Iliac Vein Compression as an Anatomical Cause of Thrombophilia: Cockett’s Syndrome Revisited

CFD Study of the Effect of the Angle Pattern on Iliac Vein Compression Syndrome

Iliac vein compression syndrome (IVCS, or May-Thurner syndrome) occurs due to the compression of the left common iliac vein between the lumbar spine and right common iliac artery. Because most patients with compression are asymptomatic, the syndrome is difficult to diagnose based on the degree of anatomical compression. In this study, we investigated how the tilt angle of the left common iliac vein affects the flow patterns in the compressed blood vessel using three-dimensional computational fluid dynamic (CFD) simulations to determine the flow fields generated after compression sites. A patient-specific iliac venous CFD model was created to verify the boundary conditions and hemodynamic parameter set in this study. Thirty-one patient-specific CFD models with various iliac venous angles were developed using computed tomography (CT) angiograms. The angles between the right or left common iliac vein and inferior vena cava at the confluence level of the common iliac vein were defined as α1 and α2. Flow fields and vortex locations after compression were calculated and compared according to the tilt angle of the veins. Our results showed that α2 affected the incidence of flow field disturbance. At α2 angles greater than 60 degrees, the incidence rate of blood flow disturbance was 90%. In addition, when α2 and α1 + α2 angles were used as indicators, significant differences in tilt angle were found between veins with laminar, transitional, and turbulent flow (p < 0.05). Using this mathematical simulation, we concluded that the tilt angle of the left common iliac vein can be used as an auxiliary indicator to determine IVCS and its severity, and as a reference for clinical decision making.

May-Thurner syndrome: an unusual cause of unprovoked deep vein thrombosis of the left lower limb

May-Thurner syndrome, an unprovoked form of deep vein thrombosis (DVT), should be kept in mind in case of DVT with no predisposing factors. We present a case of a 37-year-old male with DVT of left lower limb due to May-Thurner syndrome, treated with anticoagulants with a plan of left common iliac vein (LCIV) stenting and inferior vena cava (IVC) filter later. Venous duplex scan showed features suggestive of May-Thurner syndrome. Hence, we proceeded for CT abdominal aortogram with bilateral lower limb angiogram, which confirmed the above findings. Management of May-Thurner syndrome is a stepwise approach, with initial anticoagulation for dissolution of the thrombus followed by endovenous stenting of the LCIV and concomitant IVC filter.

Guidance for the treatment of deep vein thrombosis and pulmonary embolism

This guidance document focuses on the diagnosis and treatment of venous thromboembolism (VTE). Efficient, cost effective diagnosis of VTE is facilitated by combining medical history and physical examination with pre-test probability models, D dimer testing and selective use of confirmatory imaging. Clinical prediction rules, biomarkers and imaging can be used to tailor therapy to disease severity. Anticoagulation options for acute VTE include unfractionated heparin, low molecular weight heparin, fondaparinux and the direct oral anticoagulants (DOACs). DOACs are as effective as conventional therapy with LMWH and vitamin K antagonists. Thrombolytic therapy is reserved for massive pulmonary embolism (PE) or extensive deep vein thrombosis (DVT). Inferior vena cava filters are reserved for patients with acute VTE and contraindications to anticoagulation. Retrievable filters are strongly preferred. The possibility of thoracic outlet syndrome and May-Thurner syndrome should be considered in patients with subclavian/axillary and left common iliac vein DVT, respectively in absence of identifiable triggers. The optimal duration of therapy is dictated by the presence of modifiable thrombotic risk factors. Long term anticoagulation should be considered in patients with unprovoked VTE as well as persistent prothrombotic risk factors such as cancer. Short-term therapy is sufficient for most patients with VTE associated with transient situational triggers such as major surgery. Biomarkers such as D dimer and risk assessment models such the Vienna risk prediction model offer the potential to customize VTE therapy for the individual patient. Insufficient data exist to support the integration of bleeding risk models into duration of therapy planning.

