Comaneci-Assisted Coiling as a Treatment Option for Acutely Ruptured Wide Neck Cerebral Aneurysm: Case Series of 118 Patients

Neurosurgery 87 (6) 2020: 1148–1156

Wide-necked cerebral aneurysms in the setting of acute subarachnoid hemorrhage (SAH) remain difficult to treat with endovascular methods despite recent progress in the neuroendovascular field.

OBJECTIVE: To evaluate the effectiveness and safety of the Comaneci device (Rapid Medical, Israel) in endovascular coil embolization of acutely ruptured, wide-necked sidewall, or bifurcation cerebral aneurysms.

METHODS: We retrospectively reviewed 45 anterior communicating artery, 24 internal carotid artery, 21 middle cerebral artery bifurcation, 15 anterior cerebral artery, and 13 posterior circulation aneurysms, which were treated using Comaneci-assisted coil embolization from August 2017 to January 2019. We evaluated procedural complications, clinical outcomes, and mid-term angiographic follow-up. Immediate and 90 d-clinical outcome and radiological follow-up were obtained in all patients.

RESULTS: Comaneci-assisted coil embolization was performed in 118 acutely ruptured aneurysms. The technique was carried out successfully in all cases. Simultaneous application of 2 separated Comaneci devices was performed in 8/118 cases (6.77%). Periprocedural thromboembolic complications related to the devicewere seen in 7/118 cases (5.93%) and severe vasospasm of the parent artery after manipulation of the Comaneci device occurred in 5/118 cases (4.2%). The procedural-relatedmorbidity rate was 2.54%, and there was no procedural related mortality. Among the available survivors, angiographic followups were obtained at 3 and 6 mo, and complete aneurysmal obliteration was confirmed in 81/112 (72.3%) and 75/112 (66.9%) cases, respectively. Mid-term follow-up reviewed total recanalization rate of 14.28%.

CONCLUSION: Comaneci-assisted embolization of wide-necked intracranial aneurysms in patients presenting with acute SAHis associated with high procedural safety and adequate occlusion rates. Furthermore, dual antiplatelet therapy can be safely avoided in this patient group.

Predictors of the Best Outcomes Following Minimally Invasive Surgery for Grade 1 Degenerative Lumbar Spondylolisthesis

Neurosurgery, 87 (6) 2020: 1130–1138

The factors driving the best outcomes following minimally invasive surgery (MIS) for grade 1 degenerative lumbar spondylolisthesis are not clearly elucidated.

OBJECTIVE: To investigate the factors that drive the best 24-mo patient-reported outcomes (PRO) following MIS surgery for grade 1 degenerative lumbar spondylolisthesis.

METHODS: A total of 259 patients from the Quality Outcomes Database lumbar spondylolisthesis module underwent single-level surgery for degenerative grade 1 lumbar spondylolisthesis with MIS techniques (188 fusions, 72.6%). Twenty-four-month follow-up PROs were collected and included the Oswestry disability index (ODI) change (ie, 24-mo minus baseline value), numeric rating scale (NRS) back pain change, NRS leg pain change, EuroQoL-5D (EQ-5D) questionnaire change, and North American Spine Society (NASS) satisfaction questionnaire. Multivariable models were constructed to identify predictors of PRO change.

RESULTS: The mean age was 64.2 ± 11.5 yr and consisted of 148 (57.1%) women and 111(42.9%) men. In multivariable analyses, employment was associated with superior postoperative ODI change (β-7.8; 95% CI [−12.9 to −2.6]; P = .003), NRS back pain change (β −1.2; 95% CI [−2.1 to −0.4]; P = .004), EQ-5D change (β 0.1; 95% CI [0.01-0.1]; P = .03), and NASS satisfaction (OR = 3.7; 95% CI [1.7-8.3]; P < .001). Increasing age was associated with superior NRS leg pain change (β −0.1; 95% CI [−0.1 to −0.01]; P= .03) and NASS satisfaction (OR=1.05; 95%CI [1.01-1.09]; P=.02). Fusion surgerieswere associated with superior ODI change (β −6.7; 95% CI [−12.7 to −0.7]; P= .03), NRS back pain change (β −1.1; 95% CI [−2.1 to −0.2]; P= .02), and NASS satisfaction (OR = 3.6; 95% CI [1.6-8.3]; P= .002).

