Sclerotherapy for Vascular Malformations

Venous malformation (VM) is the most common type of congenital vascular malformations and consists of malformed veins that do not function properly. Although present at birth, they are not always clinically evident until later in life. VM can occur anywhere in the body but are predominantly located in the head and neck (40%), trunk (20%) and extremities (40%).

Lymphatic Malformation (LM) is a clump of lymph vessels that forms a growing, jumbled, spongy cluster. Lymphatic malformations are unusual growths but they are benign (not cancerous). These malformations are typically apparent at birth or by two years of age. Lymphatic malformations usually slowly grow larger as the patient grows, but on occasion they do get smaller spontaneously. Certain events such as puberty, infection, trauma or bleeding into a lymphatic malformation can cause them to grow rapidly.

Vascular malformations diagnosis

• Clinical history and physical presentation
• Doppler ultrasound scan
• Magnetic Resonance Imaging (MRI) 
  
  

Treatment Options

• Conservative: Without significant symptoms, compression therapy (compression stocking) may be used for mild swelling and discomfort
• Surgery: Allows the possibility of complete removal
• Sclerotherapy: Injection of a sclerosant agent to collapse the abnormal vessels and enable scar together which lead to reduction of the malformation.
• Medication Therapy: Oral sirolimus etc.
• Ablative therapies: Cryotherapy; laser therapy; Radiofrequency Ablation; thermal ablation etc.
  
  

Sclerotherapy
Sclerotherapy is a minimally invasive procedure where the doctor injects medicine into abnormal vein or lymph vessels to make the vessel seal itself closed.

Sclerotherapy is performed by an Interventional Radiologist typically under general anaesthesia. Using ultrasound guidance, a needle will be directed into the malformation followed by contrast injection. The contrast will be followed by fluoroscopy (x-ray) to monitor the flow. If the contrast fills out the appropriate portions of the malformation, a special chemical solution (sclerosant) will be injected. This may be repeated depending on the size and distribution of the malformation. The solution irritates the vessel, causing it to swell. This swelling cut off the flow of blood or lymphatic fluid and the vessel shrinks over time.

When to consider sclerotherapy

Sclerotherapy may be done for vascular malformations that:

• are painful
• tend to bleed
  
• push on important or critical structures (eg: airway)
  
• get in the way of activities
  
• psychosocial reasons
  
  

Types of sclerosant used in the hospital

1. Absolute Ethanol (Alcohol)
   Most effective and potent but it is associated with higher local complications such as nerve injury and necrosis. It is typically used for the deeper lesions (eg: an intramuscular VM) and lesions located away from important structures.
2. Sodium Tetradecyl Sulfate (STS) or Fibro-Veins
   Widely used as sclerosing agent for decades and it is associated with fewer side effects. The mechanism of action of STS is to produce maximum endothelial damage with minimal thrombus formation leading to fibrosis of the VM, leading to shrinkage. The results may or may not be permanent. It usually causes swelling after injection, but it will typically shrink in 2-4 weeks.
3. Bleomycin
   Bleomycin causes the least amount of swelling after injection and the most appropriate to agent to treat sites where swelling is poorly tolerated such as orbits and airways. Bleomycin is a chemotherapeutic drug with thermotherapeutic properties. Its use can lead to lung fibrosis (scarring of the lung). Such lung problems have more commonly associated with larger drug doses, in older patients, patients with abnormal kidney function and when bleomycin in used in conjunction with another chemotherapy medicine.
4. Doxycyclin
   It is effective in extensive LMs because large volumes can be used in a single session and generally well tolerated. It is commonly used together with other sclerosants.
   
   

Risk of sclerotherapy

• Sclerotherapy may not block the target vessels.
  
• The sclerosant may block other vessels besides the target vessels.
• The sclerosant may cause blistering, scarring, or loss of sensation in the skin over target vessels.
• The skin over the target vessels may change color (hyperpigmentation).
  
  

Expected Outcomes

Most patients are discharged on the same day of the procedure. Patients with an underlying bleeding disorder or those with malformations around the head or neck may require hospital admission following sclerotherapy. Bruising, swelling or firmness at the treatment sites can be expected.

The treatment is usually repeated in 6 to 8 weeks.

Radiation dose

The dose you will receive is very small. There is usually no expected side effects from the radiation.

Clinic Discussion

A clinic discussion is recommended for you to have a better understanding of the clinical diagnosis. During this clinic consultation, you will be counselled on various treatment options. Treatment benefits, risks and expectations will be explored and discussed before proceeding any procedure.

Important points to note:

If you are unable to keep to the appointment, please inform us early.

To get a new appointment, please contact:

Angiography Suite
Children's Tower, Level 2
Tel: 6394 8260
Fax: 6394 8730

Operation hours:
8.00am to 5.30pm (Monday to Friday)