Correlation of venous symptoms with iliac vein stenosis on magnetic resonance imaging

Magnetic resonance imaging (MRI) is used in patients with lower extremity venous disease to screen for iliac vein stenosis. The objective of the present study was to determine the prevalence of iliac vein stenosis and associated lower extremity venous symptoms in consecutive patients undergoing MRI of the pelvis.

A retrospective study of all consecutive adult patients who had undergone MRI of the pelvis for various indications from March 2012 to June 2016 was performed. The electronic medical records (EMRs) were reviewed for patient characteristics and, specifically, for the presence and laterality of venous symptoms. All MRI scans were reviewed, and the maximal degree of iliac vein stenosis was recorded. All the patients also responded to a brief telephone survey inquiring about the presence of venous symptoms. Two thresholds of venous stenosis, ≥50% and ≥70%, were used to correlate its presence with the presence of venous symptoms determined from the EMR review and telephone survey results.

A total of 120 patients were included, with a mean age of 53 ± 14 years; 79% were women and 79% were white. The prevalence of iliac vein stenosis ≥50% was significantly greater on the left than on the right (34.2% vs 16.7%; P < .001). The survey demonstrated that 44 of the 120 patients (36.7%) had had venous symptoms compared with only 30 patients (25%) according to the EMR review (P = .001). No differences were found between patients with positive vs negative survey results for venous symptoms and the occurrence of iliac vein stenosis ≥50% on the right (17.2% vs 15.2%; P = .78) or the left (38% vs 26.8%; P = .22). We also found no differences when the occurrence of iliac vein stenosis ≥70% was used as threshold between the right (2.3% vs 3%; P = .99) and the left (10.1% vs 2.4%; P = .16). Analysis of the venous symptoms from the EMR review yielded similar results.

In our study, iliac vein stenosis was more common on the left and was encountered in up to one third of patients who had undergone MRI of the pelvis. No correlation was found in our study between the presence of iliac vein stenosis and the occurrence of ipsilateral venous symptoms. Venous symptoms were underreported in the EMRs. Further studies are necessary to identify the predictors of pathologic iliac vein stenosis.