Hereditary Hemorrhagic Telangiectasia

What is HHT?

Hereditary Hemorrhagic Telangiectasia (HHT) is a genetic disorder which affects about one in 5,000 people and causes arterial blood to flow directly into the veins, creating weakened ballooned vessels that can rupture.

Interventional radiologists are one of the few specialists who can permanently treat this disease that affects approximately half a million people worldwide. As vascular experts, interventional radiologists perform embolization – blocking the blood flow to the affected area – to prevent a life-threatening rupture.

In the normal circulatory system, arteries take oxygenated blood from the heart and push it out to all parts of the body under high pressure, while the veins return the blood back to the heart. Small capillaries typically connect the arteries to the veins. A person with HHT lacks capillaries in a few blood vessels in critical locations. Arteries connect directly into veins, creating a fragile site that can rupture and bleed. These abnormal blood vessels are called telangiectasis (tel-AN-jee-eck-TAZE-ee-ya) if they involve small blood vessels (nose, stomach and small bowel) and arterioveneous malformations (AVM) if it involves a larger blood vessel (lung, brain and liver). Telangiectases often occur near the surface of the skin like the mucous membrane in the nose while AVMs appear in the internal organs of the body.

Treatment for Lung AVMs

Interventional radiologists, vascular experts who treat patients internally using imaging to guide them, can permanently treat lung AVMs using a minimally invasive procedure known as embolization. During this procedure, an interventional radiologist makes a small nick in the skin, inserts a catheter into the femoral vein in the groin and then directs it to the abnormal blood vessels in the lung. Next, Dacron platinum coils are placed in the artery feeding the AVM to permanently block the blood flow to the AVM.

How to Prepare for Lung Embolization

  • The embolization treatments typically require one day of hospital admission to monitor for complications.
  • You should have your last meal before midnight the day of the procedure. If you take blood pressure medication, please take it as scheduled with a sip of water.
  • If you taking blood-thinning medication e.g. Coumadin or you are taking anti-diabetic medication, e.g Glucophage (Metformin), please contact our clinic immediately at (352) 265-0875 or (352) 265-0116 to report either of these conditions.
  • If you are allergic to contrast please call the above-mentioned numbers to report this condition.
  • We strongly recommend that you are well hydrated and as regular with your bowel movements as your body tolerates, prior to the procedure. (Sometimes constipation can be an added complication that can be prevented)

What to Expect

Prior to your procedure you will be prepared in the Holding area where you will change into a hospital gown and an IV will be placed. Through the IV you will receive pre-sedation medications that will keep you relaxed and comfortable. Other medications, like antibiotics could be given here as well. On average, Lung Embolizations last 1.5 to 3 Hours. This time varies according to the extent of your disease and your body’s anatomy. Please be aware that the process time does not include the time you spend the holding area being prepared with an IV, catheter medications and pre-medication for the procedure. Overall, your procedure duration maybe several hours and normally you will spend the night in the hospital.

Procedure Complications

The major complication of embolization procedures is rupture of the vessels used as a pathway for the procedure. Other complications could include hemorrhage, infection, pulmonary embolism, and non-target embolization of nearby organs including, but not limited to the brain (this could cause a stroke).

After Treatment Care

After the procedure, you may experience minimal chest pain, nausea, and low grade fevers (up to 102°F) for up to a week. You should report these complications if they are not controlled by the medications provided.

Additional Information

HHT/OWR Foundation International Website

Gene Review – Developed at the University of Washington

WebMD – HHT

eMedicine – OWR

Department of Radiology
College of Medicine
University of Florida
PO Box 100374, Gainesville, FL 32610-0374

Phone: (352) 265-0291
Fax: (352) 265-0279
PACS Support: (352) 265-0526