Objective: To investigate the effect of placental vascular distribution on residual anastomoses (RA) after fetoscopic laser occlusion of chorioangiopagous ressels (FLOC) for twin to twin transfusion syndrome (TTTS). Methods: A total of 57 cases of TTTS after laser surgery were retrospectively analyzed from April 2014 to April 2019 in Peking University Third Hospital. The patients were divided into RA group (24 cases) and non-RA group (33 cases) according to whether RA occurred in the placenta after laser surgery. The clinical characteristics, perioperative conditions, pregnancy outcomes and placental structure characteristics of the two groups were compared. Multivariate logistic regression was used to analyze the risk factors of placental vascular distribution for RA. The RA group was further divided into non-remission group and remission group, and the placental characteristics and pregnancy outcome of the two groups were compared. Results: (1)General clinical characteristics: the age, application of assisted reproductive technology, incidence of gestational hypertension, gestational diabetes mellitus, preoperative maximum amniotic fluid depth of the donor and recipient twins, Quintero stage and placental position of TTTS patients in the two groups were compared respectively, and there were no statistically significant differences (all P>0.05).The gestational age of patients received FLOC in the RA group was significantly higher than the non-RA group [(23.0±2.4) vs (21.9±2.7) weeks, P=0.033].(2) Perioperative conditions and pregnancy outcomes: the delivery gestational age of the RA group was significantly lower than that of the non-RA group (median:31.8 vs 34.4 weeks, P=0.002);The newborn birth weight in the RA group was significantly lower than that in the non-RA group [(1 648±597) and (2 013±481) g, P=0.003].The birthweight difference in the RA group was significantly higher than that in the non-RA group (median:0.30 vs 0.11, P=0.005). (3) The placental structure and the risk factors influencing RA happened: the differences in the proportion of four types of placental vascular distribution in the RA group and non-RA group were different significantly (χ²=10.214, P=0.012), with a detail of parallel type 29% (7/24) and 3% (1/33), staggered type 58% (14/24) and 76% (25/33), hybrid 8% (2/24) and 21% (7/33), monoamniotic membrane type 4% (1/24) and 0 respectively. Multivariate logistic regression analysis showed that parallel placental vascular distribution was an independent risk factor for RA after FLOC (OR=24.5, 95%CI 1.7-336.2, P=0.017). (4) Placental characteristics and pregnancy outcomes in the remission and non-remission groups of the RA group: the incidence of three kinds of anastomoses, the total number, total diameter and proportion of RA, and the placental territory discordance ratio were compared between the two groups, and there were no statistical significances (P>0.05);The birth weight difference ratio in the non-remission group was higher than that in the remission group (median:0.41 vs 0.28, P=0.036). Conclusion: The parallel type of placental vascular distribution may be an independent risk factor for RA in TTTS after laser surgery.
目的： 探讨胎盘浅表血管分布类型对胎儿镜激光手术治疗双胎输血综合征（TTTS）术后残留吻合血管（RA）发生的影响。 方法： 回顾性分析2014年4月至2019年4月间于北京大学第三医院行胎儿镜激光凝固吻合血管术（FLOC）治疗TTTS，且最终在本院分娩的57例产妇的临床资料和分娩后胎盘灌注情况。根据术后胎盘是否发生RA分为RA组（24例）和无RA组（33例），比较两组的临床特征、围术期情况、妊娠结局和胎盘浅表血管分布类型等结构特点。多因素logistic回归分析RA发生的风险因素。进一步将RA组TTTS产妇分为未缓解组和缓解组，比较两组的胎盘特征和妊娠结局。 结果： （1）一般临床特征：RA组和无RA组TTTS产妇的年龄、辅助生殖技术应用、妊娠期高血压疾病、妊娠期糖尿病发生率、术前供血儿和受血儿最大羊水深度、Quintero分期以及胎盘位置分别比较，差异均无统计学意义（P均>0.05）。FOLC手术孕周RA组显著大于无RA组［分别为（23.0±2.4）和（21.9±2.7）周，P=0.033］。（2）围术期情况和妊娠结局：分娩孕周RA组显著小于无RA组（中位数分别为31.8和34.4周， P=0.002）；新生儿出生体重RA组显著小于无RA组［分别为（1 648±597）和（2 013±481） g， P=0.003］；新生儿出生体重差额比RA组显著大于无RA组（中位数分别为0.30和0.11， P=0.005）。（3）胎盘结构特点和影响RA发生的风险因素：RA组和无RA组孕妇胎盘浅表血管分布为平行型的比例分别为29%（7/24）和3%（1/33），交错型分别为58%（14/24）和76%（25/33），混合型分别为8%（2/24）和21%（7/33），单羊膜型分别为4%（1/24）和0，两组产妇4种血管分布类型所占比例比较，差异有统计学意义（χ²=10.214，P=0.012）。多因素logistic回归分析显示，平行型胎盘浅表血管分布是FLOC术后RA发生的独立风险因素（OR=24.5，95%CI为1.7~336.2，P=0.017）。（4）RA组内的胎盘结构特点和妊娠结局：未缓解组和缓解组产妇动脉-动脉、动脉-静脉、静脉-静脉吻合血管的发生率、RA总数目、RA总直径、RA比例、胎盘面积差额比分别比较，差异均无统计学意义（P均>0.05）；未缓解组的新生儿出生体重差额比显著大于缓解组（中位数分别为0.41和0.28，P=0.036）。 结论： 平行型胎盘浅表血管分布可能是FLOC治疗TTTS术后RA发生的独立风险因素。.