(AS2) Predicting Function-based Resection Limitation Due to Poor Participation During Awake Surgery. a Preoperative Scoring System from a Monocentric Consecutive Series of 384 Patients

Introduction: Failure in achieving a function-based resection related to the patient’s insufficient participation for any reason is a drawback of awake surgery. We assessed preoperative parameters to predict the risk of patient’s insufficient intraoperative cooperation leading to the arrest of the awake resection before the identification of eloquent boundaries.

Methods: Observational, retrospective, single-institution cohort analysis (2009-2022) of 384 awake surgeries. The intraoperative insufficient cooperation was defined as a patient unable to perform efficient neurological, language, and/or neurocognitive intraoperative tasks for any reason during the whole duration of the awake phase.

Results: An insufficient patient’s intraoperative cooperation occurred in 20/384 patients (5.2%), leading to awake surgery failure in 3/384 patients (i.e. no resection, 0.8%) and precluded a function-based resection to be achieved in 17/384 patients (i.e. resection limitation, 4.4%). It was related to iterative spontaneous errors during neurocognitive tasks (2.3%), increasing tiredness (1.3%), headaches (0.5%), posture discomfort (0.5%), sudden deterioration of the neurological condition (0.3%), and uncontrolled high blood pressure (0.3%). The insufficient patient’s intraoperative cooperation significantly reduced the resection rates (55.0%Vs.94.0%,p < 0.001) and precluded supratotal resection to be achieved (0%Vs.11.3%, p=0.017). Age ≥70-year-old (aOR 7.01,[95%CI1.43-34.40], p=0.016), uncontrolled epileptic seizures (aOR 4.77,[95%CI0.07-0.61],p=0.004), previous oncological treatment (aOR 5.06,[95%CI 1.81-14.14],p=0.002), hyperperfusion on MRI (aOR 4.17, [95%CI 1.09-15.86], p=0.036), and mass effect on midline (aOR 3.89,[95%CI 1.29-11.72]p=0.015) were independent predictors of insufficient cooperation during awake surgery. An Awake Surgery Intraoperative Cooperation score (0 to 5) was calculated using these independent preoperative predictors: 98.9% of patients with a score < 2 presented a good intraoperative cooperation, while 84.8% of patients with a score≥2 presented a good intraoperative cooperation.

Conclusion : Function-based resection under awake conditions can be safely performed with a low rate of insufficient patient’s intraoperative cooperation. The risk can be assessed preoperatively by careful patient selection.