Arteriovenous Malformation (Peripheral)

Introduction

A peripheral arteriovenous malformation, often shortened to peripheral AVM, is an abnormal connection between arteries and veins that develops outside the brain and spinal cord. In a healthy circulation, blood flows from arteries through tiny vessels called capillaries before returning to the veins. In an AVM, that capillary network is missing in one area. Blood rushes directly from high-pressure arteries into low-pressure veins through a tangle of abnormal vessels called the nidus.

If you or your child has been diagnosed with a peripheral AVM, you are likely now thinking about what happens next: how it will be monitored, whether it needs treatment, what treatment involves, and what life looks like with this condition over years and decades. This article walks through those questions. Peripheral AVMs are uncommon, complex, and managed by specialist teams that combine vascular surgery, interventional radiology, plastic and reconstructive surgery, and other disciplines. Care is highly individual, and the descriptions below are intended to help you understand the medical landscape rather than replace the conversation with your own team.

What Is a Peripheral Arteriovenous Malformation?

An arteriovenous malformation is a type of vascular anomaly. The international classification used by specialists, developed by the International Society for the Study of Vascular Anomalies (ISSVA), divides vascular anomalies broadly into two groups: vascular tumours (such as infantile haemangiomas, which grow as cell collections) and vascular malformations (errors in how blood or lymphatic vessels formed). AVMs sit in the malformation group. They are further described as high-flow lesions because blood moves through them at arterial speed and pressure.

The word “peripheral” in this context means anywhere other than the brain or spinal cord. A peripheral AVM may involve a hand, a foot, an entire limb, the face, the scalp, the jaw, the neck, the chest or abdominal wall, the pelvis, the uterus, the lungs, or other internal organs. Each location brings its own pattern of symptoms and treatment considerations.

Peripheral AVMs are almost always present at birth, although they may not become visible or symptomatic until later in life. They are caused by a problem in how blood vessels formed during early development. They are not caused by anything a parent did or did not do during pregnancy. They are not contagious, and in most cases they are not inherited.

A few important distinctions help frame the rest of this article:

• AVM versus haemangioma: A haemangioma is a benign vascular tumour that typically appears in infancy, grows for a period, and then often shrinks. An AVM does not shrink on its own and tends to persist or worsen.
• AVM versus venous malformation: A venous malformation is a low-flow lesion involving abnormal veins only. It feels soft, often bluish, and is usually less aggressive than an AVM.
• AVM versus arteriovenous fistula (AVF): A fistula is a single direct connection between an artery and a vein, often acquired (for example, after trauma or as a deliberately created connection for dialysis). An AVM is a tangle of many abnormal vessels and is almost always congenital.

Specialists describe peripheral AVMs by both location and behaviour.

By location

• Limb AVMs are among the most common peripheral AVMs. They may involve the soft tissue, muscle, bone, or skin of an arm or leg. Lower-limb AVMs can affect walking and posture.
• Head and neck AVMs can involve the scalp, face, lips, tongue, jaw, or ear. Because the face is highly vascular and visible, even small AVMs in this area can cause significant cosmetic and functional concerns.
• Trunk and chest wall AVMs may involve the skin and muscle of the chest, back, or abdomen.
• Pelvic AVMs, including uterine AVMs, can cause heavy bleeding, pelvic pain, or symptoms related to pressure on nearby organs.
• Visceral peripheral AVMs involve internal organs such as the liver, lungs, kidneys, or bowel. Pulmonary AVMs in particular can affect oxygen exchange and may be linked to a genetic condition called hereditary haemorrhagic telangiectasia (HHT).

By clinical stage

Many specialists use the Schobinger staging system to describe how active a peripheral AVM is:

• Stage I (quiescent): The AVM is present but quiet. It may look like a pink stain on the skin and feel warm. There may be no symptoms.
• Stage II (expansion): The AVM grows, becomes pulsatile (you can feel a heartbeat in it), and may produce an audible sound through a stethoscope called a bruit.
• Stage III (destruction): The AVM causes pain, skin breakdown, ulceration, or bleeding.
• Stage IV (decompensation): Rarely, very large AVMs cause heart strain because so much blood is being shunted through the malformation that the heart has to work harder.

Many peripheral AVMs progress through these stages over years or decades, often triggered by puberty, pregnancy, injury, or sometimes by incomplete treatment. The stage helps the team decide whether to observe, intervene partially, or treat more aggressively.

