The Mixed Sellar Barrier: A New Subtype of this Novel Concept

The use of the recent concept of sellar barrier revealed that a specific group of patients were difficult to categorize. For this reason, we propose to add a new subtype: the mixed sellar barrier. The aim of this work was to define the new mixed barrier subtype and analyze this in a series of operated patients.

A retrospective study was carried out. From January to December 2018, 72 patients with pituitary adenomas underwent surgery by transsphenoidal approach. Patients with more than 1 surgery were excluded. Each patient's magnetic resonance imaging (MRI) was analyzed and classified using the following criteria: strong barrier (>1 mm), weak barrier (<1 mm), and mixed barrier (<1 mm in one region and >1 mm in another part).

Mixed sellar barrier is the coexistence of 2 types of sellar barrier (strong and weak). The presence of a mixed sellar barrier on MRI was associated with the presence of a mixed sellar barrier intraoperatively (P < 0.0001). By using the new MRI classification that includes the mixed sellar barrier, we found a stronger statistically significant association regarding the risk of cerebrospinal fluid leak (for the extreme categories; i.e., strong and weak) compared to the original work.

The new mixed sellar barrier subtype was precisely defined and illustrated. The correlation between MRI and intraoperative findings for this new subtype has been demonstrated in this study. A prospective study with a larger series of patients is required for validation.