• Journal of Korean Neurosurgical Society
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• v.45 no.2
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• pp.67-73
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• 2009

Objective : Although endoscopic procedures for lumbar disc diseases have improved greatly, the postoperative outcomes for high grade inferior migrated discs are not satisfactory. Because of anatomic limitations, a rigid endoscope cannot reach all lesions effectively. The purpose of this study was to determine the feasibility of endoscopic transforaminal suprapedicular approach to high grade inferior-migrated lumbar disc herniations. Methods : Between May 2006 and March 2008, a suprapedicular approach was performed in 53 patients with high grade inferior-migrated lumbar disc herniations using a rigid endoscope and a semi-rigid flexible curved probe. One-to-four hours after surgery, the presence of remnant discs was checked with MRI. The outcomes were evaluated with the visual analogue scale (VAS) score and the Oswestry Disability Index (ODI) one week after surgery. Results : The L2-3 level was involved in 2 patients and the L3-4 level was involved in 14 patients, while the L4-5 level was involved in 39 patients. There were single piece-type in 34 cases and a multiple piece-type in 19 cases. Satisfactory results were obtained in all cases. The mean preoperative VAS for leg pain was $9.32{\pm}0.43$ points (range, 7-10 points), whereas the mean ODI was $79.82{\pm}4.53$ points (range, 68-92 points). At the last follow-up examination, the mean postoperative VAS for leg pain was $1.78{\pm}0.71$ points and the mean postoperative ODI improved to $15.27{\pm}3.82$ points. Conclusion : A high grade inferior migrated lumbar disc is difficult to remove sufficiently by posterolateral endoscopic lumbar dscectomy using a rigid endoscope. However, a satisfactory result can be obtained by applying a transforaminal suprapedicular approach with a flexible semi-rigid curved probe.

• Journal of Korean Neurosurgical Society
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• v.48 no.4
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• pp.319-324
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• 2010

Objective : The aim of this study was to analyze the correlation between thromboembolic complications and anti platelet drugs before and after neurointervention. Methods : Blood samples and radiographic data of patients who received a neurointervention (coil embolization, stent placement or both) were collected prospectively. Rapid platelet function assay-aspirin (RPFA-ASA) was used to calculate aspirin resistance in aspirin reaction units (ARU). For clopidogrel resistance, a P2Y12 assay was used to analyze the percentage of platelet inhibition. ARU > 550 and platelet inhibition < 40% were defined as aspirin and clopidogrel resistance, respectively. Results : Both aspirin and clopidogrel oral pills were administered in fifty-three patients before and after neurointerventional procedures. The mean resistance values of all patients were 484 ARU and < 39%. Ten (17.0%) of 53 patients showed resistance to aspirin with an average of 597 ARU, and 33 (62.3%) of 53 patients showed resistance to clopidogrel with an average of < 26%. Ten patients demonstrated resistance to both drugs, 5 of which suffered a thromboembolic complication after neurointervention (mean values : 640 ARU and platelet inhibition < 23%). Diabetic patients and patients with hypercholesterolemia displayed mean aspirin resistances of 513.7 and 501.8 ARU, and mean clopidogrel resistances of < 33.8% and < 40.7%, respectively. Conclusion : Identifying individuals with poor platelet inhibition using standard regimens is of great clinical importance and may help prevent cerebral ischemic events in the future. Neurointerventional research should focus on ideal doses, timing, choices, safety, and reliable measurements of anti platelet drug therapy, as well as confirming the clinical relevance of aggregometry in cerebrovascular patients.

• Journal of Korean Neurosurgical Society
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• v.53 no.1
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• pp.39-42
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• 2013

