Bech-Hanssen O, Caidahl K, Mykèn P S, Kjellman U, Larsson S, Wallentin I
Department of Clinical Physiology, Sahlgrenska University Hospital, Sweden.
J Heart Valve Dis. 1996 Mar;5(2):128-35.
Prosthesis size is known to have an effect on long term outcome after heart valve replacement. We evaluated 115 patients subjected to aortic valve replacement to assess the ability by preoperative echocardiography to identify patients having small aortic roots and thereby likely to receive a small prosthesis (size 19 or 21), previously shown to be associated with a worse prognosis.
From an initial part of the study (Group A), comprising 67 patients, we evaluated the influence of image quality on the accuracy for prediction of patients receiving a small prosthesis. In a second series of 48 patients (Group B), we tested the predictive value of various limits of aortic annulus diameter to define patients at risk of receiving a small prosthesis.
The measurement of aortic annulus diameter in Group A gave a reasonable correlation to subsequent prosthetic dimension (r = 0.73, n = 59). However, there was a considerable variation of echocardiographic aortic annulus diameter among patients receiving prostheses of the same size. In Group B, an aortic annulus diameter of < or = 22 mm correctly identified 10 of 13 patients receiving a small prosthesis (sensitivity 77%). Twenty-two of 25 patients (88%) with an aortic annulus diameter > 22 mm received a large prosthesis.
We conclude that the echocardiographic measurement of the aortic annulus diameter is a fairly sensitive method to identify patients receiving a small prosthesis. However, the predictive accuracy is dependent upon training as well as image quality. Furthermore, the value of planning in advance the type of prosthesis, annuloplasty or homograft for aortic valve replacement remains to be shown.
已知人工瓣膜尺寸会对心脏瓣膜置换术后的长期疗效产生影响。我们评估了115例行主动脉瓣置换术的患者，以通过术前超声心动图来判断其识别主动脉根部较小、因而可能接受小尺寸人工瓣膜（尺寸为19或21）患者的能力，此前研究表明小尺寸人工瓣膜与较差的预后相关。
在研究的初始部分（A组），纳入67例患者，我们评估了图像质量对预测接受小尺寸人工瓣膜患者准确性的影响。在第二组48例患者（B组）中，我们测试了主动脉瓣环直径的不同界值对定义有接受小尺寸人工瓣膜风险患者的预测价值。
A组中主动脉瓣环直径的测量结果与随后的人工瓣膜尺寸有合理的相关性（r = 0.73，n = 59）。然而，接受相同尺寸人工瓣膜的患者之间，超声心动图测量的主动脉瓣环直径存在相当大的差异。在B组中，主动脉瓣环直径≤22 mm可正确识别13例接受小尺寸人工瓣膜患者中的10例（敏感性77%）。25例主动脉瓣环直径>22 mm的患者中有22例（88%）接受了大尺寸人工瓣膜。
我们得出结论，超声心动图测量主动脉瓣环直径是识别接受小尺寸人工瓣膜患者的一种相当敏感的方法。然而，预测准确性取决于培训以及图像质量。此外，预先规划主动脉瓣置换术的人工瓣膜类型、瓣环成形术或同种异体移植物的价值仍有待证实。
