A combined subtemporal and transventricular/transchoroidal fissure approach to medial temporal lesions.
OBJECTIVE
To minimize therapeutic morbidity such as cognitive function disturbance and vascular injury to perforating arteries, preoperative functional mapping of the basal temporal lobe functions was performed and the medial temporal lesions were resected via a combined subtemporal and transventricular/transchoroidal fissure approach.


METHODS
Twenty-one patients with medial temporal lesions including tumors, arteriovenous malformations, and medial temporal lobe epilepsy underwent operation. The neurovascular structures in the ambient cistern were first dissected free from the medial temporal lobe with a conventional subtemporal approach. Then, the temporal horn was opened through the basal surface of the temporal lobe. Finally, the ambient cistern was accessed from the temporal horn through the choroidal fissure. In five patients whose lesions were revealed to be located on the dominant side by preoperative intracarotid amytal administration test (Wada test), functional mapping of the basal temporal lobe language cortex was monitored for 1 week by use of a subdural electrocorticogram grid before the extirpation surgery. The entrance point from the temporal base to the temporal horn was determined by the result of the functional mapping.


RESULTS
The lesions were resected safely and completely in all cases. Language and cognitive functions were preserved even in patients with the basal language area on the dominant side.


CONCLUSIONS
Surgeons can confirm the important neurovascular structures from the subtemporal route and from the transtemporal horn route by a combined subtemporal and transventricular/transchoroidal fissure approach. This approach is especially effective for avoiding ischemic complications by allowing direct confirmation of the anterior choroidal and thalamoperforating arteries.
Miyamoto
Susumu
S
Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto, Japan. miy@hsp.ncvc.go.jp
Kataoka
Hiroharu
H
Ikeda
Akio
A
Takahashi
Jun
J
Usui
Keiko
K
Takayama
Motohiro
M
Satow
Takeshi
T
Hashimoto
Nobuo
N
D000328:Adult; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000601:surgery*; D002648:Child; D002831:Choroid Plexus / Q000601:surgery*; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control; D004833:Epilepsy, Temporal Lobe / Q000601:surgery*; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods*; D013702:Temporal Lobe / Q000503:physiopathology / Q000601:surgery*