Understanding the diagnosis of superior mesenteric artery syndrome: analysis of the location of duodenal impression on upper gastrointestinal studies.

BACKGROUND: Upper gastrointestinal (GI) contrast studies are frequently requested to aid superior mesenteric artery syndrome diagnosis, a rare entity. Compression of the third duodenal part is expected to be mid-to-left of the midline where the superior mesenteric artery arises from the aorta; however, a duodenal impression to the right of the midline due to normal anatomic impression by the inferior vena cava (IVC) is often encountered and frequently misdiagnosed. OBJECTIVE: The purpose of this study was to determine the frequencies of (1) normal right-of-midline duodenal impressions and (2) mid-to-left of midline compressions in upper GI studies in a tertiary pediatric referral center. MATERIALS AND METHODS: All upper GI studies performed at our institution over 2 years were retrospectively evaluated to determine whether the duodenum had vertical duodenal impression to the right of the vertebral midline, mid-to-left of the vertebral midline, or no identifiable duodenal impression at all. RESULTS: In total, 538 upper GI studies were included in this analysis. A total of 275 male and 247 female patients between 0 and 17 years of age (median: 6 years, range: 1 month-17 years) were included. Of 538 total upper GI studies, there were 240 studies (44.6%) with a right-of-midline impression. There were only 10 studies (1.9%) with a mid-to-left of midline compression, and 9/10 also showed a concurrent right-sided impression sign. CONCLUSION: Right-of-midline duodenal impression is a normal anatomic finding caused by the IVC and should not be confused with superior mesenteric artery syndrome. In the presence of an appropriate clinical context, proximal duodenal dilation, "to-and-fro" motion of contrast, and duodenal impression at mid-to-left of midline, a diagnosis of superior mesenteric artery syndrome should be considered.

Screening for placental insufficiency by transvaginal uterine artery Doppler at 22-24 weeks of gestation.

OBJECTIVE: To determine the value of routine transvaginal color Doppler assessment of the uterine arteries at 22-24 weeks of gestation in the prediction of placental insufficiency. METHODS: Women with singleton pregnancies scheduled for routine ultrasound scans at 22-24 weeks were offered Doppler assessment of the uterine arteries by transvaginal ultrasound. The pulsatility index (PI) was obtained for each artery and the mean value was calculated. A mean PI >95th percentile was considered increased. Screening characteristics for predicting placental insufficiency, defined as preeclampsia, fetal growth restriction or intrauterine death, were calculated. RESULTS: Doppler examination of the uterine arteries was carried out in 1,057 singleton pregnancies. The mean uterine artery PI was 1.03 and the 95th percentile was 1.55. In 54 cases (5.1%) the mean PI was >1.55 (screen-positive). In the study population there were 48 cases of preeclampsia (5.1%), 72 fetal growth restrictions (7.5%) and 7 intrauterine deaths (0.7%). The screen-positive group showed an incidence of 47.1% of combined adverse results. The relative risks after a positive screening test were 7.3 (CI 4.2-12.6) for pre-eclampsia, 3.9 (CI 2.3 - 6.6) for fetal growth restriction and 4.5 (CI 3.2-6.4) for overall placental insufficiency. CONCLUSIONS: Uterine artery Doppler at 22-24 weeks identifies women at higher risk for the development of subsequent complications of placental insufficiency. This test could be used in combination with other markers to stratify the level of care offered in the third trimester of pregnancy.