Hemodynamics of the ductus venosus

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Abstract

Although the ductus venosus has a similar function in human as in animal pregnancies (to regulate the shunting of oxygenated blood from the umbilical vein towards the left atrium), the amount of blood shunted in the human fetus seems to be less (25–40%) than in the animal (50%). The degree of shunting depends both on the resistance of the portal vasculature in the liver as well as the resistance of the ductus venosus itself. Neural and endocrine regulation plays a role in this distribution, as do fluid mechanical forces; blood viscosity and umbilical venous pressure are powerful determinants. There is a high degree of shunting at reduced umbilical venous pressure, and by increasing hematocrit, and viscosity, the distribution shifts from the liver to the ductus venosus. Additionally, the ductus venosus acts as transmission line in the opposite direction for the atrial pressure waves. Shape, viscosity, compliance, and particularly the diameter of the inlet are suggested to influence the pulsatility of the blood velocity at the ductus venosus inlet – and determine the degree of wave transmission into the umbilical vein. Occurrence of umbilical venous pulsation, an important diagnostic sign, is also dependent upon the size and compliance of the umbilical vein.

Section snippets

Functional anatomy

There are good reasons for starting the description of the function of the ductus venosus by describing the foramen ovale and ductus venosus as a unit. In spite of a large body of documentation of this functional relationship, it is rarely correctly presented in writing nor in figures. Both in conventional ultrasound imaging [1] (Fig. 1), color Doppler [2], and at post mortem examination [3], it is possible to appreciate the narrow trumpet-shaped ductus venosus connecting the umbilical vein to

Degree of shunting

Fetal sheep and monkey experiments using microsphere techniques showed that 50% of the umbilical blood was shunted through the ductus venosus [7], [10], [11], [28]. The fraction was slightly less when using dye dilution methods [29]. Applying the microsphere method in previable human fetuses (≤22 weeks), Rudolph et al. [14] found that 52% of the umbilical flow was shunted through the ductus venosus, but with very wide ranges (8–92%). These fetuses were exteriorised and therefore not under

Neural and endocrine regulation of the shunt

Adrenergic nerves have been traced in the area of the ductus venosus inlet [23], and both an α-adrenergic constriction and a β-adrenergic distention have been reported [24], [41]. Prostaglandins and a peroxidase P450 mechanism show activity in the area and have lead to the assumption that such mechanisms are responsible for the ductus venosus patency during pregnancy and its closure after birth in the same way as for the ductus arteriosus [41], [42], [43], [44], [45], [46]. However, changes in

Fluid dynamic determinants

The pressure gradient between the umbilical vein and the central venous pressure is the driving pressure for the blood flow in the ductus venosus and liver circuit in parallel. In the human fetus this pressure gradient is not known, but we assume that it is close to that measured in the umbilical vein (range 0–11 mmHg) [53], [54], [55], [56]. It has been established that the fetus is capable of varying this pressure by changing the arterial pressure and placental flow [6], [7], [28], [57], [58]

Velocity profile

The blood flows with a low and steady velocity in the umbilical vein. According to fluid dynamic principles, such a flow tends to be laminar with a parabolic profile of the velocity distribution across the vessel [61] (Fig. 6). In a parabolic flow the mean velocity is half of the maximum velocity found in the center of the vessel (Vmean=0.5·Vmax). When the blood enters the ductus venosus, it is accelerated and changes velocity profile. A similar situation is found in the heart. Blood that

Pressure gradient

As mentioned previously, the blood flow through the ductus venosus depends on the pressure drop between the umbilical vein and the IVC (the porto-caval or umbilico-caval pressure gradient). Since the high blood flow velocity at the inlet of the ductus venosus reflects this pressure gradient, it has been suggested that the pressure gradient can be calculated from the velocity using a Bernoulli equation [17]. Computational modeling has shown that less that 30% of the energy dissipates along the

Ductus venosus as a transmitter for pressure waves

In addition to directing blood towards the heart, the ductus venosus is involved in transporting waves away from the heart. This has been exploited in diagnostic Doppler ultrasound. The normal pulsatile pattern of blood velocity in the ductus venosus (Fig. 7a) is substituted by excessive pulsation, particularly due to reduced velocity during atrial contraction, in cases of increased afterload, congestive heart failure or abnormal atrial contractions [67], [68], [69], [70], [71], [72], [73], [74]

Conclusion

The ductus venosus represent a unique section of the circulation previously not well explored, probably due to the insignificant role in clinical medicine in later life. This is in contrast to fetal life where it plays a prominent role regulating the distribution of umbilical venous return. It also offers itself as a diagnostic tool in a vast area of fetal medicine. Knowing how important the distribution of umbilical blood is to the fetus, this should be an area of focus using all the

Condensation

Ductus venosus shunts 30% of umbilical blood towards the heart, and transmits atrial pulsation in the opposite direction, towards the umbilical vein. Both functions are modified by the geometry, mechanical properties, viscosity, and particularly the inlet diameter of this vessel.

