无支架异种生物瓣膜主动脉瓣替换术后左室功能变化

Changes of Left Ventricular Function Following Aortic Valve Replacement Using Stentless Bioprosthesis

评价无支架异种生物瓣膜主动脉瓣替换术后２年左室功能的变化。将８０例同期施行主动脉瓣替换病人分为２组，５０例（年龄６９．３±９．３岁）应用ＴｏｒｏｎｔｏＳＰＶＴＭ瓣；３０例（年龄７１．６±７．７岁）作为对照组接受支架人工瓣膜替换。术前、术后１、６、１２及２４个月间记录Ｍ型及Ｄｏｐｐｌｅｒ超声心动图，采用计算机图像数字分析，定量测定左室功能的变化。随访期间，Ｔｏｒｏｎｔｏ组主动脉瓣跨瓣压差为０．８±０．６ｋＰａ（６．０±４．５ｍｍＨｇ），明显低于对照组２．３±０．９ｋＰａ（１７．３±６．８ｍｍＨｇ）；术后１个月，左室心肌质量下降２５％，左室＋Ｖｃｆ及－Ｖｃｆ明显增加（２．０±０．８／１．４±０．３ｓ－１，Ｐ＜０．０１；２．８±１．２／１．８±０．７ｓ－１，Ｐ＜０．０１）。术后６个月，左室功能进一步改善，心室肥厚的消退更趋完全，该变化在其后的随访期间保持稳定。结论：与支架瓣膜相比，无支架异种生物瓣膜具有较大瓣口开放面积及低跨瓣压差。

Aim:To describe the characteristic changes in left ventricular(LV)function during the first two years after stentless aortic valve replacement(AVR).Clinical material and method:From June 1992 to October 1995 AVR was performed in 80 patients,of whom,50 patients(age,69.3±9.3 years)received a Toronto SPVTM(ToV group),and 30(age,71.6±7.7 years),a stented valve(StV group).LV function was studied by two dimensional imaging directed at LV,Mmode echocadiograms,which were digitalized offline by computer system to qualify subsequent LV function.Doppler echocardiograms were recorded before operation and 1,6,12 and 24 months after AVR.Results:During followup,the Doppler estimated aortic valve pressure gradient was 0.8±0.6kPa in ToV group and 2.3±0.9kPa in StV group(P<0.01).Within the first month after AVR,a 25% fall of LV mass index(P<0.01)and of+Vcf of LV from 1.4±0.3cm/s to 2.0±0.8cm/s(P<0.01)and of Vcf from 1.8±0.7cm/s to 2.8±1.2cm/s(P<0.01)were found in ToV group.Six months after AVR,further improvement of LV function and almost complete regression of LV hypertrophy had been documented and remained stable up to 24 months after AVR.Conclusion:Stentless bioprosthesis used for AVR provides larger effective valve orifice area and lower crossvalve pressure gradient than stented one and therefore yields better improvement in LV function and a rapid regression of LV hypertrophy.