Lumbar Drain Use during Middle Fossa Approaches for Nonneoplastic Pathology of the Skull Base.

Introduction The middle fossa craniotomy (MFCs) is commonly utilized for spontaneous cerebrospinal fluid (CSF) leaks, encephaloceles, and superior semicircular canal dehiscence (SSCD). This study compares postoperative outcomes of MFCs with and without LD use. Methods A retrospective cohort study of adults over the age of 18 years presenting for the repair of nonneoplastic CSF leak, encephalocele, or SSCD via MFC from 2009 to 2021 was conducted. The main exposure of interest was the placement of an LD. The primary outcome was the presence of postoperative complications (acute/delayed neurologic deficit, meningitis, intracranial hemorrhage, and stroke). Secondary outcomes included operating room (OR) time, length of stay, recurrence, and need for reoperation. Results In total, 172 patients were included, 96 of whom received an LD and 76 who did not. Patients not receiving an LD were more likely to receive intraoperative mannitol ( n = 24, 31.6% vs. n = 16, 16.7%, p = 0.02). On univariate logistic regression, LD placement did not influence overall postoperative complications (OR: 0.38, 95% confidence interval [CI]: 0.05-2.02, p = 0.28), CSF leak recurrence (OR: 0.75, 95% CI: 0.25-2.29, p = 0.61), or need for reoperation (OR: 1.47, 95% CI: 0.48-4.96, p = 0.51). While OR time was shorter for patients not receiving LD (349 ± 71 vs. 372 ± 85 minutes), this difference was not statistically significant ( p = 0.07). Conclusion No difference in postoperative outcomes was observed in patients who had an intraoperative LD placed compared to those without LD. Operative times were increased in the LD cohort, but this difference was not statistically significant. Given the similar outcomes, we conclude that LD is not necessary to facilitate safe MCF for nonneoplastic skull base pathologies.

Clinical tool for prognostication of discharge outcomes following craniotomy for meningioma.

BACKGROUND: Patients' comorbidities might affect the immediate postoperative morbidity and discharge disposition after surgical resection of intracranial meningioma. OBJECTIVE: To study the impact of comorbidities on outcomes and provide a web-based application to predict time to favorable discharge. METHODS: A retrospective review of the prospectively collected national inpatient sample (NIS) database was conducted for the years 2009-2013. Time to favorable discharge was defined as hospital length of stay (LOS). A favorable discharge was defined as a discharge to home and a non-home discharge destination was defined as an unfavorable discharge. Cox proportional hazards model was built. Full model for time to discharge and separate reduced models were built. RESULTS: Of 10,757 patients who underwent surgery for meningioma, 6554 (60%) had a favorable discharge. The median hospital LOS was 3 days (interquartile range [IQR] 2-5). In the full model, several clinical and socioeconomic factors were associated with a higher likelihood of unfavorable discharge. In the reduced model, 13 modifiable comorbidities were negatively associated with a favorable discharge except for drug abuse and obesity, which are not associated with discharge. Both models accurately predicted time to favorable discharge (c-index:0.68-0.71). CONCLUSION: We developed a web application using robust prognostic model that accurately predicts time to favorable discharge after surgery for meningioma. Using this tool will allow physicians to calculate individual patient discharge probabilities based on their individual comorbidities and provide an opportunity to timely risk stratify and address some of the modifiable factors prior to surgery.

Resection of a ventral intramedullary spinal cord ependymoma through an anterior cervical approach: illustrative case.

BACKGROUND: Although posterior myelotomy leaves patients with dorsal column deficits, few reports have explored the anterior cervical approach for cervical intramedullary tumors. The authors describe the resection of a cervical intramedullary ependymoma through an anterior approach with a two-level corpectomy and fusion. OBSERVATIONS: A 49-year-old male presented with a C3-5 ventral intramedullary mass with polar cysts. Because of the ventral location of the tumor and the added benefit of avoiding a posterior myelotomy and dorsal column deficits, an anterior C4-5 corpectomy offered a direct route and excellent visualization of the ventrally located tumor. After a C4-5 corpectomy, microsurgical resection, and C3-6 anterior fusion with a fibular allograft filled with autograft, the patient remained neurologically intact. Magnetic resonance imaging (MRI) on postoperative day (POD) 1 confirmed gross-total resection. The patient was extubated on POD 2 and was discharged home on POD 4 with a stable examination. At 9 months, the patient developed mechanical neck pain refractory to conservative treatment and underwent a posterior fusion to address pseudarthrosis. MRI at 15 months showed no evidence of tumor recurrence with the resolution of neck pain. LESSONS: An anterior cervical corpectomy provides a safe corridor to access ventral cervical intramedullary tumors and avoids posterior myelotomy. Although the patient required a three-level fusion, we believe the tradeoff of decreased motion compared to dorsal column deficits is preferred.