CONCLUSION: Preoperative employment and surgeries, including a fusion, were predictors of superior outcomes across the domains of disease-specific disability, back pain, leg pain, quality of life, and patient satisfaction. Increasing age was predictive of superior outcomes for leg pain improvement and satisfaction.

 

Neurological events due to pedicle screw malpositioning with lateral fluoroscopy–guided pedicle screw insertion

J Neurosurg Spine 33:806–811, 2020

The risk of novel postoperative neurological events due to pedicle screw malpositioning in lumbar fusion surgery is minimized by using one of the several image-guided techniques for pedicle screw insertion. These techniques for guided screw insertion range from intraoperative fluoroscopy to intraoperative navigation. A practical technique consists of anatomical identification of the screw entry point followed by lateral fluoroscopy used for guidance during insertion of the screw. This technique is available in most clinics and is less expensive than intraoperative navigation. However, the safety of lateral fluoroscopy–guided pedicle screw placement with regard to novel postoperative neurological events due to screw malposition has been addressed only rarely in the literature. In this study the authors aimed to determine the rate of novel postoperative neurological events due to intraoperative and postoperatively established screw malpositioning during lateral fluoroscopy–assisted screw insertion.

METHODS Included patients underwent lateral fluoroscopy–assisted lumbosacral screw insertion between January 2012 and August 2017. The occurrence of novel postoperative neurological events was analyzed from patient files. In case of an event, surgical reports were screened for the occurrence of intraoperative screw malposition. Furthermore, postoperative CT scans were analyzed to identify and describe possible screw malposition.

RESULTS In total, 246 patients with 1079 screws were included. Novel postoperative neurological events were present in 36 patients (14.6%). In 8 of these 36 patients (3.25% of the total study population), the neurological events could be directly attributed to screw malposition. Screw malpositioning was caused either by problematic screw insertion with immediate screw correction (4 patients) or by malpositioned screws for which the malposition was established postoperatively using CT scans (4 patients). Three patients with screw malposition underwent revision surgery without subsequent symptom relief.

CONCLUSIONS Lateral fluoroscopy–assisted lumbosacral screw placement results in low rates of novel postoperative neurological events caused by screw malposition. In the majority of patients suffering from novel postoperative neurological events, these events could not be attributed to screw malpositioning, but rather were due to postoperative neurapraxia of peripheral nerves, neuropathy, or intraoperative traction of nerve roots.

Cognitive functioning in patients with low-grade glioma: effects of hemispheric tumor location and surgical procedure

J Neurosurg 133:1671–1682, 2020

The authors evaluated the cognitive performance of patients with low-grade glioma (LGG) before and after surgery, and specifically investigated 1) the effects of hemispheric tumor location and 2) the type of surgery (either with or without intraoperative stimulation mapping [ISM]).

METHODS Patients underwent neuropsychological assessment 1 day before (T0) and 3 months after (T3) surgery. ISM targeted motor and/or language functions, but no other cognitive functions. Using 2-way mixed ANOVAs, differences between groups (i.e., for patients with right- vs left-sided lesions and normative controls [NCs], and also for patients operated on with vs without ISM and NCs), effects over time (T0–T3), and interaction effects in cognitive functioning were explored. Individual changes over time were assessed with reliable change indices for each neuropsychological test.

RESULTS In total, 77 patients with LGG were included (38 and 39 patients with right- and left-sided lesions, respectively; and 42 patients with and 35 patients without ISM). The majority of patients who were operated on with ISM had left-sided lesions. Patients with right- and left-sided lesions scored significantly lower on 6 and 3 out of 8 tests, respectively, compared to NCs. No significant differences between hemispheric groups were found at T0 or at T3. Patients with left-sided lesions showed significant deterioration of performance on verbal memory and sustained attention over time. Patients who underwent operation with versus without ISM scored significantly lower on 6 and 3 out of 8 tests, respectively, compared to NCs. Patients in the ISM group scored significantly lower on the Stroop test, shifting attention test, and verbal fluency test than patients without ISM. Also, the ISM group showed a significant decline in mean cognitive flexibility and sustained attention performance over time.

CONCLUSIONS Cognitive impairments were found in patients irrespective of hemispheric tumor location, whereby patients who were operated on with ISM performed slightly worse after surgery than patients without ISM. The authors conclude that there is room for improvement of cognitive functioning in surgically treated patients with LGG. The use of specific tests for higher cognitive functions during surgery may potentially improve functional outcome, but that is to be determined in future studies and balanced against oncological outcome. Implementation of neuropsychological assessments into the clinical management of patients with LGG should be encouraged, to inform and alert patients and clinicians on the status of cognitive functioning.

