| 英文描述 | An arteriovenous fistula is an abnormal communicating channel between the arterial and venous systems, bypassing the normal capillary circulation. Aneurysms or varices are dilated vascular channels. Can be congenital, but most follow trauma and neoplasia. Signs depend on the location of the lesion, which includes the limbs, ear, flank, tongue, neck, and intraorbital area, with exophthalmos occurring in the latter case. The lesions may pulsate, and a bruit may be heard. Dx by angiography. Usually painless, and signs improve when pressure is placed on the artery proximal to the lesion. An arteriovenous fistula of the jejunum was associated with gastrointestinal hemorrhage in a dog, and was diagnosed at surgery. |
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