Cirsoid aneurysm

A cirsoid aneurysm is the dilation of a group of blood vessels due to congenital malformations with AV (arterio venous) shunting.

Cirsoid means resembling a varix. Sometimes, a minor traumatic episode, such as a fall or bump on the head, can lead to the formation of a cirsoid aneurysm. Oftentimes these are trivial traumatic episodes.

It most commonly occurs over the head. It can also occur in places where medium vessels lie over bones without much intervening tissues between them and the skin.

The superficial temporal artery is the most commonly involved artery.

Cirsoid aneurysms of the scalp were first described in 1833 by Brecht.(4) Only 10%–20% of these arteriovenous fistulas develop following penetrating trauma to the scalp. In 90% of patients, the superficial temporal artery is the main supply to the fistula with only one dominant feeding artery in 71% of patients.(3) In the remaining cases, there is usually involvement of both the superficial temporal and occipital arteries.(3,4) Untreated patients can develop progressive scalp and facial cosmetic deformity from the markedly tortuous subcutaneous vessels. However, this condition is not life-threatening. Surgical resection of the fistula is usually successful, as was for this patient. Endovascular and percutaneous occlusion of the fistulas have been described. However, the results have been mixed.

The problem with an arterial approach is that there is recruitment of surrounding normal arteries following occlusion of the arterial feeder and draining venous structures. Arterial approaches may not often be successful in occluding the entire fistula. The results of endovascular occlusion are dependent on the angioarchitecture of the fistula, the supplying arteries and draining venous structures. Arterial approaches may not often be successful in occluding the entire fistula due to the problem of multiple feeding arteries being recruited to supply the fistula. Occlusion of the venous pouch usually requires later surgical removal of the embolic material. A delayed venous phase angiogram is needed to identify all feeding arteries and draining veins, especially if there is drainage into the deep venous sinuses and cortical veins. If the draining sinus is isolated from the rest of the cerebral circulation, it may be possible to consider a transvenous approach using newer embolic material, such as Onyx.