Introduction: Treatment selection for patients=60 years with intracranial arteriovenous malformations(AVMs) requires careful consideration of natural history and post-treatment hemorrhagic risk. We aim to directly compare the natural history of AVMs with post-treatment hemorrhagic risk in patients=60 years.
Methods: We retrospectively reviewed our institutional AVM database of 683 patients. Patients=60 years at diagnosis were included. Treatment modality was divided into 4 groups: surgeryembolization(SE), radiosurgeryembolization(RE), embolization only(EM), and observation(OB). Natural history of AVMs was defined as the annual risk of hemorrhage under observation. Risk of hemorrhage after treatment was also calculated.
Results: Seventy-three patients(10.7%) satisfied inclusion criteria, and 61 patients with complete data were included. Average age was 68.47.5 years, with 55.7%(n=34) male. Spetzler-Martin grades were: grade I(n=14,23.0%), grade II(n=25,41.0%), grade III(n=17,27.9%), grade IV(n=4,6.6%), grade IV(n=1,1.6%). Twenty-seven(44.3%) patients presented with intracerebral hemorrhage(ICH). Treatment modality for all patients were: SE(n=11,18.0%), RE(n=16,26.2%), EM(n=2,3.3%), OB(n=32,52.5%). At last follow-up, average modified Rankin Scale(mRS) was similar between observed and treated patients(p=0.883). Overall obliteration rate is 65.5%, with 100.0% obliteration in SE and 43.8% in RE group(p<0.001). Four patients(12.5%) who underwent OB experienced spontaneous obliteration. During an average follow-up period of 2.83.2 years, five patients experienced hemorrhage, with 2(12.5%) in RE, 2(6.3%) in OB and 1(9.1%) in SE, corresponding to a natural history of 2.3% annual hemorrhage rate and a post-treatment hemorrhagic risk of 3.6%. This post-treatment hemorrhage risk was 2.4% in SE and 4.9% in RE group. One patient in SE experienced delayed angio-negative hemorrhage 13 years after AVM obliteration. Presentation with ICH was associated with a trend toward higher risk of follow-up hemorrhage(p=0.093).
Conclusions: Definitive treatment for AVM patients=60 years should be considered cautiously. Although post-treatment obliteration rate is higher, the subsequent hemorrhagic risk may exceed that of its natural history. For AVMs deemed to be high risk for hemorrhage, surgical treatment achieves a higher rate of obliteration.
Patient Care: Our current study demonstrates that for patients over the age of 60, a general conservative management should be considered given similar or even higher post-treatment risk. If definitive treatment must be initiated for patients deemed to be at high risk for subsequent hemorrhages, a surgical approach appears to be the optimal treatment modality. This study identifies the superior treatment strategy for a select cohort of patients, and helps to reduce unnecessary procedures that may expose patients to a greater risk of hemorrhage.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Understand that the natural history of AVM in patients over 60 years old is 2.3%
2) Understand that the post-treatment hemorrhagic risk is 3.6%, with SE being 2.4% and RE being 4.9%
3) By comparing these hemorrhagic risks, a more prudent selection of management strategy for this population should be considered in the context of AVM hemorrhage risk.