Altered Motor Excitability in Patients With Diffuse Gliomas Involving Motor Eloquent Areas: The Impact of Tumor Grading

Neurosurgery 88( 1) 2021: 183–192

Diffuse gliomas have an increased biological aggressiveness across the World Health Organization (WHO) grading system. The implications of glioma grading on the primary motor cortex (M1)-corticospinal tract (CST) excitability is unknown.

OBJECTIVE: To assess the excitability of the motor pathway with navigated transcranial magnetic stimulation (nTMS).

METHODS: Retrospective cohort study of patients admitted for surgery with diffuse gliomas within motor eloquent areas. Demographic, clinical, and nTMS-related variables were collected. The Cortical Excitability Score (CES 0 to 2 according to the number of abnormal interhemispheric resting motor threshold (RMT) ratios) was calculated for patients where bilateral upper and lower limb mapping was performed.

RESULTS: A total of 45 patients were included: 9 patients had a low-grade glioma and 36 patients had a high-grade glioma. The unadjusted analysis revealed an increase in the latency of the motor evoked potential of the lower limb with an increase of theWHOgrade (P = .038). The adjusted analysis confirmed this finding (P = .013) and showed a relation between the increase in the WHO and a decreased RMT (P = .037) of the motor evoked responses in the lower limb.When CES was calculated, an increase in the score was related with an increase in the WHO grade (unadjusted analysis—P = .0001; adjusted analysis— P = .001) and in isocitrate dehydrogenase (IDH) wild-type tumors (unadjusted analysis— P = .020).

CONCLUSION: An increase in the WHO grading system and IDH wild-type tumors are associated with an abnormal excitability of the motor eloquent areas in patients with diffuse gliomas.

Lateral transorbital approach: an alternative microsurgical route for supratentorial cerebral aneurysms

J Neurosurg 134:72–83, 2021

Transorbital approaches for neurosurgery have recently attracted attention and several anatomical studies have aimed to improve these techniques, but significant deficiencies in clinical practice remain, especially for aneurysm surgery. The authors present an alternative microsurgical route and the results of an analysis of patients with intracranial aneurysms who underwent a lateral transorbital approach (LTOA) using lateral orbito-zygoma-sphenotomy (LOZYGS).

METHODS The clinical and surgical results of a series of 54 consecutive patients with 1 or more aneurysms who underwent surgery via LTOA are reported. A lateral orbitotomy was performed after making a 3-cm skin incision parallel to the lateral orbital rim. A second bone flap, which included the zygoma and sphenoid bones that form the lateral orbital wall, was removed. The lesser sphenoid wing, including the anterior clinoid process, was fully drilled, except in cases of middle cerebral artery (MCA) aneurysms. Cisternal dissection was performed using the classic microsurgical technique starting from the proximal Sylvian fissure and carotid cistern. After the aneurysm was clipped following microsurgical principles, the dura mater was closed in a watertight fashion and 2-piece bone reconstruction was achieved.

RESULTS Sixty aneurysms in 54 patients were clipped using the LOZYGS route. Twenty-one aneurysms were located on the MCA, 30 on the anterior communicating artery, 8 on the internal carotid artery, and 1 at the apex of the basilar artery. The unruptured-to-ruptured aneurysm ratio was 17:43. The operative field was moved to the orbit using the LTOA to avoid interference by bone and muscle tissues. Early proximal control was achieved using a short working distance and direct exposure of the base of the cerebrum, without any requirement for retraction. Because different view angles and surgical corridors were used, no segment of the aneurysm or the parent artery remained unexposed. Therefore, the introduction of additional tools was not required.

CONCLUSIONS The LTOA allowed enhanced broad-perspective exposure of the operative field, early proximal control, and satisfactory surgical freedom. This alternative surgical approach safely exposed the target area and the operative field. The LOZYGS route is safe and effective for the LTOA and microsurgical clipping of anterior circulation aneurysms. According to the authors’ surgical experience and clinical experience, the LTOA can be considered an alternative surgical route to supratentorial aneurysm surgery.

Syringomyelia Resolution Following Chiari Surgery: A Novel Scale for Communication and Research

Neurosurgery 88( 1) 2021: 131–139

The pathophysiological connection between Chiari malformation and syringomyelia is accepted. Debate remains, however, how can we best define changes in syringomyelia following surgery.

OBJECTIVE: To introduce a grading system focusing on syrinx reduction based on routinely and reproducible radiological information, and provide a suggestion of the application of this scale for prediction of patient’s prognoses.

METHODS: Data from 48 patients with Chiari malformation and syringomyelia were compiled. We calculated syrinx cross-sectional area by approximating an ellipse in the largest axial plane. We compared the percentage of reduction or enlargement following surgery. The percentage change was grouped into four grades: Grade 0 = Increasing size, grade I ≤ 50% reduction, grade II = 50% to 90% reduction, grade III ≥ 90% reduction.

