J Thorac Cardiovasc Surg 2004;127:303-304
© 2004 The American Association for Thoracic Surgery
Aortic insufficiency in patients with Marfan syndrome: A surgical dilemma
Carlos Del Campo, MD
Department of Cardiothoracic Surgery, Western Medical Center Anaheim and University of California Irvine, Fullerton, CA 92835, USA
To the Editor:
The excellent article by de Oliveira and colleagues1 and the related editorial by Miller2 are vital reading for all those involved in the management of patients with Marfan syndrome (MFS). In their article, de Oliveira and colleagues1 reported the results of surgery for aortic root aneurysm in patients with MFS. Sixty-one of these patients underwent aortic valve–sparing operations, with reimplantation of the aortic valve in 39 patients and remodeling of the aortic root in 22. Patient age ranged between 12 and 59 years. Freedom from reoperation at 10 years was 100%, but only 2 patients had a full 10-year follow-up. Twenty-one percent of patients required reexploration for bleeding (only 3% in the reimplantation group). Perhaps the most significant finding was that 25% of patients had more than 2+ aortic insufficiency during the follow-up period. Thus if aortic insufficiency continues to progress through a longer follow-up period, reoperation will be necessary in a significant number of patients.
Histologic evaluation of the leaflets of the aortic valve has demonstrated four different layers. The subendocardial ventricular layer is composed of elastic fibers oriented in various directions.3 The noncoaptational parts of the aortic leaflets are composed of an elastic grid reinforced with collagen fibers and bundles. The remaining layers have irregular amounts of arbitrarily oriented elastic fibers and collagen fibers.3 MFS is caused in part by mutations within the gene for fibrillin 1, which is the main protein of the microfibril network. Microfibrils play a crucial role in the trophicity and function of elastic tissue.4 In MFS, these mutations lead to the formation of thoracic aortic aneurysms5 and appear to be related to proteolytic degradation.6 If the progression of aortic insufficiency in de Oliveira and colleagues' series1 is due to causes inherent in the surgical technique, this problem could probably by prevented by modifications in the surgical technique. David has already modified this technique several times,2 and all these modifications are included in the cases in this study. If aortic insufficiency is due to a structural deficiency of the native aortic leaflets, however, then all patients are at a potentially high risk for reoperation.
Kon and associates7 have recently reported the results of root replacement with the Freestyle bioprosthesis (Medtronic, Inc, Minneapolis, Minn) in 104 consecutive patients with multiple etiologies of aortic valve disease who took part in the worldwide study for submission to the Food and Drug Administration for premarket approval of this valve. Patient age ranged from 48 to 87 years. Freedom from reoperation was 100% at 8 years, with no structural valve deterioration. More significantly, only 2% had mild aortic insufficiency. Comparison of these two series is difficult because of the differences in population and etiology, but in the absence of prospective or randomized studies, we must base our decisions on extrapolation from current data. Thus there is no conclusive evidence that valve-sparing operations for patients with MFS have an advantage relative to Freestyle root replacement. Antimineralization treatment and zero-pressure fixation8 make this valve more attractive for implantation than a homograft because of the lower rate of calcification with no significant changes in the elastic properties of the elastic wall,8,9 and reoperation if needed is simpler with the Freestyle bioprosthesis because of lessened inflammatory reaction in the host tissues. A Freestyle root replacement with graft extension could be a reasonable operation for patients with MFS for whom anticoagulation is contraindicated or not acceptable. Further long term data are needed, however, before any of these operations can be recommended with certainty.
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- de Oliveira NC, David TE, Ivanov J, Armstrong S, Eriksson MJ, Rakowski H, et al. Results of surgery for aortic root aneurysm in patients with Marfan syndrome. J Thorac Cardiovasc Surg. 2003;125:789–796[Abstract/Free Full Text]
- Miller DC. Valve-sparing aortic root replacement in patients with the Marfan syndrome. J Thorac Cardiovasc Surg. 2003;125:773–778[Free Full Text]
- Sauren AA, Kuupers W, van Steenhoven AA, Veldpaus FE. Aortic valve histology and its relation with mechanics—preliminary report. J Biomech. 1980;13:97–104[Medline]
- Le Parc JM, Molcard S, Tubach F, Boileau C, Jondeau G, Muti C, et al. Marfan syndrome and fibrillin disorders. Joint Bone Spine. 2000;67:401–407[Medline]
- Marque V, Kieffer P, Gayraud B, Lartaud-Idjouadiene I, Ramirez F, Atkinson J. Aortic wall mechanics and composition in a transgenic mouse model of Marfan syndrome. Arterioscler Thromb Vasc Biol. 2001;21:1184–1189[Abstract/Free Full Text]
- Reinhardt DP, Ono RN, Notbohm H, Muller PK, Bachinger HP, Sakai LY. J Biol Chem. 2000;275:12339–12345[Abstract/Free Full Text]
- Kon ND, Riley RD, Adair SM, Kitzman DW, Cordell AR. Eight-year results of aortic root replacement with the Freestyle stentless porcine aortic root bioprosthesis. Ann Thorac Surg. 2002;73:1817–1821[Abstract/Free Full Text]
- Melina G, Rubens MB, Amrani M, Khaghani A, Yacoub MH. Electron beam tomography for cusp calcification in homograft versus Freestyle xenografts. Ann Thorac Surg. 2001;71(5 Suppl):S368–370[Abstract/Free Full Text]
- Kon ND, Riley RD, Adair SM, Kitzman DW. Comparison of results using the Freestyle stentless porcine aortic root bioprosthesis with the cryopreserved aortic allograft. Huysmans HA, David TE, Westaby S. Stentless bioprosthesis. 2nd ed. Oxford, UK: Isis Medical Media; 1999. p. 127–133
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