The cost of a plastic surgery team assisting with cranioplasty.

OBJECTIVES: Cranioplasty is a commonly performed neurosurgical procedure that restores cranial anatomy. While plastic surgeons are commonly involved with cranioplasties, the cost of performing a cranioplasty with neurosurgery alone (N) vs. neurosurgery and plastic surgery (N + P) is unknown. METHODS: A single-center, multi-surgeon, retrospective cohort study was undertaken on all cranioplasties performed from 2012 to 22. The primary exposure variable of interest was operating team, comparing N vs. N + P. Cost data was inflation-adjusted to January 2022 using Healthcare Producer Price Index as calculated by the US Bureau of Labor Statistics. RESULTS: 186 patients (105 N vs. 81 N + P) underwent cranioplasties. The N + P group has a significantly longer length-of-stay (LOS) 4.5 ± 1.6days, vs. 6.0 ± 1.3days (p < 0.001), but no significant difference in reoperation, readmission, sepsis, or wound breakdown. N was significantly less expensive than N + P during both the initial cranioplasty cost ($36,739 ± $4592 vs. $41,129 ± $4374, p 0.014) and total cranioplasty costs including reoperations ($38,849 ± $5017 vs. $53,134 ± $6912, p < 0.001). Univariable analysis (threshold p = 0.20) was performed to justify inclusion into a multivariable regression model. Multivariable analysis for initial cranioplasty cost showed that sepsis (p = 0.024) and LOS (p = 0.003) were the dominant cost contributors compared to surgeon type (p = 0.200). However, surgeon type (N vs. N + P) was the only significant factor (p = 0.011) for total cost including revisions. CONCLUSIONS: Higher costs to N + P involvement without obvious change in outcomes were found in patients undergoing cranioplasty. Although other factors are more significant for the initial cranioplasty cost (sepsis, LOS), surgeon type proved the independent dominant factor for total cranioplasty costs, including revisions.

Association between preoperative hematologic markers and aggressive behavior in meningiomas.

INTRODUCTION: Meningiomas have varying degrees of aggressive behavior. Some systemic hematologic makers are associated with malignancy, but their value in predicting aggressive meningioma behavior is not fully understood. OBJECTIVE: To evaluate the association between preoperative markers such as neutrophil-lymphocyte ratio (NLR), neutrophil-monocyte ratio (NMR), monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), and prognostic nutritional index (PNI), and diagnostic and prognostic factors including WHO grade, proliferation index, presence of edema on preoperative MRI, and tumor recurrence. METHODS: A retrospective review of patients treated between 2000 and 2019 with a preoperative complete blood count (CBC) differential lab draw before intracranial meningioma resection was conducted. All preoperative steroid dosages were converted to dexamethasone equivalents. Primary outcomes included presence/absence of perilesional edema, WHO grade, Ki-67/MIB-index, and recurrence. Univariate and multivariable regression analyses were conducted. RESULTS: A total of 209 meningioma patients were included. Of these, 143 (68 %) were WHO grade I, 61 (29 %) grade II and 5 (2 %) were grade III. Recurrence was reported in 19 (9.1 %) tumors. No hematologic markers were associated with recurrence. In separate multivariable logistic analyses, no biomarkers were associated with perilesional edema or WHO grade. MLR was associated with higher MIB-index (p = 0.018, OR 6.57, 95 % CI 1.37-30.91). CONCLUSION: Most hematologic markers were not associated with meningioma invasiveness, grade, proliferative index, or aggressiveness. Preoperative MLR was associated with high proliferation index in patients undergoing surgery for intracranial meningioma. Higher MLR could be a surrogate for meningioma proliferation and has potential to be used as an adjunct for risk-stratifying meningiomas.