RESULTS: A total of 89.6% of patients had syrinx improvement after surgery. A total of 5 patients were grade 0, 14 were grade I, 20 patients were grade II, and 9 patients met criteria for grade III. The mean postoperative syrinx area was 24.1 mm2 (0-169 mm2) with a mean syrinx reduction of 62.7%.

CONCLUSION: Radiological improvement of syringomyelia can be mathematically defined and standardized to assist in communication in outcome-based trials. Radiological resolution is expected most patients.

Neurosurgical Choice for Glossopharyngeal Neuralgia: A Benefit–Harm Assessment of Long-Term Quality of Life

Neurosurgery 88( 1) 2021: 131–139

Microvascular decompression (MVD) and vagoglossopharyngeal rhizotomy (VGR) are effective treatment for glossopharyngeal neuralgia (GN). However, surgical choice is controversial due to the need to maximize pain relief and reduce complications.

OBJECTIVE: To retrospectively compare safety, efficacy, long-term quality of life (QOL), and global impression of change following MVD and VGR for treatment of GN. METHODS: Patient database reviews and telephone surveys were conducted to assess baseline characteristics and long-term outcomes. The effects of pain and complications on QOL were assessed using Brief Pain Inventory-Facial (BPI-Facial) questionnaire. Complication tolerance and surgery satisfaction were sorted using the global impression of change survey.

RESULTS: Of 87 patients with GN, 63 underwentMVD alone, 20 underwent VGR alone, and 4 underwent VGR following a failed MVD. The long-term rate of pain relief was slightly, but not significantly, lower following MVD than VGR (83.6% vs 91.7%, P = .528). However, long-term complications occurred much more frequently following VGR (3.0% vs 50.0%, P < .001). The BPI-Facial, which evaluates pain and complications, showed that MVD had better postoperative QOL than VGR (P < .001). However, 91.7% of patients who underwent VGR experienced no or mild complications. There was no significant difference in the overall satisfaction rates between the groups (83.3% vs 83.6%, P > .99).

CONCLUSION: Although VGR resulted in lower postoperative QOL due to a high complication rate, most of these complications were mild. The overall satisfaction rates for the 2 surgeries were similar.

Odontoid screw placement for Anderson type II odontoid fractures: how do duration from injury to surgery and clinical and radiological factors influence the union rate? A multicenter retrospective study

J Neurosurg Spine 34:27–31, 2021

Anderson type II odontoid fractures are severe conditions, mostly affecting elderly people (≥ 70 years old). Surgery can be performed as a primary treatment or in cases of failed conservative management. This study aimed to investigate how duration from injury to surgery, as well as clinical, radiological, and surgical risk factors, may influence the union rate after anterior odontoid screw placement for Anderson type II odontoid fractures.

METHODS The authors conducted a retrospective multicenter study. Demographic, clinical, surgical, and radiological data of patients who underwent anterior odontoid screw placement for Anderson type II fractures were retrieved from institutional databases. Study exclusion criteria were prolonged corticosteroid drug therapy (> 4 weeks), polytraumatic injuries, oncological diagnosis, and prior cervical spine trauma.

RESULTS Eighty-five patients were included in the present investigation. The union rate was 76.5%, and 73 patients (85.9%) did not report residual instability. Age ≥ 70 years (p < 0.001, OR 6), female gender (p = 0.016, OR 3.61), osteoporosis (p = 0.009, OR 4.02), diabetes (p = 0.056, OR 3.35), fracture diastasis > 1 mm (p < 0.001, OR 8.5), and duration from injury to surgery > 7 days (p = 0.002, OR 48) independently influenced union rate, whereas smoking status (p = 0.677, OR 1.24) and odontoid process angulation > 10° (p = 0.885, OR 0.92) did not.

CONCLUSIONS Although many factors have been reported as influencing the union rate after anterior odontoid screw placement for Anderson type II fractures, duration from injury to surgery > 7 days appears to be the most relevant, resulting in a 48 times higher risk for nonunion. Early surgery appears to be associated with better radiological outcomes, as reported by orthopedic surgeons in other districts. Prospective comparative clinical trials are needed to confirm these results.

Giant Fusiform and Dolichoectatic Aneurysms of the Basilar Trunk and Vertebrobasilar Junction

Neurosurgery 88:82–95, 2021

Giant fusiform and dolichoectatic aneurysms of the basilar trunk and vertebrobasilar junction (BTVBJ-GFDA) are extremely difficult to treat. OBJECTIVE: To evaluate factors influencing survival and outcome of BTVBJ-GFDA by performing a retrospective multicenter cohort study.

METHODS: A total of 32 patients with BTVBJ-GFDA were included in this study. Clinicopathological characteristics, treatment measures, and outcomes were collected from medical records and imaging studies. Autopsy and histological findings of the aneurysm and adjacent brain tissue were also obtained in 9 cases.

