Kunzelman K S, Reimink M S, Cochran R P
Department of Bioengineering, University of Washington, Seattle, USA.
J Card Surg. 1997 Sep-Oct;12(5):322-9. doi: 10.1111/j.1540-8191.1997.tb00146.x.
Sizing the mitral annulus remains one of the more subjective areas of annuloplasty surgery. We compared the dimensions of annuloplasty rings to annuloplasty sizers and to human mitral valve annuli to determine whether any discrepancies exist that might impact repair results.
The anterior and posterior length of rigid rings, flexible rings, and corresponding sizers were measured. The ratio of the anterior length to the total length was calculated (A/T ratio) and compared to normal human ratios.
Nearly all rings had A/T ratios between 30% and 35% (except for the 32-mm rigid ring at 37.5%). For both rigid and flexible rings, the ring A/T ratios and the sizer A/T ratios differed significantly (except for the 28-mm rigid ring and sizer). In comparison to the average human A/T ratio (36.6%), the ratio for most rings was significantly lower.
The mismatch between rings and sizers results in three possible scenarios: the length of the anterior portion of the ring can be equal to, smaller than, or larger than the anterior portion of the sizer. The clinical implications are that the valve could become stenotic when the ring is implanted or that the anterior portion of the annulus could be altered (stretched or buckled). We feel that to assure improved long-term results, more accurate matching of sizers to rings is essential and that better matching to normal human anatomical ratios would be ideal.
确定二尖瓣环大小仍然是瓣环成形术外科手术中主观性较强的领域之一。我们将瓣环成形环的尺寸与瓣环成形测量器以及人体二尖瓣环的尺寸进行比较，以确定是否存在可能影响修复结果的差异。
测量刚性环、柔性环及相应测量器的前后长度。计算前长度与总长度的比值（A/T比值），并与正常人体的比值进行比较。
几乎所有环的A/T比值都在30%至35%之间（32毫米刚性环除外，其为37.5%）。对于刚性环和柔性环，环的A/T比值与测量器的A/T比值均存在显著差异（28毫米刚性环及其测量器除外）。与人体平均A/T比值（36.6%）相比，大多数环的比值显著更低。
环与测量器之间的不匹配会导致三种可能情况：环前部的长度可能等于、小于或大于测量器的前部。临床意义在于，植入环时瓣膜可能会变狭窄，或者瓣环前部可能会改变（拉伸或弯曲）。我们认为，为确保获得更好的长期效果，测量器与环更精确的匹配至关重要，而与正常人体解剖学比值更好的匹配则更为理想。
