31 Surgical Treatments of Cerebral Arteriovenous Malformations: Reduction in Bleeding Risks and Seizure Control Kazuhiko NOZAKI, M.D., Nobuo HASHIMOTO, M.D, Susumu MIYAMOTO, M.D., and Akiyo SADATO, M.D. Department of Neurosurgery, Kyoto University School of Medicine, Kyoto, apan Summary: We retrospectively analyzed the clinical courses and outcomes of cerebral arteriovenous malformations in 212 patients (3-79 years old) admitted to our institute between anuary 1987 and December 1999 to evaluate the reduction in bleeding risks and seizure outcome after surgical treatment for cerebral arteriovenous malformations. Cerebral arteriovenous malformations were located in the cerebral hemisphere in 141, basal gangliathalamus in 19, cerebellum in 24, corpus callosum in 12, brainstem in 6, and others in 10 (Spetzler & Martin grade I 17, II 44, III 81, IV 56, V 11, VI 3). The initial presentation was hemorrhage in 119, seizure in 40, ischemia in 21, headache in 18, and asymptomatic in 14. The annual re-bleeding risk was 11.9% in 119 cases with hemorrhagic onset, and the annual bleeding risk was 3.2% in 93 cases with non-hemorrhagic onset. In 127 cases who suffered from hemorrhage, total extirpation was done in 97 and complete obliteration was achieved in 109 in combination with transarterial embolization or radiosurgery or both. In 85 cases without hemorrhage, complete obliteration was obtained in 55 cases. Surgical morbidity and mortality were 5.9% and 0.7%, respectively. Recurrence of arteriovenous malformations after microsurgical extirpation occurred in 4 cases after angiographical cure, and the annual bleeding risk after angiographical cure was 0.14%. In 40 cases with seizure onset, hemorrhage occurred in 4 cases, progressive neurological deficits occurred in 4 cases, and repeated seizure occurred in 4 cases. Microsurgery was performed in 28 epileptic cases and 125 non-epileptic cases. In epileptic cases, seizure was improved in 26 cases and no aggravation of seizure was observed. In non-epileptic cases, 9 cases experienced de novo seizure attack within 2 years after microsurgery, and 4 cases suffered from seizure 2 or more years after microsurgery. In 153 operated cases, 141 were seizure free with or without medication 2 years after the operation. Microsurgical resection of cerebral arteriovenous malformations not only effectively eliminates hemorrhagic risk from nidus but also improves seizure outcome. Key words: cerebral arteriovenous malformation hemorrhage seizure Surg Cereb Stroke (pn) 31: 8791, 2003
Table 1 Patients background 212 cases (1987.11999.12) Age:31y (379 y), Follow-up period: 7y1m Onset : hemorrhage 119 : seizure 40 : ischemia 21 : others 32 Location of nidus : supratentorial 177 : hemispheric 141 : deep-seated 36 : infratentorial 35 : cerebellum 24 : brainstem 11 Table 2 Annual bleeding risks of cerebral arteriovenous malformations At birth before any treatment 2.6% 186 times of hemorrhage during 87579 months Initial hemorrhage before any treatment 16.6% 47 times of hemorrhage during 3405 months After the start of any treatment angiographical cure 8.2% 33 times of hemorrhage during 4819 months After angiographical cure 0.14% 2 times of hemorrhage during 17408 months
Table 3 Recurrent cases of cerebral arteriovenous malformations after angiographical cure Age/Sex Location of nidus Size Onset Treatment Recurrence (cm) 15/F cerebellum 3 hemorrhage TAE+op hemorrhage 9y after reop 23/F lt frontal lobe 3 epilepsy op on angio 6y after radiosurgery 24/M lt basal ganglia 2 hemorrhage TAE+op hemorrhage 7y after reop 27/F corpus callosum 2 hemorrhage op on angio 3y after radiosurgery abbreviation: TAE; transarterial embolization, op; operation, angio; angiography Table 4 Treatment modalities for 50 cases associated with seizure Table 5 Seizure outcome after microsurgery Extirpation 28 (total 28) with preop TAE 10 Radiosurgery 10 (obliteration 2) Palliative TAE 13 Observation 18 Angiographical obliteration 30/50 (60%) abbreviation: TAE; transarterial embolization Epileptic cases 28 improvement 26 / 28 (93%) no change 2 / 28 ( 7%) aggravation 0 / 28 ( 0%) Non-epileptic cases 125 seizure within 2 years after surgery 9 (7%) seizure 2 or more years after surgery 4 (3%) Seizure control 2 years after operation no seizure without medication 101 no seizure with medication 40 seizure with medication 12
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