Navigation Guided Biopsy Is as Effective as Frame-Based Stereotactic Biopsy.

BACKGROUND: Stereotactic biopsy is a standard procedure for brain biopsy. However, with advances in technology, navigation-guided brain biopsy has become a well-established alternative. Previous studies have shown that frameless stereotactic brain biopsy is as effective and safe as frame-based stereotactic brain biopsy is. In this study, the authors evaluate the diagnostic yield and complication rate of frameless intracranial biopsy. MATERIALS AND METHODS: We reviewed data from biopsy performed patients between March 2014 and April 2022. We retrospectively reviewed medical records, including imaging studies. Various intracerebral lesions were biopsied. Diagnostic yield and post-operative complications were compared with those of frame-based stereotactic biopsy. RESULTS: Forty-two frameless navigation-guided biopsy were performed, and the most common pathology was primary central nervous system lymphoma (35.7%), followed by glioblastoma (33.3%), and anaplastic astrocytomas (16.7%), respectively. The diagnostic yield was 100%. Post-operative intracerebral hematoma occurred in 2.4% of cases, but it was not symptomatic. Thirty patients underwent frame-based stereotactic biopsy, and the diagnostic yield was 96.7%. There was no difference in diagnostic rates between two methods (Fisher's exact test, p = 0.916). CONCLUSIONS: Frameless navigation-guided biopsy is as effective as frame-based stereotactic biopsy is, without causing further complications. We consider that frame-based stereotactic biopsy is no longer needed if frameless navigation-guided biopsy is used. A further study will be needed to generalize our results.

Supratotal Resection of Glioblastoma: Better Survival Outcome than Gross Total Resection.

OBJECTIVE: Supratotal resection (SupTR) of glioblastoma allows for a superior long-term disease control and increases overall survival. On the other hand, aggressive conventional approaches, including gross total resections (GTR), are limited by the impairment risk of adjacent eloquent areas, which may cause severe postoperative functional morbidity. This study aimed to analyze institutional cases with respect to the potential survival benefits of additional resection, including lobectomy, as a paradigm for SupTR in patients of glioblastoma. METHODS: Between 2014 and 2018, 15 patients with glioblastoma underwent SupTR (GTR and additional lobectomy) at the authors' institution. The postoperative Karnofsky performance score (KPS), progression-free survival (PFS), and overall survival (OS) were analyzed for the patients. RESULTS: Patients with SupTR showed significantly prolonged PFS and OS. The median PFS and OS values for the entire study group were 33.5 months (95% confidence intervals (CI): 18.5-57.3 months) and 49.1 months (95% CI: 24.7-86.6 months), respectively. Multivariate analysis revealed that the O6-DNA-methylguanine methyltransferase (MGMT) promoter methylation status was the only predictor for both superior PFS (p = 0.03, OR 5.7, 95% CI 1.0-49.8) and OS (p = 0.04, OR 6.5, 95% CI 1.1-40.2). There was no significant difference between the pre- and postoperative KPS scores. CONCLUSIONS: Our results suggest that SupTR with lobectomy allows for a superior PFS and OS without negatively affecting patient performance. However, due to the small number of patients, further studies that include more patients are needed.

Extended Time Window (>6 Hour) Mechanical Thrombectomy; Good Clinical Outcome in the Younger Age Population in Thrombectomy Cases: Relationship between Age and Prognosis.

BACKGROUND: Mechanical thrombectomy (MT) has become increasingly common in recent years, as studies have shown that it can be an effective treatment for acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). However, the efficacy of MT in the extended time window (6 to 24 h) is still uncertain. Our study aims to evaluate the outcomes of MT in the extended time window for AIS patients. METHODS: We reviewed data on AIS patients who received MT beyond six hours of stroke onset from 2015 to 2022. The patients' occlusions were in the internal carotid artery (ICA), middle cerebral artery (MCA), or posterior circulation. Our evaluation included the modified Rankin scale (mRS) and 90-day mortality rates, as well as complications, such as symptomatic intracranial hemorrhage (sICH). RESULTS: Thirty-one patients were included in this study, with a mean age of 75.6 ± 15.1 years, of whom 54.8% were male. The median NIHSS score at presentation was 17. Successful recanalization (TICI 2b to 3) was achieved in 90.3% of patients and the rate of sICH was 6.4%. No difference was observed between the two age groups. The younger age group (<80 years old) showed a better clinical outcome (mRS 0-2; p < 0.05, Fisher's exact test) compared with the older age group. The overall mortality rate was 6.4%. CONCLUSION: Our study shows that (MT) can be performed effectively and safely within an extended time window, resulting in satisfactory functional outcomes, particularly in the younger age group.

