Flow diverter

Flow diverter
Common sites (intracranial) of saccular aneurysms (treated with flow diverter)
Specialty	Interventional neuroradiology
ICD-10-PCS	Z95.828
[ edit on Wikidata]

A flow diverter is an endovascular prosthesis used to treat intracranial aneurysms. ^[1] 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. ^[2] 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. ^[3]

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 aneurysms, that are difficult to coil because of the tendency of the coils to fill the parent artery (referred to as prolapse). Another situation is fusiform shape or circumferential aneurysms. ^[4] Prior to flow diverters many intracranial aneurysms went untreated. ^[5] Flow diverters can be placed in the parent vessel or within the aneurysm, which are called intrasaccular flow diverters. ^{[6] [7]} These devices can be used to treat aneurysms by doing a cerebral angiogram via femoral artery or radial artery access. ^[7]

Risks and complications

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. ^[8] 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 ]}

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. ^[9]

See also

• Blood flow
• Interventional neuroradiology
• Intracranial aneurysm

References

1. Alderazi Yazan J.; Shastri Darshan; Kass-Hout Tareq; Prestigiacomo Charles J.; Gandhi Chirag D. (2014). "Review Article: Flow Diverters for Intracranial Aneurysms". Stroke Research and Treatment. 2014: 1–12. doi: 10.1155/2014/415653 . PMC   4054970 . PMID   24967131.
2. Pierot, Laurent (2011). "Flow diverter stents in the treatment of intracranial aneurysms: Where are we?" . Journal of Neuroradiology. 38 (1): 40–46. doi:10.1016/j.neurad.2010.12.002. PMID   21257202.
3. Thomas, A. J.; Krings, T.; Pereira, V. M.; Moore, J. M.; Phan, K.; Dmytriw, A. A. (2019-03-21). "On Flow Diversion: The Changing Landscape of Intracerebral Aneurysm Management". American Journal of Neuroradiology. 40 (4): 591–600. doi: 10.3174/ajnr.A6006 . ISSN   0195-6108. PMC   7048527 . PMID   30894358.
4. Guo S.; Jiang P.; Liu J.; Yang X; Li Y.; Wu Z. (2017). "A comparative study of CFD of canine model of common carotid fusiform aneurysm and vertebrobasilar fusiform aneurysm in human patients". International Angiology. 37 (1): 32–40. doi:10.23736/S0392-9590.17.03869-X. PMID   28945061.
5. Alderazi, Yazan J.; Shastri, Darshan; Kass-Hout, Tareq; Prestigiacomo, Charles J.; Gandhi, Chirag D. (2014). "Flow Diverters for Intracranial Aneurysms". Stroke Research and Treatment. 2014: 415653. doi: 10.1155/2014/415653 . PMC   4054970 . PMID   24967131.
6. Mouchtouris, Nikolaos; Hasan, David; Samaniego, Edgar A.; Saiegh, Fadi Al; Sweid, Ahmad; Abbas, Rawad; Naamani, Kareem El; Tahir, Rizwan; Zanaty, Mario; Khanna, Omaditya; Chalouhi, Nohra; Tjoumakaris, Stavropoula; Gooch, M. Reid; Rosenwasser, Robert; Jabbour, Pascal (1 May 2022). "The Woven EndoBridge (WEB) device: feasibility, techniques, and outcomes after FDA approval". Journal of Neurosurgery. 136 (5): 1266–1272. doi: 10.3171/2021.5.JNS21889 . PMID   34624864. S2CID   238528662.
7. Mouchtouris, Nikolaos; Al Saiegh, Fadi; Sweid, Ahmad; Amllay, Abdelaziz; Tjoumakaris, Stavropoula; Gooch, Reid; Rosenwasser, Robert; Jabbour, Pascal M. (November 2019). "Transradial Access for Newly Food and Drug Administration–Approved Devices for Endovascular Treatment of Cerebral Aneurysms: A Technical Note". World Neurosurgery. 131: 6–9. doi:10.1016/j.wneu.2019.07.149. PMID   31356971.
8. Kamran M.; Yarnold J.; Grunwald I.Q.; Byrne J.V. (2011). "Assessment of angiographic outcomes after flow diversion treatment of intracranial aneurysms: a new grading schema". Neuroradiology. 53 (7): 501–508. doi:10.1007/s00234-010-0767-5. PMID   20838782. S2CID   1377177.
9. Darsaut, Tim E.; Bing, Fabrice; Makoyeva, Alina; Gevry, Guylaine; Salazkin, Igor; Raymond, Jean (2014). "Flow Diversion of Giant Curved Sidewall and Bifurcation Experimental Aneurysms with Very-Low-Porosity Devices". World Neurosurgery. 82 (6): 1120–1126. doi:10.1016/j.wneu.2013.09.036. PMID   24071065.

Further reading

• Jabbour, Pascal M. (2012). Neurovascular surgical techniques (First ed.). New Delhi: Jaypee Medical. ISBN   978-93-5090-088-8 . Retrieved 23 September 2015.
• Krishna, Chandan; Sonig, Ashish; Natarajan, Sabareesh K.; Siddiqui, Adnan H. (October 2014). "The Expanding Realm of Endovascular Neurosurgery: Flow Diversion for Cerebral Aneurysm Management". Methodist DeBakey Cardiovascular Journal. 10 (4): 214–219. doi:10.14797/mdcj-10-4-214. PMC   4300059 . PMID   25624975.