Anatomic study on arteries concerning with transsphenoidal cavernous sinus surgical approach

Objective: To demonstrate anatomical data and morphological characteristics of arteries in cavernous sinus (CS) and provide anatomical guides for treatment of lesions involving CS. Methods: Ten fixed cadavers' heads (six male, four female), the arteries of which were injected with red latex, were used to perform transsphenoidal approach. The anterior wall of sphenoidal sinus and the floor of sellar turcica were opened as possible to expose floor dura mater of sella and inferior wall of CS. Then all branches of parasellar internal carotid artery (PSICA) were dissected carefully. Anatomical data and morphological characteristics of these branches were measured and demonstrated, the result of which were compared with those from transcranial approach. Results: According to morphological charateristics, ICA in CS could be divided to two parts: PSICA and paraclival ICA (PCICA) in transsphenoidal approach. The PSICA could be subdivided into three parts: upper, lower horizontal and vertical part. In 9 of 20 sides CS (45%), Meningohypophyseal trunk originated from medial wall of inferior horizontal part of PSICA, 4 sides (20%) from the roof wall, 5 sides (25%) from lateral wall, 2 sides (10%) from medial wall of superior horizontal part. In 16 of 20 sides (80%), The inferolateral trunk (artery of the inferior cavernous sinus) arised from the lateral wall of vertical part, 1 sides (5%) from inferior horizontal part, 3 sides (15%) from meningohypohyseal trunk. McConnell's capsular arteries were only found in 5 sides (25%) of all species, which arised from the medial side of vertical part. The diameter of this artery was about 0.85±0.21mm, which was smaller than another branch of ICA. Conclusions: In transsphenoidal approach, because of the change of optic view and field, the morphological features of ICA in CS and intracavernous branches in transsphenoidal approach are different from those in transcranial approach. The branches, which coursed medially, are a troublesome problem for treatment of those lesions involving this region, which also is the major reason of artery blooding in transsphenoidal cavernous sinus approach. In order to reduce the blooding interoperation or post operation, understanding these anatomical and morphological features of arteries in this region is most important.