Blood blister-like aneurysm is a broad-based bulge at a non-branch point of a vessel, which is unlike saccular (or 'berry') aneurysms which usually occur at branch points.
A focal defect in the arterial wall covered with fibrous tissue is usually seen. Potential causes include atherosclerotic vascular disease with ulceration, hemodynamic stress, and dissection.
- shape: blood blister-like or half-domed shallow outpouching with wide neck
- common sites: supraclinoid ICA (dorsal wall), less likely MCA, ACA, basilar artery
- size: usually small (<6 mm) with a mean of 3 mm 1
- rapid change in size and morphology on follow-up angiograms
- CT angiography: often negative
- digital subtraction angiography: is the best diagnostic tool
Treatment and prognosis
These aneurysms are difficult to treat:
- endovascular coiling is difficult due to their small size and wide neck; flow-diverter stents are an acceptable alternative 4
- surgical clipping carries a high risk of tearing the aneurysm or internal carotid laceration during surgery
They have a higher complication rate than saccular aneurysm because they are often missed on CTA, have a higher rate of rebleed, tend to rupture at a smaller size and have a high risk of rupture if there is an underlying dissection (45% in a small series) 4,5.
- 1. Osborn AG, Salzman KL, Barkovich AJ. Diagnostic Imaging. Lippincott Williams & Wilkins. (2009) ISBN:1931884722. Read it at Google Books - Find it at Amazon
- 2. Gaughen JR, Raghavan P, Jensen ME et-al. Utility of CT angiography in the identification and characterization of supraclinoid internal carotid artery blister aneurysms. AJNR Am J Neuroradiol. 2010;31 (4): 640-4. doi:10.3174/ajnr.A1893 - Pubmed citation
- 3. Park JH, Park IS, Han DH et-al. Endovascular treatment of blood blister-like aneurysms of the internal carotid artery. J. Neurosurg. 2007;106 (5): 812-9. doi:10.3171/jns.2007.106.5.812 - Pubmed citation
- 4. Gonzalez AM, Narata AP, Yilmaz H, Bijlenga P, Radovanovic I, Schaller K, Lovblad KO, Pereira VM. Blood blister-like aneurysms: single center experience and systematic literature review. (2014) European journal of radiology. 83 (1): 197-205. doi:10.1016/j.ejrad.2013.09.017 - Pubmed
- 5. Chung JH, Shin YS, Lim YC, Park M. Ideal internal carotid artery trapping technique without bypass in a patient with insufficient collateral flow. Journal of Korean Neurosurgical Society. 2009;45(4):260. doi:10.3340/jkns.2009.45.4.260 - Pubmed citation