Defining the efficacy of aortic root enlargement procedures: a comparative analysis of surgical techniques.

BACKGROUND: Aortic root enlargement (ARE) procedures are believed to allow implantation of larger valve prostheses; however, little evidence exists to support the specific efficacy of various techniques.

METHODS: Using a cadaveric model, 20 adult (72.4 ± 15.3 years) hearts were stratified into 4 groups based on annular diameter: <20 mm, 20-22 mm, 22-24 mm, and >24 mm. Each heart underwent an aortic valve replacement following a Nicks, Manougian, aortoventriculoplasty and modified Bentall procedure, with appropriate reversals between procedures.

RESULTS: All 4 groups experienced similar increases in annular diameter (P = 0.43) and prosthesis size implanted (P = 0.51) with each enlargement technique. The Nicks, Manougian, modified Bentall and aortoventriculoplasty procedures enlarged the annulus by 0.43 ± 0.45 mm, 3.63 ± 0.95 mm, 0.78 ± 0.65 mm, and 6.08 ± 1.19 mm, respectively (P < 0.001). No significant change in prosthesis size was observed after the Nicks procedure (P = not significant). Increases of 1.3 ± 0.5, 1.3 ± 0.5, and 2.7 ± 0.6 prosthesis sizes were achieved with the Manougian, modified Bentall and aortoventriculoplasty techniques respectively (P < 0.001).

CONCLUSIONS: ARE procedures appear equally efficacious in both small and larger aortic roots. Although all 4 ARE techniques increased the annular diameter, only the Manougian, modified Bentall and aortoventriculoplasty procedures allowed for the implantation of a larger prosthetic valve. The Nicks procedure, which is likely the most commonly performed ARE, does not allow for the implantation of a larger prosthesis. Surgeon preference and patient factors may help in selecting the most appropriate ARE technique, as the modified Bentall and Manougian procedures achieved similar increases in valve size.