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Complete Aortic Valve Cusp Replacement in the Pediatric Population Using Tissue-Engineered Bovine Pericardium

2015; Elsevier BV; Volume: 100; Issue: 5 Linguagem: Inglês

10.1016/j.athoracsur.2015.04.056

1552-6259

Domenico Mazzitelli, Christian Nöbauer, J. Scott Rankin, Manfred Vogt, Rüdiger Lange, Christian Schreiber,

Coronary Artery Anomalies

Three clinical cases of severe pediatric aortic valve defects undergoing complete aortic valve cusp replacement using tissue-engineered bovine pericardium are reported. All patients achieved excellent early results, and are being followed without complications. Three clinical cases of severe pediatric aortic valve defects undergoing complete aortic valve cusp replacement using tissue-engineered bovine pericardium are reported. All patients achieved excellent early results, and are being followed without complications. Drs Mazzitelli, Rankin, and Schreiber disclose a financial relationship with Admedus Ltd.The Video can be viewed in the online version of this article [http://dx.doi.org/10.1016/j.athoracsur.2015.04.056] on http://www.annalsthoracicsurgery.org.In the past decade, pediatric aortic valve repair has consisted primarily of shaving leaflets and then leaflet extension using autologous pericardium [1d'Udekem Y. Aortic valve surgery in children.Heart. 2011; 97: 1182-1189Crossref PubMed Scopus (33) Google Scholar, 2De La Kerda D. Cohen O. Fishbein M.C. et al.Aortic valve-sparing repair with autologous pericardial leaflet extension has greater early re-operation rate in congenital versus acquire valve disease.Eur J Cardiothorac Surg. 2007; 31: 256-260Crossref PubMed Scopus (20) Google Scholar]. Although this approach has been successful, durability of repair has been a problem, with average time to reoperation of 5 to 8 years. Ozaki and associates [3Ozaki S. Kawase I. Yamashita H. et al.A total of 404 cases of aortic valve reconstruction with glutaraldehyde-treated autologous pericardium.J Thorac Cardiovasc Surg. 2014; 147: 301-306Abstract Full Text Full Text PDF PubMed Scopus (145) Google Scholar] have refined an operation in adults where all three leaflets are replaced with glutaraldehyde-fixed autologous pericardium, suturing the pericardial leaflets directly to the aortic annulus. The outcomes of the Ozaki group, now beyond 6 years, have been excellent—with good durability and low valve-related complications [3Ozaki S. Kawase I. Yamashita H. et al.A total of 404 cases of aortic valve reconstruction with glutaraldehyde-treated autologous pericardium.J Thorac Cardiovasc Surg. 2014; 147: 301-306Abstract Full Text Full Text PDF PubMed Scopus (145) Google Scholar]. Stability of repair also has been excellent, and although adults and children could be different, the technique might be useful in pediatric patients. The purpose of this report is to explore the application of this procedure to pediatric aortic valve reconstruction using tissue-engineered bovine pericardium as the leaflet substitute [4Neethling W.M.L. Strange G. Firthe L. Smit F.E. Evaluation of a tissue-engineered bovine pericardial patch in paediatric patients with congenital cardiac anomalies: initial experience with the ADAPT-treated CardioCel patch.Interact Cardiovasc Thorac Surg. 2013; 17: 698-702Crossref PubMed Scopus (53) Google Scholar, 5Brizard C.P. Brink J. Horton S.B. et al.New engineering treatment of bovine pericardium confers outstanding resistance to calcification in mitral and pulmonary implantations in a juvenile sheep model.J Thorac Cardiovasc Surg. 2014; 148: 3194-3201Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar]. Drs Mazzitelli, Rankin, and Schreiber disclose a financial relationship with Admedus Ltd. The Video can be viewed in the online version of this article [http://dx.doi.org/10.1016/j.athoracsur.2015.04.056] on http://www.annalsthoracicsurgery.org. In this series, tissue-engineered bovine pericardium, CardioCel (Admedus, Perth, Australia), was used for pediatric aortic valve leaflet replacement. This tissue has been shown in both preclinical and patient studies to heal better than glutaraldehyde-fixed autologous pericardium, with very low tissue calcium levels [4Neethling W.M.L. Strange G. Firthe L. Smit F.E. Evaluation of a tissue-engineered bovine pericardial patch in paediatric patients with congenital cardiac anomalies: initial experience