Decoding VExUS: a practical guide for excelling in point-of-care ultrasound assessment of venous congestion

Abstract

Venous congestion, often associated with elevated right atrial pressure presents a clinical challenge due to its varied manifestations and potential organ damage. Recognizing the manifestations of venous congestion through bedside physical examination or laboratory tests can be challenging. Point-of-care ultrasound (POCUS) is emerging as a valuable bedside tool for assessing venous congestion, with the Venous Excess Ultrasound (VExUS) technique gaining prominence. VExUS facilitates non-invasive quantification of venous congestion, relying on measurements of the inferior vena cava (IVC) size and Doppler assessments of the hepatic vein (HV), portal vein (PV), and intrarenal vein, thereby providing real-time insights into hemodynamic status and guiding therapeutic interventions. The grading system outlined in VExUS aids in stratifying the severity of congestion. However, achieving proficiency in VExUS requires a comprehensive understanding of Doppler techniques and their clinical applications. This review article provides practical guidance on performing VExUS, encompassing equipment requirements, preparation, machine settings, and examination techniques for assessing the inferior vena cava (IVC), hepatic vein (HV), portal vein (PV), and intrarenal vein. Potential pitfalls and troubleshooting strategies are discussed to ensure accurate interpretation of Doppler waveforms.

Keywords: Point-of-care ultrasound; VExUS; Venous congestion; Venous excess ultrasound.

Fig. 1

Hand and probe position for the IVC short axis view with the transducer orientation marker set at 3 o’clock (arrow). IVC, inferior vena cava

Fig. 2

IVC short-axis view. IVC, inferior vena cava

Fig. 3

Hand and probe position for the IVC long axis view with the transducer orientation marker set at 12 o’clock (arrow). IVC, inferior vena cava

Fig. 4

IVC long-axis view. IVC, inferior vena cava; HV, hepatic vein

Fig. 5

The optimal mesaurement location of the IVC in the long-axis view is either 2 cm below the RA-IVC junction or approximately 1 cm below the HV-IVC junction. IVC, inferior vena cava; RA, right atrium; HV, hepatic vein

Fig. 6

Measurement of the IVC in the short-axis view. IVC, inferior vena cava

Fig. 7

The junction of an imaginary line extending from the xiphoid process to the midaxillary line to visualize the HV in coronal view. HV, hepatic vein

Fig. 8

Position the transducer at the junction of an imaginary line extending from the xiphoid process to the midaxillary line, orienting the orientation marker towards the patient’s right axilla (arrow) to visualize the HV in coronal view. HV, hepatic vein

Fig. 9

Pulsed wave Doppler mode with the sample volume (Doppler gate) positioned within the HV, approximately 1–2 cm away from its junction with the IVC. IVC, inferior vena cava; HV, hepatic vein

Fig. 10

Pulsed-wave Doppler tracing of the HV in abdominal preset. HV, hepatic vein

Fig. 11

Pulsed-wave Doppler tracing of the HV in cardiac preset. HV, hepatic vein

Fig. 12

a The waveform of the HV, alongside simultaneous ECG, aids in identifying each wave. b The waveform of the HV. HV, hepatic vein; ECG, electrocardiogram

Fig. 13

The A wave is generated by the contraction of the RA during atrial systole, increasing the RAP and pushing blood backward toward the liver. RA, right atrium; RAP, right atrial pressure; IVC, inferior vena cava; HV, hepatic vein; RV, right ventricle; SVC, superior vena cava; PA, pulmonary artery

Fig. 14

The S wave arises during ventricular systole when the tricuspid annulus moves towards the cardiac apex, directing blood flow from the HV into the IVC and RA, thereby generating the antegrade S wave. IVC, inferior vena cava; RA, right atrium; HV, hepatic vein; RV, right ventricle; SVC, superior vena cava; PA, pulmonary artery

Fig. 15

The V wave, appearing towards the end of ventricular systole, represents a transitional phase as the tricuspid annulus returns to its original position, inducing a retrograde wave that may manifest either above or below the baseline. RA, right atrium; IVC, inferior vena cava; HV, hepatic vein; RV, right ventricle; SVC, superior vena cava; PA, pulmonary artery

