- Rupture status
- Aneurysm size
- Dome volume:
- Neck size:
- Aspect ratio:
- Aneurysm location
- Anterior circulation
- Cavernous ICA
- Superior hypophyseal
- Posterior communicating
- Anterior choroidal
- ICA other
- ICA bifurcation
- Anterior communicating
- ACA other
- Posterior circulation
- Basilar trunk
- Basilar tip
- Procedure assistance
- Coil type
- Multiple coil types
- Stent data
- Multiple stents
Mascitelli, Justin R et al. “An Update To The Raymond–Roy Occlusion Classification Of Intracranial Aneurysms Treated With Coil Embolization”. Journal of NeuroInterventional Surgery 7.7 (2014): 496-502. Web. 11 Dec. 2016.
<click here to access MS ppt file>
Hospital, Massachusetts. “Endovascular Procedures To Prevent Ruptured Brain Aneurysms”. Massachusetts General Hospital. N.p., 2016. Web. 11 Dec. 2016.
Mascitelli, Justin R et al. “An Update To The Raymond–Roy Occlusion Classification Of Intracranial Aneurysms Treated With Coil Embolization”. Journal of NeuroInterventional Surgery 7.7 (2014): 496-502.
- ‘jailing’ of microcatheter
- stent deployed after the aneurysm is catheterized but before coil deployment
- microcatheter pinned between intima and stent, coils are kept within the aneurysm and outside of vessel lumen
- ‘coil through’
- stent fully deployed across aneurysm neck
- aneurysm catheterized through the tines of the stent
- ‘coil stent’
- unassisted coil embolization to completion followed by stent deployment
- capitalizes on biologic benefit of vascular remodeling or to constrain a prolapsed coil loop
- ‘balloon stent’
- stent placement after completion of balloon assisted embolization
- other techniques
- coiling with ‘Y stent’ configuration for basilar tip aneurysms
- depositing single or multiple stents for flow diversion for blister dorsal carotid wall aneurysms
FINAL RESULT OF ALL STENT-ASSISTED COILING:
Spiotta, Alejandro M et al. “Comparison Of Techniques For Stent Assisted Coil Embolization Of Aneurysms”. Journal of NeuroInterventional Surgery 4.5 (2011): 339-344.
- Clipping Most aneurysms
- Coiling Most aneurysms
- Flow diversion Large proximal ICA aneurysms, blister aneurysms
- Flow diversion with adjunctive coiling Large and giant aneurysms with wide necks
- Intrasaccular flow diversion Bifurcation aneurysms with neck ≥4 mm
- Coiling with assistive stenting Wide-neck aneurysms and aneurysms with branch vessels near/incorporating aneurysm neck
- Parent vessel sacrifice or branch vessel sacrifice with bypass Dissecting aneurysms, giant aneurysms with branch vessels incorporating aneurysm neck
- Parent vessel sacrifice without bypass Distal PICA aneurysms, distal PCA aneurysms, distal mycotic aneurysms
Walcott, Brian P. et al. “Blood Flow Diversion As A Primary Treatment Method For Ruptured Brain Aneurysms—Concerns, Controversy, And Future Directions”. Neurocritical Care (2016): pp 1-9.
Infectious intracranial aneurysms (IIA) [also known as mycotic aneurysms] comprise ~0.7-5.4% of all intracranial aneurysms. There are currently no standardized treatment protocols. A recent article from the Journal of Stroke and Cerebrovascular Diseases presented a case series of IIAs managed by coil embolization.
IIAs are commonly located on the peripheral branches of MCA. [see Figure below]
- Concurrent systemic infection
- headache, fever, ?neurological deficit
- symptoms of heart failure
- impaired LV ejection fraction
- valvular abnormalities (i.e. MR)
- Blood culture growth
- CT head, CT angio, MRI, MRA
- unusually distal location of aneurysm on neuroimaging
- may present with ICH, SAH, or cerebral infarction
- spontaneous resolution, diminished size or thrombosis
- growth and rupture
- conservative treatment with antibiotics for nonruptured, small, minimally symptomatic aneurysms, repeat angio at a later date to document resolution
- curative treatment for ruptured, symptomatic or enlarging IIAs
- Mainstay of treatment is surgical – for ruptured IIAs in unstable patients, or failed endovascular therapy
- microsurgical neck clipping
- excision of aneurysm
- trapping +/- bypass surgery
- endovascular therapy – should be first line? for ruptured IIAs in clinically stable patients
Endovasclar Therapy of IIAs:
- endocarditis treated with antibiotics for a few weeks
- Once infection is cleared, endovascular therapy is performed under GA
- IV heparin to aPTT 2x control
- 6 – or 7- Fr guiding catheter placed via R femoral artery
- microcatheter advanced until neck of aneurysm is reached
- optional [parent artery occlusion to see if any neurological deficit is induced]
- parent artery occlusion with occlusion of IIA [Guglielmi detachable coils was used in the study; onyx, n-butyl 2-cyanoacrylate or stents were not used]
- aneurysm obliteration
Advantage of Endovascular coiling:
- most distal MCA aneurysms are located deep in the cortex, with SAH or ICH – difficult to locate aneurysm intraoperatively
- safer for deep aneurysms or aneurysms in eloquent areas
- shorter anesthetic time [for patients with multiple comorbidities]
Disadvantages of Endovascular Coiling:
- cannot assess elevated ICP
Nonaka, Senshu et al. “Endovascular Therapy For Infectious Intracranial Aneurysm: A Report Of Four Cases”. Journal of Stroke and Cerebrovascular Diseases (2015): n. pag. Web. 19 Jan. 2016.
