Volume 37 · Issue 04 · 2021

Suture technique is one of the important techniques in neurosurgery. With the popularization of the concept of microscopic neurosurgery and the continuous expansion of the application field of neurosurgical suture, in addition to traditional tissue suture, the concepts of vascular anastomosis, nerve anastomosis and skull base reconstruction have also been introduced. At the same time, with the advancement of material science, a variety of new suture materials have emerged, which have a positive impact on the development of neurosurgery. Neurosurgery is relatively complicated, and different tissues and different suture methods have different requirements for suture techniques and suture materials. Therefore, it is particularly important to master the suture technology and select suture materials correctly.

To explore the clinical characteristics, treatment strategies and short-term outcomes of multiple intracranial aneurysms (MIA) and single intracranial aneurysms (SIA).

A retrospective study was conducted on 1 082 patients with MIA or SIA who were diagnosed and treated at the neurosurgery departments of 13 medical centers including Tianjin Medical University General Hospital from January 2017 to December 2018. According to the number of aneurysms, the patients were divided into MIA group [118 cases (269 aneurysms)] and SIA group (964 cases). We observed the general characteristics of aneurysms in the 2 groups, collected and compared the clinical data of the 2 groups of patients. The modified Rankin scale (mRS) score of 0-2 at discharge was defined as a good short-term outcome, and 3-6 points as a poor short-term outcome. The independent variables with P<0.5 in the univariate analysis and the clinically concerned independent variables were included in the multivariate binary logistic regression model, and the clinical data of the MIA group and the SIA group were further matched with 1 ∶1 propensity scores to compare the treatment methods, length of stay at hospital and short-term outcomes of the 2 groups of patients after matching.

The diameter of the aneurysm in the MIA group was 5.1±3.5 mm (0.2-25.0 mm), and that in the SIA group was 5.7±3.8 mm (0.9-35.0 mm). There was no difference between the 2 groups in gender, history of diabetes, history of smoking, history of alcohol drinking, grade of essential hypertension, CT Fisher grade, Hunt-Hess grade, Glasgow coma score (GCS), or World Federation of Neurological surgeons (WFNS) scale scores (all P>0.05). Compared with the SIA group, the patient′s age in the MIA group was older, and the difference was statistically significant [(62.4±11.7)years old vs. (58.8±11.6)years old,P=0.002]. The age, gender, history of diabetes, history of alcohol drinking, history of smoking, grade of essential hypertension, and CT Fisher grade at hospital admission were included in the multivariate binary logistic regression model analysis. The results showed that the patients in the MIA group was older, while the proportion of patients with hypertension (Grade 3) was higher in the SIA group, and the differences were statistically significant (allP<0.05). Through propensity score matching, no pair was accurately matched, there were 118 pairs of fuzzy matching, and a total of 118 pairs were successfully matched. After matching, there was no significant difference in the length of hospital stay between the 2 groups of patients (P>0.05). Compared with the SIA group, the short-term outcome in the MIA group was better (P=0.008). The difference in treatment methods between the 2 groups was also statistically significant (P=0.042), and the more endovascular treatment was reported in the MIA group.

Compared with MIA patients, SIA patients are more likely to have Grade 3 essential hypertension, while MIA patients are older, more inclined to undergo endovascular treatment and associated with better short-term outcomes.

To investigate the application value of temporary occlusion technique in keyhole microsurgery for ruptured posterior communicating artery (PCoA) aneurysms.

The clinical data of 20 patients with ruptured PCoA aneurysms (including 7 patients with 7 unruptured aneurysms at other sites) who underwent microsurgery via keyhole approaches at Neurosurgery Department of the Second Affiliated Hospital of Soochow University from January 2016 to December 2018 were analyzed retrospectively. Operations via supraorbital keyhole approach were performed in 3 cases and those via pterional keyhole approach in 17 cases. In 15 cases, temporary occlusion was conducted in proximal and distal segments of internal carotid artery (ICA) to the aneurysm, out of whom 12 underwent simultaneous occlusion in PCoA. In 3 cases, we temporarily blocked the proximal segment of ICA to the aneurysm and partially clipped the aneurysm dome; 2 cases only underwent partial clipping of the aneurysm dome. The operation status was documented and clinical outcomes were followed up.

