Low-Flow Vascular Malformations

Vascular malformations involve the abnormal development of blood vessels in various parts of the body. These malformations can be categorized based on the volume of blood they allow to pass through.

There are two types:

• a) Low-flow vascular malformations are lymphatic or venous.
• b) High-flow vascular malformations are arterial or arterio-venous.

Low-flow VMs are formed by either venous or lymphatic or both of the blood vessels. These are called Low flow vascular malformations considering the speed of flow of fluid in them. They are the abnormal bunch of vessels conducting blood or lymph fluid within them and forming a mass-like appearance.

They can develop small stones like nodules within them because of the slow speed of the fluid passing through them.

These can occur in any part of the body and are usually painless.

They are quite very commonly seen by plastic surgeons on the face, hands, and feet.

Physically they appear as –

• Very soft swellings which, on touching, feel like bags of worms, as commonly mentioned.
• They usually decrease in size after lying down and increase on prolonged standing.
• They appear bluish-pink in color and do not cause any pain.
• On deeper palpation, small nodules can be felt in them.

They may cause complications such as:

• Body part disfigurement
• Recurrent ulceration or bleeding
• Oozing of fluid from the multiple vesicles present over the skin overlying the swelling (in a few cases).
• Compression of underlying structures leads to related symptoms like pain, distal limb ischemia, swelling, etc.
• In young children, if the malformation is large, it may lead to disproportionate body growth.

To avoid the above complications, early treatment is recommended as soon as diagnosis is made.

• In smaller children, treatment may be delayed until they reach the age of 2 years, as these malformations can regress spontaneously.
• In adults, a “wait and see” approach is generally not advisable.

If left untreated, the swelling can become so large that it can involve major blood vessels or vital organs completely. In such cases, surgery is avoided and not done because it may lead to dysfunction of the involved organ which may cause more severe complications.

Diagnosis involves a clinical examination to assess features such as soft consistency, bluish color, and increased size with a change in body position. Additionally, an MRI scan is routinely performed to determine the anatomical extent of the lesion in all dimensions.

Various modalities of treatment for them include:

• A. Medical treatment by beta blockers . It helps only in small children if the malformation is made of small capillaries.
• B. Ultrasound-guided injection of sclerosant or bleomycin into the swelling for the treatment of small, single lymphatic and venous malformation
• C. Wide local excision surgery is the treatment of choice in low-flow VMs with preservation of surrounding vital structures.

The surgical procedure for low-flow VM can be highly challenging and technically demanding if it is big and widespread. Surgery is the treatment of choice for low-flow vascular malformations inaccessible locations like the face and is usually done by plastic surgeons.

The procedure requires a lot of preparation from both the patient and the doctor.

During the surgery, feeder vessels are identified, ligated and mass is debulked or excised.

1. Possible complications – should be discussed at length with Dr Amit Agarwal as the low-flow vascular malformations can be quite deep and involve a lot of nearby important structures.

2. Requirement of more than one stage in excision- Sometimes in few cases-

• a) if the extent of the malformation is too extensive and deep and
• b) if the excision requires the sacrifice of major vessels or nerves or
• c) If it endangers the survival of the part,
• Then complete excision is not done and part of the malformation which is near the vital structures is left behind so that the function of the part is less disturbed.
• The remaining part can be exercised in a separate stage after a few months.

3. The method of coverage of the created defect after the excision of malformation should be agreed upon by the patient and his or her attendants.

After removal of the malformation, a defect may be created which may require simple skin suturing or post-surgical reconstruction with flap/skin graft cover.

• Skin grafting may be done if the defect is not very deep and vitals structures are embedded deep and not exposed.
• Flap Reconstruction which is usually done when any critical part is exposed like bones, tendons, and joints and it becomes really important to preserve them for normal functioning. This can be done with the local flap or microsurgical-free flaps . A well-blood-supplied tissue is taken from the adjacent area or from other areas of the body to cover the part of the limb with it.

The recurrence rate is high in LARGE and GIANT low-flow malformations as complete excision is not possible in such cases and debulking is done to lessen the symptoms of the malformation on the body.