Predictive Factors for Postoperative Opioid Use in Elective Endoscopic Endonasal Skull Base Surgery.

OBJECTIVE: In 2017, the United States opioid epidemic was declared a public health emergency. Increased efforts have been made to understand and reduce patient opioid use in neurosurgery. However, the factors associated with postoperative opioid use remain understudied in endoscopic endonasal skull base surgery (EESBS). We identified the demographic and surgical factors associated with postoperative opioid use in EESBS. METHODS: A retrospective review was conducted of patients who underwent elective EESBS between January 2015 and December 2020. Patient demographics, relevant clinical history, and operative data were collected and analyzed. Total opioid use was calculated 24, 48, and 72 hours postoperatively. Multivariable linear regression analyses were performed to identify factors associated with opioid use. RESULTS: There were 454 patients included. A history of anxiety/depression and younger patient age were associated with a significant increase in opioid use at 24 (28.2 MME, p < 0.001), 48 (53.4 MME, p < 0.001), and 72 (89.4 MME, p < 0.001) hours after surgery. Nasoseptal flap use was significantly associated with increased opioid use at 24 (12.8 MME, p < 0.49) and 48 (19.6 MME, p < 0.048) h postoperatively while controlling for intraoperative variables and surgical approach (trans-sellar vs. expanded). No significant association was observed for patient sex, history of migraines, preoperative opioid use, length of surgery, or surgical approach. CONCLUSION: In patients undergoing EESBS, patient history of anxiety/depression, younger patient age, and nasoseptal flap use are associated with increased postoperative opioid use. Knowledge of these risk factors may guide perioperative prescribing patterns to both adequately control postoperative pain and reduce opioid use. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:494-499, 2023.

Predictive Factors for Postoperative Opioid Use in Elective Skull Base Craniotomies.

Objective In 2017, the United States officially declared opioid overuse a public health emergency. Due to a paucity of published benchmark data in skull base neurosurgery, we quantified postoperative opioid use in patients undergoing skull base craniotomies and identified factors that influence postoperative opioid use. Setting Tertiary academic medical center. Participants Patients who underwent elective craniotomies by two skull base neurosurgeons between January 2015 and May 2020. Main Outcome Measures Demographic and perioperative data were retrospectively extracted from the electronic medical record. Surgical approaches were categorized as having either "significant" or "minimal" muscle dissection. Univariate and multivariate linear regression analyses were performed to identify predictors of postoperative opioid use at 24, 48, and 72 hours. Results We included 300 craniotomies, 206 were supratentorial and 94 were infratentorial. This included 195 women and 105 men, with a mean age of 54.9 years. In multivariable analysis, a history of anxiety or depression, preoperative opioid use, and a history of migraines independently predicted a significantly greater opioid use at 24, 48, and 72 hours. Increased age and minimal muscle dissection independently predicted lower opioid consumption. Sex, infratentorial versus supratentorial approach, length of surgery, and postoperative steroid use did not impact total opioid use. Conclusion Younger age, history of anxiety or depression, preoperative opioid consumption, preexisting history of migraines, and significant intraoperative muscle dissection were associated with higher postoperative opioid consumption. These risk factors provide insight on potential targets for minimizing postoperative opioids in craniotomies.

Clinically feasible MTR is sensitive to cortical demyelination in MS.

OBJECTIVE: Presently there is no clinically feasible imaging modality that can effectively detect cortical demyelination in patients with multiple sclerosis (MS). The objective of this study is to determine if clinically feasible magnetization transfer ratio (MTR) imaging is sensitive to cortical demyelination in MS. METHODS: MRI were acquired in situ on 7 recently deceased patients with MS using clinically feasible sequences at 3 T, including relatively high-resolution T1-weighted and proton density-weighted images with/without a magnetization transfer pulse for calculation of MTR. The brains were rapidly removed and placed in fixative. Multiple cortical regions from each brain were immunostained for myelin proteolipid protein and classified as mostly myelinated (MM(ctx)), mostly demyelinated (MD(ctx)), or intermediately demyelinated (ID(ctx)). MRIs were registered with the cortical sections so that the cortex corresponding to each cortical section could be identified, along with adjacent subcortical white matter (WM). Mean cortical MTR normalized to mean WM MTR was calculated for each cortical region. Linear mixed-effects models were used to test if mean normalized cortical MTR was significantly lower in demyelinated cortex. RESULTS: We found that mean normalized cortical MTR was significantly lower in cortical tissue with any demyelination (ID(ctx) or MD(ctx)) compared to MM(ctx) (demyelinated cortex: least-squares mean [LSM] = 0.797, SE = 0.007; MM(ctx): LSM = 0.837, SE = 0.006; p = 0.01, n = 89). CONCLUSIONS: This result demonstrates that clinically feasible MTR imaging is sensitive to cortical demyelination and suggests that MTR will be a useful tool to help detect MS cortical lesions in living patients with MS.

Cortical remyelination: a new target for repair therapies in multiple sclerosis.

OBJECTIVE: Generation and differentiation of new oligodendrocytes in demyelinated white matter is the best described repair process in the adult human brain. However, remyelinating capacity falters with age in patients with multiple sclerosis (MS). Because demyelination of cerebral cortex is extensive in brains from MS patients, we investigated the capacity of cortical lesions to remyelinate and directly compared the extent of remyelination in lesions that involve cerebral cortex and adjacent subcortical white matter. METHODS: Postmortem brain tissue from 22 patients with MS (age 27-77 years) and 6 subjects without brain disease were analyzed. Regions of cerebral cortex with reduced myelin were examined for remyelination, oligodendrocyte progenitor cells, reactive astrocytes, and molecules that inhibit remyelination. RESULTS: New oligodendrocytes that were actively forming myelin sheaths were identified in 30 of 42 remyelinated subpial cortical lesions, including lesions from 3 patients in their 70s. Oligodendrocyte progenitor cells were not decreased in demyelinated or remyelinated cortices when compared to adjacent normal-appearing cortex or controls. In demyelinated lesions involving cortex and adjacent white matter, the cortex showed greater remyelination, more actively remyelinating oligodendrocytes, and fewer reactive astrocytes. Astrocytes in the white matter, but not in cortical portions of these lesions, significantly upregulate CD44, hyaluronan, and versican, molecules that form complexes that inhibit oligodendrocyte maturation and remyelination. INTERPRETATION: Endogenous remyelination of the cerebral cortex occurs in individuals with MS regardless of disease duration or chronological age of the patient. Cortical remyelination should be considered as a primary outcome measure in future clinical trials testing remyelination therapies.