The 27 aneurysms of 20 patients were all successfully clipped in one stage. Among the 20 ruptured PCoA aneurysms, 18 had no bleeding during the operation, and 2 had a small amount of bleeding from the aneurysm during the replacement of the permanent clip, which did not affect the operation. Intraoperative somatosensory evoked potential monitoring showed that the patients did not develop obvious ischemic events. After the aneurysm was clipped, indocyanine green fluorescence angiography showed that the parent arteries were unobstructed, and the aneurysms were obliterated completely. Digital subtraction angiography examinations of all patients within 1 week after surgery showed that there was no residual aneurysm and the parent arteries were patent. The postoperative follow-up lasted for 13-48 (29.4±9.9) months, and there were no newly-developed symptoms of neurological deficits. No recurrence of aneurysm was identified by imaging follow-up.

Temporary occlusion technique in microsurgery of ruptured PCoA aneurysms via keyhole approaches can effectively help reduce the incidence of premature rupture of aneurysms, facilitate complete clipping of aneurysms and preservation of parent arteries.

To evaluate the safety and efficacy of the prophylactic administration of tirofiban in the treatment of unruptured intracranial aneurysms with flow diverter (FD).

A retrospective analysis was conducted on the clinical data of 256 patients harboring 337 unruptured intracranial aneurysms who were treated with FD at Department of Cerebrovascular Intervention, Zhengzhou University People's Hospital from February 2015 to October 2019. Clopidogrel and aspirin were administrated to all 256 patients before procedure, of whom 170 (66.4%) patients with high risk of thrombosis received the intravenous tirofiban administration during or immediately after FD deployment (tirofiban group for short), while 86 (33.6%) patients only received the dual antiplatelet therapy (conventional group for short). The baseline characteristics, surgical outcomes, postprocedural complications and mRS (modified Rankin scale) scores were compared between the two groups.

There were no significant differences in gender, age, maximum diameter of aneurysm, location of aneurysm, type of aneurysm and coils usage between the two groups (P>0.05). However, there was statistically significant difference in the type of FD application between the two groups (P<0.001). FDs were all successfully deployed in 337 aneurysms of 256 patients, with the surgical success rate of 100%. The FDs covered the aneurysm neck completely with good apposition to the vessel wall and parent artery patency. Postprocedural thromboembolic events occurred in 8 (3.1%) patients, 2 of them (2/170, 1.2%) were in the tirofiban group and 6 (6/86, 7.0%) were in the conventional group. The difference was statistically significant (P<0.05). Postprocedural hemorrhagic events occurred in 3 (1.2%) patients, 1 of them (1/170, 0.6%) was in the tirofiban group and 2 (2/86, 2.3%) were in the conventional group. There was no statistical significance (P>0.05). No significant difference was noted in mRS score either at discharge or at follow-up between two groups (P>0.05).

The intraprocedural administration of tirofiban combined with oral dual antiplatelet agents seems to be efficient in prevention of thromboembolic events in the treatment of unruptured intracranial aneurysms with FD without increasing hemorrhagic risks.

To preliminarily discuss the single-center experience of using throm-boelastography (TEG) to guide perioperative antiplatelet therapy in patients undergoing stent-assisted coiling for the treatment of intracranial aneurysms.

A retrospective analysis was conducted on the clinical data of 240 patients with intracranial aneurysms who underwent stent-assisted coiling at Neurosurgery Department, the First Affiliated Hospital of Chongqing Medical University from January 2013 to December 2019. Patients were divided into standard group (58 cases) and adjustment group (182 cases) according to whether TEG was performed. Patients in the standard group were treated with aspirin 100 mg and clopidogrel 75 mg after surgery. Patients in the adjustment group were treated with an antiplatelet regimen adjusted based on the TEG parameters. We analyzed and compared the incidence of bleeding or ischemic events during antiplatelet therapy, the score of GOS (Glasgow Outcome Scale) at discharge between the 2 groups. The difference in TEG parameters between patients who developed ischemia and those who did not in the adjustment group was studied as well.

The age, gender, Hunt-Hess grades at admission, history of smoking, history of alcohol drinking, diabetes, history of hypertension, operation time, whether the aneurysm was ruptured, the location and size of aneurysm, whether there were multiple aneurysms, or the type of stent implanted was not statistically significant between the 2 groups (all P>0.05). The incidence of bleeding events in the adjustment group was 0.5% (1/182), which was lower than that (6.9%, 4/58) in the standard group (P=0.013). The incidence of ischemic events in the adjustment group was 23.6% (43/182), which was not significantly different from that (20.7%, 12/58) in the standard group (P>0.05). The GOS scores in the 2 groups were both grade V at discharge. In the adjustment group, there was no statistically significant difference in the arachidonic acid inhibition rate, adenosine diphosphate (ADP) inhibition rate, or maximal concentration of ADP distribution between patients who developed ischemia and those who did not (allP>0.05).

