Microneurosurgical management of proximal middle cerebral artery aneurysms.
BACKGROUND
The M1As are located in the main trunk (M1) of the MCA, between the bifurcation of the ICA and the main bifurcation of M1. Proximal MCA aneurysms are often small and thin-walled, which makes their proper clipping tedious. There are few reports on their microsurgery.


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 selection, the catchment area in the southern and eastern Finland.


RESULTS
These 2 centers have treated more than 10000 patients with aneurysm since 1953. We review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of M1As which form 7.4% of all intracranial and 14% of all MCA aneurysms in our patients.


CONCLUSIONS
Proximal MCA aneurysms are often wide-necked and intimately connected to an M1 branch at its origin on M1, features that favor exosurgery rather than endosurgery. The direction and course of the parent and branching arteries and the orientation of the fundus are the most important factors affecting the efficacy and safety of clipping.
Dashti
Reza
R
Department of Neurosurgery, Helsinki University Central Hospital, 00260 Helsinki, Finland.
Rinne
Jaakko
J
Hernesniemi
Juha
J
Niemelä
Mika
M
Kivipelto
Leena
L
Lehecka
Martin
M
Karatas
Ayse
A
Avci
Emel
E
Ishii
Keisuke
K
Shen
Hu
H
Peláez
José G
JG
Albayrak
Baki S
BS
Ronkainen
Antti
A
Koivisto
Timo
T
Jääskeläinen
Juha E
JE
D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D008866:Microsurgery / Q000379:methods*; D019635:Neurosurgical Procedures / Q000379:methods*; D011859:Radiography