Arteriovenous Malformations (AVM)
Arteriovenous malformations (AVMs) are present at birth but are not usually seen until later in infancy. They do not typically appear as an AVM at birth but may be seen as a telangiectasia that goes undetected until the infant is older. This is a type of vascular malformation characterized by fast-flow. AVM is defined as an abnormal connection between arteries and veins. To illustrate how normal connections occur, arteries give rise to very small capillaries and then to veins. If an abnormal connection occurs between an artery and a vein it will be a larger connection than the normal small capillaries, thus causing an enlarged nest of entangled arteries and veins. The AVM tends to become larger with time, which can ultimately cause heart problems.
Stages of AVM
There are four stages of AVMs:
- Stage 1: quiet phase – warm pink-blush stain.
- Stage 2: expansion phase – enlargement with pulsation and tense veins forming.
- Stage 3: destruction phase – AVM outgrows the limits of the surrounding area such as the skin and may ulcerate causing bleeding and pain, then a cycle of expansion and destruction occurs.
- Stage 4: decompensation phase – similar to stage 2 with heart failure.
Treatment of AVMs
Our extensively trained craniofacial plastic surgeon offers a range of options to help. Treatment is started when the AVM is causing symptoms such as those found in Stage 3 and 4. This includes pain, ulceration, bleeding, and increased heart output which could lead to heart failure. Ligation or embolization of the feeding vessels of the AVM will fail because new vessels will arise to feed the AVM. Embolization of the center of the AVM is used within 24 to 72 hours prior to total excision. This will reduce the bleeding during excision of the AVM.