Capillary malformation

Salmon patch (erythema nuchae) and port wine stains (naevus flamus) are examples of capillary malformations (CMs). Salmon patches are very common, occurring in approximately 40% of newborns. They are red macular lesions commonly involving the nape of the neck, the upper eyelids or on the forehead between the eyebrows. They become more prominent when the infant cries or has a fever, and usually disappear by 2 years of age. Port wine stains (Figure 13.2a) occur in 0.3% of newborns and are well-demarcated purple or dark red patches most commonly affecting the face. They are usually dermatomal in distribution and unilateral, growing proportionately over time with the child. They do not regress spontaneously and can evolve from being flat to become nodular and thickened. Associated bone and soft tissue hypertrophy can occur. Port wine stains are usually an isolated abnormality, but can occur as part of the Sturge–Weber syndrome. This is the association of a capillary vascular malformation affecting one branch of the trigeminal nerve of the face, with a leptomeningeal vascular malformation and vascular malformation of the eye (Figure 13.2b).

Venous malformations

Venous malformations (VMs) consist of abnormal venous channels of varying size within a connective tissue and fatty stroma, which connect with adjacent veins. Local intravascular coagulopathy is a feature, which combined with slow venous flow makes them prone to thrombosis. Pain and swelling secondary to thrombosis are common presenting symptoms of VMs in late childhood or early adulthood. Symptoms may also relate to the size and site of VM. For example, those located within muscles can be painful on movement. The lesions are non-pulsatile, often with associated swelling and blue discolouration of the skin, and can be tender (Figure 13.3). They classically distend when dependent and empty on elevation of the lesion, depending on the number and integrity of the venous channels. Firm small calcified phleboliths may be palpable secondary to thrombosis. Rarely, VMs are multiple, located in the skin and visceral organs, as part of the blue rubber bleb naevus syndrome.

Lymphatic malformations

Lymphatic malformations are the second most common vascular malformation. Arising from lymphatic vessels, the majority are present at birth with 90% seen at 2 years of age. Lymphatic malformations are most commonly located in the neck, where they are often known as cystic hygromas (Figure 13.4).

Mixed malformations

There is considerable overlap between venous and lymphatic malformations with many lesions having various different tissue morphologies within different areas of the same malformation.

Imaging vascular malformations

The diagnosis of vascular anomalies is mostly through clinical assessment, but a handheld Doppler ultrasound is a useful adjunct to gauge the presence of arterial flow.

Duplex ultrasound is an accessible, non-invasive first-line investigation that can give more specific information regarding exact location, presence of vascular spaces and flow characteristics.

Magnetic Resonance Imaging (MRI) gives detailed analysis of lesions without ionising radiation and can more fully assess the extent of infiltrative and deeper lesions. MRI is also useful in evaluation of those vascular anomalies that are clinically indeterminate and can aid in their differentiation from more sinister lesions. Detailed information regarding the anatomical extent, and vascular supply, can be obtained as a prelude to treatment (Figure 13.6a and b).

Computed Tomography (CT) is not routinely used in the assessment of vascular anomalies. The radiation dose of a diagnostic CT is justified only in rare circumstances.

Catheter venography/angiography is essential for treatment planning of both low- and high-flow malformations, providing detailed information about flow characteristics and feeding and draining vessels. It is usually performed during the same session as the treatment (Figure 13.7b and c).

Percutaneous sclerotherapy is the primary treatment if conservative measures have failed to manage symptoms, in particular pain. Sclerotherapy aims to obliterate the venous lumen and shrink the lesion. Following direct puncture of the venous channels using ultrasound and fluoroscopic guidance, agents such as ethanol, bleomycin or sodium tetradecyl sulphate are injected (Figure 13.6c).

Swelling and pain in the region of the malformation generally increases in the first 2 weeks post procedure, and patients must be warned of the expected time course of symptom improvement, which can take several months. Extensive VMs may require multiple treatment sessions. Approximately 20% of the patients can expect to have complete relief of symptoms after one course of treatment, 60% should have a decrease in symptoms, while 20% receive no therapeutic benefit. Complications occur in up to 15% of the cases. These include skin necrosis and nerve damage (which can be transient). PE (pulmonary embolism), DVT (deep vein thrombosis), DIC (disseminated intravascular coagulation) and death are very rare post sclerotherapy.

Lymphatic malformations

Percutaneous sclerotherapy using a variety of sclerosants (notably bleomycin or doxycycline) can achieve satisfactory long-term outcomes, particularly in lesions with a macro-cystic component. There are difficult-to-treat subsets of lymphatic malformations that may also require surgical debulking.