Pedicled frontal periosteal rescue flap via eyebrow incision for skull base reconstruction (SevEN-002).

PURPOSE: Cerebrospinal fluid (CSF) leakage is one of the major complications after endoscopic endonasal surgery. The reconstructive nasoseptal flap is widely used to repair CSF leakage. However, it could not be utilized in all cases; thus, there was a need for an alternative. We developed a pericranial rescue flap that could cover both sellar and anterior skull base defects via the endonasal approach. A modified surgical technique that did not violate the frontal sinus and cause cosmetic problems was designed using the pericranial rescue flap. METHODS: We performed 12 cadaveric dissections to investigate the applicability of the lateral pericranial rescue flap. An incision was made, extending from the middle to the lateral part of the eyebrow. The pericranium layer was dissected away from the galea layer, from the supraorbital region towards the frontoparietal region. With endoscopic assistance, the periosteal flap was raised, the flap base was the pericranium layer at the eyebrow incision. After a burr-hole was made in the supraorbital bone, the pericranial flap was inserted via the intradural or extradural pathway. RESULTS: The mean size of the pericranial flap was 11.5 cm × 3.2 cm. It was large enough to cross the midline and cover the dural defects of the anterior skull base, including the sellar region. CONCLUSION: We demonstrated a modified endoscopic technique to repair the anterior skull base defects. This minimally invasive pericranial flap may resolve neurosurgical complications, such as CSF leakage.

The Korean Society for Neuro-Oncology (KSNO) Guideline for Adult Diffuse Midline Glioma: Version 2021.1.

BACKGROUND: There have been no guidelines for the management of adult patients with diffuse midline glioma (DMG), H3K27M-mutant in Korea since the 2016 revised WHO classification newly defined this disease entity. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for DMG since 2019. METHODS: The Working Group was composed of 27 multidisciplinary medical experts in Korea. References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of keywords. As 'diffuse midline glioma' was recently defined, and there was no international guideline, trials and guidelines of 'diffuse intrinsic pontine glioma' or 'brain stem glioma' were thoroughly reviewed first. RESULTS: The core contents are as follows. The DMG can be diagnosed when all of the following three criteria are satisfied: the presence of the H3K27M mutation, midline location, and infiltrating feature. Without identification of H3K27M mutation by diagnostic biopsy, DMG cannot be diagnosed. For the primary treatment, maximal safe resection should be considered for tumors when feasible. Radiotherapy is the primary option for tumors in case the total resection is not possible. A total dose of 54 Gy to 60 Gy with conventional fractionation prescribed at 1-2 cm plus gross tumor volume is recommended. Although no chemotherapy has proven to be effective in DMG, concurrent chemoradiotherapy (± maintenance chemotherapy) with temozolomide following WHO grade IV glioblastoma's protocol is recommended. CONCLUSION: The detection of H3K27M mutation is the most important diagnostic criteria for DMG. Combination of surgery (if amenable to surgery), radiotherapy, and chemotherapy based on comprehensive multidisciplinary discussion can be considered as the treatment options for DMG.

The Korean Society for Neuro-Oncology (KSNO) Guideline for Antiepileptic Drug Usage of Brain Tumor: Version 2021.1.

BACKGROUND: To date, there has been no practical guidelines for the prescription of antiepileptic drugs (AEDs) in brain tumor patients in Korea. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for AED usage in brain tumors since 2019. METHODS: The Working Group was composed of 27 multidisciplinary medical experts in Korea. References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of the keywords. RESULTS: The core contents are as follows. Prophylactic AED administration is not recommended in newly diagnosed brain tumor patients without previous seizure history. When AEDs are administered during peri/postoperative period, it may be tapered off according to the following recommendations. In seizure-naïve patients with no postoperative seizure, it is recommended to stop or reduce AED 1 week after surgery. In seizure-naïve patients with one early postoperative seizure (<1 week after surgery), it is advisable to maintain AED for at least 3 months before tapering. In seizure-naïve patients with ≥2 postoperative seizures or in patients with preoperative seizure history, it is recommended to maintain AEDs for more than 1 year. The possibility of drug interactions should be considered when selecting AEDs in brain tumor patients. Driving can be allowed in brain tumor patients when proven to be seizure-free for more than 1 year. CONCLUSION: The KSNO suggests prescribing AEDs in patients with brain tumor based on the current guideline. This guideline will contribute to spreading evidence-based prescription of AEDs in brain tumor patients in Korea.