Preliminary observations have suggested that TEG parameters may be able to help identify patients with a relatively higher risk of bleeding after stent-assisted coiling of intracranial aneurysms, which thus could guide antiplatelet therapy individually.

To investigate the clinical application value of whole-brain CT perfusion (CTP) imaging in patients with aneurysmal subarachnoid hemorrhage (aSAH).

A retrospective analysis was performed on the clinical data of 237 aSAH patients admitted to Department of Neurosurgery, the First Affiliated Hospital of Wannan Medical College from June 2016 to January 2019. All patients underwent regular CT, CTP and derived CT angiography (CTA) scan within 24 h with quantitative and qualitative analyses. Patients were divided into two groups (DCI group and non-DCI group) according to whether delayed cerebral ischemia (DCI) occurred. The factors determined to be significant in univariate analysis were identified for further multivariate logistic regression analysis. Prediction model was established based on the analysis results, and the diagnostic efficacy was evaluated by receiver operator characteristic curve (ROC) analysis.

A total of 248 aneurysms were identified in 237 patients, 74 of whom (31.2%) developed DCI during hospitalization. CTP quantitative analyses showed that there were significant differences in all perfusion parameters between the two groups (all P<0.05). CTP qualitative analyses showed that the incidence rate of DCI in patients with normal perfusion, localized hypoperfusion, and diffused hypoperfusion maps were 6.8% (4/59), 28.0% (14/50), and 43.8% (56/128), respectively. Univariate analyses showed that there were significant differences in age, Glasgow Coma Scale (GCS) score, Hunt-Hess grade, Fisher grade, qualitative and quantitative CTP parameters (allP<0.05). Further multivariate logistic regression analysis showed that GCS, Fisher grade, qualitative CTP analysis, CBF (cerebral blood flow) and CBV (cerebral blood volume) were all significant independent predictors of DCI (allP<0.05). The area under the ROC curve of the logistic regression prediction model based on the above parameters was 0.832 with a sensitivity of 81.1% and a specificity of 72.4%.

Whole-brain CTP model can be used to quantitatively and qualitatively assess the whole cerebral perfusion status and predict the risk of DCI occurrence.

To preliminary evaluate the safety and efficacy of bilateral deep brain stimulation (DBS) of subthalamic nucleus (STN) for the treatment of primary cervical dystonia (CD) and to preliminarily investigate its efficacy for different subtypes of CD.

The clinical data of 9 patients with primary CD treated with bilateral STN-DBS at Neurosurgery Department of Chinese PLA General Hospital-Sixth Medical Center from September 2014 to April 2019 were retrospectively analyzed. The severity, disability and pain were assessed with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) before and at 1, 3, 6 and 12 months after the stimulator was turned on. The improvement rate of TWSTRS scores was calculated, and the linear mixed model was used to compare the difference before and after operation to evaluate the effect of treatment and preliminarily explore the improvement for different subtypes of CD. Stimulation-related adverse events were documented to evaluate the safety.

9 patients underwent bilateral STN-DBS successfully. Post-operative MRI scan showed that the electrodes were ideally located at or close to the planned targets. No infection, anaphylaxis or rejection reaction was observed. Eight patients experienced dyskinesia, 1 patient experienced manic symptoms and sleep disturbance, and 2 patients experienced mild weakness with poor coordination in unilateral hand. All of those were alleviated by programming. The median follow-up time (range) for the 9 patients was 37 (12-62) months. The median (P₂₅, P₇₅) improvement rates of total TWSTRS scores of 9 patients at 1, 3, 6 and 12 months after the stimulator was turned on were 15.7% (11.6%, 37.2%), 53.5% (42.8%, 71.8%), 87.5% (53.2%, 100.0%) and 100.0% (84.1%, 100.0%) respectively. With the prolonging of follow-up time, the scores of total TWSTRS, severity, disability and pain showed a trend of gradual decrease (all P<0.05). At the 12-month follow-up, the improvement rate of TWSTRS score was 100.0% in 4 patients with phasic-type CD and 94.2% (72.3%, 100.0%) in 5 patients with tonic-type CD.

