双胎反向动脉灌注序列征无心畸胎胎儿血流自然阻断前后的超声表现及泵血儿预后相关因素

Ultrasound imaging of acardia twin before and after blood spontaneously blocked and pump twin′s outcome analysis in twin reversed arterial perfusion sequence

目的总结双胎反向动脉灌注序列征(TRAP)无心畸胎胎儿血流自然阻断前后超声表现及影响泵血儿预后的相关因素。方法对2001年1月至2012年9月湖北省妇幼保健院产前超声检查确诊的7例(双胎中泵血儿存活)TRAP胎儿血流阻断前后的超声声像图特征进行总结,并对影响泵血儿预后的相关因素进行分析。结果 7例TRAP双胎儿产前超声表现:(1)无心畸胎胎儿:血流阻断前超声显示7例无心畸胎胎儿全身皮肤水肿、有脊柱和下肢而无心脏结构;均为单脐动脉,脐动脉反向灌注朝向胎儿。其中3例有部分头颅;4例无头颅;7例中4例体内血流微弱(脐动脉搏动指数UA-PI<0.7);5例生长速度慢于泵血儿。血流阻断后超声显示7例无心畸胎胎儿不继续生长,体内无血流,中、晚孕期结构显示不清,呈纸样胎儿;羊膜腔内见一条从胎盘连于无心畸胎胎儿脐部的细线状无血流的脐带结构。(2)泵血儿:7例泵血儿中3例存活,3例宫内死胎引产,1例脑积水、心功能不全引产。产前超声监测显示,对TRAP中泵血儿预后影响大的相关因素为:(1)泵血儿心脑功能异常(高输出性心功能衰竭);(2)双胎儿染色体异常;(3)双胎儿附属结构异常,羊水量多或过少及脐带缠绕;(4)无心畸胎胎儿生长发育快、体内血流不丰富。结论无心畸胎胎儿血流不丰富,生长发育速度慢提示无心畸胎胎儿体内血流可能会自然阻断,无心畸胎胎儿体内血流阻断后泵血儿预后好,但仍需对泵血儿行动态超声监测。

Objective To discuss the ultrasound imaging of acardia twin before and after spontaneously blood blocked in twin reversed arterial perfusion sequence（TRAP）,and to analyze the influence factor for the prognosis of pump twin.Methods Seven TRAP with pump twins and acardia′s blood flow blocked were diagnosed by US and autopsy in Hubei Women and Children′s Hospital between 2001 January to 2012 September.The ultrasound images,clinical data and pump twin＇ outcome were analyzed.Results Ultrasound images showed skin edema,acardia,spine and lower limbs in seven acardia cases before blood blocked,among which 4 were acardius acephalus,3 were acardius anceps.Single umbilical artery were detected in 7 cases with reversed umbilical artery perfusion toward fetus.Four cases had rare blood flow（UA-PI ratio 0.7.Five acardia cases had slower growing rate than the pump twin.Ultrasound images showed no growing,no blood flow in the acardia,the acardia twin became vagued in the second and third trimester,and finally developed into a paper fetus.A linear umbilical cord extend from umbilical region to placenta were found in 7 cases whose blood flow were spontaneously blocked.Pump twin′s outcome：3 pump twins survived,3 died in uterus,and 1 was induced labor due to hydrocephalus and cardiac failure.The most important factors that affected the prognosis of pump twin included： faster growing in acardia twin with less blood supply,abnormal brain and heart function in pump twin,chromosome abnormalities,abnormal amniotic fluid and cord entanglement.Conclusions Less blood flow and slow growth speed prompt in acardia twin suggested spontaneously acardia blood block.It is mandatory to monitor the pump twin after the spontaneous block of acardiac＇s blood flow.