Introduction: Concurrent arterial aneurysms[AA;constituting 2.7-16.7% patients harbouring arteriovenous malformation;AVM] considerably aggravate risk of intracranial haemorrhage. An effective classification and management strategy for AA with AVMs(AA+AVM) is provided.

Methods: Radiological assessment of anatomical relationship of AA+AVM, Spetzler Martin(SM) grading and flow status of AVM, and origin of intracranial bleeding was done in 16 patients having a concurrent AA+AVM, assigning an abbreviated nomenclature succinctly describing the radiological entity. Their modified Rankin’s score (mRS) at admission was compared with the score at follow-up.

Results: Five patients presented with SAH and 11 with intracerebral/intraventricular haemorrhage (mRS 0 in 5, 2 in 6, 3 in 1, 4 in 3, and 5 in 1). The AAs included the following: I.Flow-related proximal(n=2); II.Flow-related distal(n=3); III.Intranidal(n=5); IV:Extra-intranidal(n=2); V.Remote major ipsilateral(n=1); VI.Remote major contralateral(n=1); VII.Deep perforator-related(n=1) VIII:Superficial(n=1); and, IX:Distal(n=0). AVMS were in SM grade I in 5, II in 3, III in 3, IV in 4 and V in 1 patients, respectively. Ten patients had a low-flow(LF) and 6, a high-flow(HF) AVM. Seven AVMs were located in the eloquent cortex. Flow-related AA, SM I-III LF AVM usually underwent aneurysm clipping with AVM excision; nidal-extranidal AA, SM I-III LF AVM, excision or embolization of both AA+AVM; and, nidal-extranidal and perforator-related AA, SM IV-V HF AVM, only endovascular embolization or radiosurgery. Surgical decision-making for remote AA also took into account their ipsilateral/contralateral filling status and vessel dominance; and, for AA associated with SM III HF AVM, it varied in each patient and depended mainly on AVM diffuseness, flow across AV fistula and eloquence of cortex. At median follow-up of 26.5 + 22.87 months, mRS was 0 in 12, 2 in 2, 3 in 1and 6 in 1 patients, respectively.

Conclusions: Patients with intracranial AVMs should be screened for presence of concurrent AAs. Further grading, management protocols and prognostication should particularly “focus on the aneurysm.” Subcategorizations of AA+AVMs, an abbreviated nomenclature, and a management protocol have been proposed.

Patient Care: While encountering AVMs with intracerebral hemorrhage, special efforts should be undertaken to identify concurrent aneurysms. A comprehensive subcategorization of concurrent aneurysms as well as an abbreviated nomenclature has been offered that perhaps will cover all clinical variations of arterial aneurysms coexisting with AVMs. A management protocol for concurrent aneurysms with AVMs has been proposed that depends on the type of aneurysm present, on whether the aneurysm or the AVM has bled, and the Spetzler Martin grade and the flow status of the AVM.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of various subcategories of coexisting arterial aneurysms with AVMs 2) Discuss an effective abbreviated nomenclature that succinctly describes the entity 3) Identify an effective treatment strategy for each type of arterial aneurysm with AVM.

References: 1. Cunha E, Sa MJ, Stein BM, Solomon RA, McCormick PC (1992) The treatment of associated intracranial aneurysms and arteriovenous malformations. J Neurosurg 77:853-859 2. Deruty R, Mottolese C, Soustiel JF, Pelissou GI (1990) Association of cerebral arteriovenous malformation and cerebral aneurysm. Diagnosis and management. Acta Neurochir 107:133–139 3.Hoffman C, Riina HA, Stieg P, Allen B, Gobin YP, Santillan A, Souweidane M (2011) Associated aneurysms in pediatric arteriovenous malformations and the implications for treatment. Neurosurgery. 69:315-322 4.Lasjaunias P, Piske R, Terbrugge K, Willinsky R (1988) Cerebral arteriovenous malformations (C. AVM) and associated arterial aneurysms (AA). Analysis of 101 C. AVM cases, with 37 AA in 23 patients. Acta Neurochir (Wien) 91:29-36