The preliminary study has suggested that bilateral STN-DBS is safe and effective in the treatment of primary CD, and both phasic and tonic-type CD patients can benefit from it.

To preliminarily observe the mechanical stimulation effect(" honeymoon period" effect) on the later therapeutic effect of vagus nerve stimulation (VNS) in children with drug-resistant epilepsy.

The clinical data of 81 children with drug-resistant epilepsy who underwent VNS at Department of Neurosurgery, Children′s Hospital Affiliated to Capital Institute of Pediatrics from October 2016 to December 2019 were retrospectively analyzed. The MSE (mechanical stimulation effect) was defined as the decrease of epileptic seizure frequency ≥ 50% in pediatric patients with merely mechanical stimulation and no electrical stimulation when the device was not turned on. All children in this series were treated with VNS and followed up for over 1 year (≥ 2 times). The content of the follow-up mainly included the control of epileptic seizures, presence or absence of MSE and their durations. The effect of epileptic seizure control was evaluated based on the McHugh scale. Grades Ⅰ and Ⅱ (seizure frequency reduction ≥50%) were considered as effective, and grades Ⅲ and Ⅴ (seizure frequency reduction <50%) as ineffective. We then analyzed the relationship of age, gender, etiology and the presence or absence of MSE to the therapeutic effect of VNS. Among the patients with " honeymoon period" effect, the duration of MSE was compared between those who demonstrated effectiveness and those who did not.

All 81 patients underwent successful operations and were followed up for a median (range) of 27.6 (12-47) months. At the last follow-up, the McHugh grades of 81 patients were grade Ⅰ in 41 cases, grade Ⅱ in 15, grade Ⅲ in 9, and grade Ⅳ or Ⅴ in 16. The MSE was observed in 22 children, out of whom 16 reported grade Ⅰ or Ⅱ and 6 cases reported grade Ⅲ or Ⅳ. The median (range) of MSE duration was 23 (10-115) days. There was no statistical difference in genders, ages, course, etiology and the presence or absence of MSE between patients with different McHugh grade(all P>0.05). The effective rate of patients with MSE was 72.7% (16/22), while the effective rate of those without MSE was 67.8% (40/59). There was no significant difference between the two groups (P>0.05). Among the 22 patients with MSE, the duration of MSE was longer in those who reported effectiveness of treatment than in those who did not, and the difference was statistically significant [the median(range) of duration were 28 (11-115) d and 13 (10-15) d, respectively,U=9.000, P<0.01].

Preliminary studies have demonstrated no relationship of MSE in children with drug-resistant epilepsy after VNS to its therapeutic effect. However, MSE seems to last longer in patients with effective treatment among those with MSE.

To evaluate the clinical effect and safety of domestic multi-channel auditory brainstem implant (ABI) device for auditory rehabilitation in Chinese neurofibromatosis type 2 (NF2) patients.

We prospectively enrolled NF2 patients with unilateral or bilateral hearing impairment who needed resection of vestibular schwannoma and were admitted to Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University from December 2015 to February 2016. The surgery was performed via the suboccipital retrosigmoid approach. The ABI electrode was implanted after tumor removal. During the operation, the electrically evoked auditory brainstem response (EABR) was recorded to assist in localizing the cochlear nucleus to ensure that the electrodes were attached to the surface of the cochlear nucleus. The lateral recess was packed with autologous fat to fix the ABI stimulation electrodes. Long-term clinical follow-up was conducted to observe the efficacy and adverse events of the application of ABI.

A total of 5 NF2 patients with hearing impairment or loss were included in this study. All the vestibular schwannomas on the surgical side were completely removed. During the operation, all patients were successfully implanted with ABI equipment and EABR waveforms were successfully recorded through electrical stimulation. Device programming and speech training were carried out at 2 to 4 weeks after the operation, and 5 patients could perceive different degrees of environmental sound in a quiet environment. The follow-up time was 57 to 60 months, and all patients had no complications related to craniotomy or device implantation. In 2 patients with bilateral hearing loss before operation, the ABI was used continuously for 54 and 27 months after the device was turned on. The average recognition rates of postoperative environmental sounds were 62.5% and 49.6%, respectively. The average recognition rates of monosyllable and two-syllable words in a closed environment were 42.5% and 33.8% respectively, and the patients had good verbal communication skills with the assistance of lip-reading. Another patient tried device programming and speech training for 2 months due to complete loss of hearing in the contralateral ear, and the device was still not turned on in another 2 patients at the last follow-up because their contralateral hearing remained.

