Clinical characteristics of a novel "Type 3" vasa previa: case series at a single center
Clinical characteristics of a novel "Type 3" vasa previa: case series at a single center
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DOI：
10.1080/14767058.2021.1960975
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发表时间：
2021-08-09
影响因子：
1.8
通讯作者：
Shiozawa, Tanri
中科院分区：
文献类型：
--
作者：
Kamijo, Kyosuke;Miyamoto, Tsutomu;Shiozawa, Tanri
目的 前置血管是指胎儿血管位于距宫颈内口 2 cm 以内的胎膜上。前置血管分为两种类型：1 型，其中血管将帆状脐带连接至胎盘；2 型，其中血管将双叶胎盘叶或胎盘与半叶胎盘连接。但也有一些非典型病例不能归为这两类。这些病例的表现为中心或边缘脐带插入，胎盘形状正常，胎儿血管也位于宫颈内口周围的膜上。这些病例最近被提议为 3 型前置血管。本研究调查了 3 型前置血管的发病率，并阐明了传统类型和 3 型前置血管的临床和超声检查特征的差异。方法这是一项单中心观察性研究，使用了 2010 年 1 月至 2020 年 4 月期间所有前置血管病例的队列。结果 在 8,723 例分娩中，有 14 例（0.16%）前置血管，所有病例均在产前由美国诊断，而非产后诊断。阴道分娩或 CS。 1 型、2 型和 3 型分别为 9 例（64%）、0 例和 5 例（36%）。所有 5 例 3 型病例均仅有 1 条胎儿前置血管异常血管，而 9 例 1 型病例中有 6 例（67%）有 2 条或以上异常血管。 7 名 1 型病例 (78%) 具有两种或多种已知危险因素，例如帆状脐带插入，而所有 3 型病例只有一种。使用常规经阴道超声检查 (TVUS) 诊断 14 例前置血管中的 2 例存在困难。在这些病例中，异常的前置血管胎儿血管只有一根静脉，壁薄，灰度TVUS无法清晰显示，血流缓慢，彩色多普勒很容易误读。这些病例最终根据彩色和脉冲多普勒检测到的非脉动血流被诊断为前置血管。结论 目前的结果表明 3 型可能占前置血管病例的很大一部分。大多数 3 型病例可能仅存在一根胎儿前置血管异常血管，并且危险因素较少，这表明 3 型病例中前置血管的诊断可能比其他类型更具挑战性。由于脉管系统成像不清晰或缺乏特定的彩色多普勒血流模式，产前诊断存在困难，因此需要考虑前置血管合并静脉前置血管。脉冲多普勒成像可能有助于这些病例的诊断。
Objective Vasa previa is a condition in which fetal blood vessels are located on fetal membranes within 2 cm of the internal cervical os. Vasa previa has been classified into two types: Type 1, in which vessels connect a velamentous umbilical cord to the placenta, and Type 2, in which vessels connect the lobes of a bilobed placenta or the placenta to a succenturiate lobe. However, there are also atypical cases that cannot be classified into these two types. These cases are manifested by a center or marginal cord insertion with a normal shaped placenta, and fetal vessels were also located on membranes around the internal cervical os. These cases were recently proposed as Type 3 vasa previa. The present study investigated the incidence of Type 3 vasa previa and elucidated differences in clinical and ultrasonographical characteristics between traditional types and Type 3. Methods This was a single-center observational study using a cohort of all vasa previa cases between January 2010 and April 2020. Results Among 8,723 deliveries, there were 14 cases (0.16%) of vasa previa, all of which were diagnosed prenatally by US, not after vaginal delivery or CS. There were 9 (64%), 0, and 5 (36%) cases of Types 1, 2, and 3, respectively. All 5 Type 3 cases had only one fetal aberrant vessel of vasa previa, while 6 out of 9 Type 1 cases (67%) had two or more aberrant vessels. Seven Type 1 cases (78%) possessed two or more known risk factors, such as velamentous cord insertion, whereas all Type 3 cases only had one. Difficulties were associated with diagnosing two out of the 14 cases of vasa previa using routine transvaginal ultrasonography (TVUS). In these cases, the aberrant fetal vessel of vasa previa was only one vein with a thin wall that was not clearly visualized by gray-scale TVUS as well as slow flow that was easily misread by color-Doppler. These cases were ultimately diagnosed as vasa previa based on non-pulsatile flow detected by color and pulsed Doppler. Conclusions The present results suggest that Type 3 may account for a large proportion of vasa previa cases. Most Type 3 cases may present with only one fetal aberrant vessel of vasa previa and fewer risk factors, suggesting that the diagnosis of vasa previa may be more challenging in Type 3 cases than in the other types. Vasa previa with a venous vasa previa needs to be considered because of the difficulties associated with an antenatal diagnosis due to unclear imaging of the vasculature or the lack of specific color Doppler flow patterns. Pulsed Doppler imaging may be helpful for the diagnosis of these cases.