Objective : Obtaining real-time image is essential for neurosurgeons to minimize invasion of normal brain tissue and to prompt diagnosis of intracranial event. The aim of this study was to report our three-year experience with a mobile computed tomography (mCT) for intraoperative and bedside scanning. Methods : A total of 357 mCT (297 patients) scans from January 2009 to December 2011 in single institution were reviewed. After excluding postoperative routine follow-up, 202 mCT were included for analysis. Their medical records such as diagnosis, clinical application, impact on decision making, times, image quality and radiologic findings were assessed. Results : Two-hundred-two mCT scans were performed in the operation room (n=192, 95%) or intensive care unit (ICU) (n=10, 5%). Regarding intraoperative images, extent of resection of tumor (n=55, 27.2%), degree of hematoma removal (n=42, 20.8%), confirmation of catheter placement (n=91, 45.0%) and monitoring unexpected complications (n=4, 2.0%) were evaluated. A total of 14 additional procedures were introduced after confirmation of residual tumor (n=7, 50%), hematoma (n=2, 14.3%), malpositioned catheter (n=3, 21.4%) and newly developed intracranial events (n=2, 14.3%). Every image was obtained within 15 minutes and image quality was sufficient for interpretation. Conclusion : mCT is feasible for prompt intraoperative and ICU monitoring with enhanced diagnostic certainty, safety and efficiency.

• Journal of Korean Neurosurgical Society
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• v.60 no.6
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• pp.755-762
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• 2017

Objective : The purpose of this study is to describe the detailed surgical technique and short-term clinical and radiological outcomes of lateral lumbar interbody fusion (LLIF) and in situ lateral screw fixation using a conventional minimally invasive screw fixation system (MISF) for revision surgery to treat rostral lumbar adjacent segment disease. Methods : The medical and radiological records were retrospectively reviewed. The surgery was indicated in 10 consecutive patients with rostral adjacent segment stenosis and instability. After the insertion of the interbody cage, lateral screws were inserted into the cranial and caudal vertebra using the MISF through the same LLIF trajectory. The radiological and clinical outcomes were assessed preoperatively and at 1, 3, 6, and 12 months postoperatively. Results : The median follow-up period was 13 months (range, 3-48 months). Transient sensory changes in the left anterior thigh occurred in 3 patients, and 1 patient experienced subjective weakness; however, these symptoms normalized within 1 week. Back and leg pain were significantly improved (p<0.05). In the radiological analysis, both the segmental angle at the operated segment and anterior disc height were significantly increased. At 6 months postoperatively, solid bony fusion was confirmed in 7 patients. Subsidence and mechanical failure did not occur in any patients. Conclusion : This study demonstrates that LLIF and in situ lateral screw fixation may be an alternative surgical option for rostral lumbar adjacent segment disease.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.304-310
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• 2011

Objective : Intrathecal methotrexate (MTX) therapy combined with whole brain radiotherapy (WBRT) is one of the major treatment modalities for leukemia and lymphoma involving the central nervous system (CNS). The purpose of this study was to retrospectively determine the incidences of leukoencephalopathy and disseminated necrotizing leukoencephalopathy (DNL) following intrathecal MTX therapy for CNS lymphoma or leukemia and to assess the potential risk factors. Methods : Between January 2000 and August 2009, 143 patients with CNS lymphoma or leukemia received intrathecal MTX therapy alone or in combination with WBRT at a single institution. Patients were followed up clinically and radiologically at regular two- or three-month intervals. Medical records were reviewed to obtain information regarding the patients' demographics, medical histories, radiologic characteristics, treatments, and clinical courses. Results : On follow-up MR images, leukoencephalopathy was found in 95 of 143 patients (66.4%). The median time to develop leukoencephalopathy was 6.6 months. Among those with leukoencephalopathy, four patients showed seven extensive white-matter changes with strongly enhancing lesions demonstrating DNL. Histological confirmation was done in six lesions of three patients and radiological diagnosis alone in one patient. Four lesions spontaneously disappeared on MR images without any treatment, with a mean duration of 14 months before disappearance of DNL. Conclusion : Leukoencephalopathy is a common phenomenon that occurs following intrathecal MTX therapy; however, DNL occurs at a very low incidence. For newly developed enhancing lesions, consideration for the occurrence of DNL should be taken to avoid unnecessary invasive procedures or therapies.

• Journal of Korean Neurosurgical Society
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• v.47 no.3
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• pp.174-179
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• 2010

Objective : Cricothyrotomy and tracheostomy are performed by physicians in various disciplines. It is important to know the comprehensive anatomy of the laryngotracheal region. Hemorrhage, esophageal injury, recurrent laryngeal nerve injury, pneumothorax, hemothorax, false passage of the tube and tracheal stenosis after decannulation are well known complications of the cricothyrotomy and tