[Surgical treatment of supratentorial arteriovenous malformations]

The authors present their experience in the surgical treatment of supratentorial arteriovenous malformations. A few morphological data on the structure of these lesions are described, owing to their surgical relevance. The principles influencing the operative decisions--such as the age of the patient, his clinical history, the site and size of the malformation--are discussed. The operative strategy adopted for the removal of these lesions are articulated in various points: the organization for a long-lasting procedure, the use of the operative microscope and bipolar coagulation, a wide surgical exposure, a particular care for dural feeders and a wide arachnoidal opening, the trial of hypotension, the early closure of deep feeders, the saving of draining veins for as long as possible, the dissection along the sulci and into the white matter, the saving of functional arteries and accessory veins, the techniques adopted against paraventricular bleeding and hemorrhage from venous sinusoids, the coagulation of deep vessels, a particular care for possible AV fistulae under the main drainage, the "backward" technique, the "rosary-like" coagulation, a particular care for a possible division of the malformation into partitions. Particular surgical problems can occur in large AVMs, with diffuse hyperemia and hemorrhages due to anomalous perfusion of the tissue adjacent to the AVM; in these cases, controlled hypotension appears useful. The problems faced in the surgical approach to AVMs located in specific areas--such as cortical AVMs with deep extension, cortico-basal and cortico-interhemispheric AVMs, callosal AVMs, AVMs of the insula and basal ganglia, intra- and para-ventricular AVMs, juxtapeduncular and juxtasplenial AVMs--are finally discussed.