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Subclavian artery thrombosis

Updated : May 20, 2024





Background

Subclavian artery thrombosis is a frequently overlooked condition, believed to be insufficiently diagnosed. This condition entails the restriction of blood flow within the subclavian artery, with a prevalence four times higher in the left subclavian artery compared to the right. Its ramifications can lead to substantial ischemia affecting the brain, upper extremities, and occasionally the heart.

In individuals with peripheral vascular disease, the occurrence of subclavian artery thrombosis ranges from approximately 10% to 18%. Additionally, those with subclavian artery thrombosis have a 50% likelihood of concomitant coronary artery disease, 26% for lower extremity artery disease, and 30% for carotid artery disease.

Despite its significance, subclavian artery thrombosis is frequently underdiagnosed by healthcare professionals. The roots of understanding this condition trace back to 1829 when Harrison first identified stenosis in the initial segment of the subclavian artery. Subsequently, in 1980, Bachman and Kim conducted the pioneering angioplasty of the subclavian artery. This underscores the historical evolution of our comprehension and therapeutic interventions for subclavian artery thrombosis.

Epidemiology

Subclavian artery thrombosis is considered relatively uncommon but may be underdiagnosed. The left subclavian artery is affected four times more frequently than the right. Subclavian artery thrombosis is considered a relatively uncommon condition compared to other vascular disorders. The incidence and prevalence can be influenced by various factors such as age, gender, and the presence of underlying health conditions.

The condition may be associated with risk factors like atherosclerosis, blood clotting disorders, trauma, or compression of the subclavian artery. Mortality rates are generally lower compared to some other cardiovascular conditions, but the impact on quality of life and the potential for complications should not be underestimated.

Anatomy

Pathophysiology

The risk factors associated with subclavian artery thrombosis mirror those implicated in thrombosis occurring elsewhere in the body. Notably, obesity, diabetes mellitus, hypertension, smoking, and metabolic syndrome are primary contributors. Similar to thromboses in other arteries, subclavian artery thrombosis involves a region experiencing heightened shear stress, leading to endothelial injury.

This initial event prompts platelet aggregation and the subsequent release of platelet-derived growth factor. This sequence initiates the proliferation of smooth muscle cells in the arterial intima, giving rise to the formation of the atherosclerotic plaque.

Etiology

Atherosclerosis: It is a primary cause, characterized by the accumulation of fatty deposits, cholesterol, and other substances on the inner walls of arteries, including the subclavian artery. This leads to the formation of plaques that can disrupt blood flow and contribute to clot formation.

Hypercoagulability: Conditions associated with increased blood clotting (hypercoagulability) can predispose individuals to subclavian artery thrombosis. This may include genetic disorders affecting clotting factors or acquired conditions such as certain cancers.

Endothelial Damage: Damage to the endothelial lining of the subclavian artery can occur due to factors such as high blood pressure, inflammation, or smoking. When the endothelium is damaged, it provides a surface for platelet adhesion and initiation of the clotting cascade.

Trauma or Compression: Physical trauma to the subclavian artery or compression by adjacent structures can lead to injury and subsequent clot formation. Trauma may be the result of accidents or repetitive stress on the blood vessel.

Stenosis or Aneurysms: Narrowing of the subclavian artery (stenosis) or the presence of aneurysms can disrupt normal blood flow and create conditions conducive to thrombosis.

Inflammatory Conditions: Inflammatory disorders, such as vasculitis, can contribute to the development of subclavian artery thrombosis. Inflammation can promote endothelial dysfunction and encourage the formation of blood clots.

Co-morbidities: Certain underlying health conditions, including obesity, hypertension, diabetes mellitus, and metabolic syndrome, are recognized as risk factors for arterial thrombosis, including subclavian artery thrombosis.

Smoking: Smoking is a well-established risk factor for vascular diseases. It can contribute to both atherosclerosis and endothelial damage, increasing the likelihood of thrombosis.

Genetics

Prognostic Factors

The prognosis is good with early intervention before the development of complications.

Clinical History

An individual with subclavian artery thrombosis has a medical history of cardiovascular risk factors such as hypertension, diabetes mellitus, hyperlipidemia, or a history of smoking, trauma to the chest or upper extremities. Occupational or recreational activities may contribute to the development of subclavian artery thrombosis. Neurological symptoms such as dizziness or lightheadedness, particularly if blood flow to the brain is compromised can be present.

