Flow diverter: Difference between revisions

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{{Infobox medical intervention
{{Infobox medical intervention
| name         = Flow diverter
| name = Flow diverter
| image       = Wikipedia intracranial aneurysms - inferior view - heat map.jpg
| image = Wikipedia intracranial aneurysms - inferior view - heat map.jpg
| caption     = Common sites (intracranial) of saccular aneurysms (treated with flow diverter)             | alt         =
| caption = Common sites (intracranial) of saccular aneurysms (treated with flow diverter) | alt =
| ICD10       = Z95.828
| ICD10 = Z95.828
| ICD9         =
| ICD9 =
| ICD9unlinked =
| ICD9unlinked =
| MeshID       =
| MeshID =
| LOINC       =
| LOINC =
| other_codes =
| other_codes =
| MedlinePlus =
| MedlinePlus =
| eMedicine   =
| eMedicine =
|Specialty=Interventional neuroradiology}}
|Specialty=Interventional neuroradiology
A '''flow diverter''' is an endovascular [[prosthesis]] used to treat intracranial [[aneurysm]]s.<ref>{{cite journal |author1=Alderazi Yazan J. |author2=Shastri Darshan |author3=Kass-Hout Tareq |author4=Prestigiacomo Charles J. |author5=Gandhi Chirag D. | year = 2014| title = Review Article: Flow Diverters for Intracranial Aneurysms | journal = Stroke Research and Treatment | volume = 2014 |pages=1–12 |doi=10.1155/2014/415653 |pmid=24967131 |pmc=4054970 |doi-access=free }}</ref>  It is placed in the aneurysm's parent artery, covering the neck, in order to divert blood flow and determine a progressive thrombosis of the sac.<ref>{{cite journal |doi=10.1016/j.neurad.2010.12.002 |pmid=21257202|url=http://www.em-consulte.com/en/article/283978|title=Flow diverter stents in the treatment of intracranial aneurysms: Where are we?|journal=Journal of Neuroradiology|volume=38|issue=1|pages=40–46|year=2011|last1=Pierot|first1=Laurent}}</ref> Flow diverting stents consist of structural [[Cobalt-chrome]] or [[Nitinol]] alloy wires and often a set of [[radiopaque]] wires woven together in a flexible braid. <ref>{{Cite journal|last1=Thomas|first1=A. J.|last2=Krings|first2=T.|last3=Pereira|first3=V. M.|last4=Moore|first4=J. M.|last5=Phan|first5=K.|last6=Dmytriw|first6=A. A.|date=2019-03-21|title=On Flow Diversion: The Changing Landscape of Intracerebral Aneurysm Management|url=http://www.ajnr.org/content/early/2019/03/20/ajnr.A6006|journal=American Journal of Neuroradiology|volume=40|issue=4|pages=591–600|language=en|doi=10.3174/ajnr.A6006|issn=0195-6108|pmid=30894358|pmc=7048527|doi-access=free}}</ref>
}}
'''Flow diverter''' is an endovascular prosthesis used to treat [[intracranial aneurysms]]. It is placed in the parent artery of the aneurysm, covering the neck of the aneurysm, in order to divert blood flow and facilitate progressive thrombosis of the aneurysmal sac. Flow diverters are primarily used to treat aneurysms that are challenging to treat with traditional methods like coil embolization.


==Medical usage==
==Medical Usage==
Flow diverters are treatment for intracranial aneurysms alternative to endosaccular coil embolization (although the techniques can be combined, especially in large/giant aneurysms). It is mainly effective in wide neck unerupted [[saccular aneurysm]]s, that are difficult to coil because of the tendency of the coils to fill the parent artery (referred to as prolapse). Another situation is [[:wikt:fusiform|fusiform]] shape or circumferential aneurysms. <ref>{{cite journal |author1=Guo S. |author2=Jiang P. |author3=Liu J. |author4=Yang X |author5=Li Y. |author6=Wu Z. | year = 2017| title = A comparative study of CFD of canine model of common carotid fusiform aneurysm and vertebrobasilar fusiform aneurysm in human patients | journal = International Angiology | volume = 37| issue = 1| pages = 32–40| pmid=28945061 | doi=10.23736/S0392-9590.17.03869-X}} </ref>
Flow diverters serve as an alternative to traditional treatments such as [[endosaccular coil embolization]], though these techniques can sometimes be combined, especially in the case of larger or giant aneurysms. Flow diverters are particularly effective for wide-necked, unresected saccular aneurysms, which are difficult to treat with coils due to the tendency of the coils to prolapse into the parent artery. Other situations where flow diverters may be used include [[fusiform]] or [[circumferential aneurysms]]. Before the introduction of flow diverters, many intracranial aneurysms went untreated due to the lack of viable options for their management.
Prior to flow diverters many intracranial aneurysms went untreated.<ref>{{cite journal|last1=Alderazi|first1=Yazan J.|last2=Shastri|first2=Darshan|last3=Kass-Hout|first3=Tareq|last4=Prestigiacomo|first4=Charles J.|last5=Gandhi|first5=Chirag D.|date=2014|title=Flow Diverters for Intracranial Aneurysms|journal=Stroke Research and Treatment|volume=2014|pages=415653|doi=10.1155/2014/415653|pmid=24967131|pmc=4054970|doi-access=free}}<!--|accessdate=23 September 2015--></ref>


