Application of intraoperative magnetic resonance imaging in endoscopic transsphenoidal surgery for recurrent pituitary adenomas

Abstract

Objective To investigate the clinical value of intraoperative magnetic resonance imaging (iMRI) in endoscopic transsphenoidal surgery for recurrent pituitary adenomas. Methods A retrospective analysis was conducted on 29 cases of surgically treated patients with recurrent pituitary adenomas at Neurosurgery Department of the First Medical Center of Chinese PLA Greneral Hospital from February 2009 to February 2015. All patients underwent surgical resection of tumor with intraoperative magnetic resonance imaging. The parameters evaluated included the extent of tumor resection, scanning frequency and timing, relief of symptoms and signs, follow-up results and complications. Results Among 24 patients with possible totally resection according to the Knosp grading, 16 showed total tumor resection through the first intraoperative scanning and the second intraoperative scanning revealed another 4 cases achieving total resection after extended resection. After more than 3 times of extended resection, intraoperative scanning revealed 2 patients with total resection and the remaining 2 patients had residual tumor tissues. The number of intraoperative scanning was 1.6±0.8 times per case and the average scanning duration was 45.9±19.3 minutes. The total time for surgery was 157.2±55.6 minutes. The postoperative headache remission ratio was 11/13 and the visual dysfunction remission ratio was 12/15. Postoperative pituitary insufficiency occurred in 2 cases, olfactory disorder in 1 case, temporary diabetes insipidation in 7 cases and cerebrospinal fluid leakage in 2 cases. Twenty-nine patients were followed up for 3 to 67 months, with an average of 46.6±19.4 months. There were 2 patients with tumor recurrence among the 22 patients with total tumor resection. Conclusion For recurrent pituitary adenomas, iMRI-assisted endoscopic resection seems to be a safe and effective treatment which has high rate of total resection and less postoperative complications. Key words: Pituitary neoplasms; Neoplasm recurrence, local; Neurosurgical procedures; Intraoperative magnetic resonance imaging; Natural orifice endoscopic surgery