Objective: Few published studies have focused specifically on the unique management issues encountered in treating patients with arteriovenous malformations (AVMs) and associated intracranial aneurysms. The primary objective of this study was to retrospectively review the clinical and radiographic features of these patients.
Methods: Medical records of all patients seen at Stanford University Hospital between 1988 and 1996 with a diagnosis of AVMs were retrospectively reviewed. Aneurysms were identified by conventional angiography and characterized by size, number, and location relative to the AVMs. AVMs were graded according to the Spetzler-Martin scale. Odds ratios were calculated for the risk of intracranial hemorrhage. Variables included age, sex, number of aneurysms, and AVM grade.
Results: Forty-five of 600 patients (7.5%) were identified as having coexisting intracranial aneurysms. All 45 patients had high-flow malformations, and 58% had AVMs of Spetzler-Martin Grade IV or higher. A majority of patients had multiple aneurysms. There was a statistically significant increase in AVM hemorrhage in female patients (odds ratio, 8.53 [1.87-38.98]; P < 0.005). There was no statistically significant correlation between the development of hemorrhage and either age, AVM grade, or the number of aneurysms. Twenty-three patients (51%) presented with intracranial hemorrhage: bleeding occurred from the AVMs in 15 and from ruptured aneurysms in 5, and the source of the bleeding could not be determined in 3. Overall, nine patients (20%) bled from ruptured aneurysms: five at presentation, two during or within 3 weeks of AVM treatment, and two from new aneurysms. Two of these nine patients died as a direct result of aneurysmal subarachnoid hemorrhage. Five patients (11%) developed new aneurysms.
Conclusion: Aneurysms associated with AVMs are at risk for rupture before, during, and immediately after treatment of the AVMs. New aneurysms may arise in patients with high-flow AVMs. The risk of intracranial hemorrhage from either source is higher in female patients. To reduce the complications of intracranial hemorrhage in these patients, we recommend a management protocol designed to treat the aneurysms by surgical or endovascular means before administering definitive therapy for the AVMs. Meticulous intraoperative blood pressure control and fluid management during aneurysm surgery is critical to avoid hemorrhage from the AVMs.