 

Asymmetrical pedicle subtraction osteotomy for correction of concurrent sagittal-coronal imbalance in adult spinal deformity

J Neurosurg Spine 33:822–829, 2020

Rigid multiplanar thoracolumbar adult spinal deformity (ASD) cases are challenging and many require a 3-column osteotomy (3CO), specifically asymmetrical pedicle subtraction osteotomy (APSO). The outcomes and additional risks of performing APSO for the correction of concurrent sagittal-coronal deformity have yet to be adequately studied.

METHODS The authors performed a retrospective review of all ASD patients who underwent 3CO during the period from 2006 to 2019. All cases involved either isolated sagittal deformity (patients underwent standard PSO) or concurrent sagittal-coronal deformity (coronal vertical axis [CVA] ≥ 4.0 cm; patients underwent APSO). Perioperative and 2-year follow-up outcomes were compared between patients with isolated sagittal imbalance who underwent PSO and those with concurrent sagittal-coronal imbalance who underwent APSO.

RESULTS A total of 390 patients were included: 338 who underwent PSO and 52 who underwent APSO. The mean patient age was 64.6 years, and 65.1% of patients were female. APSO patients required significantly more fusions with upper instrumented vertebrae (UIV) in the upper thoracic spine (63.5% vs 43.3%, p = 0.007). Radiographically, APSO patients had greater deformity with more severe preoperative sagittal and coronal imbalance: sagittal vertical axis (SVA) 13.0 versus 10.7 cm (p = 0.042) and CVA 6.1 versus 1.2 cm (p < 0.001). In APSO cases, significant correction and normalization were achieved (SVA 13.0–3.1 cm, CVA 6.1–2.0 cm, lumbar lordosis [LL] 26.3°–49.4°, pelvic tilt [PT] 38.0°–20.4°, and scoliosis 25.0°–10.4°, p < 0.001). The overall perioperative complication rate was 34.9%. There were no significant differences between PSO and APSO patients in rates of complications (overall 33.7% vs 42.3%, p = 0.227; neurological 5.9% vs 3.9%, p = 0.547; medical 20.7% vs 25.0%, p = 0.482; and surgical 6.5% vs 11.5%, p = 0.191, respectively). However, the APSO group required significantly longer stays in the ICU (3.1 vs 2.3 days, p = 0.047) and hospital (10.8 vs 8.3 days, p = 0.002). At the 2-year follow-up, there were no significant differences in mechanical complications, including proximal junctional kyphosis (p = 0.352), pseudarthrosis (p = 0.980), rod fracture (p = 0.852), and reoperation (p = 0.600).

CONCLUSIONS ASD patients with significant coronal imbalance often have severe concurrent sagittal deformity. APSO is a powerful and effective technique to achieve multiplanar correction without higher risk of morbidity and complications compared with PSO for sagittal imbalance. However, APSO is associated with slightly longer ICU and hospital stays.

Changes in intracranial pressure and pulse wave amplitude during postural shifts

Acta Neurochirurgica (2020) 162:2983–2989

Monitoring of intracranial pressure (ICP) and ICP pulse wave amplitude (PWA) is an integrated part of neurosurgery. An increase in ICP usually leads to an increase in PWA. These findings have yet to be replicated during the positional shift from supine to upright, where we only know that ICP decreases. Our main aim is to clarify whether the positional shift also results in a change in pulse wave amplitude.

Method Our database was retrospectively reviewed for subjects having had a standardized investigation of positional ICP. In all subjects, mean ICP and PWA were determined with both an automatic and a manual method and compared using Student’s t test. Finally, ICP and PWA were tested for correlation in both in supine and upright position.

Results The study included 29 subjects. A significant change in ICP (Δ14.1 mmHg, p < 0.01) and no significant change in PWA (Δ0.4 mmHg, p = 0.06) were found. Furthermore, a linear correlation between ICP and PWA was found in both supine and upright positions (p < 0.01).

Conclusions We found that during the positional shift from supine to upright, ICP is reduced while PWA remains unaffected. This indicates that the pressure-volume curve is shifted downward according to a hydrostatic pressure offset, while the slope of the curve does not change. In addition, the correlation between ICP and PWA in both supine and upright position validates the previous research on the matter.