Conditional Recurrence-Free Survival After Surgical Resection of Meningioma.

BACKGROUND: Recurrence after meningioma resection warrants serial surveillance imaging, but little evidence guides the optimal time interval between imaging studies/surveillance duration. OBJECTIVE: To describe recurrence-free survival (RFS) after meningioma resection, conditioned to short-term RFS. METHODS: A retrospective cohort study for adults presenting for meningioma resection from 2000 to 2018 was conducted. The primary outcome was postoperative follow-up RFS. Conditional RFS Kaplan-Meier analysis was performed at 1, 2, 3, 5, and 10 years, conditioned to 6-month and 12-month RFS. RFS probabilities conditioned to 6-month RFS were estimated in subgroups, stratified by World Health Organization grade, extent of resection, and need for postoperative radiation. RESULTS: In total, 723 patients were included. Median age at surgery was 57.4 years (IQR = 47.2-67.2). Median follow-up was 23.5 months (IQR = 12.3-47.8). Recurrence was observed in 90 patients (12%), with median time to recurrence of 14.4 months (IQR = 10.3-37.1). Conditioned to 6-month postoperative RFS, patients had 90.3% probability of remaining recurrence-free at 2 years and 69.4% at 10 years. Subgroup analysis conditioned to 6-month RFS demonstrated grade 1 meningiomas undergoing gross total resection (GTR) had 96.0% probability of RFS at 1 year and 82.8% at 5 years, whereas those undergoing non-GTR had 94.5% and 79.9% probability, respectively. RFS probability was 78.8% at 5 years for non-grade 1 meningiomas undergoing GTR, compared with 69.7% for non-grade 1 meningiomas undergoing non-GTR. Patients with non-grade 1 meningiomas undergoing upfront radiation had a 1-year RFS of 90.1% and 5-year RFS of 51.7%. CONCLUSION: Recurrence risk after meningioma resection after an initial recurrence-free period is reported, with high-risk subgroups identified. These results can inform objective shared decision-making for optimal follow-up.

Comparison of supratentorial meningioma resection outcomes by dural reconstruction technique.

OBJECTIVE: Excision of intracranial meningiomas often requires resection or coagulation of the dura mater. The choice of dural closure technique is individualized and based on surgeon preference. The objective of this study was to determine outcomes following various dural closure techniques for supratentorial meningiomas. METHODS: A retrospective, single-center cohort study was performed for patients who underwent excision of supratentorial meningiomas from 2000 to 2019. Outcomes including operative time, postoperative in-hospital complications, readmission, causes of readmission including surgical site infection, pseudomeningocele, need for shunt surgery, and imaging appearance of pseudomeningocele on long-term follow-up imaging were compared. Univariate and multivariable analyses were conducted. RESULTS: A total of 353 patients who had complete clinical and operative data available for review were included. Of these patients, 227 (64.3%) had nonsutured dural graft reconstruction and 126 (35.7%) had sutured dural repair, including primary closure, artificial dura, or pericranial graft. There was significant variability in using nonsutured dural reconstruction compared with sutured dural repair technique among surgeons (p < 0.001). Tumors with sagittal sinus involvement were more likely to undergo nonsutured closure (n = 79, 34.8%) than dural repair (n = 26, 20.6%) (p = 0.003). There were no other differences in preoperative imaging findings or WHO grade. Frequency of surgical site infection and pseudomeningocele, need for shunt surgery, and recurrence were similar between those undergoing nonsutured and those undergoing sutured dural repair. The mean operative time for the study cohort was 234.9 (SD 106.6) minutes. The nonsutured dural reconstruction group had a significantly shorter mean operative time (223.9 [SD 99.7] minutes) than the sutured dural repair group (254.5 [SD 115.8] minutes) (p = 0.015). In a multivariable linear regression analysis, after controlling for tumor size and sinus involvement, nonsutured dural graft reconstruction was associated with a 36.8-minute reduction (95% CI -60.3 to -13.2 minutes; p = 0.002) in operative time. CONCLUSIONS: Dural reconstruction using a nonsutured graft and sutured dural repair exhibit similar postoperative outcomes for patients undergoing resection for supratentorial meningiomas. Although sutured grafts may sometimes be necessary, nonsutured graft reconstruction for most supratentorial meningioma resections may suffice. The decreased operative time associated with nonsutured grafts may ultimately result in cost savings. These findings should be taken into consideration when selecting a dural reconstruction technique for supratentorial meningioma.

