Vascular Malformations
Vascular Malformations Investigations
Ultrasound
MRI
Biopsy
Angiography
Arteriovenous Malformations
Arteriovenous Malformations are abnormal structures arising from arteries and veins. These can be quite difficult to treat. They can also be found in association with other malformations or as part of a syndrome. They may first appear as a red patch but enlarge with time. They grow in proportion to the child’s growth and at puberty they may enlarge even further. The overlying tissue enlarges with time and if involving a limb, there will be an enlargement of the whole limb.
Arteriovenous malformations are investigated by duplex ultrasound, angiography and MRI.
Larger symptomatic lesions are treated with embolisation.
Venous Malformations
Venous malformations are abnormal vein structures present from birth. They grow in proportion with the body but never regress on their own, they will not resolve without treatment.
Lesions may appear as soft, bluish lumps on the skin, or as colourless lumps when deeper. Very deep malformations within muscles or joints may not be visible at all and can present with localised pain. While venous malformations are generally soft and compressible, repeated clotting can cause them to harden in certain areas. In some cases, malformations arising from major vein trunks may resemble advanced varicose veins.
Diagnosis is made using duplex ultrasound and MRI. Ultrasound helps confirm the diagnosis and determine the type of malformation, while MRI establishes its extent.
At Sydney Skin and Vein Clinic, venous malformations are treated with Endovenous Laser Ablation (EVLA) for larger lesions and ultrasound-guided foam sclerotherapy for smaller ones. EVLA in particular has proven highly effective in providing long-term relief.
Lymphatic Malformations
The most common lymphatic abnormality is lymphatic hypoplasia, reduced or absent lymphatics, which can cause lymphoedema, a form of swelling caused by a build-up of lymphatic fluid in the tissue. This may be present from birth or first noticed in childhood.
The second type is cystic lymphatic malformation, which may consist of large (macro) or small (micro) cysts, or both. Surface lesions can appear as fluid-filled blebs or warty skin lesions, while deeper lesions present as swelling beneath normal looking skin. Although always present from birth, these malformations may go unnoticed until a complication such as bleeding, infection or sudden swelling occurs. If located near the airway or eye, such swelling can be critical.
Cystic lymphatic malformations may occur alongside other vascular malformations, including capillary, venous, and arteriovenous combinations. The visible surface of a malformation is rarely an accurate indication of its full extent. MRI is the most reliable method for assessing the deeper components, while ultrasound and Doppler flow studies assist in diagnosis and evaluation of associated vascular elements.
Treatment requires a multidisciplinary team of specialists including dermatologists, interventional radiologists and surgeons. A thorough diagnosis and assessment of the malformation’s extent is essential before treatment begins.
Treatment depends on the size and location of the lesion, and typically involves draining the cysts under ultrasound or fluoroscopic guidance, followed by injection of a sclerosant. The choice of sclerosant depends on the size of the lesion, with agents including doxycycline, sodium tetradecyl sulphate, bleomycin and OK-432. Note that OK-432 is not a registered drug in Australia, and the other agents are more commonly used. Most patients require three to four sclerotherapy treatments, after which any residual cysts may be surgically removed.
Capillary Malformations
Capillary malformations, formerly known as port-wine stains, are caused by structural defects in the capillary vessel wall. They commonly appear on the face shortly after birth and tend to darken and thicken in texture with age.
While capillary malformations may occur in isolation, they can also be associated with underlying venous, arteriovenous or lymphatic malformations, soft tissue abnormalities, or syndromes such as Klippel-Trenaunay or Sturge-Weber.
Treatment can begin as early as six months of age. Without early treatment, capillary malformations will not resolve on their own. Treatment often requires a combination of approaches, which may include Pulse Dye Laser therapy.
Complex Malformations
These malformations are often mistaken for “varicose veins”; however, they are present from birth and are unilateral, affecting a single limb or one arm and leg on the same side of the body.
Klippel-Trenaunay Syndrome is a combination of capillary, venous and lymphatic malformations. It typically presents with a discrepancy in limb length, with one leg longer and wider than the other, alongside a capillary malformation and a large vein on the affected side. Complications can include blood clots, skin changes above the lateral ankle such as pigmentation, dermatitis, lipodermatosclerosis and leg ulcers. Children with Klippel-Trenaunay Syndrome should be reviewed by an orthopaedic surgeon and physiotherapist to monitor limb length changes, as scoliosis and other spinal problems may also develop. Compression stockings are important in slowing the progression of this condition.
At Sydney Skin and Vein Clinic, we treat Klippel-Trenaunay Syndrome using Endovenous Laser Ablation and ultrasound-guided foam sclerotherapy.
Parkes Weber Syndrome is similar to Klippel-Trenaunay Syndrome, with the addition of an arteriovenous malformation.