Acknowledgments

The text was revised by Dr Tone Scheie Jensen. This work was supported by British Heart Foundation, Norwegian Research Council and Norwegian National Health Association.

References (86)

  • G.S. Dawes

    The umbilical circulation

    AmJObstetGynecol

    (1962)
  • T.W.A. Huisman et al.

    Ductus venosus blood flow velocity waveforms in the human fetus – a doppler study

    Ultrasound Med Biol

    (1992)
  • T. Kiserud et al.

    Umbilical flow distribution to the liver and ductus venosus: an in vitro investigation of the fluid dynamic mechanisms in the fetal sheep

    Am J Obstet Gynecol

    (1997)
  • G. Pennati et al.

    Computational analysis of the ductus venosus fluid dynamics based on Doppler measurements

    Ultrasound Med Biol

    (1996)
  • G. Pennati et al.

    Blood flow through the ductus venosus in human fetuses: calculation using Doppler velocimetry and computational findings

    Ultrasound Med Biol

    (1998)
  • T. Kiserud et al.

    The blood velocity profile in the ductus venosus inlet expressed by the mean/maximum velocity ratio

    Ultrasound Med Biol

    (1998)
  • K. Hecher et al.

    Fetal venous, intracardiac, and arterial blood flow measurements in intrauterine growth retardation: relationship with fetal blood gases

    Am J Obstet Gynecol

    (1995)
  • U. Gembruch et al.

    Longitudinal study in 18 cases of fetal supraventricular tachycardia: Doppler echocardiographic findings and pathophysiologic implications

    Am Heart J

    (1993)
  • G. Acharya et al.

    Pulsations of the ductus venosus blood velocity and diameter are more pronounced at the outlet than at the inlet

    Eur J Obstet Gynecol Reprod Biol

    (1999)
  • G. Rizzo et al.

    Umbilical vein pulsation: a physiological finding in early gestation

    Am J Obstet Gynecol

    (1992)
  • S. Gudmundsson et al.

    Venous Doppler ultrasonography in the fetus with nonimmune hydrops

    Am J Obstet Gynecol

    (1991)
  • T.W.A. Huisman et al.

    Flow velocity waveforms in the ductus venosus, umbilical vein and inferior vena cava in normal human fetuses at 12–15 weeks of gestation

    Ultrasound Med Biol

    (1993)
  • N. Montenegro et al.

    Ductus venosus revisited: a Doppler blood flow evaluation in first trimester of pregnancy

    Ultrasound Med Biol

    (1997)
  • T. Kiserud et al.

    Foramen ovale: an ultrasonographic study of its relation to the inferior vena cava, ductus venosus and hepatic veins

    Ultrasound Obstet Gynecol

    (1992)
  • J. Barcroft

    Researches On Pre-natal Life

    (1946)
  • B.M. Patten et al.

    Functional limitations of the foramen ovale in the human foetal heart

    Anat Rec

    (1929)
  • G.S. Dawes

    Foetal and Neonatal Physiology

    (1968)
  • A.M. Rudolph

    Distribution and regulation of blood flow in the fetal and neonatal lamb

    Circ Res

    (1985)
  • J. Lind et al.

    Angiocardiographic studies on the human foetal circulation

    Pediatrics

    (1949)
  • J. Lind

    Human fetal and neonatal circulation

    Eur J Cardiol

    (1977)
  • D.I. Edelstone et al.

    Liver and ductus venosus blood flows in fetal lambs in utero

    Circ Res

    (1978)
  • D.I. Edelstone et al.

    Preferential streaming of ductus venosus blood to the brain and heart in fetal lambs

    Am J Physiol

    (1979)
  • A.M. Rudolph et al.

    The circulation of the fetus in utero. Methods for studying distribution of blood flow, cardiac output and organ blood flow

    Circ Res

    (1967)
  • A.M. Rudolph et al.

    Studies on the circulation of the previable human fetus

    Pediatr Res

    (1971)
  • K.G. Schmidt et al.

    Assessment of flow events at the ductus venosus – inferior vena cava junction and at the foramen ovale in fetal sheep by the use of multimodal ultrasound

    Circulation

    (1996)
  • A.W. Chako et al.

    Embryonic development in the human of the sphincter of the ductus venosus

    Anat Rec

    (1953)
  • D.M. Barclay et al.

    The mechanism of closure of the ductus venosus

    Br J Radiol

    (1942)
  • D.H. Barron

    The sphincter of the ductus venosus

    Anat Rec

    (1942)
  • A.A. Pearson et al.

    The innervation of the umbilical vein in human embryos and fetuses

    Am J Anat

    (1969)
  • G. Gennser et al.

    Histochemical evidence of an aminergic sphincter mechanism in the ductus venosus of the human fetus

  • B. Ehinger et al.

    Histochemical and pharmacological studies on amine mechanisms in the umbilical cord, umbilical vein and ductus venosus of the human fetus

    Acta Physiol Scand

    (1968)
  • F. Coceani et al.

    Autonomic mechanisms in the ductus venosus of the lamb

    Am J Physiol

    (1984)
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