Matched case-control analysis of outcomes following surgical resection of incidental meningioma.

PURPOSE: The management of incidentally discovered meningioma remains controversial. We sought to compare outcomes following surgical resection of incidental meningioma to a matched cohort of symptomatic meningiomas. METHODS: A retrospective single-center case-control study was conducted for patients undergoing resection of incidental meningioma from 2000 to 2019. A 1:1 case-control matching for incidental and symptomatic meningioma was performed using the following variables: age at initial visit, gender, tumor location/size, and presence of peritumoral edema. Primary outcomes included (1) WHO grading/histopathological subtype/MIB-1 index, (2) extent of resection (gross total resection or subtotal resection), and (3) recurrence. Outcomes were compared between groups using descriptive/bivariate analyses. RESULTS: A total of 91 incidental meningiomas were analyzed. Trauma was the most common reason (n = 19, 21%) to obtain imaging, and tumor size the leading reason to operate (n = 37, 41%). Median time-to-surgery from initial clinical encounter was 5-months (Q1:3, Q3:16.5). More incidental meningioma patients (n = 47, 52%) were privately insured compared to their matched symptomatic cohort (n = 30, 33%) (P = 0.006). Patients with incidental meningioma had significantly higher mean Karnofsky Performance Scale at time-of-surgery (93.2, SD:11.1 vs. 81.4, SD:12.7) (P < 0.001). There were no significant differences in primary/secondary outcomes between the groups. Incidental meningioma was not associated with recurrence on Cox proportional hazards analysis (HR: 0.795, 95%CI: 0.3-2.1, P = 0.637). CONCLUSION: Matched case-control analysis demonstrated no significant differences in clinical, histopathological, and functional outcomes following resection of incidental and symptomatic meningioma. While non-operative management with close follow-up and serial imaging is preferred for incidental meningiomas, those undergoing resection when indicated can anticipate similar safety and efficacy as symptomatic meningiomas.

Does Plastic Surgery Involvement Decrease Complications After Cranioplasty? A Retrospective Cohort Study.

OBJECTIVES: To compare postoperative outcomes after cranioplasties performed by neurosurgery only (N) versus neurosurgery and plastic surgery combined (N+P). METHODS: A single-center, multisurgeon, retrospective cohort study was undertaken on all cranioplasties performed from November 2006 to December 2021. The primary exposure variable was operating team (N vs. N+P). The primary outcome was the need for reoperation. Secondary outcomes included surgical site infections, complications, length of stay (LOS), and length of drain placement. RESULTS: Of 188 patients undergoing cranioplasty during the study period, 106 (56%) patients were in the N group, and 82 (44%) were in the N+P group. Patient demographics were similar between the 2 groups. For the primary outcome, a total of 20 (18.9%) reoperations were seen in the N group, and 13 (15.9%) in the N+P group (P = 0.708). However, the median time to reoperation was slightly longer in the N+P group in the survival analysis. Wound dehiscence (1.9% vs. 3.7%, P = 0.454), surgical site infection (5.7% vs. 9.8%, P = 0.289), and complication rate (30.2% vs. 32.9%, P = 0.688) did not differ between the 2 groups. Furthermore, the N group had less Jackson-Pratt drain use (58.5% vs. 85.4%, P < 0.001), earlier drain removal (1.9 ± 1.6 vs. 3.4 ± 3.9 days, P < 0.001), and shorter LOS (3.8 ± 5.9 vs. 4.7 ± 3.9 days, P < 0.001). On multivariate regression analysis controlling for age, body mass index, smoking, craniectomy type, reason for craniectomy, and graft type, N+P was associated with increased drain use (odds ratio = 4.90, 95% confidence interval 2.28-11.30, P < 0.001) and longer drain duration (ß = 1.50, 95% confidence interval 0.43-2.60, P = 0.007). CONCLUSIONS: Despite similar complication and reoperation rates between groups, reoperations in the N group occurred sooner, whereas the N+P group more commonly used drains and kept drains in for longer.

Outcomes following surgical resection of cystic intracranial meningiomas.

