Ulnar Artery Thrombosis

What is an Ulnar Artery Thrombosis?

Ulnar artery thrombosis is a condition where a blood clot forms in the ulnar artery, leading to reduced blood flow to the hand. It can result from trauma, repetitive stress (as seen in hypothenar hammer syndrome), or underlying vascular disorders.

Symptoms include pain, cold intolerance, discoloration, and weakness in the affected hand. Diagnosis typically involves Doppler ultrasound, angiography, or MRI. Treatment options range from conservative management with anticoagulation to surgical intervention in severe cases.

Ulnar artery: What is it?

The ulnar artery is a blood vessel located in your arm. It supplies oxygen-rich blood to your hands, wrists, and forearms.

The brachial artery has two branches, one of which is the ulnar artery. The radial artery is the other branch. On the outside of your forearm, the ulnar artery is closest to your ulnar side. On the inside of your forearm, the radial artery is closest to your thumb.

The ulnar artery can be affected by conditions like ulnar artery thrombosis, often caused by repetitive hand movements.  Knowledge of its location is essential for medical procedures, such as arterial blood gas sampling.

Anatomy

What is the location of the ulnar artery?

Your arm contains the ulnar artery. It extends through the outer edge of your forearm and begins just below the bend of your elbow. It divides into the superficial palmar arch, the artery network that passes through your palm, at your wrist.

Which branches make up the ulnar artery?

• The ulnar artery and the forearm are connected by the common interosseous artery.
• Your hands and fingers are connected to the ulnar artery by the superficial palmar arch and deep palmar branch.
• The ulnar artery is connected to your wrist by palmar and dorsal carpal branches.
• The ulnar artery and the pronator teres muscle, which aids in arm twisting, are connected by ulnar recurrent arteries.

Function

Your circulatory system includes your ulnar artery. It supplies your hands and forearms with oxygen-rich blood, including your:

• Provides blood to the forearm’s muscles, bones, and nerves.
• Provides blood to the two digits and the medial hand.
• Supplies blood to the carpal bones
• Provides blood to the elbow joint’s proximal tissues.
• It’s a major artery that supplies oxygen-rich blood to the forearm, wrist, hand, and fingers.  
• It plays a crucial role in the circulatory system of the upper limb.

Types of Ulnar Artery Thrombosis

There are several ways that ulnar artery thrombosis can appear, and each has unique traits and health consequences. For an accurate diagnosis and successful treatment, it is essential to understand the various forms of ulnar artery thrombosis. Let’s examine the various ways this illness manifests.

• Acute ulnar thrombosis: Reduced blood supply to the hand and fingers due to an abrupt blockage of the ulnar artery is known as acute ulnar thrombosis, and it frequently results in pain and coldness in the affected area. Chronic ulnar artery thrombosis is characterized by a long-term constriction or blockage of the ulnar artery, which leaves the hand feeling weak, tingly, and numb.
• Chronic Ulnar Artery Thrombosis: Long-term narrowing or blockage of the ulnar artery, resulting in persistent symptoms such as numbness, tingling, and weakness in the hand.
• Embolic Ulnar Artery Thrombosis: When a blood clot forms elsewhere in the body and moves to the ulnar artery, it can cause an abrupt blockage and possibly harm to the hand’s tissue.
• Traumatic Ulnar Artery Thrombosis: Damage or damage to the ulnar artery that causes a blood clot to form and interferes with normal blood flow; frequently, this condition necessitates immediate medical attention.
• Ulnar artery Thrombosis: that occurs repeatedly, known as recurrent ulnar thrombosis, may be a sign of an underlying vascular disease or risk factors that should be managed to avoid more difficulties.

Causes of Ulnar Artery Thrombosis

Numerous conditions that impair ulnar artery blood flow can result in ulnar artery thrombosis. Some typical causes include vasculitis, hypercoagulable states, repetitive motions that compress or injure the artery, atherosclerosis, and trauma or injury to the artery. Reduced blood flow and possible consequences may arise from a blood clot that forms in the ulnar artery as a result of these circumstances.

