Intravascular Ultrasound (IVUS) for Deep
Venous Work - Want or Need?
MR Toh1, K Damodharan2, MNHH Lim1, CJQ Yap1, S Dubenec3, PJ Tosenovsky4 and TY Tang1,5
1 Department of Vascular Surgery, Singapore General Hospital, Singapore
2Department of Interventional Radiology, Singapore General Hospital, Singapore
3 Department of Vascular Surgery, Royal Prince Alfred Hospital, Sydney, Australia
4 Department of Vascular Surgery, Royal Perth Hospital, Australia
5 Duke NUS Graduate Medical School, Singapore
Submission: March 18, 2020; Published: April 02, 2020
*Corresponding author: TY Tang, Senior Consultant, Department of Vascular Surgery, Singapore General Hospital Level 5; Academia, 20 College Road, Singapore
How to cite this article:MR Toh, K Damodharan, MNHH Lim, CJQ Yap, S Dubenec, PJ Tosenovsky, TY Tang. Intravascular Ultrasound (IVUS) for Deep Venous
Work - Want or Need?. J Cardiol & Cardiovasc Ther. 2020; 16(2): 555931. DOI: 10.19080/JOCCT.2020.16.555931
Intravascular ultrasound (IVUS) is an invasive modality that facilitates the endoluminal visualization of blood vessels. Increasingly, IVUS has gained favour in the management of chronic venous disease, which is a highly prevalent condition, occurring in approximately 30% of the general population. Contributing
factors include previous deep vein thrombosis and iliocaval venous compression. In particular, prolonged compression of the iliocaval system has been associated with more severe disease and higher treatment failure rates . Conventional vein ligation and stripping are inadequate, and deep venous stenting is required to
prevent disease recurrence.
Initial diagnosis involves non-invasive and readily accessible tools such as ultrasound and computed tomography/magnetic resonance imaging. Unfortunately, these can only detect late signs such as venous insufficiency/reflux and obvious stenosis/occlusion. Early stenosis and endoluminal changes are only visualized on direct venography and IVUS. Direct venography with multiplanar views is the current gold standard imaging technique. However, a significant number of stenoses and morphological changes will still be missed (Figure 1) .
In a multicentric prospective study (VIDIO study) by Gagne
et al., IVUS identified significant lesions missed on three-view
venography in 26% of patients . Treatment for 57 of 100 cases
was revised after IVUS interrogation, with stents being placed in
54 patients who did not have appreciable lesions on venography
alone . The discrepancy in detection rates may be explained
by the non-circular geometry of veins. Considering most venous
narrowing are eccentric, vessel areas derived from diameters seen
on venography would exceed the areas measured directly with
IVUS . Hence, the degree of stenosis on venography falls below
that of IVUS by an average of 11% . While multiple views can
be obtained to improve the accuracy of venography, the operators
and patients will be exposed to more radiation and contrast. IVUS
is a more feasible alternative.
In addition, IVUS delineates the finer endoluminal features
indicative of irreversible venous changes veins such as webs,
trabeculation and scars . Thrombi appear hyperechoic and
thrombus age may be inferred from the degree of echogenicity
. Segments such as the ilio-caval bifurcation and ilio-femoral
vein underlying the inguinal ligament, whilst not visible on frontal
venographic projection, are easily visualized on IVUS . IVUS
allows the identification of hemodynamically significant lesions
and dynamic venous compressions, which would otherwise be
missed on static venography images . Besides enhancing the
diagnosis rates, IVUS avoids unnecessary stenting. Apparent
stenoses from respiratory variation seen on venography can be
excluded with IVUS, by asking the patient to take deep breaths or
perform the Valsalva manoeuvre. In the VIDIO trial, three patients
with significant lesions on venography were not stented based on
their IVUS findings .
IVUS improves the precision of stent placement by
determining the exact native vein diameter, diseased segment
length and the appropriate landing sites. For adequate treatment,
stents must be of sufficient length to extend into healthy venous
segments both proximal and distal to the stenosis. In accordance
with CIRSE standards, stents deployed under sole venography
imaging should arbitrarily extend from the lesion by 5mm in both
directions to circumvent the underestimation of stenosis length
from venography . The iliac confluence is a popular site for
proximal landing zone. Unfortunately, the iliac confluence is often
unclear on venography and the stent may be placed away from the
desired proximal landing site by as much as an entire vertebral
body . This inaccuracy can compromise the intervention
outcome. Insufficient placement into the inferior vena cava risks
early postoperative stent occlusion while excess placement may
compromise the blood flow in the contralateral iliac vein . We
recently discussed how IVUS can guide the accurate placement of
stents across culprit lesions located near the ilio-caval bifurcation
. If needed, a contralateral puncture IVUS may be performed to
aid accurate stent deployment .
IVUS also identifies tandem compression sites such as
the external and internal iliac vein confluence, which may be
compressed by the external iliac artery. These sites are obvious on
IVUS but missed on venography. Clinically this would mean that a
longer stent would be used to treat the lesion. Undersized stents
can migrate and re-expose the stenosed sites, and in rare instances,
embolize to the lungs . IVUS prevents these complication rates
by ensuring the correct size and placement of the stents. Once
the stent is deployed, IVUS assesses the dilatation response and
confirms adequate apposition of the stent to the venous wall .
Stagnant flow secondary to stent or outflow tract problems can
be promptly picked up with IVUS and managed within the same
Most of the IVUS applications in deep venous work involve
non-occlusive chronic venous diseases. Nonetheless, IVUS is
becoming increasingly relevant in thrombotic venous diseases. In
acute deep vein thrombosis, IVUS helps to localize the guidewire
by confirming the site of the thrombus and post-thrombectomy/
thrombolysis, IVUS reveals any venous wall irregularities and
residual intraluminal thrombus that requires further treatment
. Unlike venography, IVUS can be used to image and treat
acute deep vein thrombosis when contrast or radiation are
contraindicated (e.g. during pregnancy) . IVUS has been used
with high success rates, for bedside insertion of inferior vena cava
filters in critically ill patients who cannot be transported to an
angiography suite .
IVUS has wide applications, but it is prudent to be aware of
its limitations. Image artefacts such as acoustic shadowing from
calcification, stent struts can obscure the underlying structures.
Image quality is also impaired by rotational distortion artefacts
created during manoeuvres in tortuous vessels, and multiple
circular echoes from reverberating ultrasound beams .
With its superior sensitivity and resolution, IVUS has
superseded venography in the diagnosis of chronic venous
disease. Furthermore, it offers intraprocedural utility in guiding
stent choice and placement. IVUS is integral to both the diagnosis
and procedural management of chronic venous disease. Hence,
we strongly recommend its routine use in deep vein work.
Excitingly, ongoing research promises to augment the capability
and applicability of IVUS. Currently under development, superharmonic
IVUS imaging offers higher imaging depth, resolution
and contrast-to-noise ratio, while accurate 3-D models of vessels
and bifurcations better facilitate pre-procedural planning .
With these exciting developments on the horizon, IVUS may
eventually become indispensable in deep venous work.
MR Toh is the main author responsible for the drafting and
editing of the manuscript. TY Tang envisaged the idea and helped
draft and edit the final manuscript version. K Damodharan, CJQ Yap, S Dubenec, PJ Tosenovsky were involved in editing and
contributing pictures to the manuscript.