Microneurosurgical management of distal middle cerebral artery aneurysms.
BACKGROUND
Distal middle cerebral artery aneurysms originate from branches of MCA distal to its main bifurcation or the peripheral branches. Distal middle cerebral artery aneurysms are the least frequently seen among the middle cerebral artery aneurysms. The purpose of this article is to review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of MdistAs.


METHODS
This review, and the whole series on intracranial aneurysms, are 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 10000 aneurysm patients since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 aneurysms, 69 patients carrying altogether 78 MdistAs formed 5% of all MCA aneurysms. Among the 18 patients with ruptured MdistAs (23%), an ICH occurred in 9 (50%).


CONCLUSIONS
Distal middle cerebral artery aneurysms are rare. The microneurosurgical treatment of MdistAs is challenging. They are often difficult to localize during the operation, and lack of collateral circulation makes their occlusion more demanding. High rate of ICH and high tendency of rebleeding urge acute or emergency surgery in most of ruptured cases. Microneurosurgical clipping is the most effective treatment of MdistAs.
Dashti
Reza
R
Department of Neurosurgery, Helsinki University Central Hospital, Helsinki 00260, Finland.
Hernesniemi
Juha
J
Niemelä
Mika
M
Rinne
Jaakko
J
Lehecka
Martin
M
Shen
Hu
H
Lehto
Hanna
H
Albayrak
Baki S
BS
Ronkainen
Antti
A
Koivisto
Timo
T
Jääskeläinen
Juha E
JE
D000208:Acute Disease; D017542:Aneurysm, Ruptured / Q000150:complications / Q000453:epidemiology / Q000601:surgery; D015901:Angiography, Digital Subtraction / Q000379:methods; D006285:Health Planning / Q000379:methods; D046648:Hematoma, Subdural, Intracranial / Q000453:epidemiology / Q000601:surgery; D006801:Humans; D006849:Hydrocephalus / Q000453:epidemiology / Q000601:surgery; D002532:Intracranial Aneurysm / Q000150:complications / Q000453:epidemiology / Q000601:surgery*; D008866:Microsurgery / Q000379:methods*; D020768:Middle Cerebral Artery / Q000033:anatomy & histology; D019635:Neurosurgical Procedures / Q000379:methods*; D011183:Postoperative Complications / Q000517:prevention & control; D011300:Preoperative Care; D013345:Subarachnoid Hemorrhage / Q000209:etiology / Q000601:surgery