Impact of Preoperative Anemia on Surgical Outcomes in Endonasal Transsphenoidal Surgery for Pituitary Adenoma: A Matched-Cohort Study

Background and Objectives: Neuroendocrine dysfunction and surgical complications are common concerns after endonasal transsphenoidal surgery (ETA). Preoperative anemia has been linked to increased morbidity in various surgical fields; however, its effect on outcomes in pituitary surgery remains unclear. This study evaluated the associations among preoperative anemia, postoperative complications, and neuroendocrine dysfunction in patients undergoing ETA for pituitary adenoma (PA). Methods This retrospective population-based study used the TriNetX global research network to identify adult patients with PAs who underwent ETA between 2005 and 2023. The patients were classified into anemia and non-anemia (control) cohorts based on their preoperative hemoglobin and hematocrit levels. Propensity score matching (PSM) was used to balance baseline characteristics. Postoperative surgical and neuroendocrine outcomes were compared using odds ratios (ORs) with 95% confidence intervals (CIs). Subgroup analysis was performed based on the severity of anemia. Primary outcomes included perioperative complications and postoperative endocrine function. Results After PSM, 2,242 patients were included in each group. The anemia group had significantly higher odds of postoperative meningitis (3.4% vs. 1.7%, OR: 2.01, p < 0.001), lumbar drain placement (7.0% vs. 2.7%, OR: 2.68, p < 0.001), and early reoperation (5.0% vs. 2.9%, OR: 1.76, p < 0.001). Neuroendocrine complications were also more frequent, including diabetes insipidus (25.3% vs. 21.6%, OR: 1.23, p = 0.004), Syndrome of inappropriate antidiuretic hormone secretion (SIADH)/hyponatremia (13.5% vs. 6.3%, OR: 2.35, p < 0.001), hypopituitarism (68.6% vs. 59.8%, OR: 1.47, p < 0.001), and an increased need for hormone replacement therapy. Subgroup analysis revealed that patients with moderate-to-severe anemia had higher risk of postoperative endocrine dysfunction and visual disturbances. Conclusion Preoperative anemia was associated with an increased risk of both surgical and neuroendocrine complications after ETA for PAs. These findings highlight the importance of identifying and managing anemia preoperatively to optimize outcomes and reduce postoperative morbidity.