Ventriculoperitoneal Shunt without Hair Shaving Using Absorbable Suture Materials.

OBJECTIVE: Infection is one of most devastating complications in ventriculoperitoneal (VP) shunt surgery. Preoperative hair removal has traditionally been performed to reduce infectious complications. We performed VP shunt surgeries and evaluated the prevalence of infection in patients who were shaved and those who were unshaven. METHODS: A retrospective analysis was conducted of 82 patients with hydrocephalus of various pathologies who underwent VP shunt surgery, with or without having the head shaved, between March 2010 and March 2017. For patients in the non-shaved group (n=36), absorbable suture materials were used for wound closure, and Nylon sutures or staples were used in the shaved group (n=46). We evaluated the infection outcomes of patients in the two groups. RESULTS: There was no difference in the average age of patients in the two groups. In the non-shaved group, there were no infections, while two patients in the shaved group required revision because of shunt infection. CONCLUSION: Non-shaved shunt surgery may be safe and effective, with no increase of infection rate. We recommend that shunt procedures could be performed without shaving the hair, which may increase patients' satisfaction without increasing infection risk.

Dural Injury in Unilateral Biportal Endoscopic Spinal Surgery.

STUDY DESIGN: Retrospective study. OBJECTIVES: Unilateral biportal endoscopic surgery (UBES) is a popular surgical method used to treat degenerative spinal diseases because of its merits, such as reduced tissue damage and outstanding visual capacity. However, dural injury is the most common complication of UBES with an incidence rate of 1.9% to 5.8%. The purpose of this study was to analyze the pattern of dural injury during UBES and to report the clinical course. METHODS: We retrospectively reviewed the medical and radiographic records of surgically treated patients who underwent UBES at a single institute between January 2018 and December 2019. RESULTS: Fifty-three patients, representing 67 segments, underwent UBES. Seven dural injuries occurred, and the incidence rate was 13.2%. Among 16 far lateral approaches, 2 dural injuries of the exiting roots occurred and were treated with fibrin sealant reinforcement. Among 51 median approaches, dural injury occurred at the thecal sac (n = 3) and traversing root (n = 2). A dural injury of the shoulder of the traversing root was treated with a fibrin sealant; however, a defect in the thecal sac required a revision for reconstruction. The other 2 thecal sac injuries were directly repaired via microscopic surgery. CONCLUSIONS: Dural injury during UBES can occur because of the various anatomical features of the meningo-vertebral ligaments. Direct repair of the central dural defect should be considered under microscopic vision. A linear tear in the lateral dura or root can be controlled with a simple patchy reinforcement under endoscopic vision.

Temporal Volume Change of Cavernous Sinus Cavernous Hemangiomas after Gamma Knife Surgery.

Cavernous hemangiomas occur very rarely in the cavernous sinus. This study aimed to evaluate the efficacy of Gamma Knife surgery (GKS) on cavernous sinus cavernous hemangioma (CSCH) and to analyze the temporal volume change. We retrospectively reviewed the clinical data of 26 CSCH patients who were treated with GKS between 2001 and 2017. Before GKS, 11 patients (42.3%) had cranial neuropathies and 5 patients (19.2%) complained of headache, whereas 10 patients (38.5%) were initially asymptomatic. The mean pre-GKS mass volume was 9.3 mL (range, 0.5-31.6 mL), and the margin dose ranged from 13 to 15 Gy according to the mass volume and the proximity to the optic pathway. All cranial neuropathy patients and half of headache patients showed clinical improvement. All 26 patients achieved mass control; remarkable responses (less than 1/3 of the initial mass volume) were shown in 19 patients (73.1%) and moderate responses (more than 1/3 and less than 2/3) in 7 patients (26.9%). The mean final mass volume after GKS was 1.8 mL (range, 0-12.6 mL). The mean mass volume at 6 months after GKS was 45% (range, 5-80%) compared to the mass volume before GKS and 21% (range, 0-70%) at 12 months. The higher radiation dose tended to induce more rapid and greater volume reduction. No treatment-related complication was observed during the follow-up period. GKS could be an effective and safe therapeutic strategy for CSCH. GKS induced very rapid volume reduction compared to other benign brain tumors.