with the ADAPT-treated CardioCel patch.Interact Cardiovasc Thorac Surg. 2013; 17: 698-702Crossref PubMed Scopus (53) Google Scholar, 5Brizard C.P. Brink J. Horton S.B. et al.New engineering treatment of bovine pericardium confers outstanding resistance to calcification in mitral and pulmonary implantations in a juvenile sheep model.J Thorac Cardiovasc Surg. 2014; 148: 3194-3201Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar]. In 7-month sheep models of mitral and pulmonary valve leaflet replacement, the mechanical properties of CardioCel were better preserved, exhibited more controlled healing, and had equivalently low calcification as glutaraldehyde-treated autologous pericardium. The safety and efficacy of this type of tissue-engineered pericardium in congenital heart surgery was demonstrated in 30 patients, and the tissue has an Food and Drug Administration on-label indication for cardiac leaflet reconstruction. The first patient was an 11-year-old girl with a unicuspid valve, a dilating ventricle from moderately severe aortic insufficiency (AI), and highly dysplastic Sievers type 2 anatomy (Fig 1). The echocardiogram showed the usual right/left coronary and right coronary/noncoronary commissural fusion, with severe thickening and AI (Video). All leaflets were prolapsing, with an AI jet directed posteriorly well down into the ventricle, and the ventricle was dilating. The valve leaflets were dysplastic with highly fused right/left coronary and right coronary/noncoronary commissures. As is common, the only normal commissure was the left coronary/noncoronary, with very little usable leaflet overall. The dysplastic leaflets were excised, and the annulus was sized to a 21-mm diameter. The noncoronary intercommissural distance was sized to a 21-mm Ozaki leaflet, and the other two were 19 mm. The annular nadirs were marked with methylene blue. Two 19-mm leaflets and one 21-mm leaflet were traced from CardioCel patches using Ozaki templates, and the leaflets were cut to size. After additional blood cardioplegia, the left coronary leaflet was sutured to the nadir of the annulus with 4-0 polypropylene and tied. By pushing the leaflet down into the ventricle, progressive running annular sutures could be placed easily, usually in one bite to save time, and working upward to the top of the commissure where the suture was brought to the outside. The other side of the leaflet was sutured progressively up the annulus and brought to the outside, creating a cusp shape. In the same way, the right coronary leaflet was sutured—and then the noncoronary—and additional commissural alignment sutures were placed above the annular sutures and tied on the outside. And finally, a third leaflet attachment to the outside of the aorta was created at the commissural tops. On echocardiography after bypass, the CardioCel leaflets coapted nicely, opened well with a low gradient, had no residual AI, and exhibited excellent coaptation height (Fig 1). The second patient was a 15-year-old boy with a bicuspid valve, a dilating ventricle, severe leaflet dysplasia, previous endocarditis, moderately severe AI, a dilated aorta, and muscular left ventricular outflow tract obstruction. There was right coronary/noncoronary leaflet fusion, and a central coaptation gap. The AI jet was eccentric and directed posteriorly. The aorta was 45 mm in diameter, but the root narrowed nicely. Grade 3 AI and a subvalvular muscle bar were evident. The aneurysm was excised 1 cm above the commissural tops, leaving the coronaries with the root. Again, the leaflets were severely dysplastic, and right coronary/noncoronary commissural fusion was evident. The muscular subaortic bar was resected. An attempt was made to shave the leaflets, but to no avail. Therefore, the dysplastic leaflets were resected, and three CardioCel leaflets were sewn into the annulus, as in the first case. Each leaflet was triply fixed to the outside of the aorta at the top of the commissures. The ascending aortic aneurysm was replaced with a 26-mm tube graft. After bypass, the leaflets opened well, with good coaptation and no residual AI. The third patient was a 5-year-old boy with a dysplastic unicuspid valve, heart failure, severe AI, and standard Sievers type 2 anatomy. The leaflets were very dysplastic, and the right/left coronary and right coronary/noncoronary commissures were fused. The diseased leaflets were