Underlying conditions:

• Certain medical problems, such as atherosclerosis, might raise the risk of blood clots.
• Blood Clotting Disorders (hypercoagulable conditions)
• Repetitive trauma
• Vasculitis (inflammation in blood vessels)
• Diabetes.
• Atherosclerosis
• Blood clotting disorders
• Repetitive wrist movements
• Smoking
• High blood pressure
• Connective tissue diseases

Symptoms

Symptoms of ulnar artery thrombosis may include reduced blood flow in the affected arm. These symptoms could show up as temperature or skin color changes, soreness, and weakness. It’s critical to get medical help right away if you encounter these symptoms to avoid any problems.

• Pain in the hand or fingers
• Numbness or a tingling sensation
• Cold fingers
• Weakness in the hand
• Pale skin in the affected area

Pain

• This is a frequent symptom, often localized to the hand, particularly in the hypothenar eminence (the fleshy base of the little finger).
• Changes in skin colour and temperature
• Fingers, especially the pinky and ring fingers, may appear pale (blanched) or bluish (cyanotic) due to reduced blood flow.
• The affected hand or fingers may feel cold.

Diagnosis

A study of the patient’s medical history, a physical examination, and specialist testing are usually used to diagnose ulnar artery thrombosis. The healthcare professional will ask about any symptoms, risk factors, and underlying medical issues during the evaluation.

• Clinical evaluation that includes obtaining a thorough history of symptoms, evaluating hand function, examining for evidence of nerve compression (such as numbness or tingling in the little and half of the ring fingers), and conducting Allen’s test to determine the hand’s blood supply.
• Ulnar artery palpation to detect any pulsations or soreness.

Allen’s test

Procedure

• To stick the hands, the patient is instructed to raise both arms over their head for 30 seconds in the original Allen test. The examiner then occludes the radial arteries in both arms while the patient tightens their fists strongly for up to 60 seconds. The patient then rapidly opens their hands so the examiner may compare the palm colors.

• As the ulnar artery recovers circulation, the hands’ natural hue should replace the first pallor. The ulnar artery is subsequently blocked in place of the radial artery, and the test is repeated. The amount of collateral blood flow is indicated by the time it takes for normal color to recover. When both hands return to their natural color after obstructing just one artery, the test is deemed successful. A persistent pallor in the palm indicates insufficient blood flow to the hand from collateral sources.

Checking for symptoms like cold fingers or weak pulses in the affected arm may be part of a physical examination. To verify the diagnosis and determine the degree of ulnar artery blockage, specialized diagnostics such as Doppler ultrasound or angiography may be performed. Prompt treatment and the avoidance of problems depend on early diagnosis.

• Physical examination
• Doppler ultrasound
• Angiography
• Magnetic resonance angiography (MRA)
• Computed tomography angiography (CTA)

Treatment for Ulnar Artery Thrombosis

To increase blood flow and stop more clot development, treatment for ulnar artery thrombosis usually consists of a combination of medication and lifestyle modifications. Surgery or thrombolysis may be required in certain situations to restore blood flow in the artery that has been damaged. For an accurate diagnosis and tailored treatment suggestions, it is imperative to speak with a healthcare professional.

Depending on the severity of symptoms and underlying cause, treatment for ulnar artery thrombosis usually consists of lifestyle changes, medication such as anticoagulants (e.g., warfarin, heparin) to prevent further clot formation, and in certain cases, surgery to remove the clot or reconstruct the affected artery. This may include thrombolysis, surgical thrombectomy, or angioplasty with stenting.

• Improve blood flow to the hand by promoting vasodilation and reducing muscle tension.
• Restore normal range of motion in the wrist and fingers.
• Manage pain.
• Educate the patient on proper hand positioning and activities to avoid further irritation.

Medical treatment

Anticoagulant drugs, vasodilators, and lifestyle modifications to enhance blood flow—such as avoiding recurrent hand trauma and controlling risk factors like smoking—may be the mainstays of treatment for mild instances.