Isolated Iliac Vein Thrombosis During Oral Contraceptive Therapy in Three "Normal" Women

Isolated iliac vein thrombosis appears to be a rare clinical entity. It is usually due to extrinsic compression on the iliac vein with consequent stasis. Diagnosis may be difficult since compression ultrasonography is usually negative. Only phlebography is surely diagnostic. This procedure should be carried out whenever there is a discrepancy between the clinical evaluation and a negative sonography. We report three women on oral contraceptive therapy in whom a diagnosis of isolated iliac vein thrombosis was suspected clinically and confirmed phlebographically. No other congenital or acquired potential cause of thrombosis was present in the propositae but for the oral contraceptives. Oral contraceptives had been taken for 12, 3, and 2 months respectively for three patients before thrombosis occurred. Two of the propositae were 25 years old and the third was 54. The latter patient had been given oral contraceptives to "prevent osteoporosis" after menopause. The discontinuation of the pill together with usual heparin and coumarin therapy were effective in every instance. A specific pathogenic role of the oral contraceptives may be surmised. In fact, no isolated iliac vein thrombosis was found in a control group of 20 women of fertile age we showed to have idiopathic deep vein thrombosis of the legs. This article emphasizes once again the importance of a careful clinical evaluation in the suspicion of deep vein thrombosis. Key Words: Oral contraceptive therapy-Deep vein thrombosis-Iliac vein thrombosis.

Iliac vein compression syndrome in an active and healthy young female

Iliac vein compression syndrome is a condition involving external compression of the left common iliac vein by the right iliac artery, which was first described in the 1850s. It predominates in females typically between the third and fourth decade of life and has been associated with thrombophilias. Importantly, the syndrome is amenable to endovascular treatment. Here, we describe a case of a young athletic female with an incidental finding of a left iliac vein thrombosis while taking oral contraceptives, who was identified as having iliac vein compression syndrome on follow-up MR venography with positive testing for Factor V Leiden mutation.

Prevalência de marcadores de trombofilia em pacientes portadores da síndrome de May-Thurner e trombose de veia ilíaca comum esquerda

CONTEXTO: A relação entre trombose venosa profunda e trombofilia tem sido pouco estudada em indivíduos portadores de compressão da veia ilíaca comum esquerda, conhecida clinicamente como síndrome de May-Thurner. OBJETIVO: Avaliar a prevalência de marcadores de trombofilia nos pacientes portadores de síndrome de May-Thurner e trombose de veia ilíaca comum esquerda. MÉTODOS: Entre março de 1999 e dezembro de 2008, 20 pacientes com síndrome de May-Thurner e trombose de veia ilíaca comum esquerda foram avaliados retrospectivamente quanto à presença de marcadores de trombofilia. RESULTADOS: Foi detectada a associação entre síndrome de May-Thurner e marcadores de trombofilia em 8 pacientes (40%). CONCLUSÃO: A presença de marcadores de trombofilia em pacientes com trombose de veia ilíaca comum esquerda e síndrome de May-Thurner é frequente, porém não difere da prevalência encontrada em pacientes portadores de trombose venosa profunda sem a síndrome associada.

Iliac vein compression and pulmonary embolism in a long distance runner: computed tomography and magnetic resonance imaging-a case report

Iliac vein compression is invoked as the explanation for deep venous thrombosis occurring more often in the left iliofemoral system than the right. The authors report a previously undescribed variant of iliac compression whereby a left iliac arterial aneurysm caused venous compression and resultant thrombosis. In this case the patient suffered a pulmonary embolism without symptoms of lower extremity venous thrombosis.

Re-evaluation of iliac compression syndrome using magnetic resonance imaging in patients with acute deep venous thromboses

BACKGROUND

The majority of proximal deep venous thromboses (DVTs) are thought to have propagated as a contiguous column from the calf veins. However, several authors have proposed that ileofemoral DVT commonly originates in the left common iliac vein (LCIV) at a site of compression by the overlying right common iliac artery (RCIA/LCIV compression). This mechanism could explain both the left-sided predominance of ileofemoral DVT and the finding that ileofemoral DVT frequently occurs either in the absence of calf vein thrombosis (isolated ileofemoral DVT) or is not contiguous with calf vein thrombosis (noncontiguous ileofemoral DVT). This mechanism remains unconfirmed.

