Systematic review of May-Thurner syndrome with emphasis on gender differences.

OBJECTIVE: May-Thurner syndrome (MTS) is increasingly recognized as a frequent source of leg swelling and a precipitating factor for venous thromboembolism. This paper is a systematic review of the English literature on MTS with an analysis focusing on gender differences in presentation and treatment.

METHODS: A systematic review of the English literature between April 1967 and December 2014 was performed using the following terms: "May-Thurner syndrome," "Cockett syndrome," and "iliac vein compression syndrome." After review, there were 174 articles in the analysis. We first analyzed all presented cases, followed by a gender comparison if case reports and case series had detailed description. Asymptomatic patients with just anatomic compression without symptoms were excluded. Statistical differences between data sets were assessed using χ2 test and Student t-test.

RESULTS: There were 1569 patients with MTS after exclusion of articles based on our criteria. The female to male ratio was 2:1 (976 [67.1%] vs 480 [32.9%]). Women presented at a younger age compared with men (38.7 ± 14.0 years vs 46.2 ± 16.9 years; P = .02). Gender comparison at presentation, which was available for 254 patients, showed that men had significantly more reported leg swelling (92.7% vs 80.8%; P = .037) and more leg pain (88% vs 74.3%; P = .045) compared with women. There was no difference in the reported proportion of patients presenting with deep venous thrombosis between the two groups (88.9% vs 81.7%; P = .14). However, women were significantly more likely to have a pulmonary embolus on presentation compared with men (9.9% vs 1.6%; P = .035). Treatment modalities included endovascular interventions without thrombolysis (53%) or with thrombolysis (33.2%), open surgery (6.8%), and medical management (7%). Endovascular treatment was more common than surgical or medical treatment (P < .001). Because of lack of granularity in the data, it was not possible to distinguish treatment methods between female and male patients. There was no statistically significant difference in complication rate between men and women based on the articles that provided that information (P = .34). However, open procedures had significantly higher complications compared with endovascular interventions (P = .021).

CONCLUSIONS: Based on the reported literature, MTS is more common in women and is at least twice as frequent in women as in men. Men tend to have more pain and swelling in the legs, whereas women tend to be younger and more likely to have a pulmonary embolus on presentation. MTS and iliac vein compression are sometimes used interchangeably in an inaccurate manner.