Journal of Vascular and Interventional Radiology
Volume 22, Issue 3, Supplement , Page S18, March 2011
.Abstract No. 34:
The incidence of May-Thurner syndrome in patients with multiple sclerosis (MS) undergoing endovascular treatment for chronic cerebrospinal venous insufficiency (CCSVI)
K. Mandato*, J.F. Johnson, G. Siskin, M. Englander, C. Vera, A. Herr
To determine the incidence of May-Thurner syndrome (MTS) in patients with MS undergoing pelvic venography prior to endovascular treatment of CCSVI.
Materials and Methods
A retrospective analysis of MS patients undergoing pelvic venography during an evaluation for CCSVI was performed. Medical records were reviewed to determine if symptoms classically attributed to MTS were present. Pelvic venograms were reviewed to diagnose MTS; findings were graded based upon the degree of left common iliac vein compression and the presence of pelvic collateral veins (Table 1). Grade 2 and Grade 3 findings were considered positive for MTS. These findings were compared with historical controls.
Grading System for May Thurner Syndrome
Grade Definition n
0 No compression of the left common iliac vein 103(64%)
1 Mild compression of the left common iliac vein with no pelvic collaterals 31(19%)
2 Moderate left common iliac vein compression with pelvic collaterals 16(10%)
3 Occlusion of the left common iliac vein with significant pelvic collaterals 11(7%)
160 patients (mean age 47 years; range 25–68 years) were included in this retrospective analysis. 66% (105/160) of these patients were female and 34% (55/160) were male. Based on the pelvic venography findings, 17% of patients were found to have MTS (Grade 2 or Grade 3 findings on venography). 74.1% (20/27) of these patients were female, but this difference was not significant (p=0.378). None of the patients with MTS had a history of deep venous thrombosis (DVT) or left lower extremity swelling.
In patients with MS undergoing pelvic venography as part of a CCSVI evaluation, there was a 17% incidence of May-Thurner syndrome. Historically, there is a reported incidence of MTS in 6.3–24% of an asymptomatic population [1, 2]. This data therefore suggests that MS patients do not have an increased incidence of MTS. Given these findings, and the fluoroscopic exposure time and contrast dose required to evaluate the pelvic vasculature for MTS as part of a CCSVI venogram, we do not support the routine performance of pelvic venography during these procedures, unless the patient has a history of DVT or leg swelling.
I disagree with the conclusion. Even though the incidence of May Thurner syndrome in people with CCSVI appears to be the same as in historical asymptomatic controls, May Thurner Syndrome causes the rerouting of blood flow to the azygous, which in CCSVI has compromised blood flow.
It is very easy for webs and membranes in the azygous to be missed, especially if IVUS is not used. By checking for May Thurner and ballooning if found, it gives the patient the best possible chance at optimizing azygous blood flow.
I am very happy to see a publication on CCSVI.