What are the causes and treatments of venous thrombosis in the arm?

By PHILIP COLERIDGE SMITH DM MA BCh FRCS Consultant Vascular Surgeon, Medical Director of the British Vein Institute and Emeritus Reader in Surgery at UCL Medical School

[VENOUS THROMBOSIS in the arm is far less common than in the leg, but may give rise to troublesome symptoms. Problems in the arm may occur in young people as part of ‘thoracic outlet syndrome’ in which the veins, arteries or nerves to the arm become compressed as they leave the chest to reach the arm.

Causes of venous thrombosis in the arm

The blood supply to the arm comes from inside the chest. The subclavian artery arises from a major branch of the aortic arch in the chest and passes under the clavicle and over the first rib to enter the arm. On the way back to the heart, the subclavian vein takes a similar route and joins the large veins in the upper part of the chest before draining back to the heart. The nerves to the arm arise in the neck and again pass between the first rib and clavicle.

A group of related conditions arise when the gap between the first rib and the clavicle is too narrow for the Prominent veins over the front of the left shoulder in a patient with a history of blood vessels and nerves. That can arise as a result of a previous subclavian vein thrombosis congenital abnormality or after injury leading to fractures of the ribs or clavicle. The resulting syndromes are known collectively as ‘thoracic outlet syndrome’. Compression of the nerves to the arm leads to pain in the arm, mainly in the hand. The subclavian artery may suffer thrombosis if compressed, leading to ischaemia of the arm. The subclavian vein can also suffer thrombosis leading to swelling in the arm.

Subclavian vein thrombosis may occur in body builders and athletes – more commonly in men, but women may also be affected. Young adults are often affected. The condition is sometimes known as ‘effort thrombosis’ or eponymously as ‘Paget Schroetter syndrome’. General causes of thrombosis, such as inherited conditions leading to thrombosis and the oral contraceptive pill, may also be factors.

Iatrogenic causes of subclavian vein thrombosis are common these days. They arise from the use of central venous catheters in intensive care units. That has been a common problem arising during the COVID-19 pandemic, since that infection is also a strong risk factor for thrombosis. Treatment of patients with cancer often necessitates injections via a central venous catheter. The combination of cancer and the catheters may lead to venous thrombosis. The subclavian vein is a common route by which central venous catheters reach large veins near the heart.

Deep vein thrombosis of the upper limb

Acute venous thrombosis in the upper limb veins presents as swelling of the arm, combined with dusky discolouration due to venous congestion. The venous obstruction is readily seen on ultrasound imaging, as is the case with DVTs arising in the lower limb.

In general, anticoagulant treatment with heparin or modern oral anticoagulants is recommended for upper limb venous thrombosis. NICE has offered very detailed advice on the investigation and treatment of deep vein thrombosis of the lower limb in NICE Guideline 158; however, that document offers no advice on the management of venous thrombosis in the arm. As a result, no detailed guidelines for management are available, which makes litigation regarding the condition much more difficult. In general, it would be considered substandard practice to manage an upper limb thrombosis without anticoagulant treatment. However, other options include thrombolytic treatment to remove venous thrombosis and stenting of the reopened vein to prevent it closing again. The initial problem causing the venous thrombosis is the reduced opening between the first rib and the clavicle. That can be opened by excising the first rib, which is effective in the venous, arterial and neurological types of thoracic outlet syndrome. Clinical series, but not randomised clinical trials, have been published in which those methods of management have been evaluated. All show potential advantages in skilled hands. Potential defendants are likely to point out that detailed evidence of efficacy of those treatments has not been published and a wide range of clinical practice is considered to be acceptable in vascular surgical practice. That is likely to lead to difficulty with any claimant’s liability and causation cases.

Outcome of upper limb venous thrombosis

In many patients the blocked subclavian vein will develop a new channel after a period of anticoagulant treatment. A larger proportion of veins appear to regain blood flow after thrombolytic treatment. In some patients swelling in the arm disappears as the thrombus is reabsorbed. Collateral venous drainage may develop around the shoulder and prominent veins may appear over the chest (pictured). Some patients develop pain or heaviness in the arm after short periods of exercise, while in others the neurological features such as pain in the arm or hand may become more troublesome. Solutions for patients with persistent symptoms include resection of the first rib or venous bypass procedures, so even when a venous thrombosis has a poor initial outcome it can be improved with additional treatment. In conclusion, venous thrombosis in the upper limb may arise from a number of causes. Anticoagulant treatment is accepted practice, but other than that a wide range of clinical practice is considered to be acceptable management. In patients with a poor late outcome, surgical solutions including first rib resection or venous bypass operations may improve the outcome. The diversity of medical opinion in this field of medicine makes litigation unsatisfactory or infeasible in many cases. q www.yourexpertwitness.co.uk 45 45