Always coordinate with the patient’s physician to ensure appropriate medical management of the underlying thrombosis, which may include anticoagulation therapy. Utilize modalities like heat therapy, ice packs, and gentle stretching to manage pain.

Physical therapy treatment

The main goal of physical therapy for ulnar artery thrombosis is to increase blood flow to the hand through range of motion (ROM) exercises, gentle mobilization techniques, and specific nerve glides and stretches to address any associated nerve compression symptoms, which are frequently related to the ulnar nerve. The patient’s condition is closely monitored, and medical professionals work together to ensure that the underlying thrombosis is managed appropriately.

Gentle range of motion exercises:

• Wrist flexion and extension
• Finger flexion and extension
• Radial and ulnar deviation movements
• Thumb movements

Soft tissue mobilization:

• Gentle massage techniques around the forearm and hand to improve blood flow
• Trigger point release for specific muscle groups

Proprioceptive exercises:

• A progressive rehabilitation program that incorporates proprioceptive exercises will increase in difficulty as proprioception improves. Proprioceptive exercise programs incorporate several concepts and activities, such as:
• Initial evaluation, both subjective and objective
• Outcome measure: to assess your development
• Exercises that are done within the joint’s range of motion as soon as instability is detected
• Activities to increase muscle response time
• Balance exercise for the finger and hand
• Strengthening exercise
• Functional dynamic exercises
• Self-management techniques at the end of the rehabilitation process
• Exercises to improve hand coordination and fine motor skills

Benefits

• There are many benefits of receiving a proprioceptive exercise program from the experienced physical therapist. Proprioceptive exercises have several advantages, including:
• Improved joint position
• Improved joint stability
• Reduced risk of injury
• Increases your self-confidence in your joint.
• Improved mobility
• Decreased muscle compensation: When proprioception is diminished, muscles may become hyperactive in an attempt to support the joint.

Splinting:

In some cases, a custom-made splint may be used to rest the hand and reduce inflammation, especially in the early stages.

• The purpose is to reduce movement in the affected hand and wrist, preventing additional clot propagation and relieving discomfort by minimizing stress on the area.
• To maximize blood flow, splints are typically worn with the wrist slightly flexed or neutral.
• The duration of splinting depends on the severity of the thrombosis and the patient’s reaction to treatment. It may be used initially before other therapies are implemented.

Joint Stiffness

If the injured nerve is left in a shortened position, the soft tissues in that area and the surrounding areas that it supplies could develop contractures. Protective detachable static splints can also help prevent contractures, and daily PROM exercises can help avoid these issues. Ultrasound and laser treatments have been reported to be beneficial for tight joints.

• Anticoagulant Therapy: Drugs such as warfarin or heparin are used to stop blood clots in the ulnar artery from forming or getting bigger, which lowers the chance of problems including tissue damage.

• Thrombolytic Therapy: To improve blood flow and lower the risk of ischemic consequences, drugs such as alteplase may be used in some situations to break the blood clot in the ulnar artery. By physically removing the blood clot from the ulnar artery, a surgical thrombectomy restores appropriate blood flow and stops additional problems.

• Angioplasty with Stenting: This minimally invasive technique involves using a balloon to enlarge the constricted or blocked ulnar artery. A stent is then frequently inserted to maintain the artery’s opening and enhance blood flow.

Surgical treatment

Thrombectomy:

• The ulnar artery blood clot is surgically removed.
• Arterial reconstruction involves using a vein transplant from another area of the body to replace the blocked portion of the ulnar artery.
• A surgical technique used to increase blood flow by removing a portion of the sympathetic nervous system.
• This procedure involves the surgical removal of the blood clot from the ulnar artery.
• It aims to restore blood flow to the hand.

Resection and Anastomosis:

• In cases where the ulnar artery is severely damaged, the affected segment may be removed.
• The healthy ends of the artery are then reconnected (anastomosis) to restore blood flow.

Grafting:

• If the damaged section of the ulnar artery cannot be directly reconnected, a graft (a section of another blood vessel, often taken from the patient’s vein) may be used to bridge the gap.

