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.

Cerebrospinal Fluid Shunting Improves Long-Term Quality of Life in Idiopathic Normal Pressure Hydrocephalus

Neurosurgery, Volume 86, Issue 4, April 2020: 574–582

The short- and long-term impact of cerebrospinal fluid shunting on quality of life (QoL) in idiopathic normal pressure hydrocephalus (INPH) is poorly understood.

OBJECTIVE: To investigate QoL in shunted INPH patients compared to the population and to investigate which factors influence QoL in INPH.

METHODS: INPH patients consecutively shunted in Sweden during 2008-2010 were scrutinized. Population-based controls were age- and sex-matched to the patients. Included participants were the following:176 INPH patients and 368controls.QoLwas assessed using the EuroQol 5-dimension 5-level (EQ5D5L) instrument, which measures overall QoL and health status in 5 dimensions. Independency (accommodation and/or need for in-home care) and comorbidities were assessed. Patients were followed up 6-45 mo after surgery (mean follow-up time: 21 mo).

RESULTS: Shunting improved QoL (P < .001) and health status in all dimensions (P < .005). Shunted INPH patients had lower QoL than controls (P < .001). The patients’health status in mobility, self-care, daily activities, and anxiety/depression was worse than the controls both before and after surgery (P < .001). The main predictors of low QoL in INPH were symptoms of depression (P < .001) and severity of gait disturbance (P = .001). Fewer INPH patients than controls lived independently (45% vs 85%, P < .001). Time after shunting had no influence on QoL.

CONCLUSION: QoL remains improved in shunted INPH patients at a mean follow-up time of 21 mo, but the patients do not reach the same QoL as the population. Symptoms of depression and severity of gait disturbance are the strongest predictors of low QoL in INPH.

Frameless Stereotactic Radiosurgery on the Gamma Knife Icon: Early Experience From 100 Patients

Neurosurgery 86:509–516, 2020

The Gamma Knife (GK) Icon (Elekta AB) uses a cone-beam computed tomography (CBCT) scanner and an infrared camera system to support the delivery of frameless stereotactic radiosurgery (SRS). There are limited data on patients treated with frameless GK radiosurgery (GKRS).

OBJECTIVE: To describe the early experience, process, technical details, and short-term outcomes with frameless GKRS at our institution.

METHODS: We reviewed our patient selection and described the workflow in detail, including image acquisition, treatment planning, mask-based immobilization, stereotactic CBCT localization, registration, treatment, and intrafraction monitoring. Because of the short interval of follow-up, we provide crude rates of local control.

RESULTS: Data from 100 patients are reported. Median age is 67 yr old. 56 patients were treated definitively, 21 postoperatively, and 23 had salvage GKRS for recurrence after surgery. Forty-two patients had brain metastases, 26 meningiomas, 16 vestibular schwannomas, 9 high-grade gliomas, and 7 other histologies. Median doses to metastases were 20 Gy in 1 fraction (range: 14-21), 24 Gy in 3 fractions (range: 19.5-27), and 25 Gy in 5 fractions (range: 25-30 Gy). Thirteen patients underwent repeat SRS to the same area. Median treatment time was 17.7 min (range: 5.8-61.7). We found an improvement in our workflow and a greater number of patients eligible for GKRS because of the ability to fractionate treatments.

CONCLUSION: We report a large cohort of consecutive patients treated with frameless GKRS. We look forward to studies with longer follow-up to provide valuable data on clinical outcomes and to further our understanding of the radiobiology of hypofractionation in the brain.

Unruptured intracranial aneurysm growth trajectory: occurrence and rate of enlargement in 520 longitudinally followed cases

J Neurosurg 132:1077–1087, 2020

As imaging technology has improved, more unruptured intracranial aneurysms (UIAs) are detected incidentally. However, there is limited information regarding how UIAs change over time to provide stratified, patient-specific UIA follow-up management. The authors sought to enrich understanding of the natural history of UIAs and identify basic UIA growth trajectories, that is, the speed at which various UIAs increase in size.

METHODS From January 2005 to December 2015, 382 patients diagnosed with UIAs (n = 520) were followed up at UCLA Medical Center through serial imaging. UIA characteristics and patient-specific variables were studied to identify risk factors associated with aneurysm growth and create a predicted aneurysm trajectory (PAT) model to differentiate aneurysm growth behavior.

