What is Hereditary Hemorrhagic Telangiectasia?
Hereditary hemorrhagic telangiectasia (HHT), commonly known as Osler-Weber-Rendu syndrome, is a blood vessel disorder characterized by arteriovenous malformations, which are abnormal connections between arteries and veins (AVMs). The most common locations affected are the nose, lungs, brain, and liver.
What are the Causes of Hereditary Hemorrhagic Telangiectasia?
Mutations in multiple separate genes cause hereditary hemorrhagic telangiectasia or HHT. You may inherit this genetic condition from your parents. It's an autosomal dominant condition, which means you have a 50% chance of inheriting it if one of your parents has it.
What are the Symptoms of Hereditary Hemorrhagic Telangiectasia?
Signs and symptoms of hereditary hemorrhagic telangiectasia include:
- Tiny red spots, particularly on the lips, face, fingertips, tongue, and inside surfaces of the mouth
- Iron deficiency anemia
- Shortness of breath
- Bleeding in the stomach or intestines.
- Blue discoloration of the skin.
Diagnosis of Hereditary Hemorrhagic Telangiectasia
Your doctor will review your symptoms and medical history, and a physical examination will be performed. Imaging tests that might be ordered to diagnose hereditary hemorrhagic telangiectasia include:
- Ultrasound: This study uses high-frequency sound waves to produce images of the tissues and it helps to understand if the liver is affected by arteriovenous malformations.
- MRI Scan: An imaging study that uses a large magnetic field and radio waves to detect any damage to the soft tissues including the brain and to identify any blood vessel abnormalities.
- Computerized Tomography (CT) Scan: This is an imaging technique that uses special x-rays to obtain cross-sectional images of the internal structures of the body including the blood vessels.
- Bubble Study: This is a special type of echocardiogram that may be recommended by your doctor to check for any abnormal blood flow in the lungs.
Treatment for Hereditary Hemorrhagic Telangiectasia
There is no cure for hereditary hemorrhagic telangiectasia, but treatments can help to alleviate symptoms and lower the risk of significant complications. There are three types of medications that can help minimize the bleeding associated with hereditary hemorrhagic telangiectasia:
- Hormone-Related Drugs: Estrogen-containing medications and anti-estrogens like tamoxifen and raloxifene may be used depending on the underlying cause.
- Drugs that Block Growth of Blood Vessels: The drugs such as bevacizumab, pomalidomide, and pazopanib can block abnormal blood vessel development.
- Drugs that Slow Clot Disintegration: Tranexamic acid can help to stop severe bleeding in an emergency and may be effective when taken on a regular basis to prevent bleeding.
The following procedures may reduce the frequency and severity of nosebleeds:
- Ablation: This procedure uses energy from lasers or a high-frequency electrical current to seal the aberrant vessels that cause nosebleeds.
- Skin Grafting: Your doctor may recommend transplanting a skin graft from another part of your body, generally your thigh, into your nose.
- Surgical Closure of the Nostrils: Joining skin flaps within the nose to permanently shut the nostrils is a possible solution in extreme cases when other approaches have failed.
The lungs, brain, and liver are the most affected organs by HHT. Procedures to treat these organs may include:
- Embolization: A long, narrow tube is threaded through your blood vessels to the problem area, where a plug or a metal coil is inserted to prevent blood from entering the AVM, which shrinks over time. Embolization is frequently used to treat AVMs in the lungs and brain.
- Surgical Removal: Surgical removal of arteriovenous malformations (AVMs) in the lungs, brain, or liver may be the best option for some people if the risks of injuring surrounding anatomical structures can be minimized.
- Stereotactic Radiotherapy: This treatment is used to treat AVMs in the brain. It involves directing beams of radiation from many different directions, all intersecting at the AVM to destroy it.