The aim of this study was to investigate the relationship between the morphological characteristics of the sphenoid sinus and endoscopic localization of the cavernous sinus (CS) using an extended endoscopic endonasal transsphenoidal approach. Thirty sides of CS in 15 adult cadaver heads were dissected to simulate the extended endoscopic endonasal transsphenoidal approach, and the morphology of the sphenoid sinus and anatomic structures of CS were observed. The opticocarotid recess (OCR), ophthalmomaxillary recess (V1V2R), and maxillomandibular recess (V2V3R) in the lateral wall of the sphenoid sinus were presented in 16 sides (53.3%), 6 sides (20%), and 4 sides (13.3%) of the 30 sides, respectively. OCR is a constant anatomic landmark in endoscopy and coincides with the anterior portion of the clinoidal triangle. The C-shaped internal carotid artery (ICA) in the lateral wall of the sphenoid sinus was presented in 11 sides (36.7%), the upper one-third of which corresponds to the middle portion of the clinoidal triangle, and the lower two-thirds of which correlates to the supratrochlear triangle, infratrochlear triangle, and ophthalmic nerve in CS, around which the medial, lateral, and anteroinferior interspaces are distributed. From a front-to-behind perspective, the C-shaped ICA consists of inferior horizontal segment, anterior vertical segment, clinoidal segment as well as partial subarachnoid segment of the ICA. OCR and C-shaped ICA in the lateral wall of the sphenoid sinus are the 2 reliable anatomic landmarks in the intraoperative location of the parasellar region of CS.

The study aimed at investigating the morphological characteristics and interconnected regularities of the cavernous sinus (CS) venous spaces using an expanded endoscopic endonasal transsphenoidal approach. Surgical dissections were performed for 15-colored silicon-injected human head specimens. The CS venous spaces were examined for their morphological and clinical characteristics using an expanded endoscopic endonasal transsphenoidal approach. The intracavernous course of the internal carotid artery (ICA) divided the CS venous spaces into four interconnected virtual compartments: medial, anteroinferior, posterosuperior, and lateral. The CS venous spaces had peculiar morphological characteristics; the medial compartment was C-shaped while the anteroinferior compartment resembled a boat's bow. The mean distances from the medial border of the inferior horizontal segment of cavernous ICA to the mid-line of the pituitary gland (PG) were 6.07 ± 1.61 mm (left) and 5.97 ± 1.89 mm (right); the mean distances from the medial border of the subarachnoid segment of cavernous ICA to the mid-line of the PG were 5.77 ± 1.16 mm (left) and 5.63 ± 1.17 mm (right); the mean distances from the medial border of the anterior vertical segment of cavernous ICA to the mid-line of the PG were 10.27 ± 1.74 mm (left) and 10.47 ± 1.90 mm (right). Morphological characteristics and the knowledge of the interconnected regularities of the CS venous spaces may help surgeons accurately locate the neurovascular structure, and thus may contribute to the effective prediction of tumor invasion and extension during endoscopic CS surgery.

Etlmaoidal roof was studied on 110 cadaveric head specimens. It is a bone plate of 28.2 nun long, 0.88 nun thick, 7.5 nma wide at the anterior edge and 9.6 mm wide at the posterior edge. The bone plate declines intero-posteriorly. The connecting types of the etlunoid roof with cribriform are horizontal (17.3%) and high plate form (82.7%). The anterior and posterior etlunoid arteries penetrate below the ethmoidal roof at the same level of cribriorfonn in etlunoid silms. The method lbr recognizing the etlunoidal roof in endoscopic nasal sinus surgeries was discussed. An antomical classification of the anterior ethmoid sinus and its clinical significance (p 84) Sixty adult cadaveric head specimens (34 male and 26 felnale) were shldied with special attention on the pnetunatization of the anterior etlmaoid sinus. The anterior ethlnoid sinus was divided into intraetlmmid t?qae (70.83%) and extraetlunoid type (29.17%), the latter was subdivided into:superorbit (17.5%), inferorbit (7.5%) and mixed (4.17%) type, according to the pattern of their extending over extraetlunoid. This classification can very well depict the syntopic relationship of the anterior etlmmidal sinus with the orbit, the frontal sinus and the maxillary sinus. The dimension , wall thickness, sinus ostia and pnetmlatization of the anterior etlunoid sinus were observed on 60 adult head specimens (34 male and 26 female). According to the cell ostia position, the cells of anterior etlunoid sinus were divided into four groups as frontal recess cell (in 88.3%),etlunoid bulla cell (100%),ixffundibulmn cell (85.8%) and maxillary sinus cell (3.3%). Clinical points relating to anterior etlunoidal surgery were discussed. Clinical anatomy of the extranasal ethmoidectomy (p 88) The anatomical structures on the medial orbital wall were measured on 60 adult head specimens (34 male and 26 female). The distances from Dacryon point to the anterior and posterior etlunoidal foramens and optic foranaen were 19, 32 and 40 nun respectively. The distances from the posterior ethlnoidal foralnen to the (contd. page 178) Surg Radiol Anat (1994) 16:178 Chinese Journal of Clinical Anatomy Abstracts vol 14, issue 2, 1996 Original articles anterior ethmoidal foramen and optic foralnen were 14 and 9 nml separately. 70% of the anterior etlunoidal