May-Thurner Syndrome in Patients With Cryptogenic Stroke and Patent Foramen Ovale

Abstract

Background and Purpose We aimed to investigate the incidence of May-Thurner syndrome (MTS) in cryptogenic stroke patients with patent foramen ovale (PFO). Methods This was a retrospective study. All consecutive patients with cryptogenic stroke having undergone PFO closure from January 1st 2002 to December 31st 2007 at our institute were included in this study. Pelvic magnetic resonance venography (MRV) studies of all patients were reviewed to determine if features of MTS were present. Medical records and invasive venography studies of all patients were reviewed when available. All patients with MTS features on MRV were reviewed by a vascular medicine specialist to define any previous incidence of DVT or any signs of chronic venous insufficiency. All patients also had lower limb venous duplex performed to rule out lower limb venous thrombosis. Results A total of 470 patients from January 1 2002 until Dec 31 2007 with cryptogenic stroke underwent PFO closure at our institute. Thirty patients (6.3%) had features consistent with MTS on MRV. These patients were predominantly female (80%) with a mean age of 43.6 ± 11.9 years. Twelve patients (40%) had abnormalities in their laboratory thrombophilia evaluation and 13 females (54.1%) were taking hormone related birth control pills. Only two patients had a history and signs of chronic venous insuffiency. All PFOs demonstrated right-to-left shunting on transesophageal echocardiography. Atrial septal aneurysms/hypermobile atrial septa were present in 70% of patients with MTS. Conclusion May-Thurner syndrome has an important clinical association with cryptogenic stroke and PFO.

Use of Magnetic Resonance Venography in Screening Patients With Cryptogenic Stroke for May-Thurner Syndrome

“…Although PFO is usually a left to right shunt, when it becomes a functional right to left shunt, emboli can pass from the venous system to the arterial system including cerebral arteries, thus ultimately leading to an ischemic event [8].…”

“…Kiernan, et. al (2009) found that 6.3% of cryptogenic stroke patients who had a PFO closure procedure demonstrated evidence of MTS on pelvic MRV [8]. However, this study reviewed radiology reports rather than MRV images and it did not compare the prevalence of MTS to normal control patients.…”

The brain's heart — Therapeutic opportunities for patent foramen ovale (PFO) and neurovascular disease

“…The coexistence of additional risk factors, such as pelvic venous clots, pelvic venous abnormalities (May-Thurner Syndrome), hypercoagulable state, smoking, or migraine with aura, may increase the risk associated with immobilization and decrease the travel time required to lead to a stroke. (Greer & Buonanno, 2001; Florez, 2003; Cramer, 2004; Ning, 2008; Kiernan, 2009; Ning, 2009) For example, May-Thurner Syndrome is a pelvic anatomic abnormality found in more than 6% of patients with PFO-related stroke, predisposing patients to excessive or pathological compression of the left common iliac vein by the right common iliac artery, thereby increasing pelvic venous congestion and stasis which may lead to thrombi formation. (Kiernan, 2009) Patients with multiple risk factors may potentially benefit from pre-flight DVT prophylaxis.…”

Cryptogenic Stroke: Cryptic Definition?

“…1 The article is innovative, being the first large-scale analysis of the association between May-Turner Syndrome, cryptogenic stroke, and patent foramen ovale (PFO). Nonetheless, it arises some uncertainties concerning the definition of "cryptogenic stroke".…”

“…In the present study, cryptogenic stroke was defined as "a sudden focal neurological event in the absence of an identifiable cause such as uncontrolled hypertension, intracranial hemorrhage, ipsilateral carotid lesion, atrial fibrillation, intracardiac thrombus, degenerative neurological disorder or neoplasm." 1 In literature, the term cryptogenic stroke usually refers to strokes with no clearly definable cause even after extensive workup. 2 Approximately 30% to 40% of ischemic strokes are cryptogenic.…”