SPECIAL FEATUREMay-Thurner Syndrome☆
Introduction
May-Thurner syndrome (MTS) is an anatomical defect described as an external compression of left common iliac vein (CIV) by right common iliac artery (CIA) against the pelvic brim and the fifth lumbar vertebra1 leading to symptoms of impaired venous outflow from the left lower extremity (LLE). Long-standing compression by a pulsatile artery causes intimal fibrosis leading to venous spur formation. This results in mechanical obstruction to venous flow, which causes increased risk of LLE deep vein thrombosis (DVT), chronic venous stasis and venous hypertension. It is not uncommon to find left CIV compression by right CIA on imaging in asymptomatic patients.2 Radiologic studies have reported up to 24% prevalence of greater than 50% compression of left CIV by right CIA.2 This anatomical abnormality has a reported prevalence of 20-34% in cadaveric studies.1 The occurrence of the LLE DVT3 is 5 times more common and is believed to be related to this anatomic defect; however, only 2-3% of LLE DVTs are reported as related to MTS.1, 2 Such under diagnosis is probably because workup is generally stopped once the diagnosis of DVT is confirmed. In this case series, we describe 6 cases of MTS presenting with LLE DVT and pulmonary embolism (PE). All 6 cases were treated with thrombolysis, anticoagulation and correction of anatomical defect by angioplasty.
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Cases
Formal, informed consent was obtained from each individual patient per institutional policy and approval from the institutional review board was obtained. A retrospective review of the picture archiving and communication system radiology database was done using May-Thurner syndrome as the keyword. We identified 6 patients above the age of 18 who underwent endovascular therapy for MTS from June 2013 to September 2015. Patients who had endovascular intervention or stent placement in the lower
Discussion
Rudolf Virchow described the famous Virchow’s triad of thrombosis in the setting of iliofemoral DVT and venous stasis in 1851. He noted DVTs occurring 5 times more commonly in the LLE compared to the right.3 May and Thurner1 explained the anatomical basis for this left-sided propensity as MTS. MTS is described as the compression of the left CIV by the right CIA against the spine and pelvic brim.1 The syndrome is reportedly seen in approximately 18-49% of patients with left-sided lower extremity
Conclusions
Left CIV compression by right CIA is a relatively under-diagnosed clinical entity. It should be considered as a possible cause of unexplained left-leg DVT and unexplained swelling and pain of the left leg, given its reported prevalence in cadaveric and radiological studies. Failure to recognize underlying MTS may increase the risk of recurrent venous thromboembolism, attributing to increased risk of morbidity and mortality. It is noted that all patients in our female cohort were multiparous.
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Cited by (11)
May-Thurner syndrome and deep vein thrombosis: A series of 8 patients
2021, Medicina ClinicaEndovascular and medical therapy of May–Thurner syndrome: Case series and scoping literature review
2021, JMV-Journal de Medecine VasculaireCitation Excerpt :Imaging is essential to assure the stent's placement because its occlusions will be more frequent if the venous lesions are not completely covered [22,23]. Angioplasty and stent in chronic cases solve chronic venous compression and prevent future recurrences [2,41]. Endovascular stenting success rates with or without adjunct of thrombolysis range from 83% to 93% [1,32,33,38,39,42–44], which was seen in this case series.
Cauda Equina Syndrome Caused by Epidural Venous Plexus Engorgement in a Patient with May-Thurner Syndrome
2019, Annals of Vascular SurgeryCitation Excerpt :In the present case, radiological examinations could not explain the exact cause of the symptoms and only perimedullary venous dilations and left iliac vein stenosis were observed on medullary angiography, consequently, faced with these findings, we decided that cauda equine syndrome justified performing a phlebography and endovascular treatment with venous stent placement, which has been reported as an effective and safe treatment with low MTS recurrence.11 In this case, venous stent placement was performed before detecting positive results of thrombophilia, and as it is known, in this group of patients the patency results are worse,14 therefore, this condition could increase doubts relating to MTS treatment. However, with the acquired experience in the present case, we would act the same way despite positive thrombophilia results.
Deep vein thrombosis associated to mutation in factor V Leiden, MTHFR and May-Thurner syndrome
2022, Medicina Interna de MexicoAdded value of computed tomography venography in the identification of abnormities in veins of lower extremities
2022, Current Medical Research and Opinion
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The authors have no financial or other conflicts of interest to disclose.