Causes and Risk Factors

Peripheral AVMs form during early development of the blood vessels, before birth. In recent years, research has identified that many sporadic (non-inherited) AVMs are caused by somatic mutations, meaning changes in genes that happen in a single cell during development and affect only the cells that grow from that one cell. The most studied of these involves a gene called MAP2K1 and the related RAS-MAPK signalling pathway. These mutations are not present in eggs, sperm, or other body cells and are not passed on to children.

A small proportion of peripheral AVMs occur as part of a wider genetic syndrome. Two important examples:

• Hereditary haemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is an inherited condition causing multiple AVMs and small vessel abnormalities, often in the lungs, liver, brain, and nose. Frequent nosebleeds in multiple family members are a classic clue.
• Capillary malformation–arteriovenous malformation (CM-AVM) syndrome is an inherited condition linked to changes in the RASA1 or EPHB4 genes, characterised by small pink skin patches alongside deeper AVMs.

Outside these inherited conditions, peripheral AVMs are not caused by lifestyle, diet, occupation, or environmental exposure. Hormonal changes (puberty, pregnancy) and trauma do not cause AVMs but can trigger growth or symptoms in a malformation that was already present.

Signs and Symptoms

If you are reading this after a diagnosis, you will likely already recognise your own symptoms in this section. It is included so that you can understand the range and watch for changes that suggest progression.

Common features of a peripheral AVM include:

• A warm area of skin, sometimes pink, red, or bluish
• A pulsing sensation or visible swelling that beats in time with the heart
• A whooshing sound (bruit) or vibration (thrill) that can be felt over the area
• Pain, which may be constant or come and go
• Enlargement of an affected limb or facial structure compared with the other side
• Skin changes including thinning, dark discolouration, ulcers, or bleeding
• Heavy or unusual bleeding (for example, from a uterine AVM or from skin breakdown over the lesion)
• For pulmonary AVMs: shortness of breath, low oxygen levels, or unexplained strokes due to small clots bypassing the lung filter
• In very large lesions, signs of heart strain such as breathlessness or reduced exercise tolerance

Symptoms that warrant prompt review by your specialist team include new or worsening pain, new bleeding, rapid increase in size, new skin ulceration, sudden swelling, or any signs of infection over the lesion (warmth, redness, fever). Bleeding from a peripheral AVM can sometimes be brisk and is a recognised reason to seek urgent care.

Diagnosis

Reaching the right diagnosis is one of the most important steps in managing a peripheral AVM, because treatment for an AVM is very different from treatment for a haemangioma, venous malformation, or arteriovenous fistula. The diagnosis is made by combining the clinical examination with imaging, and the imaging is usually arranged by a specialist team familiar with vascular anomalies.

Clinical examination

A vascular surgeon, interventional radiologist, or vascular anomaly specialist will examine the lesion, feel for warmth and pulsation, listen for a bruit, and assess the affected limb or area for swelling, length differences, and skin changes. They will ask about how long it has been present, how it has changed, and any family history of vascular conditions or nosebleeds.

Ultrasound with Doppler

MRI and MR angiography (MRA)

Magnetic resonance imaging gives a detailed view of how deep the AVM extends, which muscles, bones, nerves, or organs are involved, and how much tissue is affected. MR angiography highlights the feeding arteries and draining veins. MRI is particularly valuable for planning treatment because it shows anatomy in three dimensions without radiation.

CT angiography

CT angiography uses contrast dye and a CT scanner to map the blood vessels. It is helpful for AVMs involving bone or the chest, and when MRI is not suitable.

Catheter angiography

This is the most detailed test and the reference standard for understanding AVM anatomy. A thin tube (catheter) is passed through an artery, usually in the groin, and contrast is injected to map the AVM in real time. Catheter angiography is often performed at the same time as treatment (embolisation) rather than as a separate test, particularly when the diagnosis is already strongly suggested by ultrasound and MRI.

Genetic testing

Where features suggest HHT, CM-AVM syndrome, or another genetic condition — multiple lesions, family history, recurrent nosebleeds, or characteristic skin findings — genetic testing may be discussed. Identifying a syndrome changes screening (for example, looking for pulmonary or brain AVMs in HHT) and has implications for other family members.

Biopsy

Biopsy is usually avoided in a suspected AVM because cutting into the lesion can cause heavy bleeding. Diagnosis is generally made on imaging.

Treatment and Management

The approach to a peripheral AVM is highly individual. Decisions depend on the location, size, Schobinger stage, symptoms, age of the patient, what structures are involved, and what the patient and family want to achieve. Many peripheral AVMs are managed long-term rather than “cured” in a single intervention. The principle followed by most multidisciplinary teams is to intervene when symptoms or complications justify the risk of treatment, and to favour the least invasive effective option.

