Vascular and Endovascular Surgery in India

AV Fistula Symptoms

Small AV Fistula doesn't cause symptoms. However, larger Arteriovenous Fistulas cause symptoms such as:

• Purplish, bulging veins
• Hypotension
• Fatigue
• Swelling in the Arms and Legs

If there is a Pulmonary AV Fistula, the skin becomes bluish; there will be clubbing of fingers and severe cough with blood in the Sputum. If there is an AV Fistula in the Gastrointestinal tract, you can observe bleeding in the tract.

In rare cases, a large Fistula can divert blood flow from the affected area (usually Arms or Legs), making that area numb, painful, cramping, and bluish-coloured.

Causes

AV Fistula may be congenital, which may be due to the abnormal development of arteries and veins in the womb.

This condition can also be seen due to Cardiac Catheterization. The catheter has a tube-like structure and consists of a needle. It is inserted into an artery or a vein. During this procedure, the blood vessel may get dilated leading to the formation of an Arteriovenous Fistula. Injuries that pierce the skin can also cause this condition.

Certain genetic conditions such as Hereditary Hemorrhagic Telangiectasia cause Pulmonary AV Fistula. In some cases, an AV Fistula is created through surgery to aid in dialysis.

Complications

AV Fistula can rupture and cause Subarachnoid Haemorrhage. They may also result in blood clots (can cause Pulmonary Embolism) or Heart Failure. The Heart pumps with increased intensity to compensate for the fall in blood pressure. Due to this, the Heart muscle weakens leading to Heart failure, which is a life-threatening condition.

Diagnosis

Your doctor observes blood flow at the suspected area with the help of a stethoscope as the blood flowing through a Fistula makes a clicking sound. If the sound is heard, your doctor may recommend you to undergo imaging tests such as:

Duplex Ultrasound: This test helps to detect Fistulas in arms and legs. The test can estimate how fast the blood flows with the support of a transducer that produces high-frequency sound waves.

Magnetic Resonance Angiography: This test helps to detect Fistulas between deeper arteries and veins. The procedure involves the use of a special dye to make the blood vessels more visible.

Computed Tomography (CT) Angiogram: This test helps to detect Fistulas with the injection of a contrast dye to produce clear images of the blood vessels. The test helps your doctor to confirm the diagnosis.

In the case of Pulmonary AV Fistula, tests such as Arterial Blood Gas, complete Blood count, Echocardiogram, Chest X-ray, and Pulmonary Arteriogram are performed.

Treatment

If the Fistula is small and doesn’t have symptoms, your doctor monitors the Fistula. If there are symptoms, then the treatment of choice would be Catheter Embolization. The process involves blocking the Fistula with the help of a Catheter. A Catheter is inserted into the artery near the Fistula, and the stent is placed at the Fistula to restore normal blood flow.

Ultrasound-guided Compression

If the Fistula is visible on ultrasound, your doctor may recommend this procedure. With the help of an ultrasound probe, your doctor compresses the Fistula and restores the blood flow.

Surgery: If the Fistulas are large and cannot be treated with Catheter Embolization, then your doctor recommends surgery. Surgery involves removal of the abnormal blood vessels.

These procedures require a skilled surgeon as the surgery is extensive and AV Fistulas present near the major structures such as the Eye or Brain are difficult to treat.

AVMs most commonly occur in the brain or spinal cords. Comparatively, Brain AVMs are very rare and affect less than one per cent of the population. AVM most commonly occurs in young adults, the deaths occurring in 10 to 15% of the patients.

Causes

Although the cause of AVM is not clear, some of the causes include:

• Genetic pattern
• Congenital (by birth)

Symptoms

If you have an AVM in your brain, it would not probably present any signs and symptoms until the AVM ruptures; the first sign includes haemorrhage.

If there is no Haemorrhage the signs and symptoms would include:

• Seizures
• Headache
• Muscle weakness or numbness in any part of the body

More serious signs and symptoms include:

• Severe headache
• Vision loss
• Severe unsteadiness
• Paralysis
• Difficulty speaking
• Confusion or inability to understand

These symptoms may begin at any age usually between ages 10 and 40. AVM can cause brain damage over time to time. After reaching middle age, brain AVM tend to remain stable and are less likely to cause any symptoms.

Pregnant women have worsened symptoms due to alterations in blood volume and blood pressure.

Call your doctor immediately if you notice any signs and symptoms such as seizures, headaches or other symptoms. It is a medical emergency if the brain is bleeding.

Risk factors

• Gender: AVM diseases are more common in males than in females
• Family History: There may be the inheritance of other medical conditions that predispose the formation of AVM

Treatment

The main goal of the treatment is to prevent haemorrhage; the treatment would also focus on reducing neurological complications such as seizures. Your doctor would determine the appropriate treatment based on your symptoms and diagnostic results.

Medications

Your doctor would prescribe medications to treat the symptoms such as headaches or seizures.

You must avoid activities that elevate your blood pressure and must avoid blood thinning agents such as warfarin.