excised, and replaced with three CardioCel leaflets. After completion, the valve opened well with excellent coaptation height and no residual leak. All 3 patients continue to do well, without further clinical problems, and with essentially unchanged echocardiograms at 8 to 10 months of follow-up. Mild AI was evident in patient 2 at the posterior commissural attachment. Congenital aortic valve disease is the most common congenital cardiac disorder and can present at any age, from infancy to late adulthood. When manifested in childhood, the magnitude of commissural fusion and leaflet dysplasia is often significant, accounting for early presentation. In that setting, leaflet disease can be the limiting factor, making native valve repair very difficult. Prosthetic valve replacements with tissue valves fail early in children, and mechanical valves fix annular diameter and require full anticoagulation therapy. Therefore, aortic valve repair is an attractive option, but results have been somewhat variable. Full replacement of the aortic valve with autologous pericardial leaflets is now possible with improved understanding of required leaflet geometry and better implant techniques [3Ozaki S. Kawase I. Yamashita H. et al.A total of 404 cases of aortic valve reconstruction with glutaraldehyde-treated autologous pericardium.J Thorac Cardiovasc Surg. 2014; 147: 301-306Abstract Full Text Full Text PDF PubMed Scopus (145) Google Scholar, 6Rankin J.S. Nöbauer C. Crooke P.S. Schreiber C. Lange R. Mazzitelli D. Techniques of autologous pericardial leaflet replacement for aortic valve reconstruction.Ann Thorac Surg. 2014; 98: 743-745Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar]. After appropriate training, the procedure becomes simple, achieving uniform results. Complete leaflet replacement has several other advantages. Leaflet tissue is sutured securely to the aortic annulus and is less subject to disruption than with native leaflet suture lines. Mobility of pericardial leaflets is excellent and gradients minimal, even in smaller aortic roots. Finally, with better leaflet templates and implant techniques, durability has been excellent [3Ozaki S. Kawase I. Yamashita H. et al.A total of 404 cases of aortic valve reconstruction with glutaraldehyde-treated autologous pericardium.J Thorac Cardiovasc Surg. 2014; 147: 301-306Abstract Full Text Full Text PDF PubMed Scopus (145) Google Scholar]. Use of tissue-engineered pericardium for this purpose also has advantages. The tissue is available "off-the-shelf " and displays highly consistent quality. It saves considerable surgical time, compared with glutaraldehyde fixation of autologous pericardium at the operating table. It can be employed in reoperations, where autologous pericardium may be suboptimal. Mechanical anisotropic properties are similar to aortic valve tissue, but with stronger tissue strength. It must be stated, though, that long-term human follow-up for valve leaflet replacement with this tissue is not currently available, which is a limitation of this technique. However, at this point, all assessments seem positive, and current information indicates that CardioCel will allow extensive autologous tissue ingrowth, thus converting to host-compatible tissue with corresponding improvement in late performance. In conclusion, pericardial leaflet replacement is a simple and reproducible procedure for aortic valve reconstruction, and applications exist for congenital aortic valve lesions. Tissue-engineered CardioCel seems to facilitate the procedure by providing a reproducible off-the-shelf material. Finally, further clinical follow-up will be required to fully establish this technique. The authors wish to thank Dr Melchior Burri (German Heart Center, Munich, Germany) for his involvement in collecting the follow-up data presented in this paper. eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiIzYmJmZWEyMjUxYjFjNGViM2E5Zjg5ZmM3ZWRkODYxNiIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjg2ODc2MTI2fQ.pehdjSGtzUhF_DCOGrTVur5VWuraiTKqL9z8lMvtKOeNwsQfrUvEefmj3elcbHrPX0pP5CIDjHKHX-wSiBA3pMRsoOtK9LcXhwxMKy_aUMEl1H0930nfippRDLU1kWSMCHeViBeMFOMDF9gHkukLnUSjYNFPbXeCJwOQS8t-va_VJe0t04MGZrAqXjXnDAYDIiaK60eLoFqZ6uFdkLSHtSZxMa_LagZNUl4-O_ni7u6b8v2v7M7Dx7hFj532AVEQoAEKxNDZEH5Ei8Jg9JfJ1cvZYNKAoVsNf1uRMp4A6pQxnomy5Xz9Oc9YOGhP9bAg2hUtTVdmGT9cskBQVS29_g Download .mp4 (144.42 MB) Help with .mp4 files Video 1