447: Quantification of ultrasound umbilical vein changes in fetal diaphragmatic hernia

Abstract

changes in fetal diaphragmatic hernia Douglas Richards, David Kays Intermountain Medical Center and the University of Utah, Maternal Fetal Medicine, Murray, UT, University of Florida, Pediatric Surgery, Gainesville, FL OBJECTIVE: Deviation of the intraabdominal umbilical vein has been described as a marker of congenital diaphragmatic hernia and has been shown to help identify liver prolapse into the fetal chest. Deviation has previously been described only as a subjective finding. The purpose of this study is to quantify the degree of deviation in affected fetuses and to determine the accuracy of measurements for determining liver prolapse. STUDY DESIGN: In patients undergoing prenatal sonography for CDH the mid-hepatic portion of the umbilical vein was identified, and the distance between the lateral edge of the vein and the inner rib margin was measured. The same was done on the right, and the ratio of left to right measurement was termed the umbilical vein ratio (UVR). For this analysis, deviation of the UV, as quantified by the UVR, was used to predict the presence and side of the hernia, as well as to diagnose liver prolapse. The 5th and 95th confidence limits for the normal UVR were determined from 80 unaffected fetuses. Of 160 cases of CDH seen at our center between 11/1995 and 9/2010, 56 fetuses were studied prospectively, and 76 had adequate images available for retrospective measurements. The first sonogram at our center was used for analysis. RESULTS: The gestational age at the time of the ultrasound was 29.4 / 6.2 weeks. Of the 132 patients, 14 had a right-sided and 118 had a left-side hernia. All but one of the cases with right-sided hernias had an UVR above the normal range, and all had liver prolapse. Of those with a left-sided hernia, only 2 had a ratio within the normal range. Of those with a left-sided hernia, an UVR of 0.4 was shown by ROC analysis to be the best predictor of liver prolapse. This cut off had a sensitivity of 0.89 for predicting prolapse, with a false positive rate of 0.14. CONCLUSION: 93% of right-sided CDH and 98% of left-sided lesions have an UVR outside of the normal range. This demonstrates that deviation may a useful indicator of CDH in screening ultrasound examinations. A UVR less 0.4 is predictive of liver prolapse.