Acute bleeding: Oral, IV: Loading dose: 4-5 g during the first hour, followed by 1 g/hour for 8 hours (or 1.25 g/hour using oral solution) or until bleeding controlled (maximum daily dose: 30 g)
- 5 g bolus followed by 1 g/h for a maximum duration of 48 h.
- Epsilon amino-caproic acid, dosage probably 24 g per day (6 times 4 g) orally
How does aminocaproic acid work?
ACA binds competitively to plasminogen; blocking the binding of plasminogen to fibrin and the subsequent conversion to plasmin, resulting in inhibition of fibrin degradation (fibrinolysis)
What do the guidelines say about the use of ACA in SAH?
- shown to reduce incidence of rebleeding with delay in aneurysm obliteration
- study one center used short-term ACA to prevent rebleeding during patient transfer, results – decreased in rebleeding, no increase in risk of DCI, 3-month clinical outcomes not affected
- increased risk of DVT but not PE
- Note: neither ACA nor TXA is FDA approved for prevention of aneurysm rebleeding
AHA/ASA Guidelines Recommend:
#3 For patients with an unavoidable delay in obliteration of aneurysm, a significant risk of rebleeding, and no compelling medical contraindications, short-term (<72 hours) therapy with tranexamic acid or aminocaproic acid is reasonable to reduce the risk of early aneurysm rebleeding (Class IIa; Level of Evidence B)
Connolly, E. S. et al. ‘Guidelines For The Management Of Aneurysmal Subarachnoid Hemorrhage: A Guideline For Healthcare Professionals From The American Heart Association/American Stroke Association’. Stroke 43.6 (2012): 1711-1737. Web. 15 Oct. 2015.
Foreman, Paul M. et al. ‘Antifibrinolytic Therapy In Aneurysmal Subarachnoid Hemorrhage Increases The Risk For Deep Venous Thrombosis: A Case–Control Study’. Clinical Neurology and Neurosurgery 139 (2015): 66-69. Web. 15 Oct. 2015.
Uptodate.com,. ‘Aminocaproic Acid’. N.p., 2015. Web. 15 Oct. 2015.
Management of unruptured intracranial aneurysm is traditionally based on the size of the aneurysm.
Calculations to classify aneurysms according to treatment difficulty:
- aspect ratio – aneurysm height-to-neck width
- neck width
- dome-neck ratio – maximum aneurysm dome width-to-neck diameter
Old criteria to define a “wide-neck” aneurysm:
- dome to neck ratio <2.0 [original definition by Debrun, et al]
- neck size >4.0 [original definition by Zubillaga, et al]
A retrospective study (2009) propose a new criteria for defining wide-neck aneurysms: (based on need to use adjunctive measures)
- wide neck – dome-to-neck ratio <1.6, aspect ratio <1.6
- very wide-neck for dome-to-neck <1.2, aspect ratio <1.2
The study found that coiling of aneurysms without adjunctive techniques (stent placement and balloon remodelling) is favored for aneurysms with aspect ratio >/=1.6, dome-to-neck ratio >/=1.6, and neck size <4mm. Coiling with adjunctive techniques is favored for aneurysms with dome-to-neck ratios <1.2 and aspect ratios <1.2. For aneurysms with dome-to-neck ratios or aspect ratios between 1.2 and 1.6, coiling can be done with or without adjunctive techniques.
Morphological parameters that may be associated with ruptured basilar tip aneurysms
- aneurysm volume
- aspect ratio – divide perpendicular height by the neck diameter
- size ratio – divide maximum eight by average composite diameter of all vessels (BAv, RPCAv, LPCAv, RSCAv, LSCAv) involved with the aneusrysm [composite diameter – average of the initial diameter of the vessel (BA1, RPCA1, LPCA1, RSCA1, LSCA1) at vessel branching point by aneurysm neck with diameter of the vessel away from the initial diameter (BA2, RPCA2, LPCA2, RSCA2, LSCA2)]
- aneurysm angle – angle between vectors formed by maximum height of the aneurysm and neck of the aneurysm
- basilar vessel angle – angle between the vector of flow and the neck of the aneurysm
- basilar flow angle – angle between vector of flow and vector formed by the maximum height of the aneurysm
- vessel to vessel angles – a study found that a larger angle between PCA (P1-P1 angle) was most strongly associated with aneurysm rupture
3D model of BTA aneurysm depicting morphological variables previously studied in the literature.
3 vessel to vessel angles -measured
- Parent-Daughter angle – average of two angles formed between BA and each PCA
- P1-P1 angle – angle formed between the two PCAs
- SCA-SCA angle – angle formed between the two SCAs
3D model of BTA aneurysm depicting angular variables of the surrounding vasculature.
Brinjikji, W., H.J Cloft, and D.F. Kallmes. ‘Difficult Aneurysms For Endovascular Treatment: Overwide Or Undertall?’. American Journal of Neuroradiology 30.8 (2009): 1513-1517. Web. 3 Oct. 2015.
Ho, Allen L., Amr Mouminah, and Rose Du. ‘Posterior Cerebral Artery Angle And The Rupture Of Basilar Tip Aneurysms’. PLoS ONE 9.10 (2014): e110946. Web. 2 Oct. 2015.
Sekhar, Laligam N. et al. ‘Basilar Tip Aneurysms’. Neurosurgery 72.2 (2013): 284-299. Web. 2 Oct. 2015.