Introduction Patients undergoing elective endovascular treatment for unruptured intracranial aneurysms (UIA) are typically observed overnight in a neurocritical care unit (NCU). However, no consensus exists on the necessity of NCU-level care following UIA treatment. This study aims to identify patients who may not require NCU-level care following elective UIA treatment, as well as determine predictors of prolonged length of stay (LOS) in this cohort.

Materials and Methods Upon obtaining institutional review board approval, we conducted a retrospective analysis of all patients with UIA who underwent endovascular treatment at a single center from 2017-2022. Per institutional protocol, all patients were admitted to NCU for close monitoring. Data on demographics, past medical history, radiographic features, procedural techniques, intraoperative events (thrombus formation and/or altered intracranial hemodynamics, rupture/perforation and/or contrast extravasation, coil extrusion, vascular dissection, or access-related complication), postoperative complications (hemodynamic instability, neurological deficits, critical laboratory derangement, and respiratory distress), and LOS were collected. Prolonged LOS was defined as exceeding 24 hours. Descriptive statistics were performed to analyze the timeframe of postoperative complications. Multivariable logistic regression analysis was performed using stepwise backward elimination to determine independent predictors of prolonged LOS.

Results A total of 209 patients were included in our analysis. Of these, 47 patients were identified as having an indication for NCU-level care within 24 hours of procedure end time. NCU indications were defined as respiratory distress or the need for close neurologic, hemodynamic, or cardiac monitoring. A total of 29 patients (61.7%) were identified as having an NCU indication at procedure end time due to intraoperative events. An additional 18 patients (38.3%) had isolated postoperative NCU indications, of which 15 (31.9%) were identified within a six-hour postoperative window and 3 (6.4%) were identified between six and 24 hours. Within the six-hour window, 77.8% (7/9) of patients exhibiting hemodynamic instability, 83.3% (5/6) with new or worsening neurologic deficit, 100% (5/5) with critical laboratory derangements, and 100% (3/3) with respiratory distress were identified. Indications identified outside the six-hour window included delayed neurologic deficit, atrial fibrillation with rapid ventricular response, and refractory hypotension, each occurring once.

Of 209 patients, 179 (85.65%) were discharged within 24 hours post-treatment and 30 (14.35%) had prolonged LOS. Notably, 25 (83.3%) of the prolonged LOS cohort possessed NCU indications. On the multivariable model, independent predictors for prolonged LOS were postoperative neurological deficits within six hours post-treatment (OR,43.44;95%CI,5.72-907.95;p=0.001), postoperative hemodynamic instability within six hours post-treatment (OR,34.39;95%CI,6.28-257.86;p<0.001), postoperative critical laboratory derangement within six hours post-treatment (OR,15.18;95%CI,1.33-172.11;p=0.022), intraoperative coil extrusion (OR,11.55;95%CI,1.75-74.87;p=0.008), and intraoperative thrombus formation and/or altered intracranial hemodynamics (OR,8.77;95%CI,2.06-35.86.22,p=0.002). No association was found with preprocedural variables or procedural techniques.

Conclusion Our analysis suggests that intraoperative events and postoperative complications, both being indications for NCU-level care, are the only independent predictors of prolonged LOS following elective endovascular treatment of UIAs. Further, most patients identified as having an indication for NCU-level care were identified within six hours of procedure end time. Thus, selective rather than default NCU admission following a recovery period may be a logical avenue for cost reduction in this cohort.

Disclosures S. Ahn: None. S. Roth: None. L. Velagapudi: None. Y. Ko: None. N. Mummareddy: None. D. Liles: None. M. Froehler: None. M. Fusco: None. R. Chitale: None.