Pain in the chest or upper back, especially if the thrombosis is associated with an underlying condition such as thoracic outlet syndrome. In some cases, symptoms may have a sudden and acute onset, especially if there is a rapid formation of a thrombus that significantly impedes blood flow. In other instances, symptoms may develop more gradually, with individuals experiencing mild symptoms that worsen over time.

Physical Examination

During a cardiovascular examination, physical assessments may reveal disparities in blood pressure between arms, as well as diminished or absent pulses when compared to the opposite arm. Additionally, the examination may identify the presence of supraclavicular or cervical bruits. Observable ischemic findings may manifest as skin changes in the fingers such as gangrenous alterations or splinter hemorrhages in the nail bed.

Furthermore, the examination encompasses an assessment of cerebral circulation, involving the palpation of carotid pulses and the auscultation for bruits in the vertebral (suboccipital region) and carotid arteries. This comprehensive examination aids in the identification and evaluation of subclavian artery thrombosis and related vascular complications.

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Congenital malformations

Fibromuscular dysplasia

Neurofibromatosis

Radiation exposure

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

Initially, anticoagulant medications may be prescribed to prevent further clot formation and promote blood flow. Commonly used anticoagulants include heparin and warfarin. Newer oral anticoagulants like direct oral anticoagulants (DOACs) may also be considered.

Thrombolytic agents may be considered in some cases to dissolve the clot. This is often reserved for acute cases with a high risk of limb ischemia or other complications. Antiplatelet medications like aspirin may be prescribed to reduce the risk of further clot formation. Dual antiplatelet therapy may be considered in some cases.

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Endovascular intervention stands out as the optimal approach for alleviating subclavian artery thrombosis, encompassing techniques such as percutaneous transluminal angioplasty with ballooning or stenting. For the management of acute arterial thrombosis, particularly in the context of subclavian artery thrombosis, rheolytic pharmacomechanical thrombectomy (PMT) utilizing the Angiojet device is a well-established and effective method.

This technique involves the supplementary application of thrombolytic therapy, achieved through either a thrombectomy catheter or an extended infusion. Notably, nearly half of the patients underwent pharmacomechanical thrombectomy alone for subclavian artery thrombosis management, while the remaining half received catheter-directed thrombolysis in conjunction with PMT. Interestingly, outcomes were notably improved in patients treated with pharmacomechanical thrombectomy alone, highlighting its efficacy as a standalone intervention.

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

Media Gallary

References

Subclavian artery thrombosis

Updated : May 20, 2024




Subclavian artery thrombosis is a frequently overlooked condition, believed to be insufficiently diagnosed. This condition entails the restriction of blood flow within the subclavian artery, with a prevalence four times higher in the left subclavian artery compared to the right. Its ramifications can lead to substantial ischemia affecting the brain, upper extremities, and occasionally the heart.

In individuals with peripheral vascular disease, the occurrence of subclavian artery thrombosis ranges from approximately 10% to 18%. Additionally, those with subclavian artery thrombosis have a 50% likelihood of concomitant coronary artery disease, 26% for lower extremity artery disease, and 30% for carotid artery disease.

Despite its significance, subclavian artery thrombosis is frequently underdiagnosed by healthcare professionals. The roots of understanding this condition trace back to 1829 when Harrison first identified stenosis in the initial segment of the subclavian artery. Subsequently, in 1980, Bachman and Kim conducted the pioneering angioplasty of the subclavian artery. This underscores the historical evolution of our comprehension and therapeutic interventions for subclavian artery thrombosis.

Subclavian artery thrombosis is considered relatively uncommon but may be underdiagnosed. The left subclavian artery is affected four times more frequently than the right. Subclavian artery thrombosis is considered a relatively uncommon condition compared to other vascular disorders. The incidence and prevalence can be influenced by various factors such as age, gender, and the presence of underlying health conditions.

The condition may be associated with risk factors like atherosclerosis, blood clotting disorders, trauma, or compression of the subclavian artery. Mortality rates are generally lower compared to some other cardiovascular conditions, but the impact on quality of life and the potential for complications should not be underestimated.

The risk factors associated with subclavian artery thrombosis mirror those implicated in thrombosis occurring elsewhere in the body. Notably, obesity, diabetes mellitus, hypertension, smoking, and metabolic syndrome are primary contributors. Similar to thromboses in other arteries, subclavian artery thrombosis involves a region experiencing heightened shear stress, leading to endothelial injury.

This initial event prompts platelet aggregation and the subsequent release of platelet-derived growth factor. This sequence initiates the proliferation of smooth muscle cells in the arterial intima, giving rise to the formation of the atherosclerotic plaque.