RESULTS The PAT model indicated that smoking and hypothyroidism had a large effect on the growth rate of large UIAs (≥ 7 mm), while UIAs < 7 mm were less influenced by smoking and hypothyroidism. Analysis of risk factors related to growth showed that initial size and multiplicity were significant factors related to aneurysm growth and were consistent across different definitions of growth. A 1.09-fold increase in risk of growth was found for every 1-mm increase in initial size (95% CI 1.04–1.15; p = 0.001). Aneurysms in patients with multiple aneurysms were 2.43-fold more likely to grow than those in patients with single aneurysms (95% CI 1.36–4.35; p = 0.003). The growth rate (speed) for large UIAs (≥ 7 mm; 0.085 mm/month) was significantly faster than that for UIAs < 3 mm (0.030 mm/month) and for males than for females (0.089 and 0.045 mm/month, respectively; p = 0.048).

CONCLUSIONS Analyzing longitudinal UIA data as continuous data points can be useful to study the risk of growth and predict the aneurysm growth trajectory. Individual patient characteristics (demographics, behavior, medical history) may have a significant effect on the speed of UIA growth, and predictive models such as PAT may help optimize follow-up frequency for UIA management.

Retrosigmoid approach for glycerin rhizotomy in the treatment of trigeminal neuralgia without overt arterial compression

J Neurosurg 132:1227–1233, 2020

Trigeminal neuralgia (TN) is a neuropathic pain disorder characterized by severe, lancinating facial pain that is commonly treated with neuropathic medication, percutaneous rhizotomy, and/or microvascular decompression (MVD). Patients who are not found to have distinct arterial compression during MVD present a management challenge. In 2013, the authors reported on a small case series of such patients in whom glycerin was injected intraoperatively into the cisternal segment of the trigeminal nerve. The objective of the authors’ present study was to report their updated experience with this technique to further validate this novel approach.

METHODS The authors performed a retrospective analysis of data obtained in patients in whom glycerin was directly injected into the inferior third of the cisternal portion of the trigeminal nerve. Seventy-four patients, including 14 patients from the authors’ prior study, were identified, and demographic information, intraoperative findings, postoperative course, and complications were recorded. Fisher’s exact test, unpaired t-tests, and Kaplan-Meier survival curves using Mantel log-rank test were used to compare the 74 patients with a cohort of 476 patients who received standard MVD by the same surgeon.

RESULTS The 74 patients who underwent MVD and glycerin injection had an average follow-up of 19.1 ± 18.0 months, and the male/female ratio was 1:2.9. In 33 patients (44.6%), a previous intervention for TN had failed. On average, patients had an improvement in the Barrow Neurological Institute Pain Intensity score from 4.1 ± 0.4 before surgery to 2.1 ± 1.2 after surgery. Pain improvement after the surgery was documented in 95.9% of patients. Thirteen patients (17.6%) developed burning pain following surgery. Five patients developed complications (6.7%), including incisional infection, facial palsy, CSF leak, and hearing deficit, all of which were minor.

CONCLUSIONS Intraoperative injection of glycerin into the trigeminal nerve is a generally safe and potentially effective treatment for TN when no distinct site of arterial compression is identified during surgery or when decompression of the nerve is deemed to be inadequate.

Occlusion Rate and Visual ComplicationsWith Flow-Diverter Stent Placed Across the Ophthalmic Artery’s Origin for Carotid-Ophthalmic Aneurysms: A Meta-Analysis

Neurosurgery 86:455–463, 2020

Flow-diverter stents (FDSs) have recently gained acceptance for the treatment of intracranial aneurysms, especially for carotid-ophthalmic aneurysms (COAs). However, complications have been reported after coverage of side branches, especially the ophthalmic artery (OA).

OBJECTIVE: To evaluate, through a meta-analysis, the occlusion rate, and the ophthalmic complications after treatment of COA by FDS.

METHODS:We reviewed on MEDLINE via PubMed, Embase via Ovid, and Cochrane central database via CENTRAL.We included all case serieswith at least 15 patients and clinical trials about flow diversion of aneurysms close to the OA’s origin. Among these studies, we only included articles with aneurysm occlusion rate and rate of new ophthalmic symptoms.

