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  Venous Angioma (Developmental Venous Anomaly, (DVA):

Contents of this page, which is Venous Angioma Page 1:

  1. What is a venous angioma (Developmental Venous Anomaly, DVA)? Click here
  2. How common are venous angiomas? Click here
  3. Why do venous angiomas develop? Click here
  4. What are the symptoms of venous angiomas? Click here
  5. More about venous angioma hemorrhage. Click here

Contents of Venous Angioma Page 2:

  1. What are the complications of venous angiomas? Click here
  2. How are venous angiomas detected? Click here
  3. How are venous angiomas treated? Click here
  4. Radiological images of a venous angioma. Click here

 


1. What is a venous angioma (Developmental Venous Anomaly, DVA)?

A venous angioma, also referred to as a "developmental venous anomaly" (DVA) or sometimes "venous malformation" is basically an extreme variation of veins draining normal brain tissue in that region. That is, a venous angioma (DVA) by itself is not necessarily "abnormal"; it's rather a variation of normal. However, having stated this, it should be noted that some studies have found that some veins (or all veins) that comprise a venous angioma have structural abnormalities compared with more normal veins. Regardless, most neurosurgeons regard venous angiomas by themselves as extreme variations of normal venous drainage.

The veins that comprise a venous angioma usually form a little cluster ("star burst" or "caput Medusae" - looks like a "head of snakes"), and these veins generally drain into a larger "collector" vein. The collector vein is usually on the surface of the brain, but sometimes there may be deep drainage too. The pattern (arrangement) of these veins is frequently simple, but may at times be more complex looking. Between the veins that make us the venous angioma is normal brain tissue. Sometimes one or more of these veins can appear extra dilated and may be more thin walled than other veins in the brain. Venous angiomas tend to occur near the frontal horns of the ventricles (fluid filled spaces of the brain) and also in the cerebellum (small part of the brain at the lower back part of the head).

Importantly, venous angiomas are frequently associated with cavernous malformations (cavernomas) and it is through this association that trouble potentially arises ( take me to the section on Cavernomas now). Venous angiomas on their own don't tend to cause any trouble and, with few (reported) exceptions, should generally be left alone (see Section 8., below).

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2. How common are venous angiomas?

The true prevalence of venous angiomas is not known, but autopsy series indicate that they are much more common than cavernous hemangiomas, aneurysms and arteriovenous malformations. The prevalence of venous angiomas (i.e., their presence at any one time in the general population) is probably somewhere between 5-10%; it is higher in imaging series compared with autopsy series. Venous angiomas therefore represent the most common blood vessel (vascular) "anomaly" in the central nervous system.

 

3. Why do venous angiomas develop?

There are no well established risk factors for venous angioma formation. They are thought to be nonhereditary (i.e., not inherited from your parents). Venous angiomas are considered "congenital anomalies", i.e., persons are born with these lesions, they don't simply "develop" these in later life. Some venous angiomas may themselves undergo evolutionary changes over the years that they are observed (i.e., the lesion itself changes radiologically, or in rare instances may have a second type of vascular anomaly develop in close proximity) but this is uncommon and it is therefore thought that most venous angiomas do not undergo any significant change at all. Most venous angiomas occur alone, while some are associated with other vascular malformations such as cavernous hemangiomas. Some venous angiomas occur in multiple sets within the brain (i.e., several of them may be found rather than just one, as in "blue rubber bleb nevus syndrome").

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4. What are the symptoms of venous angiomas?

Alone, venous angiomas tend not to cause any symptoms. That is, the majority of venous angiomas are thought to remain dormant or silent throughout life. However, some do cause problems such as seizures or brain hemorrhage. Hemorrhage from these vessels, although very rare, can cause sudden onset of headache, associated with one or more of the following: nausea, vomiting, sleepiness ("somnolence" or "obtundation") and weakness in one or more limb(s), or some other neurological disability. They are typically not associated with chronic headaches or migraines, however, theoretically, one or more veins comprising the angioma can spontaneously "clot off" (thrombose), leading to local venous hypertension (back pressure buildup in the region's venous system) that can manifest as headache. Interestingly, if the venous angioma occurs in association with a cavernoma ( take me to the section on Cavernomas now), it is the cavernoma that usually causes a problem, and not the venous angioma.

5. More about brain venous angioma hemorrhage.

Hemorrhage from a venous angioma is a very rare event. It is more likely to occur if the venous angioma is associated with a cavernous hemangioma, and in such a setting, it is the cavernous hemangioma that usually bleeds, not the venous hemangioma ( take me to the section on Cavernomas now). If the venous angioma itself is thought to have bled, it is probable that one or more of abnormal-walled vein comprising the angioma ruptured. Again, this has been reported in the literature, but is rare.

For general information about brain hemorrhage, click here.

 

 

 


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