How I do it: trans-cortical approach for insular diffuse glioma

Acta Neurochirurgica (2020) 162:3025–3030

The function-based resection using trans-cortical approach for removing insular diffuse glioma shares a positive benefit-to-risk ratio with a low rate of permanent morbidity.

Method The technique requires intraoperative functional brain mapping to be performed under awake condition using direct electrical stimulations at both cortical and subcortical levels to identify brain connectivity supporting neurocognition.

Conclusion The trans-cortical approach is a safe and efficient technique to remove insular diffuse glioma. Intraoperative functional brain mapping under awake condition allows preserving brain connectivity and tailoring the resection. Great care must be taken in preventing vascular damages, and particularly the lenticulostriate arteries.

Pseudarthrosis in anterior cervical discectomy and fusion with a self-locking, stand-alone cage filled with hydroxyapatite

J Neurosurg Spine 33:717–726, 2020

The goal of this study was to evaluate the incidence of pseudarthrosis after the treatment of cervical degenerative disc disease (CDDD) with anterior cervical discectomy and fusion (ACDF) in which self-locking, stand-alone intervertebral cages filled with hydroxyapatite were used.

METHODS The authors performed a retrospective cohort study of 49 patients who underwent 1- to 3-level ACDF with self-locking, stand-alone intervertebral cages without plates, with a minimum 2 years of follow-up. The following data were extracted from radiological and clinical charts: age, sex, time and type of pre- and postoperative signs and symptoms, pain status (visual analog scale [VAS]), functional status (Neck Disability Index [NDI]), history of smoking, bone quality (bone densitometry), and complications. Pseudarthrosis was diagnosed by a blinded neuroradiologist using CT scans. Clinical improvement was assessed using pre- and postoperative comparison of VAS and NDI scores. The Wilcoxon test for paired tests was used to evaluate statistical significance using a p value of < 0.05.

RESULTS Three patients (6%) developed symptomatic pseudarthrosis requiring reoperation, with only 1 patient showing clinical worsening due to pseudarthrosis, while the other 2 with pseudarthrosis had associated disc disease at an adjacent level. The rate of symptomatic pseudarthrosis according to the number of operated levels was 0% for 1 level, 8.7% (2/23 patients) for 2 levels, and 7.7% (1/13 patients) for 3 levels. The total pseudarthrosis rate (including both symptomatic and asymptomatic patients) was 16.4%. Considering the clinical outcomes, there was a significant improvement of 75.6% in neck pain and 95.7% in arm pain, as well as a 64.9% improvement in NDI scores. Complications were observed in 18.4% of patients, with adjacent-level degenerative disease being the most prevalent at 14.3%.

CONCLUSIONS ACDF with self-locking, stand-alone cages filled with a hydroxyapatite graft can be used for the surgical treatment of 1- to 3-level CDDD with clinical and radiological outcomes significantly improved after a minimum 2-year follow-up period. Comparative studies are necessary.

 

Intraoperative CT and cone-beam CT imaging for minimally invasive evacuation of spontaneous intracerebral hemorrhage

Acta Neurochirurgica (2020) 162:3167–3177

Minimally invasive surgery (MIS) for evacuation of spontaneous intracerebral hemorrhage (ICH) has shown promise but there remains a need for intraoperative performance assessment considering the wide range of evacuation effectiveness. In this feasibility study, we analyzed the benefit of intraoperative 3-dimensional imaging during navigated endoscopyassisted ICH evacuation by mechanical clot fragmentation and aspiration.

Methods 18 patients with superficial or deep supratentorial ICH underwent MIS for clot evacuation followed by intraoperative computerized tomography (iCT) or cone-beamCT (CBCT) imaging. Eligibility for MIS required (a) availability of intraoperative iCT or CBCT, (b) spontaneous lobar or deep ICH without vascular pathology, (c) a stable ICH volume (20–90 ml), (d) a reduced level of consciousness (GCS 5–14), and (e) a premorbid mRS ≤ 1. Demographic, clinical, and radiographic patient data were analyzed by two independent observers.

Results Nine female and 9 male patients with a median age of 76 years (42–85) presented with an ICH score of 3 (1–4), GCS of 10 (5–14) and ICH volume of 54 ± 26 ml. Clot fragmentation and aspiration was feasible in all cases and intraoperative imaging determined an overall evacuation rate of 80 ± 19% (residual hematoma volume: 13 ± 17 ml; p < 0.0001 vs. Pre-OP).Based on the intraoperative imaging results, 1/3rd of all patients underwent an immediate re-aspiration attempt. No patient experienced hemorrhagic complications or required conversion to open craniotomy. However, routine postoperative CT imaging revealed early hematoma re-expansion with an adjusted evacuation rate of 59 ± 30% (residual hematoma volume: 26 ± 37 ml; p < 0.001 vs. Pre-OP).

