Aortic root enlargement: What are the operative risks?

Objective: Despite concern that small aortic valve prostheses can lead to prosthesis-patient mismatch with diminished left ventricular mass regression and poor long-term outcome after aortic valve replacement, there remains reluctance to perform aortic root enlargement procedures. We therefore examined the operative risks of aortic valve replacement with and without root enlargement. Methods: We reviewed perioperative outcomes among patients undergoing aortic valve replacement at our institution between January 1993 and December 2001. Risk factors for operative death were evaluated by means of multivariable analysis. Results: Of 2366 patients undergoing aortic valve replacement with (1173) or without (1193) concomitant procedures, 249 (10.5%) underwent posterior root enlargement. Patients undergoing complex root enlargement (Konno-Rastan procedures) were excluded. Patients undergoing aortic root enlargement were significantly younger, twice as often female, and more often undergoing a reoperation but were similar with respect to functional class. The mean valve implant size was less in the aortic root enlargement group (21.5 ± 1.6 vs 23.2 ± 2.3 mm, P < .0001). As expected, mean crossclamp time and bypass time were somewhat longer with root enlargement. Raw operative mortality was higher with aortic root enlargement (5.6% vs 2.9%, P = .0324); however, by means of multivariable analysis, advanced functional class (P = .0020; odds ratio, 1.87), preoperative congestive heart failure (P < .0001; odds ratio, 3.22), and smaller valve implant size (P = .012; odds ratio, 1.16), but not aortic root enlargement, were independent risk factors for operative death. Conclusions: Aortic root enlargement itself does not increase operative risk, although it is most often required among high-risk patients. Surgeons should not be reluctant to enlarge the aortic root to permit implantation of adequately sized valve prostheses.