Stereotactically guided cavernous malformation surgery.

The incidence of a significant hemorrhage in the natural history of cavernomas is below 1% per year, but the risk of a second hemorrhage in patients with initial bleeding cavernomas is between 14% and 29%. In the light of these figures, all cavernomas ought to be resected if surgical-related morbidity can be minimized. Stereotactically guided neurosurgery offers the advantage of planning the least traumatic approach before craniotomy due to the knowledge of the exact localisation of the lesion. During a 2-year period 12 patients (age 16-54 years) with intracranial supratentorial cavernomas (size 0.5-1.8 cm) were treated by stereotactically guided microsurgery. The cavernomas were seated in a depth between 0.4 and 4.5 cm. 4 patients had an overt hemorrhage in their history. In six cases a seizure was the first symptom (altogether 8 patients had seizures preoperatively). Two patients were asymptomatic. Standard CRW (Cosman, Roberts, Wells) stereotactic system was used in all cases. The skin incision and the osteoplastic craniotomy (mean diameter 2.8 cm) were planned stereotactically. In 11 patients a transsulcal approach was used. The size of the corticotomy could be limited to less than 1 cm. Using the stereotactic method, all cavernomas were found with a high degree of accuracy. After lesionectomy a total of 1 to 2 mm of the surrounding yellow-stained brain tissue was sucked away because it contains hemosiderin and therefore iron, which may have an epileptogenic effect. No relevant surgical-related neurological morbidity was found in any patient a half year after surgery. Seven out of eight patients were free of seizures. One still had problems.