 21 prostheses, whereas 51% of the AVR+ARE patients received size 23 prostheses. Postoperative gradients were reduced (p < 0.01) and indexed effective orifice areas were larger (p < 0.0001) in the AVR+ARE group. While the incidence of postoperative prosthesis-patient mismatch (indexed effective orifice area < or = 0.85 cm2/m2) was lower in the AVR+ARE group (p < 0.0001), the presence of mismatch did not significantly impact long-term outcomes after surgery. The ARE was associated with a trend toward better freedom from late congestive heart failure (p = 0.19), but not an improvement in long-term survival (p = 0.81).
CONCLUSIONS: For patients with small aortic roots, ARE at the time of AVR is a safe procedure that reduces postoperative gradients and the incidence of prosthesis-patient mismatch. However, ARE does not appreciably improve long-term clinical outcomes.