Transmitted Arterio-arterial Anastomosis Waveforms Causing Cyclically Intermittent Absent/Reversed End-diastolic Umbilical Artery Flow in Monochorionic Twins
Autor: | D.G. Talbert, L. Y. Wee, Nicholas M. Fisk, Myles J.O. Taylor, T. Vanderheyden |
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Rok vydání: | 2003 |
Předmět: |
Adult
medicine.medical_specialty Diastole Intrauterine growth restriction Anastomosis Models Biological Ultrasonography Prenatal Umbilical Arteries Arterio-Arterial Fistula Pregnancy Interquartile range medicine.artery Internal medicine Diseases in Twins medicine Humans Computer Simulation Prospective Studies Ultrasonography Doppler Color Fetus business.industry Obstetrics and Gynecology Umbilical artery Fetofetal Transfusion Twins Monozygotic Anatomy medicine.disease Fetal Diseases Reproductive Medicine Cardiology Female Monochorionic twins business Blood Flow Velocity Developmental Biology |
Zdroj: | Placenta. 24:772-778 |
ISSN: | 0143-4004 |
Popis: | Objectives: To characterize the phenomenon of retrograde transmission of arterio-arterial anastomosis (AAA) interference patterns on umbilical artery (UA) waveform by (a) documenting the periodicity, (b) correlation with in vivo and in vitro demonstration of AAAs and (c) reproducing these patterns by computer modelling. Methods: Monochorionic twins (MC) twins underwent placental and umbilical Doppler studies. AAAs were sought by pulse wave Doppler of their bi-directional interference pattern and confirmed by postnatal injection studies. The periodicity of transmitted patterns in the UA was determined. Determinants of the transmitted patterns were ascertained by computer modelling of physiological and fetal variables. Results: Among 83 prospectively studied MC twin pregnancies; a transmitted pattern was observed in 6 (7 per cent) patients for 15–114 days. This was found in 20 per cent (6/30) of smaller MC twins discordant for growth restriction but in no appropriately grown twins. It was only observed in association with AAAs validated both in vivo and in ex vivo. Computer modelling demonstrated that this pattern could be reproduced by summating end diastolic flow with a high pulsatility index in the UA in the presence of a large AAA. Consistent with this, MC twins with a transmitted pattern had larger AAAs (median diameter 4.3 mm interquartile range 4.1–5.2) compared to MC twins discordant for intrauterine growth restriction (2.1 mm interquartile range 1.5 to 2.8) (P |
Databáze: | OpenAIRE |
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