Selection of treatment modalities for cerebral arteriovenous malformations: a retrospective analysis of 348...

The objective was to establish the selection criteria for the optimal management modalities for cerebral arteriovenous malformations. We analysed the complications and late outcomes in 348 consecutive cases (132 microsurgical resections, 202 stereotactic radiosurgeries, 8 embolisations only, 6 combined treatments) managed at Yonsei University Hospital from 1988 to 1997. Files for all patients were analysed. The outcome was classified into good for the patients who returned to their previous job with or without neurological deficits, fair for the patients who were unable to return to work but performed daily activities independently with minor deficits, and poor for the patients who were performing dependent daily activities with major deficits. The outcome of microsurgery was considered good in 108 patients (81.8%), fair in 18 (13.6%), poor in 4 (3.1%), and 2 (1.5%) patients died. Initial insults and haemodynamic complications were the major cause of an unfavourable outcome. The cumulative occlusion rate of the nidus after radiosurgery was 10.2% within 12 months, 75.3% within 24 months, and 89.8% within 36 months. Perilesional imaging changes with neurological deficits (4 permanent and 6 transient, 4.8%) and haemorrhage (16 patients, 7.7%) during the latent interval were the major cause of an unfavourable outcome (1 poor, 4 dead after radiosurgery). Postradiosurgery bleeding occurred frequently within 6 months (6 patients), and between 13 and 24 months (8 patients). In conclusion, selection of treatment modality for cerebral AVMs depends on the preoperative evaluation of the risk/benefit ratio in each case. Microsurgical removal, which eliminates the risk of bleeding immediately, is preferred for lesions in non-eloquent areas. Radiosurgery is an effective treatment modality for small lesions in eloquent areas, but has a substantial risk of haemorrhage during the latency period. Results of this study suggest that microsurgical removal should be considered for lesions in eloquent areas with high haemorrhage risk, such as prior haemorrhage, medium to large size lesion, and single deep venous drainage.