Awake versus Asleep Craniotomy for Eloquent Glioma Resection: Is There Truly a Difference in Intraoperative Costs? A Time-Driven Activity-Based Cost Analysis

Introduction: Maximal resection is the goal of surgical treatment for gliomas, which are often found in eloquent areas of the brain responsible for critical functions like motor control, cognition, language processing, and sensation. Despite the efficacy of surgery, there is significant controversy whether these surgeries should be performed “awake” or asleep under general anesthesia. A prevailing criticism of awake craniotomy is that it is an expensive alternative to surgery under general anesthesia, though there is mixed evidence to support this claim. To date, no study has directly compared the intraoperative costs of these two modalities using time-driven activity-based costing (TDABC).

Methodology: We conducted a retrospective analysis of 68 awake craniotomies and 330 asleep craniotomies for resection of eloquent gliomas. These procedures were performed from 2017 to 2022 at a large academic medical center. Costs were calculated using the TDABC methodology. Detailed process maps were constructed to capture all material and personnel resources utilized intraoperatively. To streamline the data extraction process, we developed software capable of automatically retrieving this information from the electronic medical record (EMR). Supply costs were calculated as the aggregate of expenses related to intraoperatively utilized items, including implants, consumables, medications, and surgical tray sterilization. Personnel costs were determined in a multi-step process: we first identified the specific personnel involved in each case, as documented in the EMR. We then calculated the per-minute wage for each personnel type and multiplied this by the total intraoperative time for each type, summing these to derive the total personnel cost. Indirect costs, such as those associated with operating room (OR) usage and turnover, were also included in the overall cost calculation. Multivariable linear regression was performed to compare costs between awake and asleep craniotomy. Covariates in these models were patient-specific factors, including tumor location, gene mutation status, World Health Organization (WHO) grade, extent of resection, and tumor size.

Results: The total cost of an awake craniotomy was $9,094 ± $1,920, compared to $6,527 ± $2,009 for an asleep craniotomy. For both procedures, this cost was primarily driven by the cost of supplies ($4,567, n = 50.2% for awake; $3,329, n = 51.0%) and personnel ($4,528, n = 49.8% for awake; $3,329, n = 51.0% for asleep). Personnel cost differences were primarily explained by the presence of neurophysiologists, who assisted with intraoperative brain mapping during awake surgery. On multivariable regression analysis accounting for confounders; however, there was no significant difference in total intraoperative cost between the two procedural modalities (p = 0.769).

Conclusion: To our knowledge, TDABC has never been applied to the field of brain tumors. We demonstrate a feasible, automatable solution to ascertain the true intraoperative cost of brain surgery, without relying on inaccurate costing methodologies like cost-to-charge ratios or reimbursement. Contrary to the prevailing notion that awake craniotomy entails higher total cost, we show no significant difference in total cost between awake and asleep craniotomy. Our findings may promote further use of the awake modality, which has been shown to be associated with greater progression-free survival and improved postoperative neurologic function compared to asleep craniotomy for glioma resection.

Publication History

Article published online:
07 February 2025