Atherosclerosis: It is a primary cause, characterized by the accumulation of fatty deposits, cholesterol, and other substances on the inner walls of arteries, including the subclavian artery. This leads to the formation of plaques that can disrupt blood flow and contribute to clot formation.

Hypercoagulability: Conditions associated with increased blood clotting (hypercoagulability) can predispose individuals to subclavian artery thrombosis. This may include genetic disorders affecting clotting factors or acquired conditions such as certain cancers.

Endothelial Damage: Damage to the endothelial lining of the subclavian artery can occur due to factors such as high blood pressure, inflammation, or smoking. When the endothelium is damaged, it provides a surface for platelet adhesion and initiation of the clotting cascade.

Trauma or Compression: Physical trauma to the subclavian artery or compression by adjacent structures can lead to injury and subsequent clot formation. Trauma may be the result of accidents or repetitive stress on the blood vessel.

Stenosis or Aneurysms: Narrowing of the subclavian artery (stenosis) or the presence of aneurysms can disrupt normal blood flow and create conditions conducive to thrombosis.

Inflammatory Conditions: Inflammatory disorders, such as vasculitis, can contribute to the development of subclavian artery thrombosis. Inflammation can promote endothelial dysfunction and encourage the formation of blood clots.

Co-morbidities: Certain underlying health conditions, including obesity, hypertension, diabetes mellitus, and metabolic syndrome, are recognized as risk factors for arterial thrombosis, including subclavian artery thrombosis.

Smoking: Smoking is a well-established risk factor for vascular diseases. It can contribute to both atherosclerosis and endothelial damage, increasing the likelihood of thrombosis.

The prognosis is good with early intervention before the development of complications.

An individual with subclavian artery thrombosis has a medical history of cardiovascular risk factors such as hypertension, diabetes mellitus, hyperlipidemia, or a history of smoking, trauma to the chest or upper extremities. Occupational or recreational activities may contribute to the development of subclavian artery thrombosis. Neurological symptoms such as dizziness or lightheadedness, particularly if blood flow to the brain is compromised can be present.

Pain in the chest or upper back, especially if the thrombosis is associated with an underlying condition such as thoracic outlet syndrome. In some cases, symptoms may have a sudden and acute onset, especially if there is a rapid formation of a thrombus that significantly impedes blood flow. In other instances, symptoms may develop more gradually, with individuals experiencing mild symptoms that worsen over time.

During a cardiovascular examination, physical assessments may reveal disparities in blood pressure between arms, as well as diminished or absent pulses when compared to the opposite arm. Additionally, the examination may identify the presence of supraclavicular or cervical bruits. Observable ischemic findings may manifest as skin changes in the fingers such as gangrenous alterations or splinter hemorrhages in the nail bed.

Furthermore, the examination encompasses an assessment of cerebral circulation, involving the palpation of carotid pulses and the auscultation for bruits in the vertebral (suboccipital region) and carotid arteries. This comprehensive examination aids in the identification and evaluation of subclavian artery thrombosis and related vascular complications.

Congenital malformations

Fibromuscular dysplasia

Neurofibromatosis

Radiation exposure

Initially, anticoagulant medications may be prescribed to prevent further clot formation and promote blood flow. Commonly used anticoagulants include heparin and warfarin. Newer oral anticoagulants like direct oral anticoagulants (DOACs) may also be considered.

Thrombolytic agents may be considered in some cases to dissolve the clot. This is often reserved for acute cases with a high risk of limb ischemia or other complications. Antiplatelet medications like aspirin may be prescribed to reduce the risk of further clot formation. Dual antiplatelet therapy may be considered in some cases.

Endovascular intervention stands out as the optimal approach for alleviating subclavian artery thrombosis, encompassing techniques such as percutaneous transluminal angioplasty with ballooning or stenting. For the management of acute arterial thrombosis, particularly in the context of subclavian artery thrombosis, rheolytic pharmacomechanical thrombectomy (PMT) utilizing the Angiojet device is a well-established and effective method.

This technique involves the supplementary application of thrombolytic therapy, achieved through either a thrombectomy catheter or an extended infusion. Notably, nearly half of the patients underwent pharmacomechanical thrombectomy alone for subclavian artery thrombosis management, while the remaining half received catheter-directed thrombolysis in conjunction with PMT. Interestingly, outcomes were notably improved in patients treated with pharmacomechanical thrombectomy alone, highlighting its efficacy as a standalone intervention.