Hypophyseal region — anatomy of the operative approaches

Abstract

Landmarks and measurements for the transnasal approach (apertura piriformis, distance to the apertura sinus sphenoidalis) in children and adults are given. Included is the anatomy of the nasal septum, its vessels and nerves. The ostium of the sphenoid sinus, its development, types and dimensions are described. Also shown are the hypophyseal capsule, the hypophyseal vessels and the hypophyseal fossa with its variations and the sella turcica region with its adjacent dural structures (petroclinoid fold, diaphragma sellae, aperture for the internal carotid artery and pituitary cistern). For the intracranial approaches the arterial circle and its branches are important for neurosurgeons. The location, number, width and course of these branches are described. Distances and the most important vessels, which are seen by frontal, frontolateral and pterional approaches, are described.

The subdiaphragmatic cistern: historic and radioanatomic findings

“…These arachnoidal layer walls form a sort of "cap" over the pituitary (Fig. 4), which could show variability in shape and dimension in different individuals and presumably in different stages of life [13,26]. Analysis of the radiological images shows some variability of the subdiaphragmatic cistern, from an absent or not visible one to a very developed subarachnoid space below the diaphragma sellae, around the pituitary stalk, with or without the presence of "arachnoidal wings" developing anteriorly, posteriorly, or laterally to the infundibulum (Fig.…”

“…However, the first definition and systematic description of the pituitary subdiaphragmatic cistern ("infradiaphragmale Hypophysenzisterne") dates back to a report published in 1954 by [13]. Sporadic studies or citations of such cisterns can be found in the literature [4,5,10,17,26,42].…”

Three-dimensional anatomical landmarks of the sphenoid ostia for a safer transsphenoidal approach

“…In addition, they found that both openings were situated halfway between the superior and inferior margin of the sphenoid sinus anterior wall. Similar to Lang, Enatsu et al propounded that both SOs were located almost halfway on the anterior aspect of the sphenoid bone vertically; they also alleged that the spatial orientation of both relative to the carotid artery and the optic nerve showed no remarkable variation in their study (9,13). They resolved, however, that vertical and horizontal data of each SO varied significantly (9).…”

“…The sphenoid sinuses border the hypophysis from the nasal cavity (4,5,8,13,15). The trans-sphenoidal approach is the most frequently used surgical procedure in determining sellar tumors.…”

“…The interest in the trans-sphenoidal approach requires knowledge regarding the morphometric aspects of the SO and structures around it (1,4,5,11,13,16,17). The main problem is whether the shape, size, and angle of the SO alter the surgical technique (12,16).…”