TY - JOUR
T1 - Surgical microanatomy of the anterior clinoid process for paraclinoid aneurysm surgery and efficient modification of extradural anterior clinoidectomy
AU - Ota, Nakao
AU - Tanikawa, Rokuya
AU - Miyazaki, Takanori
AU - Miyata, Shiro
AU - Oda, Jumpei
AU - Noda, Kosumo
AU - Tsuboi, Toshiyuki
AU - Takeda, Rihei
AU - Kamiyama, Hiroyasu
AU - Tokuda, Sadahisa
PY - 2015
Y1 - 2015
N2 - BACKGROUND: Anatomic variations of the anterior clinoid process (ACP) should be recognized before clinoidectomy to ensure a safe approach. This study describes the incidence of caroticoclinoid foramen (CCF), interclinoid osseous bridge, and pneumatization of the ACP during extradural anterior clinoidectomy. The problems and technical issues encountered in such cases are described. -METHODS: Using multidetector-row computed tomography, 144 sides in 72 cases of paraclinoid aneurysm treated by extradural anterior clinoidectomy were analyzed preoperatively. -RESULTS: CCF, interclinoid osseous bridge, and pneumatization of the ACP were observed in 16.6%, 2.77%, and 27.7% of cases. Pneumatized patterns were divided into 3 groups according to route: pneumatization via the optic strut (in 74.1%), pneumatization via the anterior root (in 14.8%), and pneumatization via optic strut and anterior root (in 11.1%). CCF and interclinoid osseous bridge represent obstacles to complete extradural removal of the ACP. The ACP should not be moved even after drilling the lateral wall of the ACP, orbital roof, and optic strut, so an intradural approach is sometimes needed. A CCF warrants careful removal to open the distal dural ring. Awareness of the routes of pneumatization for the ACP should reduce the risk of tears in the paranasal mucosa. If tears arise in the mucosa, suturing and closure are needed to prevent liquorrhea. -CONCLUSIONS: Preoperative computed tomography is useful to detect variations in the anatomy around the ACP. When performing extradural anterior clinoidectomy in such anomalous cases, appropriate modifications are needed to ensure a safe approach.
AB - BACKGROUND: Anatomic variations of the anterior clinoid process (ACP) should be recognized before clinoidectomy to ensure a safe approach. This study describes the incidence of caroticoclinoid foramen (CCF), interclinoid osseous bridge, and pneumatization of the ACP during extradural anterior clinoidectomy. The problems and technical issues encountered in such cases are described. -METHODS: Using multidetector-row computed tomography, 144 sides in 72 cases of paraclinoid aneurysm treated by extradural anterior clinoidectomy were analyzed preoperatively. -RESULTS: CCF, interclinoid osseous bridge, and pneumatization of the ACP were observed in 16.6%, 2.77%, and 27.7% of cases. Pneumatized patterns were divided into 3 groups according to route: pneumatization via the optic strut (in 74.1%), pneumatization via the anterior root (in 14.8%), and pneumatization via optic strut and anterior root (in 11.1%). CCF and interclinoid osseous bridge represent obstacles to complete extradural removal of the ACP. The ACP should not be moved even after drilling the lateral wall of the ACP, orbital roof, and optic strut, so an intradural approach is sometimes needed. A CCF warrants careful removal to open the distal dural ring. Awareness of the routes of pneumatization for the ACP should reduce the risk of tears in the paranasal mucosa. If tears arise in the mucosa, suturing and closure are needed to prevent liquorrhea. -CONCLUSIONS: Preoperative computed tomography is useful to detect variations in the anatomy around the ACP. When performing extradural anterior clinoidectomy in such anomalous cases, appropriate modifications are needed to ensure a safe approach.
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U2 - 10.1016/j.wneu.2014.12.014
DO - 10.1016/j.wneu.2014.12.014
M3 - Review article
C2 - 25527880
AN - SCOPUS:84931080451
SN - 1878-8750
VL - 83
SP - 635
EP - 643
JO - World Neurosurgery
JF - World Neurosurgery
IS - 4
ER -