O'Neill W W, Chandler J G, Gordon R E, Bakalyar D M, Abolfathi A H, Castellani M D, Hirsch J L, Wieting D W, Bassett J S, Beatty K C
Department of Internal Medicine, William Beaumont Hospital, Royal Oak, Mich 48073, USA.
N Engl J Med. 1995 Aug 17;333(7):414-9. doi: 10.1056/NEJM199508173330703.
The outlet struts of Björk-Shiley convexo-concave heart valves can occasionally fracture. By December 31, 1994, 564 complete strut fractures had been reported to the manufacturer, approximately two thirds of which were fatal. There are no reliable diagnostic methods to detect valves that may be at risk for strut fracture. The outlet strut has two legs, and one leg often appears to break before the other, potentially permitting detection of the single-leg separation while the valve is still functionally intact.
We used high-resolution cineradiography and defined valve profiles to evaluate 315 patients selected on the basis of their having mitral convexo-concave valves with an estimated fracture rate of 0.46 percent or higher per year. Two examinations were scheduled six months apart, with early reimaging performed when initial ratings were indeterminate.
Three patients had unsatisfactory studies, the most recent examinations in 277 patients were rated as apparently normal, 23 had findings considered minimally suspicious, and 1 had findings termed suspicious. The number of false negative results in this study group is unknown. Eleven cineradiograms were rated as showing probable or definite single-leg separations. All five "definite" ratings and five of the six "probable" ratings were confirmed by removal of the valves. One valve with a "probable" rating was intact. Two complete outlet-strut fractures occurred three and seven months after apparently normal radiographic examinations. Unsuspected new positive findings were not found at six months among 288 patients who completed the examination cycle.
Cineradiographic imaging can detect some single-leg separations in mitral convexo-concave valves and may help the estimated 41,000 patients with these valves worldwide and their physicians decide about elective valve removal.
比约克-希利凸凹型心脏瓣膜的出口支柱偶尔会发生断裂。截至1994年12月31日，制造商已收到564例完整支柱断裂的报告，其中约三分之二是致命的。目前尚无可靠的诊断方法来检测可能存在支柱断裂风险的瓣膜。出口支柱有两条腿，其中一条腿往往比另一条腿先断裂，这有可能在瓣膜功能仍然完好时检测到单腿分离。
我们使用高分辨率电影血管造影术并定义瓣膜轮廓，以评估315例患者，这些患者入选的依据是他们患有二尖瓣凸凹型瓣膜，估计每年的断裂率为0.46%或更高。安排两次间隔六个月的检查，当初次评级不确定时进行早期再次成像。
3例患者的检查结果不理想，277例患者的最近一次检查被评为明显正常，23例有被认为轻度可疑的发现，1例有可疑的发现。该研究组假阴性结果的数量未知。11张电影血管造影片被评为显示可能或确定的单腿分离。所有5个“确定”评级和6个“可能”评级中的5个通过移除瓣膜得到证实。1个“可能”评级的瓣膜完好无损。在两次明显正常的影像学检查后3个月和7个月分别发生了2例完整的出口支柱断裂。在完成检查周期的288例患者中，6个月时未发现意外的新阳性结果。
电影血管造影成像可以检测二尖瓣凸凹型瓣膜中的一些单腿分离，可能有助于全球约41000例患有这些瓣膜的患者及其医生决定是否进行择期瓣膜置换。
