Main Differences Between Charcot-Bouchard and Saccular Aneurysms
Charcot-Bouchard aneurysms are small microaneurysms (typically <1mm) that form in deep penetrating arteries like lenticulostriate vessels due to chronic hypertension, while saccular aneurysms are larger berry-like outpouchings that occur at major arterial bifurcations of the Circle of Willis.
Size and Morphology
Charcot-Bouchard aneurysms:
- Microscopic in size, typically measuring 0.3-1.0 mm in diameter
- Multiple small dilations along penetrating vessels
- Not visible on standard angiography due to their minute size
Saccular aneurysms:
- Range from small (<5mm) to giant (≥25mm) 1
- Defined morphologically as having a distinct neck and dome structure 1
- Classified as saccular when axial and lateral dimensions are nearly equal 1
- Readily visible on angiography and imaging studies 1
Location
Charcot-Bouchard aneurysms:
- Located on small penetrating arteries including lenticulostriate arteries, pontine perforators, and posterior inferior cerebellar artery branches 2
- Deep brain structures: basal ganglia, thalamus, pons, cerebellum
- These are NOT typical sites for saccular aneurysms 2
Saccular aneurysms:
- Occur at major arterial bifurcations of the Circle of Willis 2, 3
- Most common locations include the anterior communicating artery (34.8% of ruptured cases), posterior communicating artery, middle cerebral artery bifurcation, and internal carotid artery 2, 4
- Proximal locations on or near the Circle of Willis represent the typical pattern 2
Pathophysiology
Charcot-Bouchard aneurysms:
- Result from chronic hypertensive damage to small vessel walls
- Associated with lipohyalinosis and fibrinoid necrosis
- Represent end-organ damage from longstanding hypertension
Saccular aneurysms:
- Develop from combination of congenital/inherited arterial wall defects and acquired degenerative vascular disease 3
- Form at hemodynamic stress points where arterial branching occurs 2, 3
- Associated with flow-related wall stress at bifurcations 5
Clinical Presentation
Charcot-Bouchard aneurysms:
- Cause deep intracerebral hemorrhage (hypertensive hemorrhage)
- Bleeding occurs in basal ganglia, thalamus, pons, or cerebellum
- Associated with chronic, poorly controlled hypertension
Saccular aneurysms:
- Typically present with subarachnoid hemorrhage when ruptured 1, 3
- May present with mass effect symptoms, cranial nerve compression, or remain asymptomatic until rupture 1
- Rupture risk correlates with size, with aneurysms <5mm having very low rupture rates while those >10mm have significant rupture risk 3
Treatment Implications
Charcot-Bouchard aneurysms:
- Not amenable to surgical or endovascular treatment due to microscopic size
- Management focuses on blood pressure control and prevention
Saccular aneurysms: