Aneurysms are focal abnormal dilatation of a blood vessel. They typically occur in arteries, venous aneurysms are rare. Aneurysms may also occur in the heart.
- hereditary connective tissue disorders
- myocardial infarction: may cause left a ventricular aneurysm
- flow related (in cerebral AVM, contralateral ICA occlusion etc)
Morphologically there are two main types of aneurysms. The morphology is not specific for any cause:
Occasionally a 3 type, serpentine aneurysm has been classified as a separate entity .
- distal thromboembolism
- pressure effects