Intraoperative mobile magnetic resonance imaging for craniotomy lengthens the procedure but does not increase morbidity

Purpose: To evaluate anesthetic aspects of care provided for craniotomy using mobile intraoperative magnetic resonance imaging (iMRI). Methods: Anesthetic factors were studied using a retrospective case-control design, The primary outcome measures were the duration of the surgical intervention; the recovery score and body temperature on arrival; and length of stay in the post-anesthetic care unit. Secondary outcome measures were estimated blood loss, perioperative transfusion requirements, and fluids administered. Results: Seventy-six patients undergoing craniotomy in the MRI theatre were compared with a case-matched control group of patients who underwent neurosurgical interventions in the conventional operating room during the same time period, The only outcome measure that differed between the two groups of patients was the duration of surgery: the mean duration of procedures for patients who underwent imaging was 407 +/- 143 min compared to 285 +/- 122 min in the conventional operating theatre (P < 0.000). Actual time spent imaging accounted for approximately 100 min (83%) of the increased duration. Conclusion: Our results do not support concerns that the MRI suite is a hostile environment for the delivery of anesthesia for craniotomy. With the exception of an increased duration of the procedure, patients undergoing anesthesia with iMRI showed no differences from those operated in the conventional operating theatres.