Anterior circulation aneurysms (ACA) arise from the internal carotid artery or from any of its branches; the most common type is saccular, responsible for 85% of ACA. Microsurgery and endovascular approach are the two ways for treatment in these patients.
Prevalence of intracranial aneurysms is estimated to be from 1% to 5% of population, most
of them are small and located in the anterior circulation11 . Rinkel GJ. Natural history, epidemiology and screening of
unruptured intracranial aneurysms. J Neuroradiol. 2008;35(2):99-103.
http://dx.doi.org/10.1016/j.neurad.2007.
https://doi.org/10.1016/j.neurad.2007...
,22 . McNulty ML, Lee VH. Management of unruptured intracranial
aneurysms and arteriovenous malformations. Am J Ther. 2011;18(1):64-9.
http://dx.doi.org/10.1097/MJT.0b013e3181e4ddc6
https://doi.org/10.1097/MJT.0b013e3181e4...
. The risk factors for aneurysms are age, female gender,
smoking, arterial hypertension, alcohol abuse, presence of one or more relatives with
subarachnoid hemorrhage and autosomal dominant polycystic kidney disease11 . Rinkel GJ. Natural history, epidemiology and screening of
unruptured intracranial aneurysms. J Neuroradiol. 2008;35(2):99-103.
http://dx.doi.org/10.1016/j.neurad.2007.
https://doi.org/10.1016/j.neurad.2007...
. The ACA have lower risk of rupture
than posterior location33 . Kolk NM, Algra A, Rinkel GJ. Risk of aneurysm rupture at
intracranial arterial bifurcations. Cerebrovasc Dis. 2010;30(1):29-35.
http://dx.doi.org/10.1159/00031344
https://doi.org/10.1159/00031344...
. The risk of
rupture is around 1% per year, size is the major risk factor for this complication, the
rupture rate for ACA less than 7 mm was 0% per year in patients with no prior SAH and
0.3% per year in previous SAH, this risk arise considerably to 8% per year in patients
with giant aneurysms11 . Rinkel GJ. Natural history, epidemiology and screening of
unruptured intracranial aneurysms. J Neuroradiol. 2008;35(2):99-103.
http://dx.doi.org/10.1016/j.neurad.2007.
https://doi.org/10.1016/j.neurad.2007...
. Among ACA the
most frequent site is anterior communicating artery44 . Hernesniemi J, Dashti R, Lehecka M, Niemelä M, Rinne J, Lehto
H et al. Microneurosurgical management of anterior communicating artery
aneurysms. Surg Neurol. 2008;70(1):8-28.
http://dx.doi.org/10.1016/j.surneu.2008.01.056
https://doi.org/10.1016/j.surneu.2008.01...
. The development and improvement of surgical and
endovascular techniques are a constant requirement.
In this elegant study entitled “Head Positioning for Anterior Circulation
Aneurysms Microsurgery”, Chaddad-Neto et al. observed that a perfect head
positioning, according to specific aneurysm location and results from cadaveric studies,
offers a best option to minimize neurovascular injury and brain retractions55 . Chaddad-Neto F, Doria-Netto HL, Campos-Filho JM, Ribas ESC, Ribas
GC, Oliveira E. Head positioning for anterior circulation aneurysms
microsurgery. Arq Neuropsiquiatr. 2014;72(11):832-40.
http://dx.doi.org/10.1590/0004-282X20140156
https://doi.org/10.1590/0004-282X2014015...
.
They have proposed a perfect positioning after their study in heads that have been placed at the ideal rotation and extension for the best exposure to aneurysms of the anterior circulation. The second part of the study was made with 110 patients with unruptured aneurysm in anterior circulation, observing the best head positioning showed in the first part (cadaveric study).
Previous studies have adopted the classical pterional incision, but without a definition
of adequate rotation and extension of the head to explore the better way to reach
aneurysm of these regions66 . Gibo H, Lenkey C, Rhoton AL Jr. Microsurgical anatomy of the
supraclinoid portion of the internal carotid artery. J Neurosurg.
1981;55(4):560-74.,77 . Rhoton AL Jr, Saeki N, Perlmutter D, Zeal A. Microsurgical anatomy
of common aneurysm sites. Clin Neurosurg. 1979;26:248-306.,88 . Ferreira MAT, Tedeschi H, Wen HT, de Oliveira E. Posterior
circulation aneurysms: guideline to management. Oper Tech Neurosurg.
2000;3(3):169-78. http://dx.doi.org/10.1053/otns.2000.16261
https://doi.org/10.1053/otns.2000.16261...
,99 . Rosner SS, Rhoton AL Jr, Ono M, Barry M. Microsurgical anatomy of
the anterior perforating arteries. J Neurosurg.
1984;61(3):468-85..
