Utility of three-dimensional computed tomography for anatomical assistance in endoscopic endonasal transsphenoidal surgery.

Endoscopic endonasal transsphenoidal surgery (ETSS) has been widely applied to pituitary adenomas. However, anatomical orientation is difficult when structures of the sphenoidal sinus are complicated. This study investigated the usefulness of three-dimensional computed tomography (3D-CT) modeling in planning surgical procedures for ETSS and providing anatomical guidance during surgery. CT data from 99 consecutive patients with pituitary adenoma treated between January 2008 and March 2014 were used to reconstruct 3D-CT models. Based on these images, the architecture of sphenoidal sinus, particularly structures surrounding the sellar floor, was visualized for preoperative simulation of surgical procedures. These 3D-CT images were also compared to surgical views during ETSS to evaluate applicability of the images. These models clearly demonstrated the morphology of the nasal cavity and structures of the sphenoidal sinus, including bony prominences of the internal carotid arteries (ICAs) and optic canals by successively eliminating sphenoidal structures. The 3D-CT images permitted determination of the maximum marginal line of the opening of the sellar floor by presenting vital structures such as ICAs and optic canals. With this 3D-CT model, the surgeon could access the sella more easily, open the floor widely enough for each individual patient, and resect the tumor maximally without complications. Preoperative 3D-CT models distinctly visualized the optic canals, bilateral ICAs, and complicated structures of sphenoidal septa. The 3D-CT images were useful for preoperative planning and as a road map during endoscopic surgery for pituitary adenoma, facilitating maximum tumor resection without complications.