Predicting Outcomes After Surgical Decompression for Mild Degenerative Cervical Myelopathy

Neurosurgery, Volume 86, Issue 4, April 2020 :565–573

Patients with mild degenerative cervical myelopathy (DCM) represent a heterogeneous population, and indications for surgical decompression remain controversial.

OBJECTIVE: To dissociate patient phenotypes within the broader population of mild DCM associated with degree of impairment in baseline quality of life (QOL) and surgical outcomes.

METHODS: This was a post hoc analysis of patients with mild DCM (modified Japanese Orthopedic Association [mJOA] 15-17) enrolled in the AOSpine CSM-NA/CSM-I studies. A kmeans clustering algorithm was applied to baseline QOL (Short Form-36 [SF-36]) scores to separate patients into 2 clusters. Baseline variables and surgical outcomes (change in SF- 36 scores at 1 yr) were compared between clusters. A k-nearest neighbors (kNN) algorithm was used to evaluate the ability to classify patients into the 2 clusters by significant baseline clinical variables.

RESULTS: One hundred eighty-five patients were eligible. Two groups were generated by k-means clustering. Cluster 1 had a greater proportion of females (44% vs 28%, P = .029) and symptoms of neck pain (32% vs 11%, P = .001), gait difficulty (57% vs 40%, P = .025), or weakness (75% vs 59%, P=.041). Although baseline mJOA correlated with neither baseline QOL nor outcomes, cluster 1 was associated with significantly greater improvement in disability (P = .003) and QOL (P < .001) scores following surgery. A kNN algorithm could predict cluster classification with 71% accuracy by neck pain, motor symptoms, and gender alone.

CONCLUSION: We have dissociated a distinct patient phenotype of mild DCM, characterized by neck pain, motor symptoms, and female gender associated with greater impairment in QOL and greater response to surgery.

Percutaneous Transforaminal Endoscopic Discectomy Versus Microendoscopic Discectomy for Lumbar Disc Herniation

SPINE Volume 45, Number 8, pp 493–503

Study Design. A prospective randomized controlled study.

Objective. To clarify whether percutaneous transforaminal endoscopic discectomy (PTED) has better clinical outcomes and less surgical trauma compared with microendoscopic discectomy (MED).

Summary of Background Data. Two kinds of minimally invasive spine surgeries, PTED and MED, are now widely used for the treatment of lumbar disc herniation (LDH). It is still a controversial issue to choose the proper surgical approach.

Methods. In this single-center, open-label, randomized controlled trial, patients were included if they had persistent signs and symptoms of radiculopathy with corresponding imagingconfirmed LDH, and were randomly allocated to PTED or MED group. The primary outcome was the score of Oswestry Disability Index (ODI) and the secondary outcomes included the score of Medical Outcomes Study 36-Item Short-Form Health Survey bodily pain and physical function scales, European Quality of Life-5 Dimensions, and Visual Analogue Scales for back pain and leg pain.

Results. A total of 250 participants were randomly assigned to two treatment groups, 241 of that received the specific surgical procedure. Two hundred twenty-two patients (92.1%) have completed the 2-year follow-up. Both the primary and secondary outcomes did not differ significantly between the two treatment groups at each prespecified follow-up time (P>0.05). For PTED, the postoperative improvement of ODI score in the median herniation subgroup was less compared with paramedian subgroup. For MED, less improvement of ODI score was found in far-lateral herniation subgroup compared with paramedian subgroup. Total complication rate over the course of 2 year was 13.44% in PTED group and 15.57% in MED group (P¼0.639). Ten cases (8.40%) in PTED group and five cases (4.10%) in MED group suffered from residue/recurrence of herniation, for which reoperation was required.

Conclusion. Over the 2-year follow-up period, PTED did not show superior clinical outcomes and did not appear to be safer procedure for patients with LDH compared with MED. PTED had inferior results for median disc herniation, whereas MED did not appear to be the best option for far-lateral disc herniation.

Level of Evidence: 2

Association between weekend admissions and mortality after aneurysmal subarachnoid hemorrhage: the “weekend effect” revisited

J Neurosurg 132:1167–1173, 2020

Higher mortality has been reported with weekend or after-hours patient admission across a wide range of surgical and medical specialties, a phenomenon termed the “weekend effect.” The authors evaluated whether weekend admission contributed to death and long-term neurological outcome in patients following aneurysmal subarachnoid hemorrhage.

METHODS A post hoc analysis of the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) study was conducted. Univariable and stepwise multivariable logistic regression analyses were performed to assess the associations between weekend admission and mortality and long-term neurological outcome.