RESULTS: A total of 11 patients did not undergo surgery, of whom 10 died; 3 from progressive brainstem compression, 4 from subarachnoid hemorrhage, 2 from brainstem infarction, and 1 from associated atherosclerotic disease. The remaining 21 patients underwent a surgical treatment, consisting of immediately proximal parent artery occlusion, remotely proximal parent artery occlusion, clip reconstruction, and distal bypass and achieved significantly longer overall survival compared with those who received conservative therapy (adjusted hazard ratio 1.508, 95% CI 1.058-2.148, P = .02). Histological examination of the aneurysms demonstrated staged clots, open lumen, and intrathrombotic channels with endothelial lining. The patients younger than 45 yr of age showed statistically longer survival than those equal and older than 45 yr (P = .03).

CONCLUSION: Surgical intervention achieved greater survival than conservative management in BTVBJ-GFDA. Narrow ideal treatment window of the blood flow within the aneurysm to maintain sufficient but not excess supply should be targeted based on the hemodynamics of both the posterior communicating arteries and perforating vessel collaterals.

KEYWORDS: Basilar trunk, Dolichoectasia, Dolichoectatic aneurysms, Fusiform aneurysms, Megadolichobasilar anomaly, Vertebrobasilar

Intraoperative MRI–based elastic fusion for anatomically accurate tractography of the corticospinal tract

Neurosurg Focus 50 (1):E9, 2021

Tractography is a useful technique that is standardly applied to visualize subcortical pathways. However, brain shift hampers tractography use during the course of surgery. While intraoperative MRI (ioMRI) has been shown to be beneficial for use in oncology, intraoperative tractography can rarely be performed due to scanner, protocol, or head clamp limitations. Elastic fusion (EF), however, enables adjustment for brain shift of preoperative imaging and even tractography based on intraoperative images. The authors tested the hypothesis that adjustment of tractography by ioMRI-based EF (IBEF) correlates with the results of intraoperative neuromonitoring (IONM) and clinical outcome and is therefore a reliable method.

METHODS In 304 consecutive patients treated between June 2018 and March 2020, 8 patients, who made up the basic study cohort, showed an intraoperative loss of motor evoked potentials (MEPs) during motor-eloquent glioma resection for a subcortical lesion within the corticospinal tract (CST) as shown by ioMRI. The authors preoperatively visualized the CST using tractography. Also, IBEFs of pre- and intraoperative images were obtained and the location of the CST was compared in relation to a subcortical lesion. In 11 patients (8 patients with intraoperative loss of MEPs, one of whom also showed loss of MEPs on IBEF evaluation, plus 3 additional patients with loss of MEPs on IBEF evaluation), the authors examined the location of the CST by direct subcortical stimulation (DSCS). The authors defined the IONM results and the functional outcome data as ground truth for analysis.

RESULTS The maximum mean ± SD correction was 8.8 ± 2.9 (range 3.8–12.0) mm for the whole brain and 5.3 ± 2.4 (range 1.2–8.7) mm for the CST. The CST was located within the lesion before IBEF in 3 cases and after IBEF in all cases (p = 0.0256). All patients with intraoperative loss of MEPs suffered from surgery-related permanent motor deficits. By approximation, the location of the CST after IBEF could be verified by DSCS in 4 cases.

CONCLUSIONS The present study shows that tractography after IBEF accurately correlates with IONM and patient outcomes and thus demonstrates reliability in this initial study.

Development and validation of a clinical prediction score for poor postoperative pain control following elective spine surgery

J Neurosurg Spine 34:3–12, 2021

Thirty percent to sixty-four percent of patients experience poorly controlled pain following spine surgery, leading to patient dissatisfaction and poor outcomes. Identification of at-risk patients before surgery could facilitate patient education and personalized clinical care pathways to improve postoperative pain management. Accordingly, the aim of this study was to develop and internally validate a prediction score for poorly controlled postoperative pain in patients undergoing elective spine surgery.

METHODS A retrospective cohort study was performed in adult patients (≥ 18 years old) consecutively enrolled in the Canadian Spine Outcomes and Research Network registry. All patients underwent elective cervical or thoracolumbar spine surgery and were admitted to the hospital. Poorly controlled postoperative pain was defined as a mean numeric rating scale score for pain at rest of > 4 during the first 24 hours after surgery. Univariable analysis followed by multivariable logistic regression on 25 candidate variables, selected through a systematic review and expert consensus, was used to develop a prediction model using a random 70% sample of the data. The model was transformed into an eight-tier risk-based score that was further simplified into the three-tier Calgary Postoperative Pain After Spine Surgery (CAPPS) score to maximize clinical utility. The CAPPS score was validated using the remaining 30% of the data.

