Purpose: To review the anesthetic management of patients with cerebral aneurysms during treatment in the interventional neuroradiology (INR) suite compared with in the operating room.Methods: This was a retrospective chart review of 100 consecutive patients treated by endovascular coiling compared with 100 patients treated by surgical clipping of a cerebral aneurysm. Information compared and analyzed included demographics, preprocedure medical history, neurological status including location and size of aneurysm, anesthetic management, complications and patient outcome. P < 0.05 was considered significant.Results: Patients in the INR group were older (54 ± 15 vs 49 ± 12 yr), had a greater incidence of pre-procedure cardiorespiratory problems (55 vs 34 patients) and had more aneurysms located in the posterior fossa (68 vs 11) (P < 0.05). General anesthesia was used in all except seven INR patients who received conscious sedation. There were some differences in the anesthetic agents and techniques. There was less monitoring of INR patients; temperature (33 vs 99 patients), intraarterial catheter (22 vs 100), central venous catheter (4 vs 78), and evoked potential monitoring (0 vs 100). There were no differences in the incidence of documented complications or in patient outcome.Conclusion: There were some differences in the anesthetic management of patients undergoing endovascular treatment of a cerebral aneurysm compared with treatment in the operating room. The patients in the INR suite were sicker and somewhat older and they received less invasive monitoring, but the complication rate and outcome did not differ.