Observation and conservative care

For small, asymptomatic, Stage I AVMs, careful observation with periodic imaging is often the recommended approach. Treatment of a quiet AVM can sometimes provoke it to become more active. Conservative measures include:

• Compression garments for limb AVMs to reduce swelling and discomfort
• Skin care to prevent breakdown over the affected area
• Avoidance of unnecessary trauma to the area
• Pain management when needed
• Education about warning signs that should prompt review

Embolisation

Embolisation is, for many peripheral AVMs, the central treatment. It is performed by an interventional radiologist or vascular interventional specialist. Through a small puncture in an artery (most often at the groin), a catheter is guided to the AVM under X-ray guidance. Material is then injected to block the abnormal vessels.

Different embolic materials are used depending on the AVM’s anatomy:

• Liquid embolic agents such as n-butyl cyanoacrylate (a medical glue) and ethylene-vinyl alcohol copolymer (Onyx) flow into the nidus and solidify there. These are often the materials of choice for the abnormal vessel tangle itself.
• Sclerosing agents such as absolute ethanol can destroy the abnormal vessel wall. Ethanol is highly effective but requires expert use because it can damage surrounding tissue and nerves if it spreads beyond the target.
• Coils and plugs are metal devices used to block larger feeding arteries or draining veins, often as part of a combined approach.
• Particles are sometimes used, although they are generally less favoured for AVMs because blocking only the feeding arteries can allow new abnormal vessels to recruit and the AVM to recur.

Most peripheral AVMs require staged embolisation — several sessions weeks or months apart — to progressively reduce the nidus while keeping each session safe. The aim is to treat the nidus itself, not just the feeding arteries, because the AVM will recur if the central tangle remains.

Sclerotherapy

Direct-puncture sclerotherapy, where a sclerosing agent is injected directly into the AVM through the skin under image guidance, is another important tool. It is sometimes combined with embolisation through arteries.

Surgery

Surgical removal (resection) of an AVM is considered when the lesion is well-defined, accessible, and complete removal is feasible without unacceptable functional or cosmetic loss. Surgery is often performed after embolisation, which reduces blood flow into the lesion and makes the operation safer and less bloody.

Specific surgical situations include:

• Removal of a localised limb or skin AVM that is causing pain, ulceration, or bleeding
• Resection of a uterine AVM, sometimes including hysterectomy when fertility is no longer a concern and bleeding is severe
• Reconstructive surgery after AVM removal in the head and neck or limb, often involving plastic surgery teams
• Amputation, which is a rare option reserved for extensive, painful, or destructive limb AVMs that cannot be controlled by other means

Surgery is most likely to achieve durable control when the entire nidus is removed. Partial removal carries a risk of regrowth, similar to incomplete embolisation.

Combined and staged approaches

In practice, many peripheral AVMs are best managed by combining modalities — embolisation to reduce flow, followed by surgical resection and reconstruction, with further embolisation if residual disease is identified later. Multidisciplinary teams including vascular surgery, interventional radiology, plastic and reconstructive surgery, dermatology, and others typically plan this together.

Medical therapies

Until recently, no drug therapies were available for peripheral AVMs. Research into the genetic causes of AVMs has begun to change this. Targeted drugs that interfere with the RAS-MAPK signalling pathway — including agents originally developed for certain cancers — are under investigation and have shown promise in selected patients with extensive or otherwise untreatable AVMs. These are specialist treatments, currently used in expert centres and often in the context of clinical trials. Whether such therapy is suitable for an individual patient is a discussion for the specialist team.

Recovery depends heavily on the type and extent of treatment. Some general patterns are useful to know.

After embolisation

Embolisation is usually performed under general anaesthesia or sedation. Most patients stay in hospital for one or a few nights. In the days after, it is common to experience:

• Swelling, warmth, and tenderness over the treated area
• Bruising and discolouration of the skin
• A flu-like reaction known as post-embolisation syndrome — low-grade fever, mild nausea, tiredness, and pain — usually settling over several days
• Pain that may require prescription pain relief initially, transitioning to simpler medication

Most people return to non-strenuous activities within one to two weeks, although this varies. The team will advise on activity restrictions specific to the treated area.

After surgery

Recovery from AVM surgery depends on the location and extent of the operation, and on whether reconstructive surgery was performed. Hospital stay may range from a couple of days for a small skin lesion to a week or more for a major resection with reconstruction. Wound care, mobility restrictions, and physiotherapy are tailored to the procedure.

