Microsurgical excision of paraventricular arteriovenous malformations

Periventricular arteriovenous malformations (AVMs) have often been deemed inoperable because of their location in critical structures. Furthermore, the excision of large lesions may be complicated by the potential for serious brain swelling and hemorrhage due to "autoregulation breakthrough." Nonetheless, the unfavorable natural history of the untreated disease in a symptomatic young patient has induced us to approach these lesions using staged microsurgical excision combined with elective barbiturate coma for maximal cerebral protection. Between 1979 and 1983, six patients (four female, aged 12 to 60 years, and 2 male, aged 14 and 29) who harbored large AVMs in the basal ganglia, thalamic, and hypothalamic areas presented with subarachnoid hemorrhage (2 cases), progressive neural deficits (3 cases), and intractable headache (1 case). Nineteen staged operations were performed for the complete excision of these lesions. Among the first three patients, there was one death due to "autoregulation breakthrough" hemorrhage into the lateral ventricle during the excision of a lesion approached through the sylvian fissure using standard anesthesia techniques. This led to the adoption of the transventricular surgical approach and elective barbiturate coma to facilitate exposure of the lesion and to protect the adjacent vital structures from potential ischemia. Three patients were treated in this fashion uneventfully. Of the five successfully treated patients, two have returned to their preoperative status and one has completely recovered from global hemispheric ischemia and hemiplegia. The hemiparesis in one patient worsened as a result of postoperative hypertensive intraventricular hemorrhage, and one patient developed mild dysphasia and hemiparesis. This experience suggests that this approach offers a valid therapeutic regimen for the treatment of this disease. During the same period, three patients--one man (age 23) and two women (aged 29 and 22)--harboring four intraventricular AVMs presented with intraventricular hemorrhage. After the acute effects of chemical ventriculitis and hydrocephalus were overcome with cerebrospinal fluid diversion, all four lesions were excised microsurgically using the transtemporal approach. One patient demonstrated significant and progressive improvement of her preoperative memory deficit. The remaining two patients have both returned to their preoperative employment.(ABSTRACT TRUNCATED AT 400 WORDS)