What are Arteriovenous Malformations (AVMs)?
Arteriovenous malformations (AVMs) are defects of the circulatory system that are generally believed to arise during embryonic or fetal development or soon after birth. Typically, AVMs go undetected for many years, but often become more evident due to the development of skin discoloration over the lesion. AVMs can occur anywhere throughout the body, and many of the symptoms that may ultimately develop depend upon their location.
When should I seek treatment for AVMs?
Most AVMs remain asymptomatic, but they may present with severe symptoms such as bleeding, pain, ulceration or ischemia. Because they can cause varying symptoms depending on the location, patients should be monitored carefully when AVMs are detected. Once a lesion of any size becomes symptomatic, it should be treated.
How are AVMs treated?
The goals of treatment are to reduce symptoms and reduce the risk of complications. Your healthcare provider will recommend the treatment option that is right for you.
Treatment for AVMs generally requires a multidisciplinary team approach, including collaboration between vascular surgeons, plastic surgeons, orthopaedists, dermatologists and psychosocial specialists. Your doctor will discuss the specific risks and potential benefits of the recommended procedure with you. When you meet with your doctor, please ask questions to make sure you understand the risks of the procedure and why the procedure is recommended.Your physician also may prescribe medication to alleviate pain and symptoms.
When is embolization and/or surgery necessary for AVMs?
When the lesions interfere with function or activities in your daily life, embolization and/or surgery may be recommended.
Some AVMs are suitable for surgical resection. Superficial lesions of the trunk, scalp, face and extremities are often amenable to excision. Surgical excision must entail complete removal of the AVM to assure a decreased chance of recurrence. Resection can often be facilitated by pre-operative transcatheter embolization as described below.
Transcatheter Embolization. Your physician may try to stop or reduce the blood supply to the malformation by injecting medication into the area using a procedure called transcatheter embolization. Initially, your surgeon will inject a dye to define the feeding arteries and draining veins that comprise the AVM. Once these are identified, they can be occluded with such embolic materials as foam, plastic particles, metal coils, ethanol or glue.
Successful embolization will at the least result in significant decrease in the size of the AVM, and at best it will completely obliterate it.
Resection Surgery. The approach to therapy for AVMs is often multidisciplinary. For example, a vascular surgeon may perform the embolization (as described above), and another specialist will resect the lesion, depending on its location. (For example, if the AVM is in a limb, often the patient is referred to Orthopaedics for the surgical resection.) Generally, the lesion is resected under general anesthesia. Recovery is usually mild, but may vary depending on the location of the lesion. The patient may expect a hospital stay of two to five days.
Focused Irradiation Therapy. This type of therapy is generally used for cerebral or spinal AVMs, which require a different approach and are referred to the Neurological Institute.
What outcomes can I expect from treatment?
Again, the most successful treatment requires close collaboration between specialties including vascular surgery, plastic surgery, orthopaedics, dermatology and psychosocial support.
At Cleveland Clinic, fewer than 5 percent of patients experience a complication from treatment.
About ¼ of patients will have complete resolution of the lesion; ¼ of patients will have some residual lesion, but no symptoms; ¼ of patients will still have some symptoms, but are improved; and ¼ will be no better.
References and Resources
National Organization for Rare Disorders (NORD)
International RadioSurgery Association
Cleveland Clinic Center for Consumer Health Information: What is Arteriovenous Malformation?
Cleveland Clinic Disease Management Project: Birthmarks: Hemangiomas & Vascular Anomalies
Vascular Anomalies Center at The Children’s Hospital at Cleveland Clinic: Vascular Malformations
National Institute of Neurological Disorders and Stroke: Arteriovenous Malformation Information Page
