Second trimester screening for the basilar artery: a new approach using slowflowHD

Abstract

Objectives

Sonographic evaluation of the basilar artery is challenging, and a limited number of reports are available about the prenatal period, as manual positioning of probes is technically difficult. The objective of this study was to describe a sonographic transabdominal approach based on slowflow HD for screening of the basilar artery during the second trimester scan.

Methods

A total of 49 women who were enrolled in a second trimester screening were included when the fetus was in the occipitoanterior position. Dopper screening of the cerebral artery was performed, which revealed the “Y” sign indicating the basilar trunk arising from two vertebral arteries in the axial oblique view when the probe was located around the junction of the vertebral processes and occipital bone and was superior to the first vertebral body, sloping slightly to the cephalic side. The Doppler ultrasound probe was placed perpendicular to the basilar artery. The flow direction was below the baseline, away from the probe in the basilar artery, consistent with a caudocephalic orientation. Peak systolic and diastolic velocities were measured.

Results

The basilar artery was identified in all 49 fetuses, with a mean gestational age of 22 weeks (range 20 to 26 weeks). The mean peak systolic velocity of the basilar artery was 15.8 cm/second (range 9.12-26.44 cm/second). There was a slight increase in peak systolic velocity according to the gestational age of the fetus.

Conclusions

This study demonstrated that evaluation of the basilar artery can be performed during the second trimester via a new transabdominal approach involving slowflow HD.

Keywords:

• Basilar artery
• prenatal
• second trimester
• slowflowHD
• ultrasound

Authors’ contribution

Zhengfeng Zhu produced the first draft of the manuscript. All authors sought consent from the patient, contributed to revisions of the final manuscript, and approved the final version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.