Fig. 16

The D wave arises during ventricular diastole when the tricuspid valve opens, permitting blood to travel from the HV into the IVC and subsequently into the RA, thereby generating the antegrade D wave. HV, hepatic vein; IVC, inferior vena cava; RA, right atrium; RV, right ventricle; SVC, superior vena cava; PA, pulmonary artery

Fig. 17

a Normally, the amplitude of the S-wave exceeds that of the D-wave. As the RAP increases in tandem with RV dysfunction and tricuspid regurgitation, b in mild to moderate venous congestion, the amplitude of the S-wave diminishes, becoming less than that of the D-wave, and c in severe venous congestion, the S-wave reverses its position, rising above the baseline, while only the D-wave remains below the baseline. RAP, right atrial pressure; RV, right ventricle

Fig. 18

The HV waveform interpretation may be challenging without concurrent ECG tracing. HV, hepatic vein; ECG, electrocardiogram

Fig. 19

Blunting and reduction in cardiac phasicity may be observed in the HV waveform in conditions such as liver cirrhosis and fatty infiltration. HV, hepatic vein

Fig. 20

Pulsed wave Doppler mode with the sample volume (Doppler gate) positioned within the PV. PV, portal vein

Fig. 21

Pulsed-wave Doppler tracing of the PV. PV, portal vein

Fig. 22

Pulsed-wave Doppler tracing of the PV with hepatic arterial flow interference. PV, portal vein

Fig. 23

Pulsed-wave Doppler tracing of the PV without hepatic arterial flow interference. PV, portal vein

Fig. 24

PVPF calculation. PVPF, portal vein pulsatility fraction; Vmax, maximum velocity; Vmin, minimum velocity

Fig. 25

a The PV waveform typically exhibits a continuous pattern with limited pulsatility and a normal PVPF (< 30%) due to hepatic sinusoids that attenuate the linear transmission of RAP. b In mild to moderate venous congestion, characterized by elevated RAP and RV dysfunction, the PVPF may rise above 30% but remain below 50%. c A PVPF exceeding 50%, with or without systolic flow reversal (below the baseline), indicates severe congestion. PV, portal vein; PVPF, portal vein pulsatility fraction; RAP, right atrial pressure; RV, right ventricle

Fig. 26

The major renal veins’ anatomy illustration

Fig. 27

Position the transducer at the junction of an imaginary line extending from the xiphoid process to the postaxillary line, orienting the orientation marker towards the patient’s right axilla (arrow) to visualize the IRV in coronal view. IRV, intrarenal vein

Fig. 28

Pulsed wave Doppler mode with the sample volume (Doppler gate) positioned within the IRV. IRV, intrarenal vein

Fig. 29

Pulsed-wave Doppler tracing of the IRV and the IRA. IRV, intrarenal vein; IRA, intrarenal artery

Fig. 30

a Under normal conditions, the IRVD exhibits a continuous pattern with minimal pulsatility and no interruptions. b However, mild to moderate venous congestion results in heightened pulsatility and interruptions in the waveform, characterized by distinct systolic (S) and diastolic (D) waves. c In severe congestion, S-reversal occurs similarly to that of the HV, leaving only the D-wave below the baseline. IRVD, intrarenal vein Doppler; HV, hepatic vein; IRA, intrarenal artery; IRV, intrarenal vein

Fig. 31

The VExUS grading system categorizes congestion based on IVC diameter and Doppler findings in HV, PV, and IRV. An IVC diameter ≤ 2 cm indicates grade 0 (no congestion). Grades 1–3 are defined by abnormalities in HV, PV, and IRV Doppler. Mild to moderate HVD abnormalities have S-wave < D-wave but still below baseline; severe abnormalities exhibit S-wave reversal. PVPF of 30–50% is mild to moderate, while > 50% is severe. IRVD is mild to moderate with pulsatility and distinct S/D waves, severe with monophasic D-only pattern. Grade 1 has no severe waveform, grade 2 has one severe waveform, and grade 3 has ≥ 2 severe waveforms, indicating severe congestion. VExUS, venous excess ultrasound; IVC, inferior vena cava; HV, hepatic vein; PV, portal vein; IRV, intrarenal vein; PVPF, portal vein pulsatility fraction; HVD, hepatic vein Doppler; PVD, portal vein Doppler; IRVD, intrarenal vein Doppler