Microsurgery for cerebral arteriovenous malformation management: a Siberian experience.

Cerebral vascular malformations remain among the most difficult neurosurgical entities to treat. We report a retrospective study of the outcome in 95 consecutive patients with angiographically revealed arteriovenous malformations (AVMs). Fifty-four patients underwent microsurgical total AVM removal (group I). Forty-one patients who refused open surgery (group II) were managed either by endovascular embolisation (16 cases), radiosurgery (three) or followed up with medical treatment for their symptoms. In the first group pretreatment with the non-selective beta-blocker propranolol before surgery, the current neuronavigation techniques, intraoperative embolisation and AVM nidus colouring in high flow AVM were used for total microsurgical excision of the lesions. All AVM patients but one survived microsurgery. The mortality rate was 1.8% for group I. Six patients with grade IV-V AVM developed new temporal neurological symptoms following surgery. Four of them recovered completely in 3-6 weeks; two patients remained with mild persistent monoparesis and with homonymous hemianopsia postoperatively. In ten of 13 epileptic patients surgery produced a cure. No patient re-bled following surgery. No postoperative normal perfusion pressure breakthrough occurred. In the second group ten patients (24%) developed intracerebral haemorrhages, six of ten patients demonstrated progressive seizures. The mortality rate in group II totalled 17% over 6 years. Microsurgical management approaches must consider preoperative correction of impaired cerebral autoregulation, neuronavigation for preoperative planning and intraoperative orientation, intraoperative embolisation and dying of the nidus for large high-flow AVMs.