Surgical management of the small aortic annulus. Hemodynamic evaluation

Replacement of the aortic valve can be accomplished with ease and safety in most instances. The presence of a small aortic root, however, remains a problem in that both mechanical and stent-mounted tissue valves produce higher resting gradients in the smaller sizes. To avoid this, a technique has been developed to enlarge the aortic annulus. In a series of 253 patients undergoing aortic valve replacement, 22 required division of the aortic annulus. Extension of the incision inferiorly to the anterior leaflet of the mitral valve and a resulting separation of the annulus facilitated implantation of a larger valve. The resulting defect is obliterated with a woven Dacron patch. Hemodynamic data obtained on 12 patients who had recatheterization one to ten months postoperatively disclosed an average resting transvalvular gradient of 13.5 mm Hg. This procedure has been used successfully in combined aortic and mitral valve replacement and heart block has not occurred. Based upon encouraging follow-up studies of the Hancock glutaraldehyde-stabilized porcine heterograft, we use this prosthesis in patients with annular diameters of less than 25 mm. Our experience suggests that enlargement of the aortic annulus is necessary in a significant number of patients undergoing aortic valve replacement.