==Risks and complications==
The flow diverter works by diverting the blood flow from the aneurysm sac, promoting thrombosis and eventual occlusion of the aneurysm. This process helps prevent the aneurysm from rupturing and minimizes the risk of bleeding in the brain.
The efficacy of flow diverters can be evaluated using a grading system developed by researchers at Oxford Neurovascular and Neuroradiology Research Unit (Kamran et al. 2011), commonly referred to as ''flow diverter grading system'' or ''Kamran grading system''.<ref>{{cite journal |author1=Kamran M. |author2=Yarnold J. |author3=Grunwald I.Q. |author4=Byrne J.V. | year = 2011 | title = Assessment of angiographic outcomes after flow diversion treatment of intracranial aneurysms: a new grading schema | journal = Neuroradiology | volume = 53 | issue = 7| pages = 501–508 | doi = 10.1007/s00234-010-0767-5 |pmid=20838782 |s2cid=1377177 }}</ref> After receiving a cerebral flow diverter, patients are placed on dual antiplatelet therapy for an extended period of time to reduce the likelihood of peri-procedural and post-procedural thromboembolic complications. {{medical citation needed|date=October 2017}}


The degree of aneurysm occlusion is graded on a five-point scale from 0 (no change in the endoaneurysmal flow) to 4 (complete obliteration of the aneurysm). The patency status of the parent artery is evaluated on a three-point scale, from no change in the parent [[artery]] diameter  to parent artery occlusion. This grading system is used in clinical practice. It has also been used and adapted by researchers to evaluate and report the effectiveness of flow diverters in general.<ref>{{Cite journal |doi = 10.1016/j.wneu.2013.09.036|pmid = 24071065|title = Flow Diversion of Giant Curved Sidewall and Bifurcation Experimental Aneurysms with Very-Low-Porosity Devices|journal = World Neurosurgery|volume = 82|issue = 6|pages = 1120–1126|year = 2014|last1 = Darsaut|first1 = Tim E.|last2 = Bing|first2 = Fabrice|last3 = Makoyeva|first3 = Alina|last4 = Gevry|first4 = Guylaine|last5 = Salazkin|first5 = Igor|last6 = Raymond|first6 = Jean}}</ref>
==Risks and Complications==
While flow diverters offer promising treatment for intracranial aneurysms, they come with certain risks and complications, including:
* '''Thromboembolic complications''' – to reduce the likelihood of peri-procedural and post-procedural thromboembolic events, patients are placed on dual antiplatelet therapy for an extended period after receiving a cerebral flow diverter.
* '''Parent artery occlusion''' – improper placement or malfunctioning of the flow diverter can result in occlusion of the parent artery, which may lead to ischemia or other complications.
* '''Incomplete occlusion''' – there is a possibility of incomplete obliteration of the aneurysm, which would require further intervention.


