Subarachnoid and Intraventricular Hemorrhage in a Patient with a Pure Arterial Malformation and Two Associated Aneurysms in the Posterior Inferior Cerebellar Artery: A Case Report and Literature Review

Abstract

Introduction Pure arterial malformations (PAMs) are rare vascular abnormalities defined as dilated, tortuous arterial loops without any associated venous compartment. PAMs are thought to be benign developmental anomalies that can be safely managed conservatively. Methods We present a case of life-threatening hemorrhage in a patient with a PAM associated with two aneurysms and review the literature describing hemorrhages associated with PAMs. Results A 65-year-old female presented with subarachnoid and intraventricular hemorrhage. A digital subtraction angiography revealed a posterior inferior cerebellar artery PAM associated with two saccular aneurysms, which were subsequently microsurgically clipped. At the 1-year follow-up, the patient was neurologically intact. In our literature review, we identified 21 papers describing a total of 37 PAMs. Patients were predominantly female (64.9%) and their median age was 35 years. Almost half (48.6%) of PAMs were associated with aneurysms. In the group of PAMs that were not associated with an aneurysm, the intracranial hemorrhage rate was 15.8%, while in cases of coexisting PAM and aneurysm it was 44.4% (p = .0789). Conclusions PAM natural history remains unknown, particularly in cases of coexistence with aneurysms. Patients so affected require careful observation. The description of PAMs as benign vascular malformations should be revised. Surgical management of hemorrhagic PAMs coexisting with aneurysms is possible and should be considered.

Microneurosurgical treatment of a small perimesencephalic pure pial arterial malformation: an under-recognized etiology of angiographically occult subarachnoid hemorrhage. Illustrative case

“…One report has suggested that PAMs are associated with aneurysms in nearly half of these patients. 6 Our literature review revealed that 14 of 50 reported PAM cases had an associated aneurysm, and of these patients with an aneurysm-associated PAM, 5 of 14 developed SAH/intracranial hemorrhage. Including the present case, 5 of 7 PAMs resulting in SAH had associated aneurysms, whereas 2 of 7 PAMs spontaneously caused SAH.…”

Endovascular treatment of a ruptured pure arterial malformation and associated dysplastic middle cerebral artery dissecting aneurysm: illustrative case

“… 11–17 Of the reported cases, the source of rupture was attributable to a pure arterial malformation vessel in two cases and an associated focal aneurysm in five cases. 11–17 The malformation was localized to the posterior circulation in five cases and anterior circulation in one case. 11 , 12 , 14–17 Interestingly, one case reported the coexistence of two pure arterial malformations in the anterior and posterior circulation.…”

“… 13 The majority of cases underwent intervention (six of seven cases). 11–16 Of the cases treated, surgical intervention (e.g., aneurysm clipping, clip trapping, bypass, parent artery occlusion) was pursued in five of six cases, whereas endovascular ethylene vinyl alcohol copolymer (Onyx) embolization was implemented in one case. 11–16 …”

“… 12 The details of previously reported cases of ruptured pure arterial malformations or associated focal aneurysms can be found in Table 1 . 11–17 …”

“…1,[6][7][8][9] Nevertheless, recent reports have illustrated that these lesions may exhibit a more aggressive course, because they have been associated with radiographic progression in angioarchitecture, aneurysm development, and rupture of the parent pure arterial malformation or associated focal aneurysms. [9][10][11][12][13][14][15][16][17] Here, we describe a case of a 58-year-old male with a large intraparenchymal hemorrhage suspected to be secondary to rupture of a dysplastic right middle cerebral artery dissecting aneurysm associated with a pure arterial malformation. We review the current literature on pure arterial malformations to better characterize the natural history of these lesions and consider the indications for intervention.…”