Another way is using lateral supraorbital approach, more frontally located modification
of the pterional approach1010 . Romani R, Laakso A, Niemelä M, Lehecka M, Dashti R, Isarakul
P et al. Microsurgical principles for anterior circulation aneurysms. Acta
Neurochir Suppl. 2010;107:3-7.
http://dx.doi.org/10.1007/978-3-211-99373-6_1
https://doi.org/10.1007/978-3-211-99373-...
. A recent
study has showed that for anterior communicating artery aneurysm there are different
surgical approaches in relation to head rotation, according to anterior, posterior,
superior and inferior projection1111 . Ozdemir M, Comert A, Ugur HC, Kahilogullari G, Tubbs RS, Egemen N.
Anterior communicating artery aneurysm surgery: which is the most appropriated
head position? J Craniofac Surg. 2014; Epub ahead of print.
http://dx.doi.org/10.1097/SCS.0b013e3182a30ea3
https://doi.org/10.1097/SCS.0b013e3182a3...
.
This issue describes robust results from a significant number of patients (n=110) and permits a useful guide to be followed with the perfect positioning and description of the external and internal anatomic landmarks for a better visualization of aneurysms. Readers can observe differences and description among head positions (rotation and extension) for different sites (ophthalmic artery, anterior and posterior communicating arteries, anterior choroidal artery, internal carotid artery bifurcation, and middle cerebral artery). The authors have divided aneurysm locations into two groups, which simplified the positioning of the patient.
References
-
1Rinkel GJ. Natural history, epidemiology and screening of unruptured intracranial aneurysms. J Neuroradiol. 2008;35(2):99-103. http://dx.doi.org/10.1016/j.neurad.2007.
» https://doi.org/10.1016/j.neurad.2007 -
2McNulty ML, Lee VH. Management of unruptured intracranial aneurysms and arteriovenous malformations. Am J Ther. 2011;18(1):64-9. http://dx.doi.org/10.1097/MJT.0b013e3181e4ddc6
» https://doi.org/10.1097/MJT.0b013e3181e4ddc6 -
3Kolk NM, Algra A, Rinkel GJ. Risk of aneurysm rupture at intracranial arterial bifurcations. Cerebrovasc Dis. 2010;30(1):29-35. http://dx.doi.org/10.1159/00031344
» https://doi.org/10.1159/00031344 -
4Hernesniemi J, Dashti R, Lehecka M, Niemelä M, Rinne J, Lehto H et al. Microneurosurgical management of anterior communicating artery aneurysms. Surg Neurol. 2008;70(1):8-28. http://dx.doi.org/10.1016/j.surneu.2008.01.056
» https://doi.org/10.1016/j.surneu.2008.01.056 -
5Chaddad-Neto F, Doria-Netto HL, Campos-Filho JM, Ribas ESC, Ribas GC, Oliveira E. Head positioning for anterior circulation aneurysms microsurgery. Arq Neuropsiquiatr. 2014;72(11):832-40. http://dx.doi.org/10.1590/0004-282X20140156
» https://doi.org/10.1590/0004-282X20140156 -
6Gibo H, Lenkey C, Rhoton AL Jr. Microsurgical anatomy of the supraclinoid portion of the internal carotid artery. J Neurosurg. 1981;55(4):560-74.
-
7Rhoton AL Jr, Saeki N, Perlmutter D, Zeal A. Microsurgical anatomy of common aneurysm sites. Clin Neurosurg. 1979;26:248-306.
-
8Ferreira MAT, Tedeschi H, Wen HT, de Oliveira E. Posterior circulation aneurysms: guideline to management. Oper Tech Neurosurg. 2000;3(3):169-78. http://dx.doi.org/10.1053/otns.2000.16261
» https://doi.org/10.1053/otns.2000.16261 -
9Rosner SS, Rhoton AL Jr, Ono M, Barry M. Microsurgical anatomy of the anterior perforating arteries. J Neurosurg. 1984;61(3):468-85.
-
10Romani R, Laakso A, Niemelä M, Lehecka M, Dashti R, Isarakul P et al. Microsurgical principles for anterior circulation aneurysms. Acta Neurochir Suppl. 2010;107:3-7. http://dx.doi.org/10.1007/978-3-211-99373-6_1
» https://doi.org/10.1007/978-3-211-99373-6_1 -
11Ozdemir M, Comert A, Ugur HC, Kahilogullari G, Tubbs RS, Egemen N. Anterior communicating artery aneurysm surgery: which is the most appropriated head position? J Craniofac Surg. 2014; Epub ahead of print. http://dx.doi.org/10.1097/SCS.0b013e3182a30ea3
» https://doi.org/10.1097/SCS.0b013e3182a30ea3
Publication Dates
-
Publication in this collection
Nov 2014
History
-
Received
22 Sept 2014 -
Accepted
29 Sept 2014