Evaluation of Fine Feeding System and Angioarchitecture of Giant Pituitary Adenoma - Implications for Establishment of Surgical Strategy

Background Giant pituitary adenomas carry higher surgical risks despite recent advances in microsurgical and/or endoscopic surgery, and postoperative acute catastrophic changes without major vessel disturbance are still extremely difficult to predict, may manifest as postoperative pituitary apoplexy, and are associated with poor outcomes. Methods Eight males and 4 females aged 31-72 years (mean 50.7 years) with giant pituitary adenomas underwent preoperative investigation of fine angioarchitecture using C-arm cone-beam computed tomography with a flat-panel detector. Angiographical findings were used to decide the surgical routes and compared with clinical outcome. Results Feeding arteries were verified in 10 of 12 patients, whereas no feeding arteries were evident in 2 patients. The patients were divided into the faint tumor staining group and the significant staining group, which was reconfirmed by region of interest analysis. The former group had faint supply from the ipsilateral superior hypophyseal arteries and meningohypophyseal trunk, and the latter group had significant supply from the meningohypophyseal and inferolateral trunks, which passed centrifugally from the inferoposterior pole of the tumor. All patients were treated through the extended transsphenoidal approach. Intraoperative bleeding was significantly greater in the latter group (P = 0.013). All patients had improvement of neurologic deficit and were released from the intensive care unit within a few days. Conclusions Major blood supply of giant pituitary adenomas originates from branches of the infraclinoidal portion of the internal carotid artery, different from the normal anterior pituitary gland. Surgical route should depend on not only tumor shape and extension but also feeding systems.