J Thorac Cardiovasc Surg 2001;121:599-600
© 2001 The American Association for Thoracic Surgery
Letters to the Editor
Division of Cardiothoracic Surgery
Department of Surgery
The Chinese University of Hong Kong
Prince of Wales Hospital
Hong Kong, China
To the Editor:
We read with great interest the recent article by Kalangos and colleagues and the commentary by Westaby. 1 In this study, the incidence of aortic incompetence was about 25% after the subcoronary implantation of the Freestyle stentless bioprosthesis (Medtronic, Inc, Minneapolis, Minn), which coincides with reports from other groups using different techniques. 2-4 Although the degree of aortic incompetence is usually mild in the early postoperative years, such a relatively high incidence potentially can jeopardize the long-term clinical outcome. We fully agree with Westaby 1 and others 4 that oversizing of the stentless valve is crucial in preventing aortic incompetence. In addition, we believe preserving the function of the native coronary sinuses and the interleaflet triangles may be equally important.
The aortic root comprises the sinuses of Valsalva, the valve leaflets, and the interleaflet triangles. The sinuses of Valsalva are considered to be the basic structural framework of the valve. Not only do they support the coronary arteries and the valve leaflets, but they also enable a competent valve closure by allowing formation of the vertices. Moreover, as suggested by Sutton, Ho, and Anderson, 5 the structures of the interleaflet triangles are critical for proper valvular function. Such an understanding of the functional anatomy of the aortic root is essential for the development of an appropriate technique in implanting stentless bioprostheses.
In the technique described by Kalangos and colleagues, 1 the inflow suture line does not include the native interleaflet triangles, and the space between the prosthesis and the native subcoronary sinus wall is not completely obliterated. As discussed above, this could lead to postoperative aortic regurgitation because the competence of the Freestyle bioprosthesis depends at least in part on the supportive structures of the aortic sinuses. In fact, our view is supported by the work of Yacoub and associates 6 and by the reported high incidence of aortic incompetence when the Freestyle bioprosthesis is used for aortic root replacement rather than as an isolated valve prosthesis. 4
On the basis of such considerations, we have modified the subcoronary implantation technique by incorporating the interleaflet triangles in the inflow suture line. Instead of using glue, we apply interrupted sutures to obliterate the space between the native noncoronary sinus and the prosthesis wall. We discourage the use of glue to obliterate the interaortic space because it may change the configuration of the sinus and could lead to early and late disastrous consequence. 7 We have now used our technique in 15 patients and have observed no evidence of aortic incompetence after a mean follow-up of 9 months.
This article has been cited by other articles:
A. A. Arifi, S. Wan, S. Nashef, C. S. Ng, I. Y. Wan, and A. P. Yim
Freestyle Xenograft Implantation Technique for Reducing Aortic Insufficiency
Asian Cardiovascular and Thoracic Annals, December 1, 2002; 10(4): 369 - 371.
[Abstract] [Full Text] [PDF]
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