RESULTS Overall, 57% of 1300 spine surgery patients experienced poorly controlled pain during the first 24 hours after surgery. Seven significant variables associated with poor pain control were incorporated into a prediction model: younger age, female sex, preoperative daily use of opioid medication, higher preoperative neck or back pain intensity, higher Patient Health Questionnaire–9 depression score, surgery involving ≥ 3 motion segments, and fusion surgery. Notably, minimally invasive surgery, body mass index, and revision surgery were not associated with poorly controlled pain. The model was discriminative (C-statistic 0.74, 95% CI 0.71–0.77) and calibrated (Hosmer-Lemeshow goodness-of-fit, p = 0.99) at predicting the outcome. Low-, high-, and extreme-risk groups stratified using the CAPPS score had 32%, 63%, and 85% predicted probability of experiencing poorly controlled pain, respectively, which was mirrored closely by the observed incidence of 37%, 62%, and 81% in the validation cohort.

CONCLUSIONS Inadequate pain control is common after spine surgery. The internally validated CAPPS score based on 7 easily acquired variables accurately predicted the probability of experiencing poorly controlled pain after spine surgery.

Impact of Intraoperative Magnetic Resonance Imaging and Other Factors on Surgical Outcomes for Newly Diagnosed Grade II Astrocytomas and Oligodendrogliomas: A Multicenter Study

Neurosurgery 88 (1) 2021: 63–73,

Few studies use large, multi-institutional patient cohorts to examine the role of intraoperative magnetic resonance imaging (iMRI) in the resection of grade II gliomas.

OBJECTIVE: To assess the impact of iMRI and other factors on overall survival (OS) and progression-free survival (PFS) for newly diagnosed grade II astrocytomas and oligodendrogliomas.

METHODS: Retrospective analyses of a multicenter database assessed the impact of patient-, treatment-, and tumor-related factors on OS and PFS.

RESULTS: A total of 232 resections (112 astrocytomas and 120 oligodendrogliomas) were analyzed. Oligodendrogliomas had longer OS (P < .001) and PFS (P = .01) than astrocytomas. Multivariate analyses demonstrated improved OS for gross total resection (GTR) vs subtotal resection (STR; P = .006, hazard ratio [HR]: .23) and near total resection (NTR; P = .02, HR: .64). GTR vs STR (P = .02, HR: .54), GTR vs NTR (P = .04, HR: .49), and iMRI use (P = .02, HR: .54) were associated with longer PFS. Frontal (P = .048, HR: 2.11) and occipital/parietal (P = .003, HR: 3.59) locations were associated with shorter PFS (vs temporal). Kaplan-Meier analyses showed longer OS with increasing extent of surgical resection (EOR) (P=.03) and 1p/19q gene deletions (P=.02). PFS improved with increasing EOR (P = .01), GTR vs NTR (P = .02), and resections above STR (P = .04). Factors influencing adjuvant treatment (35.3% of patients) included age (P=.002, odds ratio [OR]: 1.04) and EOR (P=.003,OR: .39) but not glioma subtype or location. Additional tumor resection after iMRI was performed in 105/159 (66%) iMRI cases, yielding GTR in 54.5% of these instances.

CONCLUSION: EOR is a major determinant of OS and PFS for patients with grade II astrocytomas and oligodendrogliomas. Intraoperative MRI may improve EOR and was associated with increased PFS.

Surgery for diaphragma sellae meningioma: how I do it

Acta Neurochirurgica (2021) 163:97–100

Surgery for diaphragma sellae meningiomas (DSM) remains challenging due to the intimate neurovascular relationships of the tumor. Excision of DSM along with a decompression of the optic apparatus requires a good knowledge of the skull base anatomy and a precise preoperative evaluation of the tumor extensions.

Method We describe the key steps of transcranial approach for DSM with a video illustration. The surgical anatomy is described along with the advantages and limitations of this approach.

Conclusions The transcranial approach allows a safe tumor excision with an early and adequate control of the neurovascular structures, while minimizing postoperative CSF rhinorrhea.

Eyebrow supraorbital keyhole craniotomy for olfactory groove meningiomas with endoscope assistance

Acta Neurochirurgica (2021) 163:101–112

Olfactory groove meningiomas (OGMs) are commonly treated with open craniotomy. Endonasal approaches have also been described. Objective To present clinical and radiographic outcomes for the minimally invasive eyebrow incision supraorbital keyhole approach with endoscopic assistance for OGMs.

Methods We performed a retrospective single-center cohort study and a systematic literature review.