OBJECTIVES

The purpose of this study was to detect RCIA/LCIV compression using multimodal magnetic resonance imaging in thrombosed and patent iliac veins, to determine whether RCIA/LCIV compression occurs more frequently in cases of left ileofemoral DVT than other types of DVT, and to determine if RCIA/LCIV compression is specifically associated with left isolated and noncontiguous ileofemoral DVT.

PATIENTS AND METHODS

This prospective study conducted at the 1355-bed University Hospital included 18 patients with ileofemoral DVT, 23 with femoropopliteal DVT, 15 with isolated calf DVT recruited consecutively, and 28 control patients in whom DVT had been excluded. Interventions included magnetic resonance direct thrombus imaging (MRDTI), venous enhanced peak arterial magnetic resonance venography (VESPA) and magnetic resonance arteriography (MRA) within 48 hours of routine conventional venography (CV). RCIA/LCIV compression of patent LCIVs was assessed using VESPA and MRA; RCIA/LCIV compression of thrombosed LCIVs was assessed using MRDTI and MRA. The extent of calf and popliteal thrombosis was detected using CV; the extent of femoral and iliac thrombosis was detected using VESPA and MRDTI.

RESULTS

RCIA/LCIV compression was more commonly detected in cases of left ileofemoral DVT (9/16 cases) than in cases of left femoropopliteal DVT (1/11 cases; P = .018), right femoropopliteal DVT (2/12 cases; P = .054), left isolated calf DVT (1/9 cases; P = .037), right isolated calf DVT (0/6 cases; P = .046) and control patients (4/28 cases; P = .006). RCIA/LCIV compression was more commonly detected in cases of left isolated ileofemoral DVT (6/6 cases; P = .005), and cases of left noncontiguous ileofemoral DVT (2/2 cases; P = .067) than in cases in which thrombosis was contiguous from the calf to the iliac veins (1/8 cases).

CONCLUSION

RCIA/LCIV compression was strongly associated with left ileofemoral DVT and was specifically associated with cases that involve independent ileofemoral thrombosis.

Cerebral infarction in conjunction with patent foramen ovale and May-Thurner syndrome

Stroke patients with paradoxical embolus mandate a search for deep venous thrombosis (DVT) in the lower extremities. Iliac vein compression, or May-Thumer syndrome, places certain patients at risk for development of DVT. The authors present 3 stroke patients with patient foramen ovale and paradoxical cerebral embolism, with demonstrated iliac vein compression as the presumed source of their embolus. May-Thumer syndrome should be considered a potential source of clot, as definitive therapy of this disorder can be curative.

Short- and medium-term duplex sonography follow-up of deep venous thrombosis of the lower limbs

PURPOSE

We conducted this study to assess the progression or regression of venous thrombi during and after treatment and to search for criteria of embolism risk.

METHODS

We prospectively studied 75 patients with lower limb deep venous thrombosis. We used B-mode sonography for the diagnosis and follow-up of these thrombi. Pulmonary scintigraphy was performed at days 1 and 10. We evaluated the topography, echogenicity, and structure of the thrombus; the location and wall attachment of its head; and the vein diameter. Each venous segment was semiquantitatively scored as follows: 0, no thrombosis; 1, partially obstructive thrombosis; or 2, complete thrombosis.

RESULTS

The decreases in the total thrombosis score were 4%, 11%, 51%, 72%, and 84% on days 5, 10, 30, 90, and 365 (1 year), respectively. Pulmonary embolism occurred in 27 patients, of whom 16 were asymptomatic. Thrombi in iliac veins exhibited a slower regression rate than those in calf and femoral veins. Pulmonary embolism occurred in 54% of patients with versus 24% of patients without a floating thrombus head.

CONCLUSIONS

Sonography is useful for the early detection of thrombus progression and the evaluation of embolism risk, which seems to be greater in patients with a floating thrombus head.