A National Consensus Survey for Current Practice in Brain Tumor Management I: Antiepileptic Drug and Steroid Usage.

BACKGROUND: The Guideline Working Group of the Korean Society for Neuro-Oncology (KSNO) conducted a nationwide questionnaire survey for diverse queries faced in the treatment of brain tumors. As part I of the survey, the aim of this study is to evaluate national patterns of clinical practice about antiepileptic drug (AED) and steroid usage for management of brain tumors. METHODS: A web-based survey was sent to all members of the KSNO by email. The survey included 9 questions of AED usage and 5 questions of steroid usage for brain tumor patients. All questions were developed by consensus of the Guideline Working Group. RESULTS: The overall response rate was 12.8% (54/423). Regarding AED usage, the majority of respondents (95.2%) routinely prescribed prophylactic AEDs for patients with seizure at the peri/postoperative period. However, as many as 72.8% of respondents prescribed AED routinely for seizure-naïve patients, and others prescribed AED as the case may be. The duration of AED prophylaxis showed wide variance according to the epilepsy status and the location of tumor. Levetiracetam (82.9%) was the most preferred AED for epilepsy prophylaxis. Regarding steroid usage, 90.5% of respondents use steroids in perioperative period, including 34.2% of them as a routine manner. Presence of peritumoral edema (90.9%) was considered as the most important factor determining steroid usage followed by degree of clinical symptoms (60.6%). More than half of respondents (51.2%) replied to discontinue the steroids within a week after surgery if there are no specific medical conditions, while 7.3% preferred slow tapering up to a month after surgery. CONCLUSION: The survey demonstrated the prevailing practice patterns on AED and steroid usage in neuro-oncologic field among members of the KSNO. This information provides a point of reference for establishing a practical guideline in the management of brain tumor patients.

A National Consensus Survey for Current Practice in Brain Tumor Management II: Diffuse Midline Glioma and Meningioma.

BACKGROUND: The Guideline Working Group of the Korean Society for Neuro-Oncology (KSNO) conducted a nationwide questionnaire survey for diverse queries faced in the treatment of brain tumors. As part II of the survey, the aim of this study is to evaluate the national patterns of clinical practice for patients with diffuse midline glioma and meningioma. METHODS: A web-based survey was sent to all members of the KSNO by email. The survey included 4 questions of diffuse midline glioma and 6 questions of meningioma (including 2 case scenarios). All questions were developed by consensus of the Guideline Working Group. RESULTS: In the survey about diffuse midline glioma, 76% respondents performed histologic confirmation to identify H3K27M mutation on immunohistochemical staining or sequencing methods. For treatment of diffuse midline glioma, respondents preferred concurrent chemoradiotherapy with temozolomide (TMZ) and adjuvant TMZ (63.8%) than radiotherapy alone (34.0%). In the survey about meningioma, respondents prefer wait-and-see policy for the asymptomatic small meningioma without peritumoral edema. However, a greater number of respondents had chosen surgical resection as the first choice for all large size meningiomas without exception, and small size meningiomas with either peritumoral edema or eloquent location. There was no single opinion with major consensus on long-term follow-up plans for asymptomatic meningioma with observation policy. As many as 68.1% of respondents answered that they would not add any adjuvant therapies for World Health Organization grade II meningiomas if the tumor was totally resected including dura. CONCLUSION: The survey demonstrates the prevailing clinical practice patterns for patients with diffuse midline glioma and meningioma among members of the KSNO. This information provides a point of reference for establishing a practical guideline in the management of diffuse midline glioma and meningioma.

A National Consensus Survey for Current Practice in Brain Tumor Management III: Brain Metastasis and Primary Central Nervous System Lymphoma.