Results Fifteen patients were identified, all with Grade I meningiomas. Radiographic gross total resection of enhancing tumor was achieved in all patients. Mean frontal lobe fluid-attenuated inversion recovery volume decreased from 11.1 ± 18.3 cm3 preoperatively to 9.9 ± 11.4 cm3 immediately postoperatively, and there was minimal new restricted diffusion (3.2 ± 2.2 cm3; max 7.5 cm3). Median length of stay was 3 days (range 2–8). Vision was improved in 4 (80%) and stable in 1 (20%) of 5 patients with a preoperative deficit. New postoperative anosmia occurred in 3 (23%) of 13 patients with any preoperative olfaction. All patients were satisfied with their cosmetic result at 3 months. After a median follow-up of 32.2 months, there were 2 (13.3%) asymptomatic radiographic recurrences, 1 treated with radiosurgery and the other with endoscopic endonasal approach (EEA). No patients required further craniotomy. Systematic review revealed the present series to be the largest to date reporting disaggregated outcomes for the eyebrow approach to OGM.

Conclusion The eyebrow incision supraorbital keyhole craniotomy with endoscopic assistance is a safe and effective approach to OGM with tumor control rates similar to more invasive open approaches and better than the endonasal approach.Rates of frontal lobe injury, CSF leak and anosmia are comparatively low.

Giant intracranial aneurysms: natural history and 1-year case fatality after endovascular or surgical treatment

J Neurosurg 134:49–57, 2021

Clinical evidence on giant intracranial aneurysms (GIAs), intracranial aneurysms with a diameter of at least 25 mm, is limited. The authors aimed to investigate the natural history, case fatality, and treatment outcomes of ruptured and unruptured GIAs.

METHODS In this international observational registry study, patients with a ruptured or unruptured GIA received conservative management (CM), surgical management (SM), or endovascular management (EM). The authors investigated rupture rates and case fatality.

RESULTS The retrospective cohort comprised 219 patients with GIAs (21.9% ruptured GIAs and 78.1% unruptured GIAs) whose index hospitalization occurred between January 2006 and November 2016. The index hospitalization in the prospective cohort (362 patients with GIAs [17.1% ruptured and 82.9% unruptured]) occurred between December 2008 and February 2017. In the retrospective cohort, the risk ratio for death at a mean follow-up of 4.8 years (SD 2.2 years) after CM, compared with EM and SM, was 1.63 (95% CI 1.23–2.16) in ruptured GIAs and 3.96 (95% CI 2.57–6.11) in unruptured GIAs. In the prospective cohort, the 1-year case fatality in ruptured GIAs/unruptured GIAs was 100%/22.0% during CM, 36.0%/3.0% after SM, and 39.0%/12.0% after EM. Corresponding 1-year rupture rates in unruptured GIAs were 25.0% during CM, 1.2% after SM, and 2.5% after EM. In unruptured GIAs, the HR for death within the 1st year in patients with posterior circulation GIAs was 6.7 (95% CI 1.5–30.4, p < 0.01), with patients with a GIA at the supraclinoid internal carotid artery as reference. Different sizes of unruptured GIAs were not associated with 1-year case fatality.

CONCLUSIONS Rupture rates for unruptured GIAs were high, and the natural history and treatment outcomes for ruptured GIAs were poor. Patients undergoing SM or EM showed lower case fatality and rupture rates than those undergoing CM. This difference in outcome may in part be influenced by patients in the CM group having been found poor candidates for SM or EM.

Clinical trial registration no.: NCT02066493 (clinicaltrials.gov)

Thoracolumbar Junction Orientation: A Novel Guide for Sagittal Correction and Proximal Junctional Kyphosis Prediction in Adult Spinal Deformity Patients

Neurosurgery (88), Issue 1, 2021:  55–62

Novel radiographic sagittal parameters of the thoracolumbar junction orientation (TLJO, thoracolumbar slope [TLS] and thoracolumbar tilt [TLT]) have been introduced and correlated with lumbopelvic parameters and thoracic kyphosis.

OBJECTIVE: To determine a predictive model for reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) based on the TLJO.

METHODS: A total of 127 patients who had fusion from sacrum to T10-L2 from 2004 to 2014 were reviewed. TK (T5-T12), PI, SS, PT, LL, and proximal junctional angle (PJA) were measured preoperatively, 6wk postoperatively, and at final follow-up. TLJO was measured by TLS and TLT. Changes between time points were determined (preop-6 wk =ΔParameter(Pre6wk) and preop-final follow/up =ΔParameter(PreFinal)). Scoliosis Research Society (SRS) and Oswestry Disability Index (ODI) questionnaires were evaluated at final follow-up. Patients were divided into 2 groups based on the presence of PJK (PJAPreFinal >15◦). Independent t-tests and receiver operating characteristic (ROC) curves were used to investigate the significance of differences and cut-off values. Pearson correlations and linear regressions were used to analyze the entire cohort to determine the relationship between the changes in parameters.

RESULTS: Compared to patients without PJK (n = 100), those with PJK (n = 27) had significantly lower SRS scores and significantly greater TKPreFinal, LLPre6wk, and TLSPre6wk. To maintain in the nonPJK group, ROC curves demonstrated a cut-off value of −9.4◦ for TLSPre6wk. PJK was significantly correlated with TKPreFinal and TLSPre6wk. The linear correlation revealed that TLSPre6wk < −25.3◦ is the risk factor of PJK > 15◦.

