**8. Treatment**

The treatment plans of cAVM are most appropriately made by a multidisciplinary team of experienced clinicians with the consideration of size, location and vascular features of the AVM [19]. While making the decision, whether a patient should undergo AVM treatment, several factors have to be considered including the short- and long-term risk of hemorrhage, feasibility, associated aneurysm, patient's age, risks of intervention, availability of interventional radiologist and size and compactness of the nidus. The short-term and long-term hemorrhage risk is associated with a history of raptured cAVM, patient age, AVM location, size and vascular morphological features.

*Cerebral Arteriovenous Malformation from Classification to the Management DOI: http://dx.doi.org/10.5772/intechopen.86659*

The three types of modalities of treatment are microsurgery and excision of cAVM, embolization and stereotactic radiosurgery. It's frequent that these modalities are used in combination to achieve the complete treatment. In a systemic review, it was found that available treatment modalities were associated with risks including 5.1–7.4% of the median rate of permanent neurologic complications or death and incomplete efficacy of 13–96% [20]. Medical management of cAVM is considered when the patient has suffered a devastating neurological deficit; cAVM is very extensive, located deep in the brain, with blood supply primarily from deep perforating vessels, which are not amenable to endovascular or radiosurgical therapy, advanced age and poorly controlled comorbidities. We will discuss these modalities in the following subheadings.

#### **8.1 Microsurgical cAVM excision**

Microsurgical AVM excision is the most effective treatment of cAVM; it has the longest history of use for the definitive treatment of cAVMs and offers the best chance of immediate cure in patients at high risk of hemorrhage [19]. Factors associated with increased surgical risk are large size, deep venous drainage, deep location, diffuse nidus and feeders from deep perforating system. Surgeons should follow few basic surgical principles, cAVM excision should be an elective procedure, irrespective of the ruptured or unraptured cAVMs, preoperative steroids, anticonvulsants and antibiotics to be started, a wider craniotomy and dural opening, if the nidus is below the surface, an arterialized draining vein (red vein) can be followed to the AVM, localization may be assisted with ultrasound or frameless stereotaxic, dura should be open carefully, circumferential dissection of the nidus layer by layer, at least one major draining vein should be preserved till end of dissection, at end of dissection this vein becomes bluish proving that feeders have been eliminated, securing the individual vessels can be done with low power bipolar coagulation, but care should be taken as the excessive bipolar coagulation usage can cause retraction into eloquent tissue leading to the significant neurological morbidity. The complete AVM excision should be documented by post-op angiogram. Excision of the whole nidus is necessary to protect against rebleeding. If cAVM are high-flow, preoperative embolization should be considered, and cAVM supplies with multiple vascular territories may require a surgical staging. If cAVM are ectatic, high blood flow and irregular vessels will help in the identification. The feeding arteries (**Table 7**) can be distinguished from draining veins not by sight or look, as the veins will have arterial blood but by noting if the distal vessel collapses with gentle occlusion of the vein. The surgeon should always secure the feeding artery as close to the nidus as possible to ensure that this is not a passage artery feeding the normal brain, unless there is definite evidence on an angiogram that an artery is a direct nidus feeder.


#### **Table 7.** *Differentiation of the artery from the vein in cAVM.*