Conclusions Routine utilization of iCTor CBCT imaging in MIS for ICH permits direct surgical performance assessment and the chance for immediate re-aspiration, which may optimize targeting of an ideal residual hematoma volume and reduce secondary revision rates.

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 Glioma-Network Interface: A Review of the Relationship Between Glioma Molecular Subtype and Intratumoral Function

 

Neurosurgery 87:1078–1084, 2020

Gliomas are a major cause of morbidity. Direct cortical stimulation mapping offers the ability to identify functional areas within the broader neural network both cortically and subcortically. Since the World Health Organization (WHO) 2016 classification categorized gliomas into molecular subgroups with varied molecular signatures and clinical behavior, it is possible that gliomas may demonstrate rates of functional network integration.

We therefore retrospectively reviewed a data registry of 181 patients with dominant hemisphere frontal, parietal, insular, or temporal gliomas. Our goal was to test the hypothesis that WHO glioma histopathology and molecular subtype influences functional language or motor sites identified within the tumor.

Intratumoral function as determined by direct cortical and subcortical stimulation mapping was identified at the highest rate in isocitrate dehydrogenase mutant astrocytomas and oligodendrogliomas. Finally, we reviewed the emerging literature exploring the interface between functional neural networks and gliomas. These data shed light on glioma molecular and histological characteristics most commonly associated within intratumoral function.

Experience with awake throughout craniotomy in tumour surgery

Acta Neurochirurgica (2020) 162:3055–3065

Awake craniotomy is the standard of care in surgery of tumours located in eloquent parts of the brain. However, high variability is recorded in multiple parameters, including anaesthetic techniques, mapping paradigms and technology adjuncts. The current study is focused primarily on patients’ level of consciousness, surgical technique, and experience based on a cohort of 50 consecutive cases undergoing awake throughout craniotomy (ATC).

Methods Data was collected prospectively for 46 patients undergoing 50 operations over 14-month period, by the senior author, including demographics, extent of resection (EOR), adverse intraoperative events, surgical morbidity, surgery duration, levels of O2 saturation and brain oedema. A prospective, patient experience questionnaire was delivered to 38 patients.

Results The ATC technique was well tolerated in all patients. Once TCI stopped, all patients were immediately assessable for mapping. Despite > 75% of cases being considered inoperable/high risk, gross total resection (GTR) was achieved in 68% patients and subtotal resection in 20%. The average duration of surgery was 220 min with no episodes of hypoxia. Early and late severe deficits recorded in 12% and 2%, respectively. No stimulation-induced seizures or failed ATCs were recorded. Patient-recorded data showed absent/minimal pain during (1) clamp placement in 95.6% of patients; (2) drilling in 94.7% of patients; (3) surgery in 78.9% of patients. Post-operatively, 92.3% of patients reported willingness to repeat the ATC, if necessary.

Conclusions The current ATC paradigm allows immediate brain mapping, maximising patient comfort during selfpositioning. Despite the cohort of challenging tumour location, satisfactory EOR was achieved with acceptable morbidity and no adverse intraoperative events.

The Effect of T1-Slope in Spinal Parameters After Cervical Disc Arthroplasty

Neurosurgery 2020 DOI:10.1093/neuros/nyaa271

Although patients with cervical kyphosis are not ideal candidates for cervical disc arthroplasty (CDA), there is a paucity of data on patients with a straight or slightly lordotic neck.

OBJECTIVE: To correlate cervical lordosis, T1-slope, and clinical outcomes of CDA.

METHODS: The study retrospectively analyzed 95 patients who underwent 1-level CDA and had 2-yr follow-up. They were divided into a high T1-slope (≥28◦) group (HTSG,n=45) and a low T1-slope (<28◦) group (LTSG, n = 50). Cervical spinal alignment parameters, including T1-slope, cervical lordosis (C2-7 Cobb angle), and segmental mobility (range of motion [ROM]) at the indexed level, were compared. The clinical outcomes were also assessed.

