Abstract
This chapter describes the surgical management of acutely ruptured arteriovenous malformations (AVM). Modern treatment of many AVMs has become successful and safe because of the technical advances that include the application of high-quality angiography, the operating microscope, bipolar cauterization, endovascular embolization, and stereotactic radiosurgery. AVMs have three structural components that include a core of dysplastic vessels (nidus), feeding arteries, and draining veins. The nidus is a tangle of abnormal vessels that connect arteries directly to veins without intervening capillaries. This absence of capillaries produces a low resistance, high-flow shunt for blood through the AVM that dilates feeding arteries and thickens the walls of draining veins. Treatment risk is affected by the malformation's size and location, the number and distribution of feeding arteries, the pattern of venous drainage, the amount of flow through the AVM, and the amount of cerebral steal from adjacent normal brain. Many of these factors are interrelated, allowing a grading system based on a few important variables. For those patients presenting with symptoms of an intracerebral hematoma from a ruptured small AVM, surgery of both lesions may be relatively easy and indicated. With technically difficult AVMs, definitive resection can be delayed for some weeks after clot removal to permit medical stabilization and some neurological recovery.