RESULTS: We included 16 studies with 913 COA treated by FDSs and covering the OA with a mean follow-up of 16.4 mo. The random-effect modeling analysis concerning the overall rate of new ophthalmic complications, after FDS deployment covering the OA, was 3.0% (CI95% 1.0-6.0). There was medium-high heterogeneity in the study reports P < .01, I2 = 70.2% [50.4%; 82.1%]. We were not able to statistically explain this heterogeneity with the performed analysis, which could be related to the design of the included studies. We found an overall aneurysm occlusion rate of 85.0% (95% CI 80.0-89.0).

CONCLUSION: Our meta-analysis found a high aneurysm occlusion rate (85%) and low rate of iatrogenic visual complications, with only 3.0% of new visual symptoms, after treatment of COA by FDS.

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.

Laser Ablation of Abnormal Neurological Tissue Using Robotic Neuroblate System (LAANTERN)

Neurosurgery 86:538–547, 2020

Stereotactic laser ablation (SLA) has demonstrated potential utility for a spectrum of difficult to treat neurosurgical pathologies in multiple small and/or retrospective single-institutional series. Here, we present the safety profile of SLA of intracranial lesions from the Laser Ablation of Abnormal Neurological Tissue using Robotic NeuroBlate System (LAANTERN; Monteris Medical) multi-institutional, international prospective observational registry.

OBJECTIVE: To determine the procedural safety of SLA for intracranial lesions.

METHODS: Prospective procedural safety and hospitalization data from the first 100 treated LAANTERN patients was collected and analyzed.

RESULTS: Mean age and baseline Karnofsky Performance Status (KPS) were 51(±17) yr and 83(± 15), respectively. In total, 81.2% of patients had undergone prior surgical or radiation treatment. Most patients had a single lesion (79%) ablated through 1 burr hole (1.2±0.7 per patient), immediately following a lesion biopsy. In total, >90% of the lesion was ablated in 72% of treated lesions. Average total procedural time was 188.2 ± 69.6 min, and average blood loss was 17.7 ± 55.6 ccs. The average length of intensive care unit (ICU) and hospital stays before discharge were 38.1 ± 62.7 h and 61.1 ± 87.2 h, respectively. There were 5 adverse events (AEs) attributable to SLA (5/100; 5%). After the procedure, 84.8% of patients were discharged home. There was 1 mortality within 30 d of the procedure (1/100; 1%), which was not attributable to SLA.

CONCLUSION: SLA is a safe, minimally invasive procedure with favorable postprocedural ICU and hospital utilization profiles.

A novel proposed grading system for cerebellar arteriovenous malformations

J Neurosurg 132:1105–1115, 2020

The objective of this study was to evaluate the existing Spetzler-Martin (SM), Spetzler-Ponce (SP), and Lawton-Young (LY) grading systems for cerebellar arteriovenous malformations (AVMs) and to propose a new grading system to estimate the risks associated with these lesions.

METHODS Data for patients with cerebellar AVMs treated microsurgically in two tertiary medical centers were retrospectively reviewed. Data from patients at institution 1 were collected from September 1999 to February 2013, and at institution 2 from October 2008 to October 2015. Patient outcomes were classified as favorable (modified Rankin Scale [mRS] score 0–2) or poor (mRS score 3–6) at the time of discharge. Using chi-square and logistic regression analysis, variables associated with poor outcomes were assigned risk points to design the proposed grading system. The proposed system included neurological status prior to treatment (poor, +2 points), emergency surgery (+1 point), age > 60 years (+1 point), and deep venous drainage (deep, +1 point). Risk point totals of 0–1 comprised grade 1, 2–3 grade 2, and 4–5 grade 3.

RESULTS A total of 125 cerebellar AVMs of 1328 brain AVMs were reviewed in 125 patients, 120 of which were treated microsurgically and included in the study. With our proposed grading system, we found poor outcomes differed significantly between each grade (p < 0.001), while with the SM, SP, and LY grading systems they did not (p = 0.22, p = 0.25, and p = 1, respectively). Logistic regression revealed grade 2 had 3.3 times the risk of experiencing a poor outcome (p = 0.008), while grade 3 had 9.9 times the risk (p < 0.001). The proposed grading system demonstrated a superior level of predictive accuracy (area under the receiver operating characteristic curve [AUROC] of 0.72) compared with the SM, SP, and LY grading systems (AUROC of 0.61, 0.57, and 0.51, respectively).

CONCLUSIONS The authors propose a novel grading system for cerebellar AVMs based on emergency surgery, venous drainage, preoperative neurological status, and age that provides a superior prognostication power than the formerly proposed SM, SP, and LY grading systems. This grading system is clinically predictive of patient outcomes and can be used to better guide vascular neurosurgeons in clinical decision-making.

 

Comprehensive analysis of perforator territory infarction on postoperative diffusion-weighted imaging in patients with surgically treated unruptured intracranial saccular aneurysms

J Neurosurg 132:1088–1095, 2020

Perforator territory infarction (PTI) is still a major problem needing to be solved to achieve good outcomes in aneurysm surgery. However, details and risk factors of PTI diagnosed on postoperative MRI remain unknown. The authors aimed to investigate the details of PTI on postoperative diffusion-weighted imaging (DWI) in patients with surgically treated unruptured intracranial saccular aneurysms (UISAs).

METHODS The data of 848 patients with 1047 UISAs were retrospectively evaluated. PTI was diagnosed on DWI, which was performed the day after aneurysm surgery. Clinical and radiological characteristics were compared between UISAs with and without PTI. Poor outcome was defined as an increase in 1 or more modified Rankin Scale scores at 12 months after aneurysm surgery.

RESULTS Postoperative DWI was performed in all cases, and it revealed PTI in 56 UISA cases (5.3%). Forty-three PTIs occurred without direct injury and occlusion of perforators (43 of 56, 77%). Poor outcome was more frequently observed in the PTI group (17 of 56, 30%) than the non-PTI group (57 of 1047, 5.4%) (p < 0.0001). Thalamotuberal arteries (p < 0.01), lateral striate arteries (p < 0.01), Heubner’s artery (p < 0.01), anterior median commissural artery (p < 0.05), terminal internal carotid artery perforators (p < 0 0.01), and basilar artery perforator (p < 0 0.01) infarctions were related to poor outcome by adjusted residual analysis. On multivariate analysis, statin use (OR 10, 95% CI, 3.3–31; p < 0.0001), specific aneurysm locations (posterior communicating artery [OR 4.1, 95% CI 2.1–8.1; p < 0.0001] and basilar artery [OR 3.1, 95% CI 1.1–8.9; p = 0.031]), larger aneurysm size (OR 1.1, 95% CI 1.1–1.2; p = 0.043), and permanent decrease of motor evoked potential (OR 38, 95% CI 3.1–468; p = 0.0045) were related to PTI.

CONCLUSIONS Despite efforts to avoid PTI, it occurred even without direct injury, occlusion of perforators, or evoked potential abnormality. Therefore, surgical treatment of UISAs, especially with the aforementioned risk factors of PTI, should be more carefully considered. The evaluation of PTI in the territory of the above-mentioned perforators could be useful in helping predict the clinical course in patients after aneurysm surgery.

Embolization of the middle meningeal artery in patients with chronic subdural hematoma—a systematic review and meta-analysis

Acta Neurochirurgica (2020) 162:777–784

Chronic subdural hematoma (CSDH) remains a neurosurgical condition with high recurrence rate after surgical treatment. The primary pathological mechanism is considered to be repeated microbleedings from fragile neo-vessels within the outer hematoma membrane. The neo-vessels are supplied from peripheral branches of the middle meningeal artery, and embolization of MMA (eMMA) has been performed to prevent re-bleeding episodes and thereby CSDH recurrence.

Objective To evaluate the published evidence for the effect of eMMA in patients with recurrent CSDH. Secondarily, to investigate the effect of eMMA as an alternative to surgery for primary treatment of CSDH. Method A systematic review of the literature on eMMA in patients with recurrent CSDH was conducted. PubMed, Embase, and Cochrane databases were reviewed using the search terms: Embolization, Medial Meningeal Artery, Chronic Subdural Haematoma, and Recurrence. Furthermore, the following mesh terms were used: Chronic Subdural Haematoma AND embolization AND medial meningeal artery AND recurrence. Eighteen papers were found and included. No papers were excluded. The number of patients with primary CSDH and the number of patients with recurrent CSDH treated with eMMA were listed. Furthermore, the number of recurrences in both categories was registered.

Results Eighteen papers with a total of 191 included patients diagnosed with CSDH treated with eMMA for primary and recurrent CSDH were identified. Recurrence rate for patients treated with eMMA for recurrent CSDH was found to be 2.4%, 95%CI (0.5%; 11.0%), whereas the recurrence rate for patients treated with eMMAfor primary CSDH was 4.1%, 95%CI (1.4%; 11.4%).

Conclusion eMMA is a minimally invasive procedure for treatment of CSDH. Although this study is limited by publication bias, it seems that this procedure may reduce recurrence rates compared with burr hole craniostomy for both primary and recurrent hematomas. A controlled study is warranted.

sEVD—smartphone-navigated placement of external ventricular drains

Acta Neurochirurgica (2020) 162:513–521

Currently, the trajectory for insertion of an external ventricular drain (EVD) is mainly determined using anatomical landmarks. However, non-assisted implantations frequently require multiple attempts and are associated with EVD malpositioning and complications. The authors evaluated the feasibility and accuracy of a novel smartphone-guided, angleadjusted technique for assisted implantations of an EVD (sEVD) in both a human artificial head model and a cadaveric head.

Methods After computed tomography (CT), optimal insertion angles and lengths of intracranial trajectories of the EVDs were determined. A smartphone was calibrated to the mid-cranial sagittal line. Twenty EVDs were placed using both the premeasured data and smartphone-adjusted insertion angles, targeting the center of the ipsilateral ventricular frontal horn. The EVD positions were verified with post-interventional CT.

Results All 20 sEVDs (head model, 8/20; cadaveric head, 12/20) showed accurate placement in the ipsilateral ventricle. The sEVD tip locations showed a mean target deviation of 1.73° corresponding to 12 mm in the plastic head model, and 3.45° corresponding to 33mm in the cadaveric head. The mean duration of preoperative measurements on CT data was 3 min, whereas sterile packing, smartphone calibration, drilling, and implantation required 9 min on average.

Conclusions By implementation of an innovative navigation technique, a conventional smartphone was used as a protractor for the insertion of EVDs. Our ex vivo data suggest that smartphone-guided EVD placement offers a precise, rapidly applicable, and patient-individualized freehand technique based on a standard procedure with a simple, cheap, and widely available multifunctional device.

Implementation of cisternostomy as adjuvant to decompressive craniectomy for the management of severe brain trauma

Acta Neurochirurgica (2020) 162:469–479

Objective To evaluate the value of an adjuvant cisternostomy (AC) to decompressive craniectomy (DC) for the management of patients with severe traumatic brain injury (sTBI).

Methods A single-center retrospective quality control analysis of a consecutive series of sTBI patients surgically treated with AC or DC alone between 2013 and 2018. A subgroup analysis, “primary procedure” and “secondary procedure”, was also performed. We examined the impact of AC vs. DC on clinical outcome, including long-term (6 months) extended Glasgow outcome scale (GOS-E), the duration of postoperative ventilation, and intensive care unit (ICU) stay, mortality, Glasgow coma scale at discharge, and time to cranioplasty. We also evaluated and analyzed the impact of AC vs. DC on post-procedural intracranial pressure (ICP) and brain tissue oxygen (PbO2) values as well as the need for additional osmotherapy and CSF drainage.

Results Forty patients were examined, 22 patients in the DC group, and 18 in the AC group. Compared with DC alone, AC was associated with significant shorter duration of mechanical ventilation and ICU stay, as well as better Glasgow coma scale at discharge. Mortality rate was similar. At 6-month, the proportion of patients with favorable outcome (GOS-E ≥ 5) was higher in patients with AC vs. DC [10/18 patients (61%) vs. 7/20 (35%)]. The outcome difference was particularly relevant when AC was performed as primary procedure (61.5% vs. 18.2%; p = 0.04). Patients in the AC group also had significant lower average postsurgical ICP values, higher PbO2 values and required less osmotic treatments as compared with those treated with DC alone.

Conclusion Our preliminary single-center retrospective data indicate that AC may be beneficial for the management of severe TBI and is associated with better clinical outcome. These promising results need further confirmation by larger multicenter clinical studies. The potential benefits of cisternostomy should not encourage its universal implementation across trauma care centers by surgeons that do not have the expertise and instrumentation necessary for cisternal microsurgery. Training in skull base and vascular surgery techniques for trauma care surgeons would avoid the potential complications associated with this delicate procedure.

Double-blind randomized clinical trial of vancomycin in spinal arthrodesis: no effects on surgical site infection

J Neurosurg Spine 32:473–480, 2020

Surgical site infection (SSI) results in high morbidity and mortality in patients undergoing spinal fusion. Using intravenous antibiotics in anesthesia induction reduces the rate of postoperative infection, but it is not common practice to use them topically, despite recent reports that this procedure helps reduce infection. The objective of this study was to determine whether the topical use of vancomycin reduces the rate of postoperative SSI in patients undergoing thoracolumbar fusion.