INTRODUCTION: Cystic meningiomas are rare, accounting for 2-7% of all intracranial meningiomas. Little is known regarding whether these meningiomas behave differently compared to solid meningiomas. We sought to study this relatively uncommon imaging appearance of meningioma and to evaluate its clinical significance. METHODS: A single-institution retrospective cohort study of surgically-treated meningioma patients between 2000 and 2019 was conducted. Cystic meningioma was defined as a tumor with an intratumoral or peritumoral cyst present on preoperative imaging. Demographics, preoperative imaging, histopathology characteristics, operative data, and surgical outcomes were reviewed. Imaging variables, histopathology and outcomes were reported for cystic meningiomas and compared with non-cystic meningiomas. Univariate/multivariable analyses were conducted. RESULTS: Of 737 total meningiomas treated surgically, 38 (5.2%) were cystic. Gross total resection (GTR) was achieved in 84.2% of cystic meningioma patients. Eighty-two percent of cystic meningiomas were WHO grade I (n = 31), 15.7% were grade II and 2.6% were grade III. Most cystic meningiomas had low Ki-67/MIB-1 proliferation index (n = 24, 63.2%). A total of 18.4% (n = 7) patients with cystic meningioma had recurrence compared to 12.2% (n = 80) of patients with non-cystic meningioma (p = 0.228). No significant difference in median time to recurrence was observed between cystic and non-cystic meningiomas (25.4, Q1:13.9, Q3:46.9 months vs. 13.4, Q1:8.6, Q3:35.5 months, p = 0.080). CONCLUSIONS: A small portion of intracranial meningiomas have cystic characteristics on imaging. Cystic meningiomas are frequently WHO grade I, have low proliferation index, and had similar outcomes compared to non-cystic meningioma. Cysts in meningioma may not be a surrogate to determine aggressive meningioma behavior.

Impact of Thrombocytopenia on Preoperative Hematoma Expansion for Acute Traumatic Subdural Hematoma.

BACKGROUND: Acute subdural hematoma is a neurosurgical emergency. Thrombocytopenia poses a management challenge for these patients. We aimed to determine the impact of thrombocytopenia on preoperative hemorrhage expansion and postoperative outcomes. METHODS: This retrospective study evaluated patients presenting at our institution with acute subdural hematoma between 2009 and 2019. Patients who underwent surgery, had thrombocytopenia (platelets <150,000/µL), and had multiple preoperative computed tomography scans were included. Case control 1:1 matching was performed to generate a matched cohort with no thrombocytopenia. Univariate analyses were conducted to determine changes in subdural thickness and midline shift, postoperative Glasgow Coma Scale score, mortality, length of stay, and readmission rates. RESULTS: We identified 19 patients with both thrombocytopenia and multiple preoperative computed tomography scans. Median platelet count was 112,000/µL (Q1 69,000, Q3 127,000). Comparing the thrombocytopenia cohort with the control group, there was a statistically significant difference in change in subdural thickness (median 5 mm [Q1 2, Q3 7.4] vs. 0 mm [Q1 0, Q3 1.5]; P = 0.001) and change in midline shift (median 3 mm [Q1 0, Q3 9.5] vs. median 0.5 mm [Q1 0, Q3 1.5]; P = 0.018). The thrombocytopenia cohort had higher in-hospital mortality (10 [52.6%] vs. 2 [10.5%]; P = 0.003). No significant differences were found in postoperative Glasgow Coma Scale score, length of stay, number of readmissions, and number of reoperations. CONCLUSIONS: Thrombocytopenia is significantly associated with expansion of hematoma preoperatively in patients with acute subdural hematoma. While the benefit of early platelet correction cannot be determined from this study, patients who present with thrombocytopenia will benefit from close monitoring, a low threshold to obtain repeat imaging, and anticipating early surgical evacuation after platelet optimization.

Loss to Follow-up and Unplanned Readmission After Emergent Surgery for Acute Subdural Hematoma.

