Melacini P, Villanova C, Thiene G, Minarini M, Fasoli G, Bortolotti U, Ramuscello G, Scognamiglio R, Ponchia A, Dalla Volta S
Department of Cardiology, University of Padova Medical School, Italy.
Am J Cardiol. 1992 Nov 1;70(13):1157-63. doi: 10.1016/0002-9149(92)90048-4.
Echocardiographic and Doppler studies were performed in 134 patients with a Hancock bioprosthesis in the mitral valve position during a follow-up period of 1 to 216 months. Among the xenografts, 57% were clinically normal and 43% had severe dysfunction. Among the normal bioprostheses, 35% had echocardiographically thickened mitral cusps (> or = 3 mm) with normal hemodynamic function; by setting the lower 95% confidence limit of valve area at 1.7 cm2 these patients had a significantly (p < 0.01) smaller valve area than that of normal control subjects. Evaluation of all thickened normal mitral valves showed the highest incidence of thickening at 9 years after implantation. Valve replacement surgery was subsequently performed in 33 patients with dysfunctioning bioprosthetic and echocardiographic diagnosis was confirmed in 91% of explanted valves (bioprosthetic stenosis 21%, incompetence 46%, and combined stenosis and regurgitation 33%). In 2 valves that were found to be stenotic on echocardiographic examination, a calcium-related commissural tear was also observed at reoperation, and in another, a paravalvular leak was found. Dystrophic calcification, isolated (64%) or occasionally associated with fibrous tissue overgrowth (21%), was the main cause of failure. Pannus was present in prostheses with longer satisfactory function (168 +/- 31 vs 124 +/- 21 months; p < 0.001). Long-term performance was evaluated by the Kaplan-Meier method for up to 18 years of follow-up. Freedom from structural valvular disfunction after mitral replacement was 89% at 6 years, 77% at 8 years, 56% at 10 years, 31% at 12 years, 16% at 15 years, and 15% at 18 years.
在1至216个月的随访期内，对134例二尖瓣位植入汉考克生物瓣的患者进行了超声心动图和多普勒研究。在异种移植物中，57%临床正常，43%有严重功能障碍。在正常生物瓣中，35%的二尖瓣叶超声心动图增厚（≥3mm），血流动力学功能正常；将瓣口面积的95%置信下限设定为1.7cm²时，这些患者的瓣口面积明显（p<0.01）小于正常对照受试者。对所有增厚的正常二尖瓣进行评估显示，植入后9年增厚发生率最高。随后对33例功能障碍生物瓣患者进行了瓣膜置换手术，91%的取出瓣膜经超声心动图诊断得到证实（生物瓣狭窄21%，关闭不全46%，狭窄合并反流33%）。在2例超声心动图检查发现狭窄的瓣膜中，再次手术时还观察到与钙相关的瓣叶联合处撕裂，另一例发现瓣周漏。营养不良性钙化是失败的主要原因，孤立性钙化占64%，偶尔与纤维组织过度生长相关占21%。在功能良好时间较长的人工瓣膜中可见血管翳（168±31个月对124±21个月；p<0.001）。采用Kaplan-Meier法对长达18年的随访进行长期性能评估。二尖瓣置换术后无结构性瓣膜功能障碍的生存率在6年时为89%，8年时为77%，10年时为56%，12年时为31%，15年时为16%，18年时为15%。