Aneurysm Excision:

• If an aneurysm has developed in the ulnar artery, the aneurysm is surgically removed.

Angioplasty with Stenting:

• This minimally invasive procedure involves inserting a balloon-tipped catheter into the narrowed or blocked artery.
• A stent, which is a tiny mesh tube, may be inserted to maintain the artery open after the balloon is inflated to enlarge it.

Lifestyle changes

You can maintain the health of your ulnar artery and circulatory system as a whole by:

• Reaching and keeping a healthy weight for your body type, age, and sex.
• Attempting to maintain a total cholesterol level below 200 mg/dL.
• Maintaining blood pressure control by avoiding readings above 140/90 mmHg.
• Engaging in regular exercise that includes both aerobic and strength training.
• Taking any prescription drugs as directed and adhering to your doctor’s treatment plan will help you manage any health issues, such as diabetes or heart disease.
• Giving up smoking.

Reducing the risk of recurrent ulnar artery thrombosis and improving blood circulation can be achieved by adopting lifestyle changes, such as stopping smoking, keeping a healthy weight, and engaging in regular exercise.

Risk Factors

Numerous risk factors that impact blood flow to the hand and fingers can result in ulnar artery thrombosis. These elements may contribute to the development of ulnar artery blood clots, which may result in problems. It is crucial to understand these risk factors to prevent this illness and, if necessary, seek prompt medical attention.

• Diabetes
• Hyperlipidemia
• Hypertension
• Obesity
• Family history of blood clots
• Sedentary lifestyle
• Autoimmune disorders
• Trauma to the wrist or hand
• Use of certain medications

Ulnar artery thrombosis is the most prevalent ailment that affects the ulnar artery. This disorder develops when a blood clot forms in your ulnar artery as a result of repetitive motions or an unexpected injury.

Atherosclerosis

• The hardening of the arteries can harm any blood vessel, including the ulnar artery, increasing the risk of clotting.
• Blood Clotting Disorders (Hypercoagulable State)
• Conditions that make the blood more prone to clotting increase the likelihood of ulnar artery thrombosis.

Vasculitis

• Inflammation of blood vessels can damage the ulnar artery, leading to thrombosis.

Diabetes

• Diabetes can damage blood arteries, increasing the risk of vascular disorders including thrombosis.
• Certain connective tissue illnesses can harm blood arteries, increasing the risk of vascular problems.

Smoking

• Smoking harms blood arteries and raises the risk of blood clots.

Conclusion

Ulnar artery thrombosis is frequently linked to repetitive trauma to the hand’s hypothenar eminence (also referred to as “hypothenar hammer syndrome”). If conservative management is unsuccessful, surgical intervention may be necessary, especially if symptoms are severe or there is significant tissue damage. Early diagnosis using imaging techniques like ultrasound is essential for the best possible care and to avoid potential complications like digit loss.

FAQs

Reference

• Professional, C. C. M. (2024, May 1). Ulnar Artery. Cleveland Clinic. https://my.clevelandclinic.org/health/body/23436-ulnar-artery
• Ulnar Artery thrombosis: Symptoms, diagnosis, and risks. (n.d.). https://www.medicoverhospitals.in/diseases/ulnar-artery-thrombosis/
• Marques, E. (2007). Ulnar artery thrombosis: Hypothenar Hammer Syndrome. Journal of the American College of Surgeons, 206(1), 188–189. https://doi.org/10.1016/j.jamcollsurg.2007.03.033
• Sapp, S. J. T. M. W. E. F. I. M. a. J., MD. (2014, July 18). Ulnar Artery Thrombosis: A 6-Year Experience. Medscape. https://www.medscape.com/viewarticle/423211?form=fpf
• Monacelli, G., Rizzo, M. I., Spagnoli, A. M., Monarca, C., & Scuderi, N. (2010, September 1). Ulnar artery thrombosis and nerve entrapment at Guyon’s Canal: our diagnostic and therapeutic algorithm. In Vivo. https://iv.iiarjournals.org/content/24/5/779