BACKGROUND: Loss to follow-up (LTF) and unplanned readmission are barriers to recovery after acute subdural hematoma evacuation. The variables associated with these postdischarge events are not fully understood. OBJECTIVE: To determine factors associated with LTF and unplanned readmission, emphasizing socioeconomic status (SES). METHODS: A retrospective analysis was conducted of surgical patients with acute subdural hematoma managed operatively from 2009 to 2019 at a level 1 regional trauma center. Area Deprivation Index (ADI), which is a neighborhood-level composite socioeconomic score, was used to measure SES. Higher ADI corresponds to lower SES. To decrease the number of covariates in the model, principal components (PCs) analysis was used. Multivariable logistic regression analyses of PCs were performed for LTF and unplanned readmission. RESULTS: A total of 172 patients were included in this study. Thirty-six patients (21%) were LTF, and 49 (28%) patients were readmitted; 11 (6%) patients were both LTF and readmitted ( P = .9). The median time to readmission was 10 days (Q1: 4.5, Q3: 35). In multivariable logistic regression analyses for LTF, increased ADI and distance to hospital through PC2 (odds ratio [OR] 1.49; P = .009) and uninsured/Medicaid status and increased length of stay through PC4 (OR 1.73; P = .015) significantly contributed to the risk of LTF. Unfavorable discharge functional status and nonhome disposition through PC3 were associated with decreased odds of unplanned readmission (OR = 0.69; P = .028). CONCLUSION: Patients at high risk for LTF and unplanned readmissions, as identified in this study, may benefit from targeted resources individualized to their needs to address barrier to follow-up and to ensure continuity of care.

Red blood cell distribution width in glioblastoma.

INTRODUCTION: Glioblastoma (GBM) is the most common and deadly adult brain tumor. Red blood cell distribution width (RDW) has been found in non-central nervous system neoplasms to be associated with survival. This study aims to assess the prognostic value of pre-operative RDW and trends in RDW over time during the disease course. METHODS: This single-institution retrospective cohort study identified patients ≥ 18 years old with pathology-proved glioblastoma treated between April 2003-May 2017 from an institutional database. A Cox proportional hazards model was developed using known prognostic clinical variables to predict overall survival time; a second model incorporating continuously valued RDW was then created. The additional prognostic value of RDW was assessed with a joint model F-test. The variation of RDW-CV over time was evaluated with linear mixed model of RDW. A post-hoc exploratory analysis was performed to assess the trend in RDW lab value leading up to time of death. RESULTS: 346 adult GBM patients were identified; complete survival data was available for all patients. The addition of RDW to the multivariable Cox proportional hazards model did not increase prognostic value. There was an upward trend in RDW throughout the post-operative disease course. In a post-hoc analysis, there was an upward trend in RDW leading up to the time of death. CONCLUSION: Although RDW has been prognostic of survival for many inflammatory, prothrombotic, and neoplastic diseases, pre-operative RDW was not associated with overall survival in GBM patients. RDW trended upwards throughout the disease course, suggesting possible systemic inflammatory effects of either glioblastoma or treatment.

Outcomes of Transzygomatic Middle Cranial Fossa Approach for Skull Base Tumors-A Single Institutional Experience.

Objective This study aimed to evaluate surgical outcomes after transzygomatic middle cranial fossa (MCF) (TZ-MCF) approach for tumor control in patients with large skull base lesions involving the MCF and adjacent sites. Setting This study was done at the tertiary skull base center. Design This is a retrospective case series. Main Outcome Measures The main outcome measures were tumor control (recurrence), new-onset cranial neuropathies, facial nerve and audiometric outcomes, cerebrospinal fluid (CSF) leak, and wound complications. Results Sixteen patients were identified with a median age of 45 years (range: 20-72). The mean maximum tumor dimension was 5.49 cm (standard deviation [SD]: 1.2, range: 3.1-7.3) and the mean tumor volume was 28.5 cm 3 (SD: 18.8, range: 2.9-63.8). Ten (62.5%) tumors were left sided. The most common pathology encountered was meningioma ( n = 7) followed by chondrosarcoma ( n = 4). Mean follow-up was 36.3 (SD: 26.9) months. Gross total resection or near total resection was achieved in nine (56.2%) and planned subtotal resection was used in seven (43.7%). Postoperative additional new cranial nerve (CN) deficits included CN V ( n = 1), CN III ( n = 2), CN VI ( n = 1), and CN X ( n = 1). Major neurological morbidity (hemiplegia) was encountered in two patients with resolution. There were no cases of CSF leak, meningitis, hemorrhage, seizures, aphasia, or death. There was no recurrence or regrowth of residual tumor. Facial nerve function was preserved in all but one patient (House-Brackmann grade 2). Conclusion Various skull base tumors involving MCF with extension to adjacent sites can be successfully resected using the TZ-MCF approach in a multidisciplinary fashion. This approach yields optimal exposure and permits excellent tumor control with acceptable CN and neurological morbidity.

Predicting for Lost to Follow-up in Surgical Management of Patients with Chronic Subdural Hematoma.

BACKGROUND: Lost to follow-up (LTF) represents an understudied barrier to effective management of chronic subdural hematoma (cSDH). Understanding the factors associated with LTF after surgical treatment of cSDH could uncover pathways for quality improvement efforts and modify discharge planning. We sought to identify the demographic and clinical factors associated with patient LTF. METHODS: A single-institution, retrospective cohort study of patients treated surgically for convexity cSDH from 2009 to 2019 was conducted. The primary outcome was LTF, with neurosurgical readmission as the secondary outcome. Univariate analysis was conducted using the student-t test and χ2 test. Multivariate logistic regression was performed to identify the factors associated with LTF and neurosurgical readmission. RESULTS: A total of 139 patients were included, 29% of whom were LTF. The mean first postoperative follow-up duration was 60 days. On univariate analysis, uninsured/Medicaid coverage was associated with increased LTF compared with private insurance/Medicare coverage (62.5% vs. 41.4%; P = 0.039). A higher discharge modified Rankin scale score was also associated with LTF (3.7 vs. 3.5; P < 0.001). On multivariate analysis, uninsured/Medicaid patients had a significantly greater risk of LTF compared with private insurance/Medicare patients (odds ratio, 2.44; 95% confidence interval, 1.13-5.23; P = 0.022). LTF was independently associated with an increased risk of neurosurgical readmission (odds ratio, 1.94; 95% confidence interval, 1.17-3.24; P = 0.011). CONCLUSIONS: Uninsured and Medicaid patients had a greater likelihood of LTF compared with private insurance and Medicare patients. LTF was further associated with an increased risk of neurosurgical readmission. The results from the present study emphasize the need to address barriers to follow-up to reduce readmission after surgery for cSDH. These findings could inform improved discharge planning, such as predischarge repeat imaging studies and postdischarge contact.

Development and evaluation of a "trackerless" surgical planning and guidance system based on 3D Slicer.

Conventional optical tracking systems use cameras sensitive to near-infrared (NIR) light and NIR illuminated/active-illuminating markers to localize instrumentation and the patient in the operating room (OR) physical space. This technology is widely used within the neurosurgical theater and is a staple in the standard of care for craniotomy planning. To accomplish, planning is largely conducted at the time of the procedure in the OR with the patient in a fixed head orientation. We propose a framework to achieve this in the OR without conventional tracking technology, i.e., a "trackerless" approach. Briefly, we investigate an extension of the 3D Slicer which combines surgical planning and craniotomy designation. While taking advantage of the well-developed 3D Slicer platform, we implement advanced features to aid the neurosurgeon in planning the location of the anticipated craniotomy relative to the preoperatively imaged tumor in a physical-to-virtual setup, and then subsequently aid the true physical procedure by correlating that physical-to-virtual plan with an intraoperative magnetic resonance imaging-to-physical registered field-of-view display. These steps are done such that the craniotomy can be designated without the use of a conventional optical tracking technology. To test this approach, four experienced neurosurgeons performed experiments on five different surgical cases using our 3D Slicer module as well as the conventional procedure for comparison. The results suggest that our planning system provides a simple, cost-efficient, and reliable solution for surgical planning and delivery without the use of conventional tracking technologies. We hypothesize that the combination of this craniotomy planning approach and our past developments in cortical surface registration and deformation tracking using stereo-pair data from the surgical microscope may provide a fundamental realization of an integrated trackerless surgical guidance platform.

Application of Indocyanine Green During Arteriovenous Malformation Surgery: Evidence, Techniques, and Practical Pearls.