CONCLUSION: As change of TLS reflects lumbopelvic realignment and influences reciprocal TK, reducing the change of TLS may be a sagittal realignment guideline to reduce the risk of PJK.

Early surgery for superficial supratentorial spontaneous intracerebral hemorrhage: a Finnish Intensive Care Consortium study

Acta Neurochirurgica (2020) 162:3153–3160

The benefits of early surgery in cases of superficial supratentorial spontaneous intracerebral hemorrhage (ICH) are unclear. This study aimed to assess the association between early ICH surgery and outcome, as well as the cost-effectiveness of early ICH surgery.

Methods We conducted a retrospective, register-based multicenter study that included all patients who had been treated for supratentorial spontaneous ICH in four tertiary intensive care units in Finland between 2003 and 2013. To be included, patients needed to have experienced supratentorial ICHs that were 10–100 cm3 and located within 10 mm of the cortex. We used a multivariable analysis, adjusting for the severity of the illness and the probability of surgical treatment, to assess the independent association between early ICH surgery (≤ 1 day), 12-month mortality rates, and the probability of survival without permanent disability. In addition, we assessed the cost-effectiveness of ICH surgery by examining the effective cost per 1-year survivor (ECPS) and per independent survivor (ECPIS).

Results Of 254 patients, 27%were in the early surgery group. Overall 12-monthmortality was 39%, while 29%survived without a permanent disability. According to our multivariable analysis, early ICH surgery was associated with lower 12-month mortality rates (odds ratio [OR] 0.22, 95% confidence intervals [CI] 0.10–0.51), but not with a higher probability of survival without permanent disability (OR 1.23, 95% CI 0.59–2.56). For the early surgical group, the ECPS and ECPIS were €111,409 and €334,227, respectively. For the non-surgical cohort, the ECPS and ECPIS were €76,074 and €141,471, respectively.

Conclusions Early surgery for superficial ICH is associated with a lower 12-month mortality risk but not with a higher probability of survival without a permanent disability. Further, costs were higher and cost-effectiveness was, thus, worse for the early surgical cohort.

Vertebral body fracture rates after stereotactic body radiation therapy compared with external-beam radiation therapy for metastatic spine tumors

J Neurosurg Spine 33:870–876, 2020

Stereotactic body radiation therapy (SBRT) is utilized to deliver highly conformal, dose-escalated radiation to a target while sparing surrounding normal structures. Spinal SBRT can allow for durable local control and palliation of disease while minimizing the risk of damage to the spinal cord; however, spinal SBRT has been associated with an increased risk of vertebral body fractures. This study sought to compare the fracture rates between SBRT and conventionally fractionated external-beam radiation therapy (EBRT) in patients with metastatic spine tumors.

METHODS Records from patients treated at the University of California, San Francisco, with radiation therapy for metastatic spine tumors were retrospectively reviewed. Vertebral body fracture and local control rates were compared between SBRT and EBRT. Ninety-six and 213 patients were identified in the SBRT and EBRT groups, respectively. Multivariate analysis identified the need to control for primary tumor histology (p = 0.003 for prostate cancer, p = 0.0496 for renal cell carcinoma). The patient-matched EBRT comparison group was created by matching SBRT cases using propensity scores for potential confounders, including the Spinal Instability Neoplastic Score (SINS), the number and location of spine levels treated, sex, age at treatment, duration of follow-up (in months) after treatment, and primary tumor histology. Covariate balance following group matching was confirmed using the Student t-test for unequal variance. Statistical analysis, including propensity score matching and multivariate analysis, was performed using R software and related packages.

RESULTS A total of 90 patients met inclusion criteria, with 45 SBRT and 45 EBRT matched cases. Balance of the covariates, SINS, age, follow-up time, and primary tumor histology after the matching process was confirmed between groups (p = 0.062, p = 0.174, and 0.991, respectively, along with matched tumor histology). The SBRT group had a higher 5-year rate of vertebral body fracture at 22.22% (n = 10) compared with 6.67% (n = 3) in the EBRT group (p = 0.044). Survival analysis was used to adjust for uneven follow-up time and showed a significant difference in fracture rates between the two groups (p = 0.044). SBRT also was associated with a higher rate of local control (86.67% vs 77.78%).

CONCLUSIONS Patients with metastatic cancer undergoing SBRT had higher rates of vertebral body fractures compared with patients undergoing EBRT, and this difference held up after survival analysis. SBRT also had higher rates of initial local control than EBRT but this difference did not hold up after survival analysis, most likely because of a high percentage of radiosensitive tumors in the EBRT cohort.