RESULTS Of 413 subjects included in the CONSCIOUS-1 study, 140 patients had been admitted during the weekend. A significant interaction was identified between weekend admission and neurological grade on presentation, suggesting that the outcomes of patients who had initially presented with a poor grade were disproportionately influenced by the weekend admission. On stepwise multivariable logistic regression in the subgroup of patients who had presented with a poor neurological grade (29 of 100 patients), admission on the weekend was found to be independently associated with death (OR 6.59, 95% CI 1.62–26.88, p = 0.009). Weekend admission was not associated with long-term neurological outcome.

CONCLUSIONS Weekend admission was an independent risk factor for death within 12 weeks following aneurysmal subarachnoid hemorrhage in patients presenting with a poor neurological grade. Further work is required to identify and mitigate any mediating factors.

Usefulness of Timed Up and Go (TUG) Test for Prediction of Adverse Outcomes in Patients Undergoing Thoracolumbar Spine Surgery

Neurosurgery 2019 DOI:10.1093/neuros/nyz480

Spine surgery rates have increased and the high postoperativemorbidity in these patients result in increased costs. Consequently, it is essential to identify patients at risk of adverse outcomes.

OBJECTIVE: To assess whether preoperative Timed Up and Go (TUG) test performance can predict high-grade postoperative complications.

METHODS: A prospective cohort study of patients undergoing elective thoracolumbar spine surgery in a tertiary care hospital between 2017 and 2018. Patients were assessed preoperatively and assigned to the slow-TUG group if unable to perform or test performance time was ≥18.4 s. Primary outcome: high-grade postoperative complications. Secondary outcomes: overall complications, length of stay (LOS), discharge to healthcare facility, readmission and emergency department (ED) presentation. Patients were followed-up until 6 wk after surgery.

RESULTS: One hundred three patients (mean age 62.95 ± 10.97 yr) were enrolled. Slow- TUG group were more likely to be classified as American Society of Anaesthesiology (ASA) class 3 (74.1% vs 47.4%, P=.02), non-independent (25.9% vs 5.3%, P<.01), and frail (92.3% vs 42.1%, P < .01). TUG was an independent predictor of high-grade complications (adjusted odds ratio (OR): 4.97, 95% CI: 1.18-22.47), overall complications (OR: 3.77, 95% CI: 1.33-11.81), discharge to a skilled-nursing facility (OR: 3.2, 95% CI: 1.00-10.70), readmission within 6 wk of surgery (OR: 9.14, 95% CI: 2.39-41.26) and LOS (adjusted incident rate ratio (IRR): 1.45, 95% CI: 1.16-1.80).

CONCLUSION: Compared to traditional risk factors, TUG is an important predictor of adverse postoperative outcomes and may be used preoperatively to identify high-risk thoracolumbar surgery patients.

 

Anterior Cervical Discectomy and Fusion in the Outpatient Ambulatory Surgery Setting: Analysis of 2000 Consecutive Cases

Neurosurgery 2019 DOI:10.1093/neuros/nyz514

In an effort to improve efficiency of care, ambulatory surgery centers (ASCs) have emerged as lower-cost options. Anterior cervical discectomy and fusion (ACDF) is one of the most prevalent spine surgeries performed and rarely requires overnight stays in the hospital, supporting its migration to the ASC. Recent analyses have called into question the safety of outpatient ACDF, potentially slowing its adoption. ASC-ACDF studies have largely been limited to small series, precluding an accurate assessment of safety.

OBJECTIVE: To analyze 2000 ASC-ACDF cases, describe patient selection and perioperative protocol, and report associated safety profile.

METHODS: A total of 2000 patients who underwent 1 to 3 level ACDF in a single ASC from 2006 to 2018 were included in this retrospective analysis. Patients were observed in a 4-h postanesthesia care unit (PACU) with a multimodal pain management regiment. Data were collected on patient demographics, comorbidities, operative details, and 30- and 90-d morbidity.

RESULTS: Of the 2000 patients, 10 (0.5%) required transfer to an inpatient setting within the 4-h observation. Reasons for transfer included hematoma (2), pain control (2), cerebrospinal fluid leak (1), and medical complications (5). Six patients (0.3%) underwent reoperation within 30 d. All-cause 30-d readmission was 1.9%.

CONCLUSION: An analysis of 2000 ACDF patients in an ASC setting with a standardized perioperative protocol demonstrates that surgical complications occur at a low rate (<1%) and can be appropriately diagnosed and managed in a 4-h PACU. In an effort to decrease healthcare costs, surgeons can safely perform ACDFs in an ASC utilizing patient selection criteria and perioperative management protocols similar to those reported here.

Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion With Expandable Lordotic Devices

Neurosurgery, Volume 86, Issue 2, February 2020, Pages E147–E155

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a well-accepted procedure for the treatment of degenerative lumbar disease. However, its ability to restore lumbar lordosis has been limited. Development of expandable lordotic interbody devices has challenged this limitation, furthering the scope ofminimally invasive surgery.

OBJECTIVE: To evaluate the radiographic and clinical effects of expandable lordotic interbody devices placed through an MIS-TLIF approach.

METHODS: We conducted a retrospective review of 32 1-level and 18 2-level MIS-TLIFs performed using lordotic expandable interbody devices. Lumbar radiographic measurements, Oswestry Disability Index scores (ODI), and Visual Analogue Scale scores (VAS)were obtained at preoperative, 6 wk follow up, and last follow up time points. Last follow up occurred at a mean of 11.5 ± 7.6 mo (mean ± SD).

RESULTS: At 6-wk follow-up, segmental lordosis, disc height, and foraminal height increased by an average of 3.4◦, 6.4 mm, and 4.4 mm, respectively. Only the 2-level group showed a significant increase in lumbar lordosis of 5.8◦. No significant changes occurred in sacral slope, pelvic tilt, or pelvic incidence. Average ODI and VAS decreased by −12.0 and −4.5, respectively. Postoperative lumbar lordosis inversely correlated with preoperative lordosis in patients with an initial Pelvic Incidence to Lumbar Lordosis mismatch (PI-LL) of >10◦, (r=−0.5, P = .009).

CONCLUSION: When applied across 2-levels, MIS-TLIF using expandable lordotic interbody devices produced a significant increase in lumbar lordosis. Preoperative lumbar lordosis was found to be a predictor of postoperative lumbar lordotic change in patients with sagittal imbalance.

Pain Outcomes Following Microvascular Decompression for Drug-Resistant Trigeminal Neuralgia: A Systematic Review and Meta-Analysis

Neurosurgery, Volume 86, Issue 2, February 2020, Pages 182–190

Microvascular decompression (MVD) is a potentially curative surgery for drug-resistant trigeminal neuralgia (TN). Predictors of pain freedom after MVD are not fully understood. OBJECTIVE: To describe rates and predictors for pain freedom following MVD.

METHODS: Using preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, PubMed, Cochrane Library, and Scopus were queried for primary studies examining pain outcomes after MVD for TN published between 1988 and March 2018. Potential biases were assessed for included studies. Pain freedom (ie, Barrow Neurological Institute score of 1) at last follow-up was the primary outcome measure. Variables associated with pain freedom on preliminary analysis underwent formal meta-analysis. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for possible predictors.

RESULTS: Outcome data were analyzed for 3897 patients from 46 studies (7 prospective, 39 retrospective). Overall, 76.0% of patients achieved pain freedom afterMVD with amean follow-up of 1.7 ± 1.3 (standard deviation) yr. Predictors of pain freedom on meta-analysis using random effectsmodels included (1) disease duration≤5 yr (OR=2.06, 95% CI=1.08- 3.95); (2) arterial compression over venous or other (OR = 3.35, 95% CI = 1.91-5.88); (3) superior cerebellar artery involvement (OR = 2.02, 95% CI = 1.02-4.03), and (4) type 1 Burchiel classification (OR = 2.49, 95% CI = 1.32-4.67).

CONCLUSION: Approximately three-quarters of patients with drug-resistant TN achieve pain freedom after MVD. Shorter disease duration, arterial compression, and type 1 Burchiel classification may predict more favorable outcome. These results may improve patient selection and provider expectations.

Safety of Outpatient Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis

Neurosurgery 86:30–45, 2020

Anterior cervical discectomy and fusion (ACDF) is being increasingly offered on an outpatient basis. However, the safety profile of outpatient ACDF remains poorly defined.

OBJECTIVE: To review the medical literature on the safety of outpatient ACDF.

METHODS: We systematically reviewed the literature for articles published before April 1, 2018, describing outpatient ACDF and associated complications, including incidence of reoperation, stroke, thrombolytic events, dysphagia, hematoma, and mortality. A random-effects analysis was performed comparing complications between the inpatient and outpatient groups.

RESULTS: We identified 21 articles that satisfied the selection criteria, of which 15 were comparative studies. Most of the existing studies were retrospective, with a lack of level I or II studies on this topic. We found no statistically significant difference between inpatient and outpatient ACDF in overall complications, incidence of stroke, thrombolytic events, dysphagia, and hematoma development. However, patients undergoing outpatient ACDF had lower reported reoperation rates (P < .001), mortality (P < .001), and hospitalization duration (P < .001).

CONCLUSION: Our meta-analysis indicates that there is a lack of high level of evidence studies regarding the safety of outpatient ACDF. However, the existing literature suggests that outpatient ACDF can be safe, with low complication rates comparable to inpatient ACDF in well-selected patients. Patients with advanced age and comorbidities such as obesity and significant myelopathy are likely not suitable for outpatient ACDF. Spine surgeons must carefully evaluate each patient to decide whether outpatient ACDF is a safe option. Higher quality, large prospective randomized control trials are needed to accurately demonstrate the safety profile of outpatient ACDF.

Prospective clinical validation of a meningioma consistency grading scheme

J Neurosurg 131:1356–1360, 2019

The present study aims to assess the clinical utility of a previously validated intraoperative meningioma consistency grading scale and its association with extent of resection (EOR) and various surgical outcomes.

METHODS The previously validated grading system was prospectively assessed in 127 consecutive patients undergoing open craniotomy for meningioma by multiple neurosurgeons at two high-volume academic hospitals from 2013 to 2016. Consistency grading scores ranging from 1 (soft) to 5 (firm/calcified) were retrospectively analyzed to test for association with surgical outcomes and EOR, categorized as gross-total resection (GTR) or subtotal resection, defined by postoperative MRI.

RESULTS One hundred twenty-seven patients were included in the analysis with a tumor consistency distribution as follows: grade 1, 3.1%; grade 2, 14.2%; grade 3, 44.1%; grade 4, 32.3%; and grade 5, 6.3%. The mean tumor diameter was 3.6 ± 1.7 cm. Tumor consistency grades were grouped into soft (grades 1 and 2), average (grade 3), and firm (grades 4 and 5) groups for statistical analysis with distributions of 17.3%, 44.1%, and 38.6%, respectively. There was no association between meningioma consistency and maximal tumor diameter, or location. Mean duration of surgery was longer for tumors with higher consistency: grades 1 and 2, 186 minutes; grade 3, 219 minutes; and grades 4 and 5, 299 minutes (p = 0.000028). There was a trend toward higher perioperative complication rates for tumors of increased consistency: grades 1 and 2, 4.5%; grade 3, 7.0%; and grades 4 and 5, 20.8% (p = 0.047). The proportion of GTR for each consistency group was as follows: grades 1 and 2, 77%; grade 3, 68%; and grades 4 and 5, 43% (p = 0.0062).

CONCLUSIONS In addition to other important meningioma characteristics such as invasiveness, tumor consistency is a key determinant of surgical outcomes, including operative duration and EOR. Future studies predicting tumor consistency based on preoperative neuroimaging will help considerably with preoperative planning for meningiomas.

 

Surgical outcomes after reoperation for recurrent non–skull base meningiomas

J Neurosurg 131:1179–1187, 2019

Recurrent meningiomas are primarily managed with radiation therapy or repeat resection. Surgical morbidity after reoperation for recurrent meningiomas is poorly understood. Thus, the objective of this study was to report surgical outcomes after reoperation for recurrent non–skull base meningiomas.

METHODS A retrospective review of patients was performed. Inclusion criteria were patients with recurrent meningioma who had prior resection and supratentorial non–skull base location. Univariate and multivariate logistic regression and recursive partitioning analysis were used to identify risk factors for surgical complications.

RESULTS The authors identified 67 patients who underwent 111 reoperations for recurrent supratentorial non–skull base meningiomas. The median age was 53 years, 49% were female, and the median follow-up was 9.8 years. The most common presenting symptoms were headache, weakness, and seizure. The WHO grade after the last reoperation was grade I in 22% of cases, grade II in 51%, and grade III in 27%. The tumor grade increased at reoperation in 22% of cases. Tumors were located on the convexity (52%), parasagittal (33%), falx (31%), and multifocal (19%) locations. Tumors involved the middle third of the sagittal plane in 52% of cases. In the 111 reoperations, 48 complications occurred in 32 patients (48%). There were 26 (54%) complications requiring surgical intervention. There was no perioperative mortality. Complications included neurological deficits (14% total, 8% permanent), wound dehiscence/infection (14%), and CSF leak/pseudomeningocele/hydrocephalus (9%). Tumors that involved the middle third of the sagittal plane (OR 6.97, 95% CI 1.5–32.0, p = 0.006) and presentation with cognitive changes (OR 20.7, 95% CI 2.3–182.7, p = 0.001) were significantly associated with complication occurrence on multivariate analysis. The median survival after the first reoperation was 11.5 years, and the 2-, 5-, and 10-year Kaplan-Meier survival rates were 91.0%, 68.8%, and 50.0%, respectively.

CONCLUSIONS Reoperation for recurrent supratentorial non–skull base meningioma is associated with a high rate of complications. Patients with cognitive changes and tumors that overlap the middle third of the sagittal plane are at increased risk of complications. Nevertheless, excellent long-term survival can be achieved without perioperative mortality.

Predicting Cognitive Improvement in Normal Pressure Hydrocephalus Patients Using Preoperative Neuropsychological Testing and Cerebrospinal Fluid Biomarkers

Neurosurgery 85:E662–E669, 2019

Though it is well known that normal pressure hydrocephalus (NPH) patients can cognitively improve after ventriculoperitoneal shunting (VPS), one of the major dilemmas in NPH is the ability to prospectively predict which patients will improve.

OBJECTIVE: To prospectively assess preoperative predictors of postshunt cognitive improvement.

METHODS: This was a prospective observational cohort including 52 consecutive patients with approximately 1-yr follow-up. Patients underwent neuropsychological testing at baseline, postlumbar drainage, and postshunt. Cerebrospinal fluid (CSF) biomarkers and cortical biopsies were also collected to examine their relationship with postshunt cognitive improvement.

RESULTS: Rey Auditory Verbal Learning Test-L (RAVLT-L) was the only neuropsychological test to demonstrate statistically significant improvement both postlumbar drain and postshunt. Improvement on the RAVLT-L postlumbar drain predicted improvement on the RAVLT-L postshunt. Patients with biopsies demonstrating Aβ+ Tau+ had lower ventricular CSF Aβ42 and higher lumbar CSF pTau compared to Aβ– Tau– patients. A receiver operating curve analysis using lumbar pTau predicted Aβ+ Tau+ biopsy status but was not related to neuropsychological test outcome.

CONCLUSION: The RAVLT can be a useful preoperative predictor of postoperative cognitive improvement, and thus, we recommend using the RAVLT to evaluate NPH patients. CSF biomarkers could not be related to neuropsychological test outcome. Future research in a larger patient sample will help determine the prospective utility of CSF biomarkers in the evaluation of NPH patients.

 

Long-Term Hearing Outcomes Following Stereotactic Radiosurgery in Vestibular Schwannoma Patients

Neurosurgery, Volume 85, (4), October 2019, 550–559

An understanding of the hearing outcomes is needed for treatment counseling for patients with vestibular schwannomas (VS).

OBJECTIVE: To determine long-term hearing results following stereotactic radiosurgery (SRS) for VS and identify any influential variables.

METHODS: Tertiary hospital retrospective cohort.

RESULTS: There were 579 tumors (576 patients) treated with SRS. Eighty-two percent (473) of tumors had ≥1 yr and 59% (344 ≥3 yr follow-up. In the 244 tumor ears, with measurable hearing before SRS who were followed ≥1 yr, 14% (31) had improved hearing, 13% (29) unchanged hearing, and 74% (158) had worsened hearing. In 175 patients with ≥3 yr followup and who had measurable hearing pretreatment, 6% (11 ears) improved hearing, 31% (54 ears) unchanged hearing, and 63% (110 ears) had worsened hearing. Patients with tumors with larger target volumes (P = 0.040) and with neurofibromatosis type 2 (NF2; P = 0.017) were associated with poorer hearing (P = 0.040). Patients with word recognition scores (WRS) of 50% or poorer had tumors with a larger volume (P = 0.0002), larger linear size (P=0.032),andNF2(P=0.045).TraditionallyreportedhearingoutcomesusingtheGardner RobertsonmaintenanceofPTA ≤50dborWRS≥50%were48%at3yr,whichoverestimates hearing outcomes compared to the above reporting standards.

CONCLUSION: Hearing declines over time in VS treated with SRS in a high proportion of cases. The frequency and magnitude of long-term hearing decline following SRS argues against prophylactic radiation for small tumors in hearing ears with undetermined growth behavior.

Outcomes and complications of different surgical treatments for idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

J Neurosurg 131:1024–1036, 2019

Different CSF diversion procedures (ventriculoperitoneal, ventriculoatrial, and lumboperitoneal shunting) have been utilized for the treatment of idiopathic normal pressure hydrocephalus. More recently, endoscopic third ventriculostomy has been suggested as a reasonable alternative in some studies. The purpose of this study was to perform a systematic review and meta-analysis to assess overall rates of favorable outcomes and adverse events for each of these treatments. An additional objective was to determine the outcomes and complication rates in relation to the type of valve utilized (fixed vs programmable).

METHODS Multiple databases (PubMed, Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus) were searched for studies involving patients with idiopathic ventriculomegaly, no secondary cause of hydrocephalus, opening pressure < 25 mm Hg on high-volume tap or drainage trial, and age > 60 years. Outcomes included the proportion of patients who showed improvement in gait, cognition, and bladder function. Adverse events considered in the analysis included postoperative ischemic/hemorrhagic complications, subdural fluid collections, seizures, need for revision surgery, and infection.

RESULTS A total of 33 studies, encompassing 2461 patients, were identified. More than 75% of patients experienced improvement after shunting, without significant differences among the different techniques utilized. Overall, gait improvement was observed in 75% of patients, cognitive function improvement in more than 60%, and improvement of incontinence in 55%. Adjustable valves were associated with a reduction in revisions (12% vs 32%) and subdural collections (9% vs 22%) as compared to fixed valves.

CONCLUSIONS Outcomes did not differ significantly among different CSF diversion techniques, and overall improvement was reported in more than 75% of patients. The use of programmable valves decreased the incidence of revision surgery and of subdural collections after surgery, potentially justifying the higher initial cost associated with these valves.

Petrosal Meningiomas: Factors Affecting Outcome and the Role of Intraoperative Multimodal Assistance to Microsurgery

Neurosurgery, Volume 84, Issue 6, June 2019, Pages 1313–1324

Petrous meningiomas (PMs) represent a subset of posterior fossa tumors accounting for ∼8% of all intracranial meningiomas. Surgical treatment of PMs is challenging because of their relationships with vital neurovascular structures of the cerebellopontine angle.

OBJECTIVE: To investigate independent pre- and intraoperative predictors of PM surgery outcome.

METHODS:We reviewed the surgical and outcome data of patients who underwent microsurgical resection of PMs from 1997 to 2016. From 2007 onward, a multimodal intraoperative protocol consisting of intraoperative neuromonitoring (IONM), endoscopy, and indocyanine green (ICG) videoangiography was applied. Outcome variables included extent of resection, Karnofsky performance status (KPS), overall survival, and progression-free survival (PFS).

RESULTS: A total of 54 patients were included. Independent predictors of gross total resection (GTR) included retromeatal location (P < .0175; odds ratio [OR] 4.05), absence of brainstem compression (P < .02; OR 3.55), and histological WHO grade I (P < .001; OR 3.47). Nongiant size (P < .012; OR 4.38), and WHO grade I (P < .0001; OR 7.7) were independent predictors of stable or improved KPS. The use of multimodal intraoperative tools to assist surgery independently predicted GTR (P < .002; OR 6.8) and good KPS (P < .018; OR 4.23). Nongiant size (P = .01) and WHO grade I (P = .002) were significantly associated with increased PFS.

CONCLUSION: Notwithstanding the limitations of a retrospective study, our results suggest that support of microsurgery by a combination of IONM, endoscopy, and ICG videoangiography may improve patient outcome in PM surgery.

Posterior fossa meningiomas: perioperative predictors of extent of resection, overall survival and progression-free survival

Acta Neurochirurgica (2019) 161:1003–1011

Posterior fossa meningiomas (PFMs) often represent surgical challenges due to their proximity to neurovascular structures. Factors predicting the extent of resection (EOR), overall survival (OS), and progression-free survival (PFS) were identified and integrated in a prediction tool to offer evidence-based personalized therapeutic strategies.

Methods All meningiomas managed surgically from 1990 to 2010 from a single-center were reviewed. A classification tree was created using the classification and regression tree recursive partitioning analysis that incorporated patient and tumor data available before surgery in order to predict the rates of gross total resection (GTR).

Results A total of 198 patients were identified (female-to-male ratio, 2.7; mean age, 59.1 years) and compared with 1271 supratentorial meningiomas (STMs) operated in the same institution during the same time period. GTR was achieved less often (59.6% versus 81.9%; p < 0.01) in PFMs than STMs. Preoperative neurological symptoms were predictive of higher Simpson grades (OR, 2.19 [1.05; 4.58]; p = 0.04). Age was associated with reduced OS (OR, 1.08 [1.04;1.12]; p < 0.001). A KPS ≥ 70 was associated with higher survival rates (OR, 2.70 [2.19;2.92]; p = 0.02). Higher WHO grades were associated with reduced OS (OR, 3.56 [1.02;12.47]; p = 0.05). The GTR rate varies from 80% in patients without a preoperative deficit to 40% patients with a preoperative deficit, younger than 60 years old, and with adjacent bone invasion.

