Rubio Eva I, Blask Anna R, Badillo Andrea T, Bulas Dorothy I
Division of Diagnostic Imaging and Radiology, Children's National Medical System, 111 Michigan Ave. NW, Washington, DC, 20010, USA.
Division of General and Thoracic Surgery, Children's National Medical System, Washington, DC, USA.
Pediatr Radiol. 2017 Apr;47(4):411-421. doi: 10.1007/s00247-016-3770-0. Epub 2017 Jan 23.
Prenatal small-bowel obstruction can result from single or multiple atresias, and it can be an isolated abnormality or part of a syndrome. It is sometimes the first manifestation of cystic fibrosis. Accurate prediction of the level of obstruction and length of bowel affected can be difficult, presenting a challenge for counseling families and planning perinatal management.
To review the prenatal US and MRI findings of small-bowel obstruction and to assess whether fetal MRI adds information that could improve prenatal counseling and perinatal management.
We retrospectively reviewed 12 prenatally diagnosed cases of small-bowel obstruction evaluated by both US and MRI from 2005 to 2015. We analyzed gestational age at evaluation, US and MRI findings, gestational age at delivery and postnatal outcomes.
The final diagnoses were jejunal atresia (7), ileal atresia (1), cystic fibrosis (3) and combined jejunal and anal atresia (1). Four of the eight with jejunal atresia were found to have multiple small-bowel atresias. Prenatal perforation was noted in three. We identified a trend of increasing complexity of bowel contents corresponding to progressively distal level of obstruction, as indicated by increasing US echogenicity and high T1 signal on MRI. Seven cases of jejunal atresia and one case of ileal atresia demonstrated small ascending, transverse and descending colon (microcolon) with filling of a normal-diameter rectum. In contrast, all three fetuses with cystic fibrosis and the fetus with jejunal-anal atresia demonstrated microcolon as well as abnormal paucity or absence of rectal meconium. Polyhydramnios was present in nine. Eight were delivered prematurely, of whom seven had polyhydramnios. The fetus with jejunal and anal atresia died in utero. Postnatally, three had short gut syndrome, all resulting from multiple jejunal atresias; these three were among a subset of four fetuses whose bowel diameter measured more than 3 cm. Eight infants had no further gastrointestinal complications. The presence of multiple atresias was not predicted by prenatal US or MRI.
MR provides useful additional information regarding meconium distribution in the small bowel, which helps to clarify the level of obstruction. MR was additionally useful in the assessment of colon and rectal contents, serving as a fetal enema. Abnormally diminished meconium in the rectum suggests cystic fibrosis or combined small-bowel and colonic obstruction, information that is useful in counseling and preparing for postnatal care.
产前小肠梗阻可由单发或多发闭锁引起，可为孤立性异常或综合征的一部分。它有时是囊性纤维化的首发表现。准确预测梗阻水平和受累肠段长度可能具有挑战性，这给为家庭提供咨询和规划围产期管理带来了难题。
回顾产前小肠梗阻的超声和磁共振成像（MRI）表现，并评估胎儿MRI是否能提供有助于改善产前咨询和围产期管理的信息。
我们回顾性分析了2005年至2015年间经超声和MRI评估的12例产前诊断为小肠梗阻的病例。我们分析了评估时的孕周、超声和MRI表现、分娩时的孕周及产后结局。
最终诊断为空肠闭锁（7例）、回肠闭锁（1例）、囊性纤维化（3例）以及空肠和肛门闭锁合并（1例）。8例空肠闭锁中有4例发现存在多发小肠闭锁。3例产前有肠穿孔。我们发现随着梗阻部位逐渐下移，肠内容物的复杂性呈增加趋势，超声回声增强以及MRI上T1信号增高提示了这一点。7例空肠闭锁和1例回肠闭锁显示升结肠、横结肠和降结肠细小（小结肠），直肠直径正常且有胎粪充盈。相比之下，所有3例囊性纤维化胎儿以及空肠 - 肛门闭锁胎儿均显示小结肠以及直肠胎粪异常减少或缺失。9例有羊水过多。8例早产，其中7例有羊水过多。空肠和肛门闭锁胎儿死于宫内。产后，3例有短肠综合征，均由多发空肠闭锁导致；这3例属于肠直径测量超过3 cm的4例胎儿亚组。8例婴儿无进一步的胃肠道并发症。产前超声或MRI未预测到多发闭锁的存在。
MRI提供了关于小肠内胎粪分布的有用补充信息，有助于明确梗阻水平。MRI在评估结肠和直肠内容物方面也很有用，可作为胎儿灌肠检查。直肠内胎粪异常减少提示囊性纤维化或小肠与结肠联合梗阻，这一信息对咨询和准备产后护理很有用。