Early postmarket results with PulseRider for treatment of wide-necked intracranial aneurysms: a multicenter experience

J Neurosurg 133:1756–1765, 2020

Traditionally, stent-assisted coiling and balloon remodeling have been the primary endovascular treatments for wide-necked intracranial aneurysms with complex morphologies. PulseRider is an aneurysm neck reconstruction device that provides parent vessel protection for aneurysm coiling. The objective of this study was to report early postmarket results with the PulseRider device.

METHODS This study was a prospective registry of patients treated with PulseRider at 13 American neurointerventional centers following FDA approval of this device. Data collected included clinical presentation, aneurysm characteristics, treatment details, and perioperative events. Follow-up data included degree of aneurysm occlusion and delayed (> 30 days after the procedure) complications.

RESULTS A total of 54 aneurysms were treated, with the same number of PulseRider devices, across 13 centers. Fourteen cases were in off-label locations (7 anterior communicating artery, 6 middle cerebral artery, and 1 A1 segment anterior cerebral artery aneurysms). The average dome/neck ratio was 1.2. Technical success was achieved in 52 cases (96.2%). Major complications included the following: 3 procedure-related posterior cerebral artery strokes, a devicerelated intraoperative aneurysm rupture, and a delayed device thrombosis. Immediately postoperative Raymond-Roy occlusion classification (RROC) class 1 was achieved in 21 cases (40.3%), class 2 in 15 (28.8%), and class 3 in 16 cases (30.7%). Additional devices were used in 3 aneurysms. For those patients with 3- or 6-month angiographic follow-up (28 patients), 18 aneurysms (64.2%) were RROC class 1 and 8 (28.5%) were RROC class 2.

CONCLUSIONS PulseRider is being used in both on- and off-label cases following FDA approval. The clinical and radiographic outcomes are comparable in real-world experience to the outcomes observed in earlier studies. Further experience is needed with the device to determine its role in the neurointerventionalist’s armamentarium, especially with regard to its off-label use.

The LACE+ Index as a Predictor of 90-Day Supratentorial Tumor Surgery Outcomes

Neurosurgery 2020 DOI:10.1093/neuros/nyaa225

The LACE+ (Length of stay, Acuity of admission, Charlson Comorbidity Index [CCI] score, and Emergency department [ED] visits in the past 6 mo) index risk prediction tool has never been successfully tested in a neurosurgery population.

OBJECTIVE: To assess the ability of LACE+ to predict adverse outcomes after supratentorial brain tumor surgery.

METHODS: LACE+ scores were retrospectively calculated for all patients (n = 624) who underwent surgery for supratentorial tumors at the University of Pennsylvania Health System(2017-2019). Confounding variables were controlled with coarsened exact matching. The frequency of unplanned hospital readmission, ED visits, and death was compared for patients with different LACE+ score quartiles (Q1, Q2, Q3, and Q4).

RESULTS: A total of 134 patients were matched between Q1 and Q4; 152 patients were matched between Q2 andQ4; and 192 patients were matched between Q3 and Q4. Patients with higher LACE+scores were significantly more likely to be readmitted within 90 d (90D) of discharge for Q1 vs Q4 (21.88% vs 46.88%, P = .005) and Q2 vs Q4 (27.03% vs 55.41%, P = .001). Patients with larger LACE+ scores also had significantly increased risk of 90D ED visits for Q1 vs Q4 (13.33% vs 30.00%, P = .027) and Q2 vs Q4 (22.54% vs 39.44%, P = .039). LACE+score also correlated with death within 90D of surgery forQ2 vsQ4 (2.63% vs 15.79%, P=.003) and with death at any point after surgery/during follow-up for Q1 vs Q4 (7.46% vs 28.36%, P = .002), Q2 vs Q4 (15.79% vs 31.58%, P = .011), and Q3 vs Q4 (18.75% vs 31.25%, P = .047).

CONCLUSION: LACE+ may be suitable for characterizing risk of certain perioperative events in a patient population undergoing supratentorial brain tumor resection.

Impact of sufficient contact between the autograft and endplate soon after surgery to prevent nonunion at 12 months following posterior lumbar interbody fusion

J Neurosurg Spine 33:796–805, 2020

Nonunion after posterior lumbar interbody fusion (PLIF) is associated with poor long-term outcomes in terms of health-related quality of life. Biomechanical factors in the fusion segment may influence spinal fusion rates. There are no reports on the relationship between intervertebral union and the absorption of autografts or vertebral endplates. Therefore, the purpose of this retrospective study was to evaluate the risk factors of nonunion after PLIF and identify preventive measures.