Preliminary studies have shown that the application of domestic multi-channel ABI is a safe and effective method of hearing reconstruction, and good intraoperative localizing of the cochlear nucleus and postoperative speech training are the keys to improving the efficacy.

To investigate the effect of preoperative administration of antiepileptic drugs (AEDs) on the cognitive functions of glioma patients.

A total of 35 patients with gliomas were admitted to Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University from July 2019 to January 2020 and their clinical data were retrospectively analyzed. According to epilepsy-related history and treatment, patients were divided into the group with seizure history and AED treatment (11 cases), group with untreated seizures (7 cases), and seizure-free group (17 cases). Additional 19 healthy adults were recruited as the control group. General clinical information, epilepsy history and AED treatment information of all patients were collected. Assessment of the patients’ cognitive functions in multiple domains were completed before surgery, and z-scores of each domain were compared between groups.

Differences in age and years of education among 3 groups of patients and the healthy control group, as well as differences in location of the lesion, WHO grade and IDH1 mutation status among 3 groups of patients, were not statistically significant (all P>0.05). However, there were significant differences in the score of executive function among the 4 groups (F=3.969, P=0.020), which was lower in the group with seizure history and AED treatment than in the group with untreated seizure, seizure-free group and healthy control group. The z-scores in those 4 groups were -0.83±0.85, 0.07±0.18, 0.06±0.44 and 0.11±0.35 respectively, and the differences between any 2 groups were significant (all P<0.05). There was no significant difference in the score of memory among 4 groups (F=2.792, P=0.050). However, the score of memory in the group with seizure history and AED treatment was lower than that in the seizure-free group. The z-scores were -0.67±0.89 and 0.06±0.68 respectively, and the difference was statistically significant (P=0.047). There was no significant difference in the score of memory between any other 2 groups (all P>0.05). In addition, there was no statistically significant difference in other domains among all groups (allP>0.05).

Preoperative administration of AEDs in glioma patients could not only lead to executive function impairment, but also may be related to damage in memory. Therefore, for some glioma patients who have a relatively light burden of epilepsy and could undergo tumor treatment in time, the risks and benefits of preoperative AEDs treatment need to be carefully evaluated.

To investigate the efficacy and safety of hybrid surgery in the treatment f chronic internal carotid artery occlusion (CICAO).

A retrospective study was conducted on the clinical data of 66 patients with CICAO who underwent hybrid surgery at Department of Neurosurgery, General Hospital of Northern Theater Command from August 2017 to August 2020. All patients were examined by digital subtraction angiography (DSA) to confirm that there was no stump at the beginning of the internal carotid artery or a nontaper change in the stump. The patient's vascular recanalization and perioperative complications were documented. We followed up the patient's clinical and imaging changes.

Of the 66 patients, 58 (87.9%) achieved successful recanalization. The incidence of perioperative complications was 6.1% (4/66). Among them, 2 cases developed hyperperfusion syndrome, 2 cases reported swelling in the neck incision and compression of the trachea, and all those recovered later. Follow-up duration was 6 to 33 months post surgery. Among 58 patients with successful recanalization, 34 patients had improved clinical symptoms and 24 patients had stable conditions. Among the 8 patients with failed recanalization, 6 had stable symptoms; 2 had worsened symptoms and had newly-developed cerebral infarction; out of 47 patients with successful recanalization undergoing DSA or CT angiography, 3 cases (with the original occluded sites located between the beginning to the clinoid segment of ICA or above) had reocclusion and 4 cases had restenosis, while none of them had obvious symptoms.

Hybrid surgery is an effective and safe method for nontaper or nonstump CICAO with relatively high recanalization rate, fewer perioperative complications and low re-occlusion rate, which can reduce the risk of ischemic stroke and improve the prognosis of patients.

To investigate the influence of advanced age on the clinical outcomes of patients undergoing mechanical thrombectomy for anterior circulation acute ischemic stroke (AIS).

Clinical data of 86 patients who underwent mechanical thrombectomy for anterior circulation AIS at Department of Neurosurgery, Beijing Hospital, National Center of Gerontology between January 2017 and November 2019 were retrospectively analyzed. Clinical characteristics and functional outcomes were compared between patients of advanced age (≥80 years old, 33 cases) and those of non-advanced age (<80 years old, 53 cases). Risk factors including advanced age for unfavorable functional outcomes (modified Rankin Scale score 3-6) at 90 days were assessed by using univariate analysis and multivariate logistic regression analysis in all patients.

Compared with non-advanced age patients, women, coronary atherosclerotic heart disease as well as atrial fibrillation were more often observed and the National Institutes of Health stroke scale (NIHSS) score at clinical visits was higher in the advanced-age group, while smoking and intra-procedural use of tirofiban were less often in the advanced-age group (both P<0.05). There were no significant differences in the Alberta Stroke Program Early Computed Tomography Score (ASPECTS), proportions of successful revascularization [modified thrombolysis in cerebral infarction (mTICI) score: 2b/3], or symptomatic intracranial hemorrhage between the 2 groups(allP>0.05). Unfavorable functional outcome was more often observed in patients of advanced age than in those of non-advanced age [63.6% (21/33)vs. 35.8% (19/53), P=0.012]. Univariate analysis revealed that proportions of advanced age, combined coronary atherosclerotic heart disease, NIHSS score on admission, time from symptom onset to femoral artery puncture, mechanical suction thrombectomy, successful revascularization, complete revascularization and symptomatic intracranial hemorrhage may be influencing factors of unfavorable functional outcomes (all P<0.05). Multivariate logistic regression analysis showed that higher baseline NIHSS at clinical visits (OR=0.846, 95%CI: 0.764-0.937, P=0.001) and unsuccessful revascularization (OR=0.130, 95%CI: 0.022-0.764, P=0.024) were independent risk factors for unfavorable functional outcomes in all patients, whereas advanced age was not. Among patients of advanced age, favorable functional outcomes were obtained in 44.4% (12/27) of those who achieved successful revascularization and in none (0/6) of those without successful revascularization.

Advanced age per se is not an independent risk factor for unfavorable functional outcomes after mechanical thrombectomy in patients with anterior circulation AIS. Favorable outcome could also be obtained in patients of advanced age if successful revascularization can be achieved.

To screen and identify CD98 light chain L-type amino acid transporter 1(LAT1) as a new glioma stem cell marker.

The flow cytometric single-color labeling method was used to detect the expression of CD98 heavy chain protein CD98hc, CD98 light chain protein LAT1 and expression of CD133 in U87 and U251 glioma cells to select possible and potential stem cell markers in glioma cells. LAT1⁺ and LAT1^- glioma cells were sorted by flow cytometry. Cellular immunofluorescence, sphere-formation assay, and in vitro limiting dilution assay were used to identify cell stemness. Differentiated glioma stem cells were cultured, and the expressions of β-tubulin Ⅲ, GFAP, and LAT1 were detected by Western blot. By constructing a nude mouse subcutaneous tumor model, we observed the tumor formation of LAT1 ⁺ and LAT1^- glioma cells under the skin of nude mice (LAT1⁺ group and LAT1^- group respectively).

Flow cytometry results showed that the positive rate of LAT1 (SLC7A5) in U87 cells was (1.99±0.18)%, the positive rate of CD133 in U87 cells was (2.18±0.29)%; the positive rate of LAT1 (SLC7A5) in U251 cells was (6.24±0.69)%, and the positive rate of CD133 in U251 cells was (4.79±0.64)%. Immunofluorescence detection results showed that the positive expression rates of Sox2, Olig2 and CD133 in LAT1⁺ -U251 and LAT1⁺ -U87 cells were higher; the positive expression rates of Sox2, Olig2 and CD133 in LAT1^--U251 and LAT1^--U87 cells were all lower. The sphere-formation assay and the limiting dilution assay showed that the sphere-formation rate of LAT1⁺ -U251 cells was better than that of LAT1⁺ -U87 cells (P=0.005); LAT1^--U251 and LAT1^--U87 cells did not form spheroids. Western blotting results showed that LAT1^--U251 cells had low expression of β-tubulin Ⅲ and GFAP when they were undifferentiated and cultured without induction; LAT1 ⁺ -U251 cells had low expression of β-tubulin Ⅲ and GFAP before differentiation, but after induced differentiation the expression of β-tubulin Ⅲ and GFAP increased significantly (all P<0.05), and the expression of LAT1 decreased significantly (P=0.007). The results of the nude mouse tumorigenesis model showed that the tumor volume of the LAT1⁺ group was larger than that of the LAT1^- group at 21 d and 28 d, and the differences were statistically significant (all P<0.05); at 28 d, the tumor weight in the LAT1⁺ group was greater than that of LAT1^- group, and the difference in tumor weight between the two groups was statistically significant (P=0.007).