BACKGROUND: The Guideline Working Group of the Korean Society for Neuro-Oncology (KSNO) conducted the nationwide questionnaire survey for diverse queries facing to treat patients with brain tumor. As part III of the survey, the aim of this study is to evaluate the national patterns of clinical practice for patients with brain metastasis and primary central nervous system lymphoma (PCNSL). METHODS: A web-based survey was sent to all members of the KSNO by email. The survey included 7 questions of brain metastasis and 5 questions of PCNSL, focused on the management strategies in specific situations. All questions were developed by consensus of the Guideline Working Group. RESULTS: In the survey about brain metastasis, respondents preferred surgical resection with adjuvant treatment for patients with a surgically accessible single brain metastatic lesion less than 3 cm in size without extracranial systemic lesions. However, most respondents considered radiosurgery for surgically inaccessible lesions. As the preferred treatment of multiple brain metastases according to the number of brain lesions, respondents tended to choose radiotherapy with increasing number of lesions. Radiosurgery was mostly chosen for the brain metastases of less than or equal to 4. In the survey about PCNSL, a half of respondents choose high-dose methotrexate-based polychemotherapy as the first-line induction therapy for PCNSL. The consolidation and salvage therapy showed a little variation among respondents. For PCNSL patients with cerebrospinal fluid dissemination, intrathecal chemotherapy was most preferred. CONCLUSION: The survey demonstrates the prevailing clinical practice patterns for patients with brain metastasis and PCNSL among members of the KSNO. This information provides a point of reference for establishing a practical guideline in the management of brain metastasis and PCNSL.

Clinical characteristics of asymptomatic Terson syndrome in the patients with aneurysmal subarachnoid hemorrhage.

AIM: To investigate clinical characteristics of asymptomatic Terson syndrome and its clinical impact in patients with aneurysmal subarachnoid hemorrhage (SAH). METHODS: This retrospective, interventional study included 31 patients with aneurysmal SAH, and the medical records were reviewed. In addition to baseline characteristics of the study population such as age, sex, and underlying medical history, multi-modal imaging analysis, including fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), were also reviewed. Glasgow Coma Scale (GCS), Hunt-Hess (HH) grade, and Fisher scale at the time of admission, and functional outcome by using modified Rankin Scale (mRS) at 6mo were compared. RESULTS: Of the 31 patients, 10 patients (32.3%) were diagnosed with Terson syndrome. All the patients with Terson syndrome did not report visual symptoms at the time of ophthalmologic screening. FA showed microvascular changes of retinal capillaries and varying degrees of disc leakage. SD-OCT allowed intuitive anatomical localization of multi-layered retinal hemorrhages and assessment of ellipsoid zone integrity. The patients with Terson syndrome showed significantly worse GCS (P=0.047) and HH grade (P=0.025) than those without, except Ficher scale (P=0.385). There was no significant difference in the mRS (P=0.250) at 6mo. Among baseline factors, the HH grade was the only significant factor associated with Terson syndrome (B=1.079, P=0.016). CONCLUSION: In our study, 32.3% of the patients have Terson syndrome without visual symptoms. The baseline HH grade is significantly correlated with Terson syndrome, and there is no significant difference in the functional outcome between the patients with and without Terson syndrome. Terson syndrome may develop without any visual symptoms as shown in our study, and ophthalmologic screening may be recommended to prevent further visual deterioration especially in the patients with poor HH grade at the time of aneurysmal SAH.

Early Experience of Automated Intraventricular Type Intracranial Pressure Monitoring (LiquoGuard®) for Severe Traumatic Brain Injury Patients.

OBJECTIVE: The LiquoGuard® system is a new ventricular-type monitoring device that facilitates intracranial pressure (ICP)-controlled or volume-controlled drainage of cerebrospinal fluid (CSF). The purpose of this study is to report the authors' experience with the LiquoGuard® ICP monitoring system, as well as the clinical safety, usefulness, and limitations of this device in the management of patients with traumatic brain injury (TBI). METHODS: Intraventricular ICP monitoring was performed on 10 patients with TBI using the LiquoGuard® monitoring system. ICP measurements, volume of drained CSF, and clinical outcomes were analyzed and discussed. RESULTS: ICP monitoring was performed on 10 patients for a mean duration of 6.9 days. With a mean 82,718 records per patient, the mean initial ICP was 16.4 mm Hg and the average ICP across the total duration of monitoring was 15.5 mm Hg. The mean volume of drained CSF was 29.2 cc/day, with no CSF drained in 4 patients. Seven of 10 patients showed 1 or 2 episodes of abnormal ICP measurements. No patient exhibited complications associated with ICP monitoring. CONCLUSION: The LiquoGuard® system is a versatile tool in the management of TBI patients. Its use is both reliable and feasible for ICP monitoring and therapeutic drainage of CSF. However, episodes of abnormal ICP measurements were frequently observed in patients with slit ventricles, and further study may be needed to overcome this issue.

