Ultrasound and Fetal MRI Complementary Contributions to Appropriate Counseling in Small Bowel Obstruction

Abstract

<b><i>Objective:</i></b> Bowel obstructions beyond the duodenum represent a heterogeneous group of congenital anomalies with a highly variable prognosis, the main issue being postnatal short bowel syndrome (SBS). The objective of our study was to evaluate the contributions of fetal MRI in cases of bowel obstruction. <b><i>Materials and Methods:</i></b> A retrospective analysis of all newborns, for whom both ante-natal ultrasound and fetal MRI were available, referred to our center for suspected bowel obstruction was performed. Examinations were reviewed blinded to the postnatal outcome. Key outcome measures included exact diagnosis and the existence of postoperative SBS. We evaluated the contribution of MRI in determining precise location and etiology of the bowel obstruction, dilatation of the proximal bowel loops, and assessment of the quality of the remaining distal bowel loops. <b><i>Results:</i></b> Twenty-five newborns were included. There were 19 single obstructions and 6 complex forms (4 apple peel syndromes and 2 multiple atresias). MRI correctly identified the affected segment of the small bowel in 59.1% of the cases. MRI identified the mechanism of obstruction in 72% of cases. MRI reliably predicted an abnormal appearance of the bowel distal to the obstruction in 100% of the severe cases (3/3) and in 66.7% of complex forms (4/6). <b><i>Conclusion:</i></b> Our study suggests that fetal MRI, when done in addition to prenatal ultrasound, is contributory in the management of fetuses with suspected bowel obstruction. MRI may be particularly useful in determining the location and origin of the bowel obstruction and in assessing the quality of the bowel distal to the obstruction, which might assist in the prediction of SBS and more detailed prenatal counseling.

Fetal intestinal loop dilatation: Follow‐up and outcome of a series of 133 consecutive cases (the DILDIG study)

“…Previous studies have highlighted the risk of duodenal dilatation being associated with anorectal or esophageal malformation 4,37–39 and the role of MRI will be particularly interesting for such screening 32–36,40 . Normal MRI findings were a factor of good prognosis (100% sensitivity and 94% specificity), giving a false‐positive rate of 2.8%, whereas the false‐positive rate for US was 35% in our series, a percentage similar to those reported in the literature 5,15,19,21,22 …”

“…The criteria we used to include cases were the cutoff of 7 mm as defined in the literature 1,2,14 or unusual moderate dilatation. The size of the dilatation as a prognostic factor is discussed in the literature, 2,6,14,[18][19][20][21] but in our series was not a significant factor.…”

“…Different prognostic factors were identified: (1) the presence or not of associated malformations, (2) the result of complementary tests in amniotic fluid, (3) the progression of dilatation between two US examinations, and (4) MRI to confirm the level of obstruction. These prognostic factors have been described in the literature but frequently independently, 15–22 and we propose a policy to improve the management of pregnancies.…”

“…Overall, despite this extensive screening policy, of the 112 live infants, 12 (10.7%) presented with an additional severe intestinal or non‐intestinal malformation not detected prenatally, thereby modifying postnatal care (four apple peel syndrome, three multiple atresia, three anorectal malformation, one type III esophageal atresia associated with anal atresia, and one biliary duct atresia). As previously reported, the diagnosis and prognosis of apple peel syndrome and multiple stenosis remain a challenge 21,32,35 and represent a potential for improvement in the future. The policy we propose should be validated in a larger series of consecutive cases of prenatally diagnosed digestive tract dilatation.…”

“…MRI was performed in 54 cases between 26 and 37 weeks (median 32 weeks). The results are presented in These prognostic factors have been described in the literature but frequently independently, [15][16][17][18][19][20][21][22] and we propose a policy to improve the management of pregnancies.…”