Mohammadi Siamak, Baillot Richard, Voisine Pierre, Mathieu Patrick, Dagenais François
Department of Cardiac Surgery, Laval Hospital, Québec City, Québec, Canada.
J Thorac Cardiovasc Surg. 2006 Aug;132(2):401-6. doi: 10.1016/j.jtcvs.2006.03.056.
Structural valve deterioration is the major cause of bioprosthetic valve failure. Because of the unique design features and anti-calcification treatment of the Freestyle (Medtronic Inc, Minneapolis, Minn) stentless bioprosthesis, development of structural valve deterioration may differ in comparison with other bioprosthetic valves. This study evaluates the mechanisms and clinical presentation of structural valve deterioration in the Freestyle stentless bioprosthesis.
Between January 1993 and August 2005, 608 patients underwent aortic valve replacement with a Freestyle stentless bioprosthesis. The implantation technique was subcoronary in 475 patients and a root replacement in 133 patients. Mean overall follow-up was 5.6 +/- 3.4 years. Follow-up was complete in all patients. Clinical and echocardiographic follow-ups were conducted prospectively.
Freedom from structural valve deterioration was 95.8% at 10 years. Twelve patients showed evidence of structural valve deterioration and underwent reoperation for aortic regurgitation (n = 10) or aortic stenosis (n = 2). The mean age of patients with structural valve deterioration was significantly lower than patients without structural valve deterioration (62.6 +/- 8.2 years vs 68.6 +/- 8.3 years, P = .02). The median time between implantation and explantation was 8.7 years (range: 1.9-13.3 years). Eleven structural valve deteriorations occurred after subcoronary implantation, and 1 structural valve deterioration occurred after root implantation (P = .4). The mechanisms of structural valve deterioration were leaflet tears in 10 patients (6 in the left coronary cusp and 4 in the right coronary cusp), severe valve calcification in 1 patient, and cusp fibrosis in 1 patient. The interval between onset of symptoms and reoperation was acute or subacute in 10 patients.
At 10 years, the Freestyle stentless bioprosthesis shows excellent freedom from structural valve deterioration. Structural valve deterioration in the Freestyle stentless bioprosthesis relates to leaflet tear with minimal calcification in the majority of cases. Because of the fast onset of symptoms with leaflet tear, patients with a Freestyle stentless bioprosthesis should be informed of the preferential mode of failure and time-frame of symptoms.
结构瓣膜退变是生物瓣膜失效的主要原因。由于Freestyle（美敦力公司，明尼阿波利斯，明尼苏达州）无支架生物瓣膜独特的设计特点和抗钙化处理，其结构瓣膜退变的发展可能与其他生物瓣膜有所不同。本研究评估Freestyle无支架生物瓣膜结构瓣膜退变的机制和临床表现。
1993年1月至2005年8月期间，608例患者接受了Freestyle无支架生物瓣膜主动脉瓣置换术。475例患者采用冠状动脉下植入技术，133例患者采用根部置换术。平均总随访时间为5.6±3.4年。所有患者均完成随访。前瞻性地进行临床和超声心动图随访。
10年时结构瓣膜无退变的比例为95.8%。12例患者出现结构瓣膜退变的证据，并因主动脉瓣反流（n = 10）或主动脉瓣狭窄（n = 2）接受再次手术。出现结构瓣膜退变的患者的平均年龄显著低于未出现结构瓣膜退变的患者（62.6±8.2岁对68.6±8.3岁，P = 0.02）。植入至取出的中位时间为8.7年（范围：1.9 - 13.3年）。11例结构瓣膜退变发生在冠状动脉下植入后，1例结构瓣膜退变发生在根部植入后（P = 0.4）。结构瓣膜退变的机制为瓣叶撕裂10例（左冠状动脉瓣叶6例，右冠状动脉瓣叶4例），严重瓣膜钙化1例，瓣叶纤维化1例。10例患者症状出现至再次手术的间隔为急性或亚急性。
10年时，Freestyle无支架生物瓣膜显示出极好的结构瓣膜无退变率。Freestyle无支架生物瓣膜的结构瓣膜退变在大多数情况下与瓣叶撕裂及极少的钙化有关。由于瓣叶撕裂症状出现迅速，应告知接受Freestyle无支架生物瓣膜置换的患者其优先的失效模式和症状出现的时间框架。