Pediatric giant cell tumor of the tendon sheath of the craniocervical junction involving the occipital condyle.

INTRODUCTION: Giant cell tumor of the tendon sheath (GCTTS), also called pigmented villonodular synovitis, is a common lesion of the synovial membrane of the hand joint, but it uncommonly involves the axial skeleton, especially in pediatric populations. Furthermore, GCTTS originating from the occipital condyle has not been reported previously. CASE REPORT: A 15-year-old girl presented with a palpable neck mass for 1 year, and imaging studies revealed a less demarcated and heterogeneously enhanced mass in the suboccipital region. The tumor was originating from the occipital condyle that eroded the skull and atlas, and it was completely resected via a far lateral transcondylar approach followed by transarticular screw fixation. After the resection, we performed occipitocervical fusion to prevent spinal instability. The patient made an uneventful recovery after surgery. Recurrence has not been observed after 5 years of follow-up. DISCUSSION: We report this rare case and briefly review the general features and unusual locations of GCTTS with recommendations for treatment modalities.

Neurosurgery concepts: Key perspectives on dendritic cell vaccines, metastatic tumor treatment, and radiosurgery.

BACKGROUND: This is a laboratory study to investigate the effect of adding brain-derived-neurotrophic factor (BDNF) in a poly (N-isopropylacrylamide-g-poly (ethylene glycol) scaffold and its effect on spinal cord injury in a rat model. METHODS: This is a laboratory investigation of a spinal cord injury in a rat model. A dorsolateral funiculotomy was used to disrupt the dorsolateral funiculus and rubrospinal tract. Animals were then injected with either the scaffold polymer or scaffold polymer with BDNF. Postoperatively, motor functions were assessed with single pellet reach to grasp task, stair case reaching task and cylinder task. Histological study was also performed to look at extent of glial scar and axonal growth. RESULTS: Animals received BDNF containing polymer had an increased recovery rate of fine motor function of forelimb, as assessed by stair case reaching task and single pellet reach to grasp task compared with control animals that received the polymer only. There is no significant difference in the glial scar formation. BDNF treated animals also had increased axon growth including increase in the number and length of the rubrospinal tract axons. CONCLUSION: BDNF delivered via a scaffold polymer results in increased recovery rate in forelimb motor function in an experimental model of spinal cord injury, possibly through a promotion of growth of axons of the rubrospinal tract.

Clinical experience of glioma surgery using "tailed bullet": overcoming the limitations of conventional neuro-navigation guided surgery.

PURPOSE: Although conventional neuro-navigation is a useful tool for image-guided glioma surgery, there are some limitations, such as brain shift. We introduced our methods using an identifiable marker, a "tailed bullet", to overcome the limitation of conventional neuro-navigation. A tailed bullet is an identifiable tumor location marker that determines the extent of a resection and we have introduced our technique and reviewed the clinical results. MATERIALS AND METHODS: We have developed and used "tailed bullets" for brain tumor surgery. They were inserted into the brain parenchyma or the tumor itself to help identify the margin of tumor. We retrospectively reviewed surgically resected glioma cases using "tailed bullet". Total 110 gliomas included in this study and it contains WHO grade 2, 3, and 4 glioma was 14, 36, and 60 cases, respectively. RESULTS: Gross total resection (GTR) was achieved in 71 patients (64.5%), subtotal resection in 36 patients (32.7%), and partial resection in 3 patients (2.7%). The overall survival (OS) duration of grade 3 and 4 gliomas were 20.9 (range, 1.2-82.4) and 13.6 months (range, 1.4-173.4), respectively. Extent of resection (GTR), younger age, and higher initial Karnofsky Performance Status (KPS) score were related to longer OS for grade-4 gliomas. There was no significant adverse event directly related to the use of tailed bullets. CONCLUSION: Considering the limitations of conventional neuro-navigation methods, the tailed bullets could be helpful during glioma resection. We believe this simple method is an easily accessible technique and overcomes the limitation of the brain shift from the conventional neuro-navigation. Further studies are needed to verify the clinical benefits of using tailed bullets.