Conclusions This study provides a classification tree of the predictors of EOR in PFMs, based upon preoperative demographic, clinical, and radiological variables. An evidence-based management protocol with estimated EORs may guide the decision making process in PFMs.

The Danish chronic subdural hematoma study—predicting recurrence of chronic subdural hematoma

Acta Neurochirurgica (2019) 161:885–894

An increasing incidence of chronic subdural hematoma (CSDH) and an unchanging high recurrence rate of 10–20% call for individualized treatment. The aim of this study was to establish individualized prediction models for the risk of recurrence treating death as a competing risk.

Methods A retrospective national cohort of unilateral CSDH was included for analysis. Using competing risk survival analysis, we tested whether available covariates were associated with the risk of recurrence. We further established a preand a postoperative prediction model, where predictors were chosen using a LASSO approach. The models were visualized in nomograms. Predictive performance was evaluated by c index and calibrations plots.

Results A total of 763 patients with surgically evacuated unilateral CSDH were included for analysis. The recurrence rate was 14% while 12% of patients died during follow-up (1 year). In our association model, hematoma size, drain type, drainage time, presence of complications, and Glasgow Coma Score were significantly associated to recurrence. Subdural drain was associated with a lower recurrence risk than subgaleal drain. The preoperative model included hematoma size, hematoma density, and history of hypertension. The postoperative model included further drain type, drainage time, and surgical complications.

Conclusion The nomograms allow easy assessment of the recurrence risk for the individual patient, providing a better possibility for individual adjustment of treatment and follow-up. The predictive performance indicates that significant unaccounted or unknown factors still remain. The association test found passive subdural drain superior to passive subgaleal drain in minimizing the risk of CSDH recurrence

Clipping aneurysms improves outcomes for patients undergoing coiling

J Neurosurg 130:1491–1497, 2019

Most intracranial aneurysms are now treated by endovascular rather than by microsurgical procedures. There is evidence to demonstrate superior outcomes for patients with aneurysmal subarachnoid hemorrhage (aSAH) treated by endovascular techniques. However, some cases continue to require microsurgery. The authors have examined the relationship between the number of aneurysms treated by microsurgery and outcome for patients undergoing treatment for aSAH at neurosurgical centers in England.

METHODS The Neurosurgical National Audit Programme (NNAP) database was used to identify aSAH cases and to provide associated 30-day mortality rates for each of the 24 neurosurgical centers in England. Data were compared for association by regression analysis using the Pearson product-moment correlation coefficient and any associations were tested for statistical significance using the one-way ANOVA test. The NNAP data were validated utilizing a second, independent registry: the British Neurovascular Group’s (BNVG) National Subarachnoid Haemorrhage Database.

RESULTS Increasing numbers of microsurgical cases in a center are associated with lower 30-day mortality rates for all patients treated for aSAH, irrespective of treatment modality (Pearson r = 0.42, p = 0.04), and for patients treated for aSAH by endovascular procedures (Pearson r = 0.42, p = 0.04). The correlations are stronger if all (elective and acute) microsurgical cases are compared with outcome. The BNVG data validated the NNAP data set for patients with aSAH.

CONCLUSIONS There is a statistically significant association between local microsurgical activity and center outcomes for patients with aSAH, even for patients treated endovascularly. The authors postulate that the number of microsurgical cases performed may be a surrogate indicator of closer neurosurgical involvement in the overall management of neurovascular patients and of optimal case selection.

Outcome After Clipping and Coiling for Aneurysmal Subarachnoid Hemorrhage in Clinical Practice in Europe, USA, and Australia

Neurosurgery 84:1019–1027, 2019

Within randomized clinical trials (RCTs), coiling of the ruptured aneurysm to prevent rebleeding results in better outcomes than clipping in patients with aneurysmal subarachnoid hemorrhage (aSAH).

OBJECTIVE: To study the association of coiling and clipping with outcome after aSAH in daily clinical practice.

METHODS: In this controlled, nonrandomized study, we compared outcomes after endovascular coiling and neurosurgical clipping of ruptured intracranial aneurysms in an administrative dataset of 7658 aSAH patients (22 tertiary care hospitals from Europe, USA, Australia; 2007-2013). Because the results contradicted those of the randomized trials, findings were further explored in a large clinical dataset from 2 European centers (2006- 2016) of 1501 patients.

