Do Anatomical Variations of Sphenoid Sinus Influence Sella Exposure and Residual Disease in Pituitary Surgery? - A Study in an Indian Population.

Endoscopic transsphenoidal surgery (ETS) is the standard practice in pituitary surgeries. The sellar exposure becomes the main factor which determines the residual disease in ETS. Not many studies can be found in the literature on the influence of anatomical variations of the sphenoid on intraoperative sella exposure.  The aim of the current study is to ascertain whether sphenoid sinus variations play a role in sellar exposure and residual tumor volume.  This is a prospective study conducted in a south Indian tertiary care center between June 2020 to June 2022, with 21 study participants who were scheduled to have ETS. The relation of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) parameters with the intraoperative area of sellar exposure and residual tumor volume was evaluated.  Sphenoid sinus dimensions, like presellar width (mean = 1.89 ± 0.51 cm), maximum width (mean = 2.94 ± 1.09 cm), presellar depth (mean = 1.14 ± 0.55 cm), suprasellar depth (mean = 1.08 ± 0.24 cm), infrasellar depth (mean = 2.36 ± 0.92 cm), presellar height (mean = 2.22 ± 0.47 cm), or the 9 internal carotid artery (ICA)-related measures, did not have any correlation with the mean intraoperative area of sellar exposure (0.57 ± 0.28 cm ). Also, the adequacy of sellar exposure did not relate to the residual tumor. Preoperative tumor volume was found to be higher (20.2 [55.3-13.2] cm ) in patients with residual tumor compared with those with no residual tumor (5.9 [6.8-5.2] cm ). Tumor extension had a significant association with the residual tumor volume.  According to the present study, anatomical variations of the sphenoid sinus do not influence the adequacy of sellar exposure. Further studies need to be undertaken concerning residual tumor volume as well as preoperative tumor volume and extension.