Fundamentals of AVM surgery: an institutional experience

ABSTRACT

Arteriovenous malformations [AVM] of the brain are congenital lesions and remain dormant for many years but can haemorrhage, cause seizure or impair brain function. Modern therapeutic modalities for AVM include microsurgery, intravascular neurosurgery and stereotactic radiosurgery. There is significant risk of intraoperative haemorrhage due to abnormal vessels as well as due to change in haemodynamic pattern of surrounding brain after excision. Inadequate coagulation of feeding vessels and draining channels, loss of plane between nidus and normal brain, persistent residual or daughter sinus and inadequate intraoperative blood pressure control are the main causes of haemorrhage. The main important aspect in AVM surgery is to identify the plane between the nidus and normal brain and work around the nidus. It is very important to aggressively reduce intraoperative haemorrhage and prevent or minimize the dilation of abnormal capillaries and arteries on the basis of fundamental surgical strategy, i.e., feeder-nidus-drainer. Adequate control is the key factor in prevention and treatment of haemorrhage. In a period of 8 years, from 1994-2003, our department dealt with 290 cases of AVM. In 212 patients, operative removal was performed, which included 89 cases with intracerebral haematoma. In 39 cases, embolisation and/or gamma knife was preferred