METHODS A randomized, double-blind clinical trial in a single hospital was performed comparing vancomycin and placebo in thoracolumbar fusion patients.

RESULTS A total of 96 patients were randomized to placebo or vancomycin treatment. The mean patient age was 43 ± 14.88 years, 74% were male, and the most common etiology was fall from height (46.9%). The overall rate of postoperative SSI was 8.3%, and no difference was found between the groups: postoperative infection rates in the vancomycin and placebo groups were 8.2% and 8.5% (relative risk [RR] of SSI not using vancomycin 1.04, 95% confidence interval [CI] 0.28–3.93, p = 0.951), respectively. Patients with diabetes mellitus had higher SSI rates (RR 8.98, 95% CI 1.81–44.61, p = 0.007).

CONCLUSIONS This is the first double-blind randomized clinical trial to evaluate the effects of topical vancomycin on postoperative infection rates in thoracolumbar fusion patients, and the results did not differ significantly from placebo. Clinical trial registration no.: RBR-57wppt (ReBEC; http://www.ensaiosclinicos.gov.br/)

 

Topping-off technique for stabilization of lumbar degenerative instabilities in 322 patients

J Neurosurg Spine 32:366–372, 2020

Semi-rigid instrumentation (SRI) was introduced to take advantage of the concept of load sharing in surgery for spinal stabilization. The authors investigated a topping-off technique in which interbody fusion is not performed in the uppermost motion segment, thus creating a smooth transition from stabilized to free motion segments. SRI using the topping-off technique also reduces the motion of the adjacent segments, which may reduce the risk of adjacent segment disease (ASD), a frequently observed sequela of instrumentation and fusion, but this technique may also increase the possibility of screw loosening (SL). In the present study the authors aimed to systematically evaluate reoperation rates, clinical outcomes, and potential risk factors and incidences of ASD and SL for this novel approach.

METHODS The authors collected data for the first 322 patients enrolled at their institution from 2009 to 2015 who underwent surgery performed using the topping-off technique. Reoperation rates, patient satisfaction, and other outcome measures were evaluated. All patients underwent pedicle screw–based semi-rigid stabilization of the lumbar spine with a polyetheretherketone (PEEK) rod system.

RESULTS Implantation of PEEK rods during revision surgery was performed in 59.9% of patients. A median of 3 motion segments (range 1–5 segments) were included and a median of 2 motion segments (range 0–4 segments) were fused. A total of 89.4% of patients underwent fusion, 73.3% by transforaminal lumbar interbody fusion (TLIF), 18.4% by anterior lumbar interbody fusion (ALIF), 3.1% by extreme lateral interbody fusion (XLIF), 0.3% by oblique lumbar interbody fusion (OLIF), and 4.9% by combined approaches in the same surgery. Combined radicular and lumbar pain according to a visual analog scale was reduced from 7.9 ± 1.0 to 4.0 ± 3.1, with 56.2% of patients indicating benefit from surgery. After maximum follow-up (4.3 ± 1.8 years), the reoperation rate was 16.4%.

CONCLUSIONS The PEEK rod concept including the topping-off principle seems safe, with at least average patient satisfaction in this patient group. Considering the low rate of first-tier surgeries, the presented results seem at least comparable to those of most other series. Follow-up studies are needed to determine long-term outcomes, particularly with respect to ASD, which might be reduced by the presented approach.

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.

 

Subperiosteal versus subdural drainage after burr hole evacuation of chronic subdural hematoma: systematic review and meta-analysis

Acta Neurochirurgica (2020) 162:489–498

The evidence for subperiosteal drainage (SPD) versus subdural drainage (SDD) in chronic subdural hematoma (CSDH) remains controversial, and most surgeons prefer to use SDD over SPD.We aimto assess the latest evidence on the use of SPD compared to SDD in patients with CSDH undergoing burr hole evacuation.

Methods We performed a systematic literature search on topics that assesses the use of SPD compared to SDD in patients with CSDH up until November 2019 from PubMed, EuropePMC, Cochrane Central Database, ScienceDirect, ProQuest, and ClinicalTrials.gov. The primary outcome was recurrent CSDH, and the secondary outcomes were mortality, surgical morbidities, and modified Rankin Score (mRS).

