Undiagnosed OSA in Pituitary Surgery: A Hidden Offender

Objectives: Obstructive sleep apnea (OSA) is a significant comorbidity in patients undergoing skull base surgery. Although the contribution of OSA to perioperative complications in various head and neck surgeries has been recognized, there is paucity of data regarding impact of OSA on patients undergoing pituitary surgery. The aim of this study was to compare the preoperative comorbidities and postoperative outcomes of patients with and without OSA undergoing endoscopic transsphenoidal pituitary surgery for pituitary adenomas.

Methods: A total of 346 patients undergoing transsphenoidal endoscopic pituitary surgery for adenoma from 2013 to 2017 at a single tertiary center were retrospectively reviewed. Patients with a known diagnosis of OSA (based on PSG) or active CPAP usage were classified as “confirmed” OSA. To address the potential underdiagnosis of OSA, patients with a self-reported history of snoring associated with apnea were classified as ‘suspected’ OSA. Furthermore, patients with hypertension and BMI > 30 were classified as “at risk of OSA.”

Results: Seventy-seven (22%) patients had a confirmed diagnosis of OSA, the majority of who were male (65%). OSA patients demonstrated a statistically significant increased preoperative BMI (p < 0.01), as well as rates of hypertension (OR, 1.85; CI, 1.10–3.11; p = 0.02) and thromboembolic events (OR, 3.78; CI, 1.37–10.44; p < 0.01). Furthermore, OSA patients more frequently underwent surgery for a functional tumor (34 vs. 19%; OR, 2.18; CI, 1.24–3.83; p < 0.01), most frequently growth-hormone secreting. Although intra-operative CSF leak rates were comparable in both groups, anterior diaphragmatic sellar leaks were more frequently encountered in the OSA group (OR, 3.26; CI, 1.14–9.30; p = 0.02). Recurrence, 30-day readmission, postoperative leak and postoperative complications (epistaxis, hypoxemia, and thromboembolic events) were comparable. Upon subgroup analysis of OSA patients with and without the use of CPAP, those who used CPAP (n = 38) were less likely to have intraoperative CSF leaks (18 vs. 46%; OR, 0.263; CI, 0.094–0.741; p = 0.01).

Inclusion of the “suspected” and “at-risk” subjects in the overall OSA group (n = 91) demonstrated that these patients were more likely to be older (p < 0.01), have a history of MI (p = 0.03), preoperative thromboembolic events (p = 0.03), as well as a prolonged hospital stay (2.80 ± 2.02 to 3.49 ± 4.07, p = 0.047).

Conclusion: The contribution of OSA to perioperative morbidity in the setting of endoscopic transsphenoidal pituitary surgery may be under recognized. For both patients with a known OSA diagnosis and those at high risk (such as those with growth hormone-secreting tumors), careful preoperative planning and perioperative management is advised to improve surgical outcomes.