RESULTS: In the administrative dataset, the crude 14-d case-fatality rate was 6.4% (95% confidence interval [CI] 5.6%-7.2%) after clipping and 8.2% (95% CI 7.4%-9.1%) after coiling. After adjustment for age, sex, and comorbidity/severity, the odds ratio (OR) for 14-d casefatality after coiling compared to clipping was 1.32 (95% CI 1.10-1.58). In the clinical dataset crude 14-d case fatality ratewas 5.7% (95% CI 4.2%-7.8%) for clipping and 9.0% (95% CI 7.3%- 11.2%) for coiling. In multivariable logistic regression analysis, the OR for 14-d case-fatality after coiling compared to clipping was 1.7 (95% CI 1.1–2.7), for 90-d case-fatality 1.28 (95% CI 0.91–1.82) and for 90-d poor functional outcome 0.78 (95% CI 0.6–1.01).

CONCLUSION: In clinical practice, coiling after aSAH is associated with higher 14-d case-fatality than clipping and nonsuperior outcomes at 90 d. Both options need to be considered in aSAH patients. Further studies should address the reasons for the discrepancy between current data and those from the RCTs.

Hemorrhagic burden in poor-grade aneurysmal subarachnoid hemorrhage

Acta Neurochirurgica (2019) 161:791–797

Volumetric assessment of aneurysmal bleeding has been evaluated in few studies and emerged as a promising outcome predictor. There is a lack of studies evaluating its impact in the poor-grade population.

Methods Retrospective review of 63 consecutive poor-grade aneurysmal subarachnoid hemorrhage (aSAH) patients, defined as grade IV and V according to theWorld Federation of Neurological Surgeons (WFNS) classifications. Global intracranial bleeding volume was calculated with its subarachnoid, intracerebral (ICH), and intraventricular (IVH) portions by means of analytical software. Univariate and multivariate analyses were performed in order to identify independent predictors of outcome. Good outcome was defined as modified Rankin Scale (mRS) 0–2 and mortality as mRS 6. The cutoff values of bleeding volumes were derived by receiver operating curve (ROC) analysis.

Results Mean follow-up was of 12.5 (± 1.5) months. Thirty (47.7%) patients achieved good outcome, whereas 19 (30.2) patients out of 63 died. Global intracranial bleeding resulted as an independent predictor of good outcome (cutoff 24 mL). Furthermore, ICH relative percentage of global volume (10% of total) and pure SAH (64% of total) emerged respectively as independent predictors of worsened and improved outcome. Global bleeding volume (cutoff 51 mL) along with global cerebral edema showed to independently predict mortality in the examined poor-grade aSAH population.

Conclusions Volumetric assessment of aneurysmal bleeding has the potential for identifying cutoff values that independently predict outcome. Further insights into the relative importance of different bleeding volumes may be implicated in better tailoring the management of this dismal aSAH population.

Association between payer status and patient-reported outcomes in adult patients with lumbar spinal stenosis treated with decompression surgery

J Neurosurg Spine 30:198–210, 2019

Insurance disparities can have relevant effects on outcomes after elective lumbar spinal surgery. The aim of this study was to evaluate the association between private/public payer status and patient-reported outcomes in adult patients who underwent decompression surgery for lumbar spinal stenosis.

METHODS A sample of 100 patients who underwent surgery for lumbar spinal stenosis from 2012 to 2014 was evaluated as part of the prospectively collected Quality Outcomes Database at a single institution. Outcome measures were evaluated at 3 months and 12 months, analyzed in regard to payer status (private insurance vs Medicare/Veterans Affairs insurance), and adjusted for potential confounders.

RESULTS At baseline, patients had similar visual analog scale back and leg pain, Oswestry Disability Index, and EQ- 5D scores. At 3 months postintervention, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.11, p < 0.001) and more leg pain (mean difference 1.26, p = 0.05). At 12 months, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.14, p < 0.001). There were no significant differences at 3 months or 12 months between groups for back pain (p = 0.14 and 0.43) or disability (p = 0.19 and 0.15). Across time points, patients in both groups showed improvement at 3 months and 12 months in all 4 functional outcomes compared with baseline (p < 0.001).

CONCLUSIONS Both private and public insurance patients had significant improvement after elective lumbar spinal surgery. Patients with public insurance had slightly less improvement in quality of life after surgery than those with private insurance but still benefited greatly from surgical intervention, particularly with respect to functional status.