Definition

Veins are blood vessels that carry oxygen-poor blood from the body back to the heart. Some veins are located near the skin's surface, while others are deep within the muscles. Veins have thinner walls than arteries and are equipped with valves that help blood flow forward, preventing it from flowing backward.

Oxygen-poor blood is carried by veins back to the heart, where it is sent to the lungs via pulmonary arteries to be cleaned and replenished with oxygen. The oxygen-rich blood is then returned to the heart through the pulmonary veins.

Obstructions in veins can impede blood flow back to the heart, disrupting the overall circulation. Any obstruction in blood flow can deprive organs of oxygen and nutrients.

Additionally, when venous blood flow is obstructed, blood may accumulate and form clots. If a clot dislodges (embolus), it can block blood vessels in other organs, such as the lungs. Pulmonary embolism is a life-threatening emergency, and a clot in the brain can lead to a stroke.

Causes

Causes of venous blood flow obstruction include:

• Varicose veins: veins that appear bent and enlarged are known as varicose veins. Damage to the venous valve causes this disorder, which prevents blood from flowing forward and instead causes it to return to its previous location. The veins widen as a result of the blood accumulation
• Spider veins: similar to varicose veins but thinner
• Venous insufficiency: Damaged valves cause blood to accumulate in deeper veins
• Blood clots (thrombosis): Caused by damage to the vein walls, often from cholesterol plaque or injury
• Thrombophlebitis: Inflammation of veins leading to clot formation
• Deep vein thrombosis (DVT): Clots forming in deep veins
• Pulmonary embolism: A clot that has traveled to the lungs, blocking blood flow

Other causes of venous obstruction include tumors/cancers, tissue swelling compressing the veins, tension pneumothorax, and cardiac tamponade. Cancer can also increase substances in the body that make blood more prone to clotting.

Risk Factor

• Advanced age
• Obesity
• Smoking
• Cancer
• Leg injury or muscle weakness
• Family history of blood clotting disorders
• Hormonal changes (menopause or pregnancy)
• History of injury, surgery, or prolonged bed rest
• Inactivity for long periods of time, either due to having to lie in bed or traveling by car or plane for long periods
• A pacemaker or blood vessel tube (catheter) is attached to the central vein

Symptoms

Venous obstruction often presents as DVT. Patients may experience leg swelling after long periods of inactivity, along with increased pain when lifting the ankle. Swelling is the most specific symptom of DVT.

Hepatic vein thrombosis symptoms include upper right abdominal pain, nausea, and fever. This vein drains deoxygenated blood from the liver to the inferior vena cava, returning it to the heart. Patients may also develop ascites (fluid buildup in the abdomen) and intestinal ischemia (lack of oxygen in the tissues).

In pulmonary embolism, chest pain and shortness of breath may occur, which is a life-threatening condition.

Diagnosis

Diagnosis is based on symptoms, patient history, physical examination, and additional tests. Examinations are conducted based on the cause of the obstruction that develops.

For DVT, blood tests help assess patient risk, including D-dimer, antithrombin III (ATIII), NT-proBNP, CRP, and erythrocyte sedimentation rate (ESR). Studies show that all patients with a positive D-dimer and leg swelling were confirmed to have DVT. Imaging includes ultrasound (USG) of the affected legs and pelvis, with CT or MRI scans as further options.

For venous insufficiency, venograms and ultrasounds are used. In a venogram, contrast dye is injected into the veins. Pictures of the blood vessels are subsequently captured with X-rays. Doctors can detect blood vessels more clearly with the use of contrast dye.

Meanwhile, ultrasonography helps to determine the rate and direction of blood flow in the blood vessels. Images are recorded by reflecting sound waves from the ultrasound instrument and presented on the screen.

Laboratory testing to check any hereditary coagulation abnormalities, liver function tests, and radiography are examples of supporting examinations for hepatic vein thrombosis. Ultrasound is the major modality that can be used with endoscopy.

Management

The treatment depends on the cause of the venous obstruction. Therapy for vein obstruction caused by blood clots (VTE) aims to avoid DVT progress. and the appearance of pulmonary embolism. Treatment is divided into two phases: a first active treatment period lasting three months, followed by a secondary phase. The first line of treatment is to deliver anti-blood clotting medications (anticoagulants) to lower the risk of embolism in DVT patients and the risk of death in pulmonary embolism patients. Thrombectomy, or removing blood clots from venous obstruction, is an uncommon procedure.

Hepatic vein obstruction treatment consists of clearing up blood clots (thrombolysis) with tPA followed by at least 3 months of long-term anticoagulant therapy.

Complications

A complication of VTE is pulmonary embolism in the pulmonary veins, which can be fatal because blood does not normally circulate to the lungs. Complications of hepatic vein thrombosis include splenomegaly (enlarged spleen), esophageal and gastric varices with or without bleeding, portal hypertensive gastropathy, and ascites.

Venous insufficiency complications include:

• Deep vein thrombosis (DVT)
• Pulmonary embolism
• Venous ulceration
• Secondary lymphedema
• Leg ulcers
• Skin discoloration
• Thrombophlebitis
• Bleeding
• Chronic pain

Chronic pain, swelling, recurrent cellulitis, and long-term, slowly healing leg ulcers are the most common but not the most serious complications of venous insufficiency.

Prevention

To prevent blood clots and other vascular issues, adopt the following healthy habits:

• Exercise 3-5 times a week
• Stop smoking
• Limit alcohol consumption
• Maintain a healthy weight
• Eat a low-saturated-fat diet
• To prevent blood clots on a lengthy trip, stand up and move regularly.
• Regular check-ups, especially if you have risk factors

When to See a Doctor?

Immediately visit the emergency unit if:

• Sudden shortness of breath
• Chest pain
• Fainting
• Sudden, severe headache
• Nausea and vomiting
• Sudden blurred or double vision
• Sudden weakness or numbness in the face or other body parts
• Difficulty speaking or understanding others
• Seizures

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