Vascular anomaly

Vascular tumors, include hemangiomas, the most common tumors in infants, occurring in 1-2%, and higher in 10% of premature infants of very low birth weight. It occurs in 20% of low weight premature infants and 2.2 to 4.5 times more frequently in females. IH most commonly presents in the head and neck region (60%), but also involves the trunk and extremities. One third of these lesions is present at birth as a telangiectatic stain or ecchymotic area. During the first four weeks of life, 70% to 90% appear. Lesions that are situated beneath the skin may not appear until 3 to 4 months of age, when the tumor is large enough. During the first 9 months, IH undergoes rapid growth, which is faster than the growth of the child. This is called the proliferating phase. After 9 months, the growth of the tumor will decrease and equal the growth of the child for about 3 months. After 12 months, the tumor will start to involute and might even disappear. Involution occurs in one-third of patient by the age of 3 years, in 50% by the age of 5 years and in 72% by the age of 7 years. Involution may result in residual telangiectasias, pallor, atrophy, textural changes and sometimes fibrofatty residuum. Since 90% of IH is small, localized and asymptomatic, treatment mainly consists of observation and awaiting until involution is complete. IH can be treated with corticosteroids, which accelerate involution: in 95% of patients, growth is stabilized and 75% of tumors decrease in size. Intralesional corticosteroids are most effective, but may require additional injections, as the effect is only temporarily. Systemic corticosteroids may cause a number of side-effects and are only used in problematic IH, which is too large to treat with intralesional injections. During the proliferating phase, the tumor is highly vascular. Patients who undergo operative treatment during this period, are at risk for blood loss. Moreover, surgery during this phase, often leads to an inferior aesthetic outcome. However, patients may require intervention during childhood, because 50% of IH leave residual fibrofatty tissue, redundant skin, or damaged structures after involution. Waiting until involution is completed, ensures that the least amount of fibro fatty residuum and excess skin is resected, giving the smallest possible scar. After regression RICH may cause a residual deformity, such as atrophic skin and subcutaneous tissue. It mainly affects the limbs (52%), but also the head and neck region (42%) and the trunk (6%). Another option is vincristine, which has many side-effects, but has a response rate of 90%. Drug therapy is often used in shrinking the tumor and treating the coagulopathy. However, many of these kaposiform hemangioendotheliomas do not completely regress and remain as a much smaller asymptomatic tumor. However, KHE still has a high mortality rate of 30%. Although complete surgical removal with a large margin has the best reported outcome, it is usually not done because of the risk of bleeding, extensiveness, and the anatomic site of the lesion. Operative management may be possible for small or localized lesions. Removal of larger areas also may be indicated for symptomatic patients or for patients who have failed pharmacotherapy. Resection is not required for lesions that are not causing functional problems, because KHE is benign and because resection could cause deformity. Pyogenic granuloma A pyogenic granuloma, is a small benign vascular tumor that primarily involves the skin (88.2%) and mucous membranes. Pyogenic granulomas are rarely congenital. It commonly develops in infants: 42.1% develops within the first 5 years of life. This vascular tumor is twice as common in males as in females and 25% of lesions seem to be associated with trauma, an underlying cutaneous condition, pregnancy, hormonal alterations and medications. Pyogenic granulomas can also arise within a capillary malformation. Of all pyogenic granulomas, 62% is distributed on the head or neck, occurring mainly on the cheek and in the oral cavity. Lesions on the face may cause visible deformity. Numerous treatment methods have been described for pyogenic granuloma. Lesions involving the reticular dermis, may be out of the reach of pulsed-dye laser, cautery or shave excision and therefore have a recurrence rate of 43.5%. Definitive management requires full-thickness skin excision. Other options are curettage or laser therapy. Furthermore, thorough curettage and cauterization are often used for small lesions and full-thickness excision for larger lesion. ==Vascular malformations==

Vascular malformation is a collective term for different disorders of the vasculature (errors in vascular development). It can be a disorder of the capillaries, arteries, veins and lymphatic vessels or a disorder of a combination of these (lesions are named based on the primary vessel that is malformed). A vascular malformation consists of a cluster of deformed vessels, due to an error in vascular development (dysmorphogenesis). However, endothelial turnover is stable in these defects. Congenital vascular malformations are always already present at birth, although they are not always visible. In contrast to vascular tumors, vascular malformations do not have a growth phase, nor an involution phase. Vascular malformations tend to grow proportionately with the child. Vascular malformations never regress, but persist throughout life. Vascular malformations can be divided into slow-flow, fast-flow and complex-combined types. Slow-flow vascular malformations • Capillary malformation (also known as port-wine stains): Capillary malformations are flat, reddish lesions that typically affect the skin, mostly around the head and the neck, and which darken with age, in contrast to birthmarks such as salmon patch, Nevus simplex or vascular stain, which lighten or disappear within the first few years of life. Capillary malformations constitute 11% of the vascular malformations. They result from a blockage or defect of the lymphatic vessels as they are forming. 28% of all vascular malformations are lymphatic malformations. Lymphatic malformations can be treated with sclerotherapy and surgical resection. Fast flow vascular malformations All fast-flow malformations are malformations involving arteries. They constitute about 14% of all vascular malformations. • Arterial malformation • Arteriovenous fistula (AVF) : a lesion with a direct communication via fistulae between an artery and a vein. • Arteriovenous malformation : a lesion with a direct connection between an artery and a vein, without an intervening capillary bed, but with an interposed nidus of dysplastic vascular channels in between. Combined-complex vascular malformations a combination of various vascular malformations. They are 'complex' because they involve a combination of two different types of vessels. • CVM: capillary venous malformation • CLM: capillary lymphatic malformation • LVM: lymphatic venous malformation • CLVM: capillary lymphatic venous malformation. CLVM is associated with Klippel–Trénaunay syndrome • AVM-LM: Arteriovenous malformation- lymphatic malformation • CM-AVM: capillary malformation- arteriovenous malformation ==Research==

The international organization dedicated to the research of vascular anomalies is the International Society for the Study of Vascular Anomalies (ISSVA) made up of multi-disciplinary doctors, scientists and healthcare providers. Geographical vascular anomaly organizations exist as well. For example, in Australia and New Zealand The Australian Vascular Anomalies Network. ==Terminology==

The International Society for the Study of Vascular Anomalies (ISSVA) classification is a basic and systematic classification of vascular anomalies with international acceptance. Terminology used widely in the past such as lymphangioma are outdated. Newer research may only reference ISSVA terminology and, as a consequence, sources of information can be missed by doctors and patients unaware of the ISSVA convention. == References ==