October 30, 2019
IVUS Shows Superiority to Venography in Identifying Treatment Zones for Iliac Vein Stenting
October 30, 2019—The Society for Vascular Surgery (SVS) announced the publication of an evaluation of a large series of iliac vein stent cases in a blinded comparison that found intravascular ultrasound (IVUS) superior to venography in determining the proper location of treatment zones. The study by Myriam L. Montminy, MD, et al is available online as an open-access article and will be published in the November edition of Journal of Vascular Surgery: Venous and Lymphatic Disorders (2019;7:801–807).
In the SVS announcement, Dr. Montminy commented, “Adequate assessment of the location and degree of stenosis and delineation of venous anatomy for optimal landing zones are key elements in the success of interventions to treat chronic obstructions of the deep venous system. While venography is more accessible and less expensive to perform than IVUS, an increasing number of studies demonstrate that IVUS is significantly more sensitive than venography in identifying stenotic lesions in the iliac-caval segments.
“Our study aimed to take this one step further by comparing these modalities in identifying the key parameters required to guide stent placement."
According to SVS, the investigators from The Rane Center at St. Dominic’s Memorial Hospital in Jackson, Mississippi, performed this retrospective, single-center cohort study of 155 limbs treated for chronic iliac vein occlusion between 2013 and 2015. Key demographics of this series included: mean age, 59 years (standard deviation, 13 years); men, 30%; left leg, 61%; postthrombotic, 72%; nonthrombotic, 28%.
Led by senior investigator Seshadri Raju, MD, the study was composed of cases that utilized both venography and IVUS. Comparisons between the modalities were made in a blinded fashion.
The investigators reported the following:
- In evaluating the main venous stenosis, venography compared with IVUS failed to identify the stenosis in 19% of cases; underestimated the degree of stenosis; and failed to locate accurately the stenosis in 68% of cases.
- In identifying the location of the iliac-caval confluence (the proximal landing zone), venography correlated with IVUS in 15% of cases, wherein IVUS revealed the confluence to be higher in 74% of cases (mean of one vertebral height higher).
- Regarding the distal landing zone, venography correlated with IVUS in 26% of cases, wherein IVUS located the optimal site lower in 64% of cases.
Dr. Montminy stated, “This study highlights that venography compared to IVUS is likely to be deficient in all three areas of concern in venous stenting cases—location of the maximal stenosis as well as the optimal proximal and distal landing zones.”
Noting that venography is still a desirable adjunct in iliac vein stenting as it provides a panoramic view of the pathologic process, including collaterals, she continued, “Additionally, IVUS may miss or provide only a partial image of certain lesions situated at the hypogastric-iliac and iliac-caval confluences due to the absence of a centering mechanism.”
Although it is currently unknown if the superiority of IVUS in identifying key parameters essential for iliac vein stenting translates into improved clinical outcomes, the results of this study further define the complementary roles venography and IVUS play in this growing area of vascular intervention, stated SVS in its press release.