RESULTS: The mean T1-slope was 28.1 ± 7.0◦. After CDA, the pre- and postoperative segmental motility remained similar and cervical lordosis was preserved. All the clinical outcomes improved after CDA. The HTSG were similar to the LTSG in age, sex, segmental mobility, and clinical outcomes. However, the HTSG had higher cervical lordosis than the LTSG. Furthermore, the LTSG had increased cervical lordosis (C2-7 Cobb angle), whereas the HTSG had decreased lordosis after CDA. Patients of the LTSG, who had more improvement in cervical lordosis, had a trend toward increasing segmental mobility at the index level (ROM) than the HTSG.

CONCLUSION: In this series, T1-slope correlated well with global cervical lordosis but did not affect the segmental mobility. After CDA, the changes in cervical lordosis correlated with changes in segmental mobility. Therefore, segmental lordosis should be cautiously preserved during CDA as it could determine the mobility of the disc.

Ultra-low-pressure hydrocephalic state in NPH: benefits of therapeutic siphoning with adjustable antigravity valves

Acta Neurochirurgica (2020) 162:2967–2974

Idiopathic normal-pressure hydrocephalus (NPH) is a condition of the elderly treated by ventriculoperitoneal shunt (VP) insertion. A subset of NPH patients respond only temporarily to shunt insertion despite low valve opening pressure. This study aims to describe our experience of patients who benefit from further CSF drainage by adding adjustable antigravity valves and draining CSF at ultra-low pressure.

Methods Single-centre retrospective case series of patients undergoing shunt valve revision from an adjustable differential pressure valve with fixed antigravity unit to a system incorporating an adjustable gravitational valve (Miethke proSA). Patients were screened from a database of NPH patients undergoing CSF diversion over 10 consecutive years (April 2008– April 2018). Clinical records were retrospectively reviewed for interventions and clinical outcomes.

Results Nineteen (10F:9M) patients underwent elective VP shunt revision to a system incorporating an adjustable gravitational valve. Mean age 77.1 ± 7.1 years (mean ± SD). Eleven patients (58%) showed significant improvement in walking speed following shunt revision. Fourteen patients/carers (74%) reported subjective improvements in symptoms following shunt revision.

Conclusions Patients presenting symptoms relapse following VP shunting may represent a group of patients with ultra-low pressure hydrocephalus, for whom further CSF drainage may lead to an improvement in symptoms. These cases may benefit from shunt revision with an adjustable gravitational valve, adjustment of which can lead to controlled siphoning of CSF and drain CSF despite ultra-low CSF pressure.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Treatment of Pediatric Hydrocephalus: Update of the 2014 Guidelines

Neurosurgery 87:1071–1075, 2020

The Congress of Neurological Surgeons reviews its guidelines according to the Institute of Medicine’s recommended best practice of reviewing guidelines every 5 yrs. The authors performed a planned 5-yr review of the medical literature used to develop the “Pediatric hydrocephalus: systematic literature review and evidence-based guidelines” and determined the need for an update to the original guideline based on new available evidence.

OBJECTIVE: To perform an update to include the current medical literature for the “Pediatric hydrocephalus: systematic literature review and evidence-based guidelines”, originally published in 2014.

METHODS: The Guidelines Task Force used the search terms and strategies consistent with the original guidelines to search PubMed and Cochrane Central for relevant literature published between March 2012 and November 2019. The same inclusion/exclusion criteria were also used to screen abstracts and to perform the full-text review. Full text articles were then reviewed and when appropriate, included as evidence and recommendations were added or changed accordingly.

RESULTS: A total of 41 studies yielded by the updated search met inclusion criteria and were included in this update.

CONCLUSION: New literature resulting from the update yielded a new recommendation in Part 2, which states that neuro-endoscopic lavage is a feasible and safe option for the removal of intraventricular clots and may lower the rate of shunt placement (Level III). Additionally a recommendation in part 7 of the guideline now states that antibiotic- impregnated shunt tubing reduces the risk of shunt infection compared with conventional silicone hardware and should be used for children who require placement of a shunt (Level I). <https://www.cns.org/guidelines/browse-guidelines-detail/pediatric- hydrocephalus-guideline>

Are There Any Risk Factors Associated with the Presence of Cauda Equina Syndrome in Symptomatic Lumbar Disk Herniation?

World Neurosurg. (2020).https://doi.org/10.1016/j.wneu.2020.05.260

Risk factors for developing cauda equina syndrome (CES) caused by lumbar disk herniation (LDH) remain controversial and have not been established yet. The aim of the study was to investigate whether there is a relationship among age, sex, body mass index (BMI), or the degree of spinal canal compromise and the presence of CES in patients undergoing lumbar microdiskectomy.