Complications

Complications associated with AVM include:

• Bleeding in the brain
• Reduced oxygen supply to the brain tissue
• Weakened blood vessels
• Damage to the brain

Diagnosis

Your neurologist would review your symptoms and conduct a physical examination. Tests used for diagnosing AV malformations include:

• Cerebral Arteriography: This test reveals the location and characteristics of the arteries and veins, which is crucial in planning the treatment.
• Computerized Tomography (CT) Scan: This test helps in giving a cross-sectional image of your brain.
• Magnetic Resonance Imaging (MRI): This test helps in giving detailed images of the brain

Surgical Intervention

Brain Tumour Surgery is considered to be the gold standard treatment for brain AVM. There are three types of surgical procedures:

Resection: If you have a rupture in the AVM, then conventional AVM brain surgery is opted for the removal of the AVM. Resection is performed when the AVM can be removed with little risk of haemorrhage or Seizures. Deep AVMs pose a higher risk of complications so; your doctor would recommend other treatment options.

• Endovascular Embolization: This procedure is less invasive than traditional type of surgery. The catheter is positioned in the arteries to the AVM, and an embolizing agent is injected to block the artery and reduce the flow into the AVM. This is a less invasive technique which is often performed before carrying out other surgical procedures to make the procedure safer by reducing the size of AVM or the bleeding.
• Stereotactic Radiosurgery (SRS): This procedure uses radiation to destroy the AVM. There is no incision required. The SRS beams are directed to damage the blood vessels and cause scarring. The scarred AVM blood vessels finally clot after one to three years of the treatment.

This treatment would be beneficial if the AVMs are small and are difficult to remove with conventional surgery.

Self-Management

Do not get worried after being diagnosed with AVM, have little control over your health and improve your quality of life just by following these simple steps:

• Gain enough knowledge about your condition; it helps in decision-making, especially regarding your treatment options
• Complications such as haemorrhage and stroke can cause emotional problems apart from physical problems. Cope with it and try hard to control your emotions.
• Keep yourself close to family and friends, talk to them and get support during recovery

Which doctors are specialized in treating brain AVMs?

• Vascular Neurosurgeons: who are specialized in the removal of brain AVMs
• Radiation Therapists: who specialized in stereotactic radiosurgery for treating the brain AVMs
• Interventional Neuroradiologists: who specialized in the Endovascular Therapy of brain AVMs
• Stroke Neurologists: who specialized in the medical management of brain AVMs

Signs and Symptoms

In some cases, VTE may not cause any symptoms and remains unnoticed. The signs and symptoms of VTE can be classified into two types based on the location of the thrombi:

If you have deep venous thrombosis, you may experience:

• Pain and tenderness in the affected leg
• swelling and feeling of warmth in your leg

A limb-threatening manifestation of DVT that your doctor would identify includes massive limb swelling, high blood pressure in the capillary bed, and eventually ischemia and gangrene if left untreated. This is because the thrombus completely occludes venous outflow.

The signs and symptoms of Pulmonary Embolism include shortness of breath, tachypnea, chest pain, and dizziness.

Causes

VTE may occur as a result of genetic predisposition as well as acquired risk factors. Experts suggest that a major theory called Virchow's triad proposes that the condition is due to alterations in the blood flow, damage to your vessel walls, and increased activation of clotting factors.

Treatment

Treatment for VTE aims at preventing the growth of blood clots and the formation of new clots. Prompt treatment is essential to avoid fatal complications.

Medications such as blood thinners also known as anticoagulants and clot dissolvers or thrombolytics are prescribed.

Surgical procedures such as clot removal are performed in the case of a very large, life-threatening clot in your lungs. Vein filters are used to prevent clots from being carried into your lungs. This procedure is typically used for those who are not suitable for anticoagulant drug therapy.

Complications

One of the major complications of VTE is its recurrence. The long-term complications of VTE include Chronic Thromboembolic Pulmonary Hypertension (CTPH) and Post-Thrombotic Syndrome (PTS).

Prevention or self-management

Following are certain measures to prevent VTE or recurrence of VTE:

• Administer blood thinners or anticoagulants as prescribed
• Wear compression stockings
• Place your legs in the elevated position
• Perform regular physical activity
• Perform pneumatic compression (as per your physical therapist's instructions)
• Avoid sitting for prolonged periods
• Maintain a healthy weight
• Quit smoking

Risk factors

The common risk factors for VTE include:

• Acute medical illness leading to hospitalization
• Infection
• Age >760
• Family history of VTE
• Cardiovascular Diseases, such as Hypertension
• Diabetes Mellitus and High Cholesterol levels
• History of smoking
• Genetic risk factors (factor V Leiden, Protein C and S Deficiency, Prothrombin Gene Mutation G20210A, and Anti-thrombin Deficiency)
• Use of birth control pills
• Being Overweight or Obese
• Sitting for Prolonged periods
• Prolonged bed rests in conditions such as Paralysis
• Cancer

Diagnosis

Your doctor begins the diagnosis with a thorough physical examination that includes checking for the signs and symptoms of VTE. The common diagnostic tests to identify VTE include:

• Blood Tests: Your blood sample is tested to determine the levels of D-dimer, a clot-dissolving substance. Also, your blood is tested for bio-markers, such as troponin and brain natriuretic peptide to identify right ventricular dysfunction (one of the causes of PE).
• Doppler Ultrasonography: The test is used to obtain a detailed view of the clot.
• Venography: During the test, a dye is injected into the vein present in the foot or ankle. Simultaneously, X-rays were taken to identify the clots.
• Imaging Studies: Computerized tomography and magnetic resonance imaging provide a detailed view of your veins and identify the clot.
• Tests to identify PE are Chest X-ray, Arterial Blood Gas determination, Pulmonary Angiography, and Ventilation-perfusion scanning.