CORRESPONDENCE: LETTER TO THE EDITOR
Is it Reasonable to Treat All Calcified Stenotic Valves With a Valve Stent?Probably Yes If We Get a Full Stent Expansion
Massimo Napodano, MD*,
Giuseppe Tarantini, MD, PhD and
Angelo Ramondo, MD
* Department of Cardiac Thoracic and Vascular Sciences, University of Padova, 2 via Giustiniani, 35128 Padova, Italy (Email: massimo.napodano{at}gmail.com).
We read with interest the article by Zegdi et al. (1) regarding the appropriateness of percutaneous valve implantation in calcified aortic valve stenosis. The study evaluated the behavior of intraoperative valved stent implantation inside human stenotic aortic valves before surgical valve replacement. The investigators reported a stent misdeployment, with an elliptical or triangular stent shape, in a large number of tricuspid (32%) and in all bicuspid valves, accounting for variable gaps at the commissures level between the stent's external surface and the inner surface of native valve (1). This finding represents the proof of concept of perivalvular leak observed early after percutaneous valve implantation in human calcified aortic valves (2,3). In addition, the investigators hypothesized that stent misdeployment and consequent valve distortion, increasing the stress on valve leaflets, may lead to premature leaflets tears or fibrosis and valve dysfunction (1).
In our opinion, some concerns exist about the results of this study. First, the intraoperative model may be not completely representative of the self-expandable valved stent behavior in the beating heart. In this regard, the deployment of the self-expanding stent continues for a long run after the implantation, as the nitinol frames get back to the original shape and dimensions (4). This mechanism may explain the reduction in perivalvular leaks observed over time after self-expandable aortic valve implantation, as recently reported by Grube et al. (2). To the contrary, in the experience reported by Zegdi et al. (1) the stent remained in place for no more than 2 min, so the investigators lacked the opportunity to evaluate the device after full stent expansion. Moreover, the stents were implanted in calcified aortic valves without balloon valvuloplasty (1), which is common practice before percutaneous valve implantation (2,3). Indeed, as acknowledged by Zegdi et al. (1), pre-dilation with appropriate balloons, providing fragmentation of the leaflets calcification (5), may improve the pliability of native valve leaflets and, therefore, favor the circular deployment and stent apposition to the aortic wall. We strongly believe these issues should be addressed to definitely establish the behavior of self-expanding stent-based percutaneous bioprosthesis in the human heart.
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1. Zegdi R, Ciobotaru V, Noghin M, et al. Is it reasonable to treat all calcified stenotic valves with a valved stent?. Results from a human anatomic study in adults. J Am Coll Cardiol 2008;51:579-584.[Abstract/Free Full Text]2. Grube E, Laborde JC, Gerkens U, et al. Percutaneous implantation of the Core-Valve self-expanding valve prosthesis in high-risk patients with aortic valve disease: the Siegburg first-in-man study Circulation 2006;114:1616-1624.[Abstract/Free Full Text] 3. Webb JG, Chandavimol M, Thompson CR, et al. Percutaneous aortic valve implantation retrograde from the femoral artery Circulation 2006;113:842-850.[Abstract/Free Full Text] 4. Jilaihawi HA, Chin D, Kovac J, et al. Continued dynamic improvement valve function from procedure to discharge in the (COREVALVE) self expanding percutaneous aortic bioprosthesis: UK TEE study (abstr) Am J Cardiol 2007;100(Suppl 8A):74L. 5. McKay RG, Safian RD, Lock JE, et al. Balloon dilatation of calcific aortic stenosis in elderly patients: postmortem, intraoperative, and percutaneous valvuloplasty studies Circulation 1986;74:119-125.[Abstract/Free Full Text]
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- Rachid Zegdi, Ghassan Sleilaty, Antoine Lafont, and Jean-Noël Fabiani
J. Am. Coll. Cardiol. 2009 53: 219-220.
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