Follow-up imaging

Because peripheral AVMs can recur or progress, follow-up is long-term. Repeat ultrasound or MRI is typically performed at intervals to confirm that the AVM remains controlled. The exact follow-up schedule will be set by the specialist team based on the location, treatment, and individual factors.

Risks and Complications

Both the AVM itself and the treatments carry risks. Understanding them helps you weigh decisions with your team.

Risks of an untreated or partially treated AVM

• Progressive enlargement and pain
• Skin breakdown, ulceration, and chronic wounds
• Bleeding, which can be severe
• Functional loss in an affected limb, joint, or facial structure
• Length or size difference in an affected limb, particularly during growth in childhood
• In large lesions, cardiac strain from high-volume blood flow
• Psychological and social impact, particularly for visible AVMs

Risks of embolisation

• Skin injury or ulceration where embolic material affects skin blood supply
• Nerve injury if embolic material reaches small nerves supplying skin or muscle
• Non-target embolisation, where material lodges in vessels supplying healthy tissue
• Allergic reaction to contrast dye
• Bleeding or bruising at the catheter entry site
• Recurrence of the AVM, particularly if the nidus has not been adequately treated
• Pulmonary effects if embolic material reaches the lungs through large draining veins, which is a specific concern for some high-flow AVMs

Risks of surgery

• Bleeding during and after surgery, sometimes substantial
• Infection
• Wound healing problems
• Scarring, including hypertrophic or keloid scars
• Damage to surrounding nerves, muscles, or other structures
• Functional or cosmetic outcomes that do not fully match expectations
• Recurrence if the nidus is not completely removed

Specialist centres experienced in vascular anomalies generally report lower complication rates than less experienced settings, which is one reason this care is concentrated in multidisciplinary teams.

Living with a Peripheral AVM

For many people, a peripheral AVM is a long-term condition rather than something that is “fixed” once. Living well with the condition includes physical, practical, and emotional dimensions.

Day-to-day care

• Skin and wound care: Keep the skin over the AVM clean, moisturised, and protected from trauma. Wear footwear that does not rub if a foot is involved.
• Compression garments: If recommended, wearing these consistently can reduce swelling and discomfort in a limb AVM.
• Activity: Most people can continue normal activity, including exercise. The team will advise on any specific limits, for example for contact sports if there is a risk of bleeding.
• Dental care for head and neck AVMs: Routine dental work is usually safe but should be coordinated with the specialist team because of bleeding risks during certain procedures.

Pregnancy

Hormonal changes during pregnancy can cause an AVM to become more active. If you have a peripheral AVM and are planning a pregnancy, or are pregnant, the AVM team and your obstetric team should plan together. Uterine and pelvic AVMs need particular attention, and the mode of delivery may be discussed in advance.

Emotional and psychological wellbeing

A visible or progressive vascular anomaly can affect self-image, mood, and social life, particularly in adolescence. Talking with a counsellor or psychologist, connecting with patient support groups for vascular anomalies, and meeting other people with similar conditions can make a real difference. The specialist team can often suggest resources.

Information for family members

For most peripheral AVMs, no special screening of family members is needed. Where a genetic condition such as HHT is identified, screening of close relatives is an important part of care and is usually coordinated through clinical genetics.

Peripheral AVM in Children

Children with peripheral AVMs face some particular considerations.

Diagnosis in childhood

Some AVMs are visible at birth as a pink or red skin patch. Others stay quiet until later, then become noticeable during a growth spurt, after an injury, or around puberty. Distinguishing an AVM from a haemangioma matters because haemangiomas often shrink with time, whereas AVMs do not. Specialist assessment, usually including Doppler ultrasound, helps make this distinction early.

Treatment timing

The decision about when to treat a paediatric AVM is delicate. Treating very early can disrupt normal growth and structures; waiting too long risks letting the AVM progress through Schobinger stages. Most teams favour observation for quiet AVMs in children, with intervention reserved for clear symptoms, complications, or evidence of progression. When intervention is needed, it is performed at centres with paediatric vascular anomaly experience.

Limb growth and orthopaedic considerations

A limb AVM can cause the affected limb to grow longer or larger than the other side, or sometimes shorter if growth plates are affected. Orthopaedic input is sometimes needed alongside vascular care.

School and daily life

Children with a peripheral AVM can usually attend mainstream school and take part in most activities. Practical adaptations depend on the location and severity. For visible AVMs, schools and families benefit from straightforward explanations to peers and teachers to prevent bullying and isolation. Psychological support, when needed, is part of comprehensive paediatric vascular anomaly care.

