To the editor,
The interesting paper by Li et al. reports an important series of
cases treated appropriately and carefully followed-up, but unfortunately
the diagnosis may not be correct in all cases.
Fusiform aneurysms appearing in angiograms may represent a variety of
different histopathological pictures, including dissection, but also other
types of aneurysms.
A light to this question, quite recurrent in my practice, is bring by
Mizutani et al.(1). They studied 85 patients with fusiform or non-
branching zones aneurysms, either operated or post-mortem. Four types of
aneurysms were found, one of witch is what the literature came to call a
"blood-blister- like aneurysms", and is not fusiform. The fusiform
aneurysms were found to have 3 different patterns. One of them is a
segmental ectasia with regular walls and a benign course. Two other types
are symptomatic and may share some features that bring confusion. First,
the classic dissecting aneurysm has typically an acute presentation with
ischemic or hemorrhagic stroke. Angiography shows fusiform dilatation with
irregular wall and associated with stenosis. Pathology was characterized
by disruption of internal elastic lamina, a false lumen packed with fresh
thrombus, no intimal thicketening and no organized thrombus. The second
is the dolichoectatic aneurysm, clinically characterized by compressive
symptoms or brainstem ischemic changes, with a chronic evolution, that may
bleed, but rarely in previously asymptomatic cases. The angiography shows
marked tortuosity and very irregular walls. The most common localization
is basilar artery. Pathology shows organized luminal thrombus, disrupted
internal elastic lamina without false lumen. As a chronic condition with
organized thrombus, parietal calcification can occur.
In the series, at least four patients had no acute presentation, and there
was no hemorrhagic stroke.
The images presented for cases 3, 4 and 8, although they had sudden
presentation, are characterized by tortuosity, ectasia and irregular
walls, extension to vertebral arteries and no stenosis. In one case the CT
images show wall calcifications. These images are more consistent with
dolichoetatic fusiform than with acute dissecting aneurysms.
More rigid criteria are needed to define dissecting aneurysms and
differentiate them from dolichoectatic aneurysms.
1- Mizutani T, Miki Y, Kojima H, Suzuki H. Proposed classification of
nonatherosclerotic cerebral fusiform and dissecting aneurysms.
Neurosurgery. 1999 Aug;45(2):253-9.
Conflict of Interest:
None declared
To the editor,
The interesting paper by Li et al. reports an important series of cases treated appropriately and carefully followed-up, but unfortunately the diagnosis may not be correct in all cases. Fusiform aneurysms appearing in angiograms may represent a variety of different histopathological pictures, including dissection, but also other types of aneurysms. A light to this question, quite recurrent in my practice, is bring by Mizutani et al.(1). They studied 85 patients with fusiform or non- branching zones aneurysms, either operated or post-mortem. Four types of aneurysms were found, one of witch is what the literature came to call a "blood-blister- like aneurysms", and is not fusiform. The fusiform aneurysms were found to have 3 different patterns. One of them is a segmental ectasia with regular walls and a benign course. Two other types are symptomatic and may share some features that bring confusion. First, the classic dissecting aneurysm has typically an acute presentation with ischemic or hemorrhagic stroke. Angiography shows fusiform dilatation with irregular wall and associated with stenosis. Pathology was characterized by disruption of internal elastic lamina, a false lumen packed with fresh thrombus, no intimal thicketening and no organized thrombus. The second is the dolichoectatic aneurysm, clinically characterized by compressive symptoms or brainstem ischemic changes, with a chronic evolution, that may bleed, but rarely in previously asymptomatic cases. The angiography shows marked tortuosity and very irregular walls. The most common localization is basilar artery. Pathology shows organized luminal thrombus, disrupted internal elastic lamina without false lumen. As a chronic condition with organized thrombus, parietal calcification can occur. In the series, at least four patients had no acute presentation, and there was no hemorrhagic stroke. The images presented for cases 3, 4 and 8, although they had sudden presentation, are characterized by tortuosity, ectasia and irregular walls, extension to vertebral arteries and no stenosis. In one case the CT images show wall calcifications. These images are more consistent with dolichoetatic fusiform than with acute dissecting aneurysms. More rigid criteria are needed to define dissecting aneurysms and differentiate them from dolichoectatic aneurysms.
1- Mizutani T, Miki Y, Kojima H, Suzuki H. Proposed classification of nonatherosclerotic cerebral fusiform and dissecting aneurysms. Neurosurgery. 1999 Aug;45(2):253-9.
Conflict of Interest:
None declared