METHODS: Between 2015 and 2019, 506 patients who had an operation for LDH compressing the dural sac were prospectively identified. The “prolapse-to-canal ratio” (PCR) was calculated as a proportion of the cross-sectional area of the disk prolapse compared with the total crosssectional area of the spinal canal.

RESULTS: In total, 35 CES (6.9%) patients were identified. Multivariate logistic regression, adjusted for age, gender, BMI, and PCR, shows that only PCR was associated with the presence of CES (P < 0.001, area under the curve 0.7431). BMI was not associated with an increased risk of CES.

CONCLUSIONS: This study demonstrates a significant correlation between the size of LDH relative to size of the spinal canal and the presence of CES. A finding of LDH causing >60% obstruction of the spinal canal should be considered a red flag, and such patients need to be watched more closely.

Surgical management for large vestibular schwannomas: a systematic review, meta-analysis, and consensus statement on behalf of the EANS skull base section

Acta Neurochir (2020) 162:2595–2617

The optimal management of large vestibular schwannomas continues to be debated. We constituted a task force comprising the members of the EANS skull base committee along with international experts to derive recommendations for the management of this problem from a European perspective.

Material and methods A systematic review of MEDLINE database, in compliance with the PRISMA guidelines, was performed. A subgroup analysis screening all surgical series published within the last 20 years (January 2000 to March 2020) was performed. Weighted summary rates for tumor resection, oncological control, and facial nerve preservation were determined using metaanalysis models. This data along with contemporary practice patterns were discussed within the task force to generate consensual recommendations regarding preoperative evaluations, optimal surgical strategy, and follow-up management.

Results Tumor classification grades should be systematically used in the perioperative management of patients, with large vestibular schwannomas (VS) defined as > 30 mm in the largest extrameatal diameter. Grading scales for pre- and postoperative hearing (AAO-HNS or GR) and facial nerve function (HB) are to be used for reporting functional outcome. There is a lack of consensus to support the superiority of any surgical strategy with respect to extent of resection and use of adjuvant radiosurgery. Intraoperative neuromonitoring needs to be routinely used to preserve neural function. Recommendations for postoperative clinico-radiological evaluations have been elucidated based on the surgical strategy employed.

Conclusion The main goal of management of large vestibular schwannomas should focus on maintaining/improving quality of life (QoL), making every attempt at facial/cochlear nerve functional preservation while ensuring optimal oncological control, thereby allowing to meet patient expectations. Despite the fact that this analysis yielded only a few Class B evidences and mostly expert opinions, it will guide practitioners to manage these patients and form the basis for future clinical trials.

Keywords

A high-definition 3D exoscope as an alternative to the operating microscope in spinal microsurgery

J Neurosurg Spine 33:705–714, 2020

Since the 1970s, the operating microscope (OM) has been a standard for visualization and illumination of the surgical field in spinal microsurgery. However, due to its limitations (e.g., size, costliness, and the limited movability of the binocular lenses, in addition to discomfort experienced by surgeons due to the posture required), there are efforts to replace the OM with exoscopic video telescopes. The authors evaluated the feasibility of a new 3D exoscope as an alternative to the OM in spine surgeries.

METHODS Patients with degenerative pathologies scheduled for single-level lumbar or cervical spinal surgery with use of a high-definition 3D exoscope were enrolled in a prospective cohort study between January 2019 and September 2019. Age-, sex-, body mass index–, and procedure-matched patients surgically treated with the assistance of the OM served as the control group. Operative baseline and postoperative outcome parameters were assessed. Periprocedural handling, visualization, and illumination by the exoscope, as well as surgeons’ comfort level in terms of posture, were scored using a questionnaire.

RESULTS A 3D exoscope was used in 40 patients undergoing lumbar posterior decompression (LPD) and 20 patients undergoing anterior cervical discectomy and fusion (ACDF); an equal number of controls in whom an OM was used were studied. Compared with controls, there were no significant differences for mean operative time (ACDF: 132 vs 116 minutes; LPD: 112 vs 113 minutes) and blood loss (ACDF: 97 vs 93 ml; LPD: 109 vs 55 ml) as well as postoperative improvement of symptoms (ACDF/Neck Disability Index: p = 0.43; LPD/Oswestry Disability Index: p = 0.76). No intraoperative complications occurred in either group. According to the attending surgeon, the intraoperative handling of instruments was rated to be comparable to that of the OM, while the comfort level of the surgeon’s posture intraoperatively (especially during “undercutting” procedures) was rated as superior. In cases of ACDF procedures and long approaches, depth perception, image quality, and illumination were rated as inferior when compared with the OM. By contrast, for operating room nursing staff participating in 3D exoscope procedures, the visualization of intraoperative process flow and surgical situs was rated to be superior to the OM, especially for ACDF procedures.

