Vascular abnormalities
The terms ‘vascular abnormalities’ or ‘vascular anomalies’ cover a mixed group of congenital (sporadic as well as inherited), developmental vascular malformations. These are the most common congenital malformations (‘birthmarks’), affecting approximately one in 22 children. They predominantly (approximately 60 %) occur in the head and neck region, the oral cavity (mouth) is frequently involved, and skin and/or mucosa (lining of the mouth) may be affected. There may be additional soft tissue abnormalities. It is worth noting that another common type of congenital malformation, cysts also predominantly affect the head and neck region.
The majority of these lesions are harmless and do not require treatment or only need minimal interventions. However, severe forms of vascular malformations may require radical interventions.
The exact diagnosis of the type and extent of a vascular abnormality not only requires the careful consideration of the medical history and examination, but typically needs to consider the results of a range of imaging investigations. For these soft tissue lesions, a range of ultrasound and MRI imaging techniques are the most suitable and most widely used diagnostic tools. The exact characterisation of some complicated and extended vascular malformations in the head and neck region, as well as in other body parts, requires sometimes sophisticated imaging modalities that are capable of showing flow of liquids.
Exact diagnosis and characterisation of extensive vascular abnormalities is important because this informs the choice of the most suitable management and treatment options. These options vary strongly, depending on the type, location and size of the lesion. In addition, vascular abnormalities very rarely may be one expression of a more profound syndrome, similar to the findings that cleft lip and palate sometimes are only one of several aspects of a more general condition or syndrome. Such causes of vascular abnormalities need to be excluded, or confirmed, over the process of arriving at a diagnosis.
The broad range of lesions affecting the vascular structures of the body are classified according to the structures affected. Broadly, these lesions are divided into two main categories:
- vascular tumours (including haemangioma);
- vascular malformations.
Haemangioma is a normally benign tumour of the lining of a blood vessel (endothelium), may not be present at birth but rapidly growing in early infancy and resolving spontaneously later in childhood. Haemangioma is the most common, benign childhood tumour. It affects approximately 10 % of white infants, for example. Haemangioma in most cases will be managed by ‘watch and wait’.
Vascular malformations are present at birth, grow at the same rate as the infant and will typically not resolve spontaneously. Vascular malformations can affect the lymphatic system, the veins (venous malformations), arteries and veins (arteriovenous malformations) or may be limited to the small, peripheral blood vessels (capillary malformations). These lesions are further subdivided into low-flow and high-flow malformations, depending on the flow rate in the affected vessels.