Study Evaluates Relationship of Iliac Vein Compression and DVT

October 16, 2018—The Society for Vascular Surgery (SVS) announced the publication of a study of a large series of patients with iliofemoral deep venous thrombosis (DVT) that suggests, in general, that compression itself is not the precipitating factor in iliac DVT; rather, it is the promoter of iliac DVT if infrainguinal thrombosis should occur.

Findings from the study, which was conducted at Nanchang University in Nanchang, China, were published by Dong Chen, MD, et al in the Journal of Vascular Surgery: Venous and Lymphatic Disorders (2018;6:689–695).

According to SVS, previous research investigating the relationship between iliac vein compression and lessening the chance of lower extremity DVT has been inconclusive. One study suggesting a strong correlation has not been fully corroborated by others. The society's announcement noted that iliofemoral DVT can be devastating—acutely, in the form of phlegmasia, and chronically, with a high incidence of postthrombotic syndrome. Understanding the etiology of this problem is potentially helpful in prevention. Particularly on the left side, compression of the iliac veins results in a spectrum of symptoms, including swelling, varicose veins, and DVT.

As reported by SVS, the investigators conducted a single-center, retrospective study composed of 278 patients with left-sided lower extremity DVT. These patients were divided into those patients with iliac DVT (n = 228) versus those with infrainguinal DVT alone (n = 50) and compared them with 232 control patients without DVT.

In studying the relationship of iliac vein compression—detected on CT imaging—with DVT, the investigators found significant compression in 75% of patients with iliac DVT, 45% of patients with infrainguinal DVT, and 53% of patients with no DVT. Most important, iliac vein compression was associated with iliac (1.88 odds ratio) but not infrainguinal DVT (0.89 odds ratio).

Dr. Chen commented in the SVS announcement, “Given the high incidence of vein compression in our patient population, yet the relatively low incidence of DVT in general, the presence of this anatomic finding alone [does] not likely result in left-sided DVT. This data suggests that, in general, compression itself is not the precipitating factor in iliac DVT; rather, it is the promoter of iliac DVT should infrainguinal thrombosis occur.”

The study demonstrated that left iliac DVT patients had more severe left iliac vein compression than left infrainguinal DVT patients did. Left iliac vein compression was not associated with the development of left infrainguinal DVT, but it did correlate with the presence of left-sided DVT with iliac vein involvement. Dr. Chen added, “The clinical significance of this study is that endovascular treatment (angioplasty and stent) is inappropriate for those with iliac compression solely to prevent DVT.”

This large, image-based research furthers the understanding of the consequences of iliac vein compression revealing that its presence is not associated with infrainguinal DVT.