Indocyanine green (ICG) is a fluorescent molecule that enables visualization of hemodynamic flow through blood vessels. The first description of its application to the resection of arteriovenous malformations (AVMs) did not occur until 2007. Since then, industry leaders have rapidly integrated this optical technology into the intraoperative microscope, and the use of ICG videoangiography (VA) has since become routine in AVM surgery among some academic centers. A number of case series have been published since the introduction of ICG VA to AVM neurosurgery. These early reports with small sample sizes were largely qualitative, assigning to the technology "usefulness" and "benefit" scores as perceived by the operators. This lack of objectivity prompted the development of FLOW 800 software, a proprietary technology of Carl Zeiss Meditec AG (Oberkochen, Germany) that can quantify relative fluorescence intensity under the microscope to generate color maps and intensity curves for ad hoc and post hoc analyses, respectively. However, subsequent case series have done little to quantify the effect of ICG VA on outcomes. The available literature predominately concludes that ICG VA, although intuitive to deploy and interpret, is limited by its dependence on direct illumination and visualization. The subcortical components of AVMs represent a natural challenge to ICG-based flow analysis, and the scope of ICG VA has therefore been limited to AVMs with a high proportion of superficial angioarchitecture. As a result, digital subtraction angiography has remained the gold standard for confirming AVM obliteration. In this review, we provide an overview of the existing literature on ICG VA in AVM resection surgery. In addition, we describe our own experiences with ICG VA and AVMs and offer the senior author's surgical pearls for optimizing the marriage of fluorescence flow technology and AVM resection surgery.

Awake craniotomy in glioma surgery: is it necessary?

INTRODUCTION: The awake craniotomy has evolved from its humble beginnings in ancient cultures to become one of the most eloquent modern neurosurgical procedures. The development of intraoperative mapping techniques like direct electrostimulation of the cortex and subcortical white matter have further argued for its place in the neurosurgeon's armamentarium. Yet the suitability of the awake craniotomy with intraoperative functional mapping (ACWM) to optimize oncofunctional balance after peri-eloquent glioma resection continues to be a topic of active investigation as new methods of intraoperative monitoring and some unfavorable outcome data question its necessity. EVIDENCE ACQUISITION: The neurosurgery and anesthesiology literatures were scoured for English-language studies that analyzed or reviewed the ACWM or its components as applied to glioma surgery via the PubMed, ClinicalKey, and OvidMEDLINE® databases or via direct online searches of journal archives. EVIDENCE SYNTHESIS: Information on background, conceptualization, standard techniques, and outcomes of the ACWM were provided and compared. We parceled the procedure into its components and qualitatively described positive and negative outcome data for each. Findings were presented in the context of each study without attempt at quantitative analysis or reconciliation of heterogeneity between studies. Certain illustrative studies were highlighted throughout the review. Overarching conclusions were drawn based on level of evidence, expert opinion, and predominate concordance of data across studies in the literature. CONCLUSIONS: Most investigators and studies agree that the ACWM is the best currently available approach to optimize oncofunctional balance in this difficult-to-treat patient population. This qualitative review synthesizes the most currently available data on the topic to provide contemporaneous insight into how and why the ACWM has become a favorite operation of neurosurgeons worldwide for the resection of gliomas from eloquent brain.

Virtual, 3-Dimensional Temporal Bone Model and Its Educational Value for Neurosurgical Trainees.

OBJECTIVE: Learning complex neuroanatomy is an arduous yet important task for every neurosurgical trainee. As technology has advanced, various modalities have been created to aid our understanding of anatomy. This study sought to assess the educational value of a virtual, 3-dimensional (3D) temporal bone model. METHODS: The 3D temporal bone model was created with assistance of computer graphic designers and published online. Its educational value as a teaching was tool was assessed by querying 73 neurosurgery residents at 4 institutions and was compared with that of a standard, 2-dimensional (2D) temporal bone resource. Data were collected via a survey, and significance among responses was analyzed via a univariate chi-square test. RESULTS: The survey response rate was 37%. Greater than 90% of residents preferred to study with the 3D model compared with the 2D resource and felt that the 3D model allowed them understand the anatomy more realistically (P = 0.001). Moreover, >90% of residents believed that reviewing the 3D model before an actual surgery could lead to improved operative efficiency and safety (P = 0.001). CONCLUSIONS: This study demonstrates the utility of a novel, 3D temporal bone model as a teaching tool for neurosurgery residents. The model contains accurate anatomic structures and allows user interaction via a virtual, immersive environment.