NS17 SURGERY REMAINS THE TREATMENT OF CHOICE FOR AVMS?

The reported annual risk of haemorrhage for conservatively managed AVMs varies from less than 1% to more than 33% depending on the combination of the presence or absence of some of the following variables: haemorrhagic presentation, presence of aneurysms, the presence of exclusive deep venous drainage, and a deep location was deep. Over time, the acquisition of wear‐and‐tear associated pathologies increases the risk of haemorrhage for those that initially present with a low haemorrhage risk. It is likely that the long‐term risk is in excess of 50% over 20 years. The combined morbidity and mortality from haemorrhage is 50%. Once an AVM has been diagnosed there are four treatment options to be considered to eliminate the risk of haemorrhage. Surgery, focussed irradiation, embolisation or a combination of treatments. Consideration needs to be given to both the likelihood of haemorrhage risk elimination and the time to achieving this goal and morbidity of the procedure. Surgery for Spezler Martin grades less than 3 have close to 100% likelihood of cure and a risk of treatment morbidity less than 5% of surgery for the vast majority of cases. This result is unlikely to be approached by other modalities. For grades above 2 AVMs when the nidus is less than 3 cm, without feeding artery aneurysms or recent haemorrhage and has lenticulostriate supply, focussed irradiation is likely to be the treatment of choice. But for all other AVMs surgery remains the only reliable curative option. Combination treatments are ineffective in reducing the risks except when embolisation precedes surgery.