Through the choroidal fissure: a quantitative anatomic comparison of 2 incisions and trajectories (transsylvian transchoroidal and lateral transtemporal).
BACKGROUND
We compared the transsylvian transchoroidal (TSTC) approach with the lateral transtemporal (LTT) approach. Both approaches proceed through the choroidal fissure but through different incisions and along different trajectories.


METHODS
Four fixed, silicon-injected heads (8 sides) were used. Nine strategic anatomic points within the dissections were compared between the TSTC and LTT approaches in 7 other silicon-injected heads (14 sides). Neuronavigation was used to gather coordinates from selected points of both approaches to calculate surgical angles and distances to common targets.


RESULTS
The surgical angle of the TSTC approach for the inferior choroidal point was wider compared with the LTT approach (P < .05). The surgical angles for the P2a-P2p point were similar for both approaches. In the TSTC approach, the P2-P3 point angle was smaller than in the LTT approach (P < .05). The TSTC approach provided (except for the P2-P3 point) significantly shorter distances to all defined anatomic targets compared with the LTT approach. When the posterior cerebral artery was the target in the TSTC approach, the hippocampus was retracted 3 to 8 mm compared with 8 to 13 mm in the LTT approach.


CONCLUSIONS
We quantitatively described anatomic features of the TSTC approach and compared them with the LTT approach. For approaching the mesial temporal region, the TSTC approach offers an adequate surgical angle and shorter or similar distances proximal to P2-P3 and requires less temporal lobe and hippocampal retraction than the LTT approach. Such information can help surgeons select the optimal approach to the mesial temporal lobe and its surrounding structures. The TSTC approach should be considered for lesions located in the medial temporal region.
Wu
Anhua
A
Department of Neurosurgery, First Affiliated Hospital of China Medical University, Shenyang, LiaoNing, PR China.
Chang
Steve W
SW
Deshmukh
Pushpa
P
Spetzler
Robert F
RF
Preul
Mark C
MC
D001932:Brain Neoplasms / Q000601:surgery; D002102:Cadaver; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000601:surgery; D002831:Choroid Plexus / Q000033:anatomy & histology / Q000601:surgery; D035301:Cranial Fossa, Middle / Q000033:anatomy & histology / Q000601:surgery; D006624:Hippocampus / Q000033:anatomy & histology / Q000601:surgery*; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery; D007431:Intraoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D020547:Lateral Ventricles / Q000033:anatomy & histology / Q000601:surgery*; D020768:Middle Cerebral Artery / Q000033:anatomy & histology / Q000601:surgery; D038361:Neuronavigation / Q000379:methods* / Q000592:standards; D019635:Neurosurgical Procedures / Q000379:methods* / Q000592:standards; D020769:Posterior Cerebral Artery / Q000033:anatomy & histology / Q000601:surgery; D013346:Subarachnoid Space / Q000033:anatomy & histology / Q000601:surgery; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000601:surgery*