Prenatal diagnosis of complete nonrotation of fetal bowel with ultrasound and magnetic resonance imaging

A case of isolated malrotation without midgut volvulus diagnosed prenatally and treated by laparoscopic surgery

BACKGROUND

Malrotation is a congenital condition that predisposes individuals to midgut volvulus, which can result in significant bowel resection. While most cases of malrotation are diagnosed by the age of 1 year, typically presenting with symptoms related to volvulus or bowel obstruction, some cases remain asymptomatic. In children with visceral malposition, gastroschisis, omphalocele, or diaphragmatic hernia, malrotation may be suspected before symptoms manifest. However, isolated malrotation without midgut volvulus diagnosed prenatally is rare. We herein present a case of isolated malrotation without midgut volvulus that was prenatally diagnosed and successfully treated with laparoscopic surgery.

CASE PRESENTATION

A 30-year-old woman (gravida 3, para 1) underwent routine obstetric ultrasound, which revealed increased blood flow in the lower uterine segment and abnormal placental attachment. To rule out placenta percreta, magnetic resonance imaging was performed at 34 weeks of gestation. Incidentally, abnormal fetal intestinal arrangement was noted, with the colon localized in the left hemi-abdomen and the small intestine distributed in the right hemi-abdomen, raising suspicion of malrotation. Postnatal contrast studies confirmed the diagnosis of malrotation without midgut volvulus. Given the risk of midgut volvulus, a laparoscopic Ladd's procedure was performed on day 6 of life. The postoperative course was uneventful, and the patient was still symptom-free 1 year postoperatively.

CONCLUSIONS

This case illustrates that malrotation can be prenatally diagnosed using fetal magnetic resonance imaging. Considering the risk of midgut volvulus, prophylactic Ladd's procedure should be performed in neonatal period. In cases where malrotation is not complicated by midgut volvulus, a laparoscopic Ladd procedure can be safely performed in neonates.

Prenatal diagnosis of bowel malposition using T2-weighted fetal MRI sequences

OBJECTIVE

The goal of this study was to investigate the capability of T2-weighted magnetic resonance imaging (MRI) in revealing fetal bowel malposition.

MATERIALS AND METHODS

All fetal MRI examinations (excluding central nervous system MRI examinations) performed in our department from January 2005 to January 2014 were retrospectively studied by 2 independent observers for situs, stomach and jejunum location on T2-weighted images. Patients data were also reviewed for results of ultrasound examinations, MRI indication, and gestational age. Abnormally positioned jejunums were classified into 3 groups: intrathoracic (A), extra-fetal (B) and abnormal intra-fetal (C). Prenatal data were compared to postnatal imaging, surgery or autopsy findings that served as standard of reference.

RESULTS

A total of 709 fetal MRI examinations were analyzed. In 64 fetus (9%), the jejunum was not present in the left subgastric area on T2-weighted MR images. In these 64 fetuses, proximal jejunum was intrathoracic (41/64, 64%, group A), extra-fetal (11/64, 17%, group B), or intra-abdominal but abnormally positioned (12/64, 19%, group C). Interobserver agreement was 100%. All diagnoses for fetuses in groups A and B (52 cases) were confirmed postnatally (41 cases) or at autopsy (11 cases). In group C, bowel malposition was suspected after ultrasound in only 2/12 fetuses (16.6%); it was confirmed postnatally in 1 fetus but not confirmed in the remaining one. In the 10 remaining fetuses (83%), malposition was confirmed postnatally although not initially suspected.

CONCLUSION

T2-weighted fetal MR images are useful for the prenatal diagnosis of bowel malposition, even when they are unsuspected on ultrasound examination.