CD98 light chain protein LAT1 is a potential glioma stem cell marker.

To explore the value of telomerase reverse transcriptase (TERT) promoter mutations in the diagnosis of molecular typing in gliomas by using whole exome sequencing technology.

A retrospective study was conducted on 135 patients with gliomas who were surgically treated and pathologically confirmed between March 2016 and October 2018 at Department of Neurosurgery, Qilu Hospital of Shandong University. Molecular characterization of gliomas was detected by whole exome sequencing. The relationship between TERT promoter mutations and other pathological characteristics was determined to explore the value of TERT promoter mutations in the diagnosis of molecular typing in gliomas.

Among 135 patients with gliomas, TERT promoter mutations were detected in 35 cases (25.9%). TERT promoter mutations were associated with 1p/19q-codeletion (χ²=14.190, P<0.001) rather thanIDH mutations (χ²=0.827, P=0.363). The frequency of TERT promoter mutations in the "astrocytoma-mut" group (including WHO grade Ⅱ, Ⅲ astrocytomas, IDH-mutant and WHO grade Ⅳ glioblastoma, IDH-mutant) was lower than that in the "oligodendroglioma" group (including WHO grade Ⅱ, Ⅲ oligodendrogliomas, IDH-mutant and 1p/19q-codeleted) as well as that in "glioblastoma-wt" group (including WHO Ⅳ glioblastoma, IDH-wildtype, giant cell glioblastoma, IDH-wildtype and gliosarcoma, IDH-wildtype) (both P<0.001). There was no significant difference in the frequency ofTERT promoter mutations between the "oligodendrogliom" group and "glioblastoma-wt" group ( P>0.05).TERT promoter mutation and IDH mutation were not present in WHO Ⅱ-Ⅲ astrocytoma patients simultaneously.

The TERT promoter mutation is mainly present in oligodendroglioma, IDH-mutant and 1p/19q-codeleted and glioblastoma, IDH-wildtype. The coexistence of TERT promoter mutation with IDH mutations may exclude the diagnosis of WHO Ⅱ or Ⅲ astrocytoma.

To systematically analyze the effect of continuous cerebrospinal fluid (CSF) drainage on the outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH).

We searched PubMed, Embase, Cochrane Library, Web of science, CNKI, Wan-Fang, and CQVIP databases about the impact of continuous CSF drainage following aSAH on the outcomes of patients. The publication of the literature searched was up to June 2020. The extracted observation indicators included: Glasgow outcome score (GOS), modified Rankin scale score (mRS), mortality rate, incidences of cerebral vasospasm (CVS), cerebral infarction and shunt-dependent hydrocephalus (SDHC) at 6 months post surgery. The collected information was analyzed using a fixed-effects model if it showed homogeneity, otherwise a random-effects model.

A total of 26 studies (2 455 patients) were included, including 8 randomized controlled trials (RCT), and 18 retrospective case-control and prospective cohort studies. Meta-analysis results showed that compared with the group without continuous CSF drainage, the outcome of the continuous CSF drainage group at 6 months after surgery was relatively better (OR=2.96, 95%CI: 1.52-5.79, P<0.01), and the mortality rate was lower (OR=0.39, 95%CI: 0.22-0.70, P<0.01), CVS (OR=0.37, 95%CI: 0.30-0.46, P<0.01), cerebral infarction (OR=0.53, 95%CI: 0.40-0.71, P<0.01) and SDHC (OR=0.53, 95%Cl: 0.31-0.90, P=0.02) had lower incidences. Compared with those who underwent ventricular drainage, patients who underwent lumbar external drainage had better therapeutic effect (OR=2.90, 95%CI: 0.64-13.08, P=0.02), while there was no statistical difference in the incidence of vasospasm between the two groups (OR=1.13, 95%CI: 0.54-2.37, P=0.75). A total of 1 293 cases of 12 studies reported that the incidence of complications related to continuous CSF drainage was 3.4% (44 cases).

Continuous CSF drainage following aSAH could improve the patient's outcome and reduce the risk of developing neurological complications after surgery. The effect of external lumbar drainage may be better than that of ventricular drainage, which, however, needs more RCT research to be verified.