METHODS The authors analyzed 138 patients who underwent 1-level PLIF between 2016 and 2018 (75 males, 63 females; mean age 67 years; minimum follow-up period 12 months). Lumbar CT images obtained soon after the surgery and at 6 and 12 months of follow-up were examined for the mean total occupancy rate of the autograft, presence of a translucent zone between the autograft and endplate (more than 50% of vertebral diameter), cage subsidence, and screw loosening. Complete intervertebral union was defined as the presence of both upper and lower complete fusion in the center cage regions on coronal and sagittal CT slices at 12 months postoperatively. Patients were classified into either union or nonunion groups.

RESULTS Complete union after PLIF was observed in 62 patients (45%), while nonunion was observed in 76 patients (55%). The mean total occupancy rate of the autograft immediately after the surgery was higher in the union group than in the nonunion group (59% vs 53%; p = 0.046). At 12 months postoperatively, the total occupancy rate of the autograft had decreased by 5.4% in the union group and by 11.9% in the nonunion group (p = 0.020). A translucent zone between the autograft and endplate immediately after the surgery was observed in 14 and 38 patients (23% and 50%) in the union and nonunion groups, respectively (p = 0.001). The nonunion group had a significantly higher proportion of cases with cage subsidence and screw loosening at 12 months postoperatively in comparison to the union group (p = 0.010 and p = 0.009, respectively).

CONCLUSIONS A lower occupancy rate of the autograft and the presence of a translucent zone between the autograft and endplate immediately after the surgery were associated with nonunion at 12 months after PLIF. It may be important to achieve sufficient contact between the autograft and endplate intraoperatively for osseous union enhancement and to avoid excessive absorption of the autograft. The achievement of complete intervertebral union may decrease the incidence of cage subsidence or screw loosening.

Reoperation, Readmission, and Discharge Disposition for PatientsWith Degenerative Lumbar Pathology Treated With Either Open or Minimally Invasive Techniques

Neurosurgery 2020 DOI:10.1093/neuros/nyaa246

Spine surgery has been transformed by the growth of minimally invasive surgery (MIS) procedures. Previous studies agree that MIS has shorter hospitalization and faster recovery time when compared to conventional open surgery. However, the reoperation and readmission rates between the 2 techniques have yet to be well characterized.

OBJECTIVE: To evaluate the rate of subsequent revision between MIS and open techniques for degenerative lumbar pathology.

METHODS: A total of 1435 adult patients who underwent lumbar spine surgery between 2013 and 2016were included in this retrospective analysis. The rates of need for subsequent reoperation, 30- and 90-d readmission, and discharge to rehabilitation were recorded for both MIS and traditional open techniques. Groups were divided into decompression alone and decompression with fusion.

RESULTS: The rates of subsequent reoperation following MIS and open surgerywere 10.4% and 12.2%, respectively (P = .32), which were maintained when subdivided into decompression and decompression with fusion. MIS and open 30-d readmission rates were 7.9% and 7.2% (P = .67), while 90-d readmission rates were 4.3% and 3.6% (P = .57), respectively. Discharge to rehabilitation was significantly lower for patients under 60 yr of age undergoing MIS (1.64% vs 5.63%, P = .04).

CONCLUSION: The use of minimally invasive techniques for the treatment of lumbar spine pathology does not result in increased reoperation or 30- and 90-d readmission rateswhen compared to open approaches. Patients under the age of 60 yr undergoing MIS procedures were less likely to be discharged to rehab.

Conservative Management of Type II Odontoid Fractures in Older People

Neurosurgery 2020 DOI:10.1093/neuros/nyaa256

Type II odontoid fractures are a common cervical fracture in older people. Lower osseous-union rates are reported in those treated conservatively compared to surgically; however, the clinical relevance of a nonunion is unknown.

OBJECTIVE: To compare pain, disability, and quality of life in older people following conservativemanagement of type II odontoid fractures demonstrating osseous-union and nonunion.

METHODS: Electronic records were searched from 2008 to 2018 for adults ≥65 yr with type II odontoid fracture, managed in a semi-rigid collar. Clinical and demographic data were retrieved from electronic patient notes. Surviving patients were invited to complete questionnaires to assess pain, disability, and quality of life. Ethical approval was granted.

RESULTS: A total of 125 patients were identified: 36 (29%) demonstrated osseous-union, 89 (71%) had nonunion, of which 33 (40%) had radiological instability. Mean age at fracture was 84 yr (osseous-union 83 yr; nonunion 84 yr). A total of 53 had deceased (41 nonunion). Median length of survival was 77 mo for osseous-union vs 50 mo for nonunion; P = .02. No patient developed myelopathy during the follow-up period. Questionnaire response rate was 39 (58%). There were no statistically significant differences between the groups in terms of pain, disability, or quality of life (P>.05). Both groups reported mild disability and pain but low quality of life.

CONCLUSION: Management with a semi-rigid collar in older people with type II odontoid fracture is associated with low levels of pain and disability without statistically significant differences between those demonstrating osseous-union or stable or unstable nonunions. Conservative management appears to be a safe treatment for older people with type II fractures.