Results There were a total of 3241 subjects from 10 studies. SPD was shown to reduce recurrent CSDH (OR 0.66 [0.52, 0.84], p < 0.001; I2: 17%, p = 0.30) compared to SDD. Recurrent CSDH was lower in SPD group in subgroup analysis at 3-months (OR 0.63 [0.49, 0.81]; I2: 68%, p = 0.04) and 6-months (OR 0.66 [0.51, 0.85], p = 0.001; I2: 77%, p = 0.01) follow-up. However, there was no difference in CSDH recurrence upon subgroup analysis of RCTs. Similar mortality was demonstrated between SPD and SDD group (p = 0.13). The occurrence of parenchymal injury/new neurological deficit was significantly lower in SPD group (OR 0.26 [0.14, 0.51], p < 0.001; I2: 49%, p = 0.08). The rate of seizure, (p = 0.57), postoperative bleeding (p = 0.29), and infection (p = 0.25) were shown to be similar in both SPD and SDD group. Overall, the rate of surgical morbidity was significantly lower in SPD group (OR 0.61 [0.44, 0.85], p = 0.003; I2: 16%, p = 0.25). mRS at the end of follow-up was similar in SPD and SDD group (p = 0.12).

Conclusion SPD was associated with less CSDH recurrence, but similar rate of mortality, seizures, postoperative bleeding, and infections compared to SDD. The rate of parenchymal injury/new neurological deficit was lower in the SPD group.

The striking effects of deep cerebellar stimulation on generalized fixed dystonia

J Neurosurg 132:712–716, 2020

Cerebellar neuromodulation could influence the pathological abnormalities of movement disorders through several connections between the cerebellum and the basal ganglia or other cortices. In the present report, the authors demonstrate the effects of cerebellar deep brain stimulation (DBS) on a patient with severe generalized fixed dystonia (FD) that was refractory to bilateral pallidotomy and intrathecal baclofen therapy.

A previously healthy 16-year-old girl presented with generalized FD. Bilateral pallidotomy and intrathecal baclofen therapy had failed to resolve her condition, following which she received DBS through the bilateral superior cerebellar peduncle (SCP) and dentate nucleus (DN). Ipsilateral stimulation of the SCP or DN improved the FD, and the ability of DBS administered via the SCP to relax muscles was better than that of DN DBS.

A considerable improvement of generalized FD, from a bedridden state to a wheelchairbound state, was observed in the patient following 6 months of chronic bilateral DBS via the SCP; moreover, the patient was able to move her arms and legs. The findings in the present case suggest that neuromodulation of deep cerebellar structures is a promising treatment for FD that is refractory to conventional treatments.

The endoscopic transpterional port approach: anatomy, technique, and initial clinical experience

J Neurosurg 132:884–894, 2020

The evolution of microsurgical and endoscopic techniques has allowed the development of less invasive transcranial approaches. The authors describe a purely endoscopic transpterional port craniotomy to access lesions involving the cavernous sinus and the anterolateral skull base.

METHODS Through single- or dual-port incisions and with direct endoscopic visualization, the authors performed an endoscopic transpterional port approach (ETPA) using a 4-mm straight endoscope in 8 sides of 4 formalin-fixed cadaveric heads injected with colored latex. A main working port incision is made just below the superior temporal line and behind the hairline. An optional 0.5- to 1-cm second skin port incision is made on the lateral supraorbital region, allowing multiangle endoscopic visualization and maneuverability. A 1.5- to 2-cm craniotomy centered over the pterion is done through the main port, which allows an extradural exposure of the cavernous sinus region and extra/intradural exposure of the frontal and temporal cranial fossae. The authors present a pilot surgical series of 17 ETPA procedures and analyze the surgical indications and clinical outcomes retrospectively.

RESULTS The initial stage of this work on cadavers provided familiarity with the technique, standardized its steps, and showed its anatomical limits. The clinical ETPA was applied to gain access into the cavernous sinus, as well as for aneurysm clipping and meningioma resection. Overall, perioperative complications occurred in 1 patient (6%), there was no mortality, and at last follow-up all patients had a modified Rankin Scale score of 0 or 1.

CONCLUSIONS The ETPA provides a less invasive, focused, and direct route to the cavernous sinus, and to the frontal and temporal cranial fossae, and it is feasible in clinical practice for selected indications with good results.