Transition to adult care

Because peripheral AVMs are lifelong, transition from paediatric to adult vascular anomaly services is an important step in the teenage years. A planned handover helps preserve continuity of imaging, follow-up, and treatment plans.

Monitoring and Long-Term Follow-Up

Even after successful treatment, a peripheral AVM can recur. Long-term follow-up is therefore central to care. A typical pattern of monitoring includes:

• Clinical review at regular intervals, more often in the first year or two after treatment, then spaced out as the situation stabilises
• Repeat ultrasound or MRI to compare with previous scans and look for recurrence
• Reassessment whenever new symptoms appear — new pain, new pulsation, swelling, bleeding, or skin changes
• Coordinated care during life events likely to affect the AVM, particularly puberty and pregnancy

If you move or change hospitals, carrying copies of your imaging, operation notes, and embolisation reports with you helps any new team understand what has already been done.

When to Seek Urgent Care

Most issues with a peripheral AVM can be addressed through scheduled clinic review. However, some situations warrant prompt attention. Contact your team or seek urgent medical care if you experience:

• Sudden or heavy bleeding from the AVM or overlying skin
• Rapid increase in size or swelling
• Severe new pain
• Skin breakdown with signs of infection — spreading redness, warmth, pus, or fever
• For pulmonary AVMs or HHT: sudden chest pain, breathlessness, neurological symptoms such as weakness, numbness, or trouble speaking
• Signs of significant blood loss after bleeding from the AVM — dizziness, paleness, fainting

For bleeding from a peripheral AVM, firm direct pressure with a clean cloth for several minutes is a useful first step while arranging urgent medical review.

Frequently Asked Questions

Will my peripheral AVM ever be completely cured?

For some small, well-defined AVMs, particularly those that can be entirely removed or completely embolised, durable control or cure is possible. For larger or more diffuse AVMs, the realistic goal is often long-term control of symptoms and prevention of progression rather than a one-time cure. Your specialist team can give you a clearer picture based on your imaging.

Can a peripheral AVM come back after treatment?

Yes. Recurrence is a recognised feature of peripheral AVMs, particularly when the nidus is not completely treated. This is why long-term follow-up is part of care and why repeat treatments over years are not uncommon.

Is a peripheral AVM cancer?

No. AVMs are not cancers. They do not spread to other parts of the body and they do not transform into cancer. They are abnormal blood vessels that formed during early development.

Can my child inherit my AVM?

Most peripheral AVMs are caused by changes that happened only in the cells of the malformation itself and are not passed on. Inherited conditions such as HHT or CM-AVM syndrome are exceptions. If a genetic condition is suspected, your team can arrange testing and genetic counselling.

Can I exercise normally?

Most people with a peripheral AVM can exercise. Specific restrictions depend on the location and stage of the AVM and on any recent treatment. Your team can advise on safe activities, including whether contact sports are appropriate.

Will pregnancy make my AVM worse?

Hormonal changes during pregnancy can cause some AVMs to become more active. The risk depends on the AVM’s location, size, and stage. If you have a peripheral AVM and are planning a pregnancy, a pre-pregnancy review with your specialist team is helpful so that monitoring and any necessary planning — including for delivery in the case of pelvic or uterine AVMs — can be in place.

How many embolisation sessions will I need?

This varies widely. Small AVMs may need one or two sessions, while larger or complex AVMs may need several sessions over months or years. The team will plan the schedule based on response, symptoms, and imaging.

Do I need to see a specific kind of doctor for this?

Peripheral AVMs are best managed by a multidisciplinary vascular anomaly team. This typically includes vascular surgeons, interventional radiologists, plastic and reconstructive surgeons, dermatologists, and others as needed. When choosing where to receive care, experience with vascular anomalies specifically — not just general vascular care — is an important consideration.

Conclusion

A peripheral AVM is a complex, lifelong vascular condition, but it is one that modern multidisciplinary care can manage well in most cases. Treatment is rarely a single event; it is more often a long-term partnership with a specialist team that adapts the approach over years as the AVM, your life, and the available techniques evolve. Embolisation, sclerotherapy, surgery, conservative care, and increasingly medical therapy can each play a role at different times.

The most important steps after diagnosis are to be seen by a team experienced in vascular anomalies, to understand the specific anatomy and behaviour of your own AVM through good imaging, and to plan follow-up that catches changes early. With those in place, many people with peripheral AVMs live active, full lives, with the condition kept under steady, careful watch.