Introduction: Pituitary adenomas (PAs) are benign neoplasms frequently encountered during workup for endocrinopathy, headache, or visual loss.1,2 Transsphenoidal surgery remains the mainstay approach for PA resection. We retrospectively assessed safety and complication rates associated with transsphenoidal PA resection.

Methods: The USC Pituitary Center REDCap electronic database was used to identify 1,171 consecutive patients who underwent microscopic (85%) or endoscopic (15%) transsphenoidal PA resection at Keck Hospital of USC between November 1992 - March 2017.3,4,5 A retrospective analysis of perioperative complications and patient/tumor risk factors was conducted.

Results: There were 2 perioperative mortalities (0.2%) in this series. Additional surgical complications included cerebrospinal fluid leak (2.6%), new neurological deficit (1.3%), meningitis (1.0%), postoperative hematoma (1%), cranial nerve paresis (0.9%), hydrocephalus (0.7%), vision loss (0.6%), stroke (0.4%), vegetative state (0.1%) and carotid artery injury (0.1%). Perioperative medical complications included bacteremia/sepsis (0.5%), pneumonia (0.4%), myocardial infarction (0.3%), and DVT/PE (0.2%). Endocrine complications were the most frequent, including transient diabetes insipidus (4.5%), symptomatic hyponatremia (4.3%), permanent diabetes insipidus (0.3%), and new hypopituitarism (3.8%). There were no significant differences between microscopic versus endoscopic approaches with regard to overall complications (16.9% vs. 19.1%; p=0.513) or major complications (5% vs. 4%; p=0.601). Risk factors for major complications included: prior transsphenoidal surgery (8.5% versus 4.5%; p=0.043), prior craniotomy (23.5% versus 4.5%; p=0.001), prior radiosurgery (33.3% versus 4.5%, p=0.007), presence of PA invasion on MRI (7.0% versus 2.4%; p=0.001), and preoperative vision loss (8.8% versus 5.0%; p<0.001).

Conclusions: In one of the largest studies assessing complications associated with transsphenoidal PA resection, the rate of death or major disability was 0.26%. Risk factors for complications included prior surgical/radiosurgical treatment and PA invasion. No differences in complication rates between endoscopic and microscopic surgery were observed. When performed at experienced pituitary centers, safety rates for patients undergoing transsphenoidal PA resection are extremely high.

Patient Care: The safety and efficacy of transsphenoidal surgeries are widely reported, dating back decades. However, with the implementation of new technology and refinement of technique, it is essential to continue updating the literature. Our retrospective chart review of transsphenoidal surgery complications will be one of the largest to date, comprising consecutive patients with PAs at a single institution. By identifying common preoperative predictors for these complications, neurosurgeons can better identify higher-risk patients and manage them pre and postoperatively.

Learning Objectives: By the conclusion of this session, participants should be able to: 1. Discuss the potential complications of transsphenoidal surgery for resection of pituitary adenomas. 2. Identify critical preoperative risk factors associated with major and minor perioperative complications, including symptomatology and tumor invasion. 3. Describe the importance of preoperative planning using CT and pituitary MRI.

References: 1. Fernandez A, Karavitaki N, Wass J. Prevalence of pituitary adenomas: a community-based, cross-sectional study in Banbury (Oxfordshire, UK). Clinical Endocrinology 2009;72:377-382. 2. Marazuela M, Astigarraga B, Vicente A et al. Recovery of visual and endocrine function following transsphenoidal surgery of large nonfunctioning pituitary adenomas. Journal of Endocrinological Investigation 1994;17:703–707. 3. Ciric I, Ragin A, Baumgartner C, Pierce D. Complications of transsphenoidal surgery: results of a national survey, review of the literature, and personal experience. Neurosurgery 1997;40:225–237. 4. Ammirati M, Wei L, Ciric I. Short-term outcome of endoscopic versus microscopic pituitary adenoma surgery: a systematic review and meta-analysis. Journal of neurology, neurosurgery, and psychiatry. 2013;84(8):843–9. 5. Harris PA, Taylor R, Thielke R, Payne J, Gonzalez N, Conde JG. Research electronic data capture (REDCap) - A metadata-driven methodology and workflow process for providing translational research informatics support, J Biomed Inform. 2009 Apr;42(2):377-81.