Tag Archives: neurointerventional

Choroid Plexus Blood Supply

a

b

 

Reference:

Haines, Duane E. Neuroanatomy : An Atlas Of Structures, Sections, And Systems. 8e, 2012.

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Heparin Drip for DCI prevention in Aneurysmal SAH?

Interesting article from Journal of Neurointerventional Surgery looking at use of heparin after endovascular treatment of cerebral aneurysms.  The study was retrospective, included ~400 patients (~200 given heparin post-coiling and ~200 matched controls), and collected data on incidence of vasospasm, DCI, and functional outcome.

Results of the study is shown in the graph below:

neurintsurg-2016-012925-F1.large.jpg

Rate of severe vasospasm was shown to be significantly reduced in the heparin group (14.2 vs 25.4% p=0.005).  The study concluded that patients who received continuous heparin after endovascular coiling of cerebral aneurysms have a reduced rate of severe vasospasm.

 

Mechanism of Action

How does heparin prevent DCI? (theoretically)  The article explains that heparin prevents secondary injury in SAH through its anti-inflammatory effects.  Heparin is the highest negatively charged biological molecule existing.  Due to the negative charges, it can bind to positively charged proteins and surfaces, including growth factors, cytokines and chemokines – thereby reducing inflammation.  It can also bind oxyhemoglobin and block free radical activity.  It can also antagonize endothelin, reducing endothelin-related vasoconstriction.

 

Limitations

The study has several limitations – including the retrospective and single-center nature of the study design, and the potential for selection bias – even with case matching.  This study adds more evidence (albeit weak) to the argument that heparin infusions may help prevent secondary brain injury in patients with aneurysmal SAH who undergo endovascular coiling.

 

Heparin would be a potential “4th H,” adding to the 3 H’s historically used in the vasospasm prevention – i.e. hypervolemia, hemodilution, hypertension.  As with the previous H’s, randomized controlled studies will need to be performed to prove this theory.  The first 3 Hs have largely been debunked, and instead, the current standard of care is to keep patients with subarachnoid hemorrhage euvolemic, and induce hypertension only in the setting of vasospasm and/or delayed cerebral ischemia.  Therefore, as with the first 3 Hs, until more evidence surfaces, the use of continuous heparin cannot be recommended in this setting.

 

 

Reference:

Bruder, Markus et al. “Effect Of Heparin On Secondary Brain Injury In Patients With Subarachnoid Hemorrhage: An Additional ‘H’ Therapy In Vasospasm Treatment”. Journal of NeuroInterventional Surgery (2017): neurintsurg-2016-012925.

ICA Segments

Segmental classification of internal carotid artery:

CMTR_0246_2_R01

Reference:

Lee, Thomas et al. “Management Of Carotid Artery Trauma”. Craniomaxillofacial Trauma and Reconstruction 07.03 (2014): 175-189.

Modified Raymond–Roy Classification

  • Class I: complete obliteration12.jpg
  • Class II: residual neck
  • Class IIIa: residual aneurysm with contrast within coil interstices
  • Class IIIb: residual aneurysm with contrast along aneurysm wall

3.jpg4.jpg

 

 

1a.JPG

<click here to access MS ppt file>

 

 

References:

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.

 

Antiplatelets for Stent-Coil Techniques

  • ASA (325 mg daily) and clopidogrel (75 mg daily) x 5 days prior to procedure
  • platelet aggregometry 1–2 days before procedure
  • further loading of aspirin and/or clopidogrel PRN
  • unanticipated stenting
    • load with IV or IA abciximab intraprocedurally
    • then load and maintain on ASA and clopidogrel
  • systemic heparinization prior to guide catheter introduction, target activated clotting time 2–2.5 greater than baseline

 

Reference:

Spiotta, Alejandro M et al. “Comparison Of Techniques For Stent Assisted Coil Embolization Of Aneurysms”. Journal of NeuroInterventional Surgery 4.5 (2011): 339-344.

 

Stent-Assisted Coiling Techniques

  1. ‘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
    • A.jpg
  2. ‘coil through’
    • stent fully deployed across aneurysm neck
    • aneurysm catheterized through the tines of the stent
    • b
  3. ‘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
    • C.jpg
  4. ‘balloon stent’
    • stent placement after completion of balloon assisted embolization
    • D.jpg
  5. 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:

E.jpg

 

 

Reference:

Spiotta, Alejandro M et al. “Comparison Of Techniques For Stent Assisted Coil Embolization Of Aneurysms”. Journal of NeuroInterventional Surgery 4.5 (2011): 339-344.

 

 

Treatment of Aneurysms

  • 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

 

Reference:

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.