CONCLUSIONS A 3D exoscope seems to be a safe alternative for common spinal procedures with the unique advantage of excellent comfort for the surgical team, but the drawback is the still slightly inferior visualization/illumination quality compared with the OM.

Crossing the Cervicothoracic Junction During Posterior Cervical Fusion for Myelopathy Is AssociatedWith Superior Radiographic Parameters But Similar Clinical Outcomes

Neurosurgery 2020 DOI:10.1093/neuros/nyaa241

For laminectomy and posterior spinal fusion (LPSF) surgery for cervical spondyloticmyelopathy (CSM), the evidence is unclear as to whether fusions should cross the cervicothoracic junction (CTJ). OBJECTIVE: To compare LPSF outcomes between those with and without lower instrumented vertebrae (LIV) crossing the CTJ.

METHODS: A consecutive series of adults undergoing LPSF for CSM from 2012 to 2018 with a minimum of 12-mo follow-up were identified. LPSF with subaxial upper instrumented vertebrae and LIV between C6 and T2 were included. Clinical and radiographic outcomes were compared.

RESULTS: A total of 79 patients were included: 46 crossed the CTJ (crossed-CTJ) and 33 did not. The mean follow-up was 22.2 mo (minimum: 12 mo). Crossed-CTJ had higher preoperative C2-7 sagittal vertical axis (cSVA) (33.3 ± 16.0 vs 23.8 ± 12.4 mm, P = .01) but similar preoperative cervical lordosis (CL) and CL minus T1-slope (CL minus T1-slope) (P > .05, both comparisons). The overall reoperation rate was 3.8% (crossed-CTJ: 2.2% vs notcrossed: 6.1%, P=.37). In adjusted analyses, crossed-CTJ was associated with superior cSVA (β = –9.7; P = .002), CL (β = 6.2; P = .04), and CL minus T1-slope (β = –6.6; P = .04), but longer operative times (β = 46.3; P = .001). Crossed- and not-crossed CTJ achieved similar postoperative patient-reported outcomes [Visual Analog Scale (VAS) neck pain, VAS arm pain, Nurick Grade, Modified Japanese Orthopedic Association Scale, Neck Disability Index, and EuroQol-5D] in adjusted multivariable analyses (adjusted P > .05). For the entire cohort, higher postoperative CL was associated with lower postoperative arm pain (adjusted Pearson’s r –0.1, P=.02). No postoperative cervical radiographic parameters were associated with neck pain (P > .05).

CONCLUSION: Subaxial LPSF for CSM that crossed the CTJ were associated with superior radiographic outcomes for cSVA, CL, and CL minus T1-slope, but longer operative times. There were no differences in neck pain or reoperation rate.

 

Intracranial Tubular Retractor Systems: A Comparison and Review of the Literature of the BrainPath, Vycor, and METRx Tubular Retractors in the Management of Deep Brain Lesions

World Neurosurg. (2020) 143:134-146

In neurosurgery, parenchymal injury resulting from focal exertion of pressure on retracted tissue is a common complication associated with the use of plate and self-sustaining retractors to access deep intraparenchymal lesions. Tubular retractors, including Vycor, BrainPath, and METRx, were developed to reduce retraction injuries via radial dispersion of force.

Our study seeks to compare these retraction systems and assess their respective indications, benefits, and associated complications. A systematic review of PubMed MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, and Cochrane Database of Systematic Reviews was performed. Twenty-nine articles (n [ 289 patients) for BrainPath, 12 articles (n [ 106 patients) for Vycor, and 3 articles for METRx (n [ 31 patients) met the inclusion criteria.

This report is the first formal comparison of the BrainPath, Vycor, and METRx tubular retraction systems. We found that all 3 retractors were effective in accessing intraparenchymal lesions. Although we found that the retractor systems were used more commonly in different locations and for different diseases, there was no significant difference in complications or mortality among the 3 retractors.