Van Allen M I, Curry C, Walden C E, Gallagher L, Patten R M
Department of Medicine, University of Washington, Seattle.
Am J Med Genet. 1987 Nov;28(3):549-65. doi: 10.1002/ajmg.1320280303.
Limb defects from 25 fetuses with limb-body wall (LBW) complex were evaluated to determine the mechanism of limb damage. The limb defects could be divided into 3 pathogenetic groups: (1) secondary to disruption of embryonic vessels and surrounding tissue (84%), (2) secondary to amniotic bands or adhesions (16%), and (3) deformation versus hemorrhage (44% with club feet), with some fetuses having more than one pathogenetic mechanism causing limb defects. The hypothesis that the majority of limb defects resulted from disruption of embryonic vessels was supported by the following findings: 96% of the LBW complex fetuses had limb defects; the lower limbs were at greater risk of damage than the upper limbs (28% rt arm, 52% lt arm, 60% rt leg, 72% lt leg); there was a distal to proximal progression of limb damage in 92% of the fetuses; statistical analysis of comparing the location of the most severe limb defect and the body wall defect did not find concordance between the side (p = 1.0) and the region (p = 0.18) of the body wall defect; and limb defects found in the human specimens were similar to those produced in experimental animals following disruption of embryonic vessels at a corresponding gestation. In the specimens with amniotic band related limb defects (16%), the most likely pathogenesis is mechanical rupture through the amnion in the presence of a persistent extraembryonic coelom or from adhesion of the amnion to necrotic embryonic tissue after the initial disruptive event. Club feet were present in 44% and may be due either to disruption of embryonic vessels or to deformation. Further studies are needed to resolve this question.
对25例患有肢体 - 体壁（LBW）复合体的胎儿的肢体缺陷进行评估，以确定肢体损伤的机制。肢体缺陷可分为3个致病组：（1）继发于胚胎血管和周围组织的破坏（84%），（2）继发于羊膜带或粘连（16%），以及（3）畸形与出血（44%有马蹄内翻足），一些胎儿有不止一种致病机制导致肢体缺陷。以下发现支持了大多数肢体缺陷是由胚胎血管破坏引起的这一假设：96%的LBW复合体胎儿有肢体缺陷；下肢比上肢受损风险更大（右臂28%，左臂52%，右腿60%，左腿72%）；92%的胎儿肢体损伤有从远端向近端发展的趋势；比较最严重肢体缺陷和体壁缺陷位置的统计分析未发现体壁缺陷的侧别（p = 1.0）和区域（p = 0.18）之间存在一致性；并且在人体标本中发现的肢体缺陷与在相应孕周破坏胚胎血管后实验动物中产生的缺陷相似。在与羊膜带相关的肢体缺陷标本（16%）中，最可能的发病机制是在存在持续的胚外体腔时通过羊膜的机械破裂，或者是在初始破坏事件后羊膜与坏死胚胎组织粘连。44%的胎儿有马蹄内翻足，可能是由于胚胎血管破坏或畸形所致。需要进一步研究来解决这个问题。
