Microneurosurgical management of middle cerebral artery bifurcation aneurysms.
BACKGROUND
Of the MCA aneurysms, those located at the main bifurcation of the MCA (MbifA) are by far the most frequent. The purpose of this article is to review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of MbifAs.


METHODS
This review, and the whole series on intracranial aneurysms, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve without patient selection the catchment area in southern and eastern Finland.


RESULTS
These 2 centers have treated more than 10,000 patients with intracranial aneurysm's since 1951. In the Kuopio Cerebral Aneurysm Data Base of 3005 patients with 4253 aneurysms, MbifAs formed 30% of all ruptured aneurysms, 36% of all unruptured aneurysms, 35% of all giant aneurysms, and 89% of all MCA aneurysms. Importantly, in 45%, rupture of MbifA caused an ICH.


CONCLUSIONS
Middle cerebral artery bifurcation aneurysms are often broad necked and may involve one or both branches of the bifurcation (M2s). The anatomical and hemodynamic features of MbifAs make them usually more favorable for microneurosurgical treatment. In population-based services, MbifAs are frequent targets of elective surgery (unruptured), acute surgery (ruptured), and emergency surgery (large ICH), even advanced approaches (giant). The challenge is to clip the neck adequately, without neck remnants, while preserving the bifurcational flow.
Dashti
Reza
R
Department of Neurosurgery, Helsinki University Central Hospital, 00260 Helsinki, Finland.
Hernesniemi
Juha
J
Niemelä
Mika
M
Rinne
Jaakko
J
Porras
Matti
M
Lehecka
Martin
M
Shen
Hu
H
Albayrak
Baki S
BS
Lehto
Hanna
H
Koroknay-Pál
Päivi
P
de Oliveira
Rafael Sillero
RS
Perra
Giancarlo
G
Ronkainen
Antti
A
Koivisto
Timo
T
Jääskeläinen
Juha E
JE
D002533:Cerebral Angiography / Q000379:methods / Q000592:standards; D002560:Cerebrovascular Circulation / Q000502:physiology; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D007431:Intraoperative Complications / Q000209:etiology / Q000517:prevention & control; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D011300:Preoperative Care / Q000592:standards; D013525:Surgical Instruments / Q000592:standards; D014656:Vascular Surgical Procedures / Q000295:instrumentation / Q000379:methods* / Q000592:standards