== See also ==
The efficacy of flow diverters is often assessed using a grading system developed by researchers at the Oxford Neurovascular and Neuroradiology Research Unit (Kamran et al., 2011), known as the Kamran grading system. This system evaluates the degree of aneurysm occlusion on a five-point scale, ranging from:
* [[Hemodynamics|Blood flow]]
* '''Grade 0''' – no change in endoaneurysmal flow
* [[Interventional neuroradiology]]
* '''Grade 4''' – complete obliteration of the aneurysm
* [[Intracranial aneurysm]]


==References==
The patency of the parent artery is also graded on a three-point scale, from no change in the diameter of the parent artery to complete occlusion of the parent artery.
{{reflist|2}}


==Further reading==
This grading system is used widely in clinical practice to evaluate the effectiveness of flow diverters and to monitor patient progress.
* {{cite book|last1=Jabbour|first1=Pascal M.|title=Neurovascular surgical techniques|date=2012|publisher=Jaypee Medical|location=New Delhi|isbn=978-93-5090-088-8|edition=First|url=https://books.google.com/books?id=fi5YkIWM4sMC&q=flow+diverter&pg=PA219|access-date=23 September 2015}}
* {{cite journal|last1=Krishna|first1=Chandan|last2=Sonig|first2=Ashish|last3=Natarajan|first3=Sabareesh K.|last4=Siddiqui|first4=Adnan H.|title=The Expanding Realm of Endovascular Neurosurgery: Flow Diversion for Cerebral Aneurysm Management|journal=Methodist DeBakey Cardiovascular Journal|date=October 2014|volume=10|issue=4|pages=214–219|doi=10.14797/mdcj-10-4-214|pmid=25624975|pmc=4300059}}


==See Also==
* [[Blood flow]]
* [[Interventional neuroradiology]]
* [[Intracranial aneurysm]]
* [[Endovascular procedures]]
* [[Aneurysm treatment]]
* [[Stroke prevention]]
[[Category:Interventional neuroradiology]]
[[Category:Endovascular procedures]]
[[Category:Neurosurgery]]
[[Category:Medical devices]]
{{Medicine|state=collapsed}}
{{Medicine|state=collapsed}}
{{Vascular diseases|state=collapsed}}
{{Vascular diseases|state=collapsed}}
<!---Place all category tags here-->
[[Category:Implants (medicine)]]
[[Category:Prosthetics]]
[[Category:Vascular diseases]]

Latest revision as of 17:39, 1 April 2025

  
Common sites (intracranial) of saccular aneurysms (treated with flow diverter)
Pronunciation
Other names
Medical specialty
Uses
Complications
Approach
Types
Recovery time
Other options
Frequency


Flow diverter is an endovascular prosthesis used to treat intracranial aneurysms. It is placed in the parent artery of the aneurysm, covering the neck of the aneurysm, in order to divert blood flow and facilitate progressive thrombosis of the aneurysmal sac. Flow diverters are primarily used to treat aneurysms that are challenging to treat with traditional methods like coil embolization.

Medical Usage[edit]

Flow diverters serve as an alternative to traditional treatments such as endosaccular coil embolization, though these techniques can sometimes be combined, especially in the case of larger or giant aneurysms. Flow diverters are particularly effective for wide-necked, unresected saccular aneurysms, which are difficult to treat with coils due to the tendency of the coils to prolapse into the parent artery. Other situations where flow diverters may be used include fusiform or circumferential aneurysms. Before the introduction of flow diverters, many intracranial aneurysms went untreated due to the lack of viable options for their management.

The flow diverter works by diverting the blood flow from the aneurysm sac, promoting thrombosis and eventual occlusion of the aneurysm. This process helps prevent the aneurysm from rupturing and minimizes the risk of bleeding in the brain.

Risks and Complications[edit]

While flow diverters offer promising treatment for intracranial aneurysms, they come with certain risks and complications, including:

  • Thromboembolic complications – to reduce the likelihood of peri-procedural and post-procedural thromboembolic events, patients are placed on dual antiplatelet therapy for an extended period after receiving a cerebral flow diverter.
  • Parent artery occlusion – improper placement or malfunctioning of the flow diverter can result in occlusion of the parent artery, which may lead to ischemia or other complications.
  • Incomplete occlusion – there is a possibility of incomplete obliteration of the aneurysm, which would require further intervention.

The efficacy of flow diverters is often assessed using a grading system developed by researchers at the Oxford Neurovascular and Neuroradiology Research Unit (Kamran et al., 2011), known as the Kamran grading system. This system evaluates the degree of aneurysm occlusion on a five-point scale, ranging from:

  • Grade 0 – no change in endoaneurysmal flow
  • Grade 4 – complete obliteration of the aneurysm

The patency of the parent artery is also graded on a three-point scale, from no change in the diameter of the parent artery to complete occlusion of the parent artery.

This grading system is used widely in clinical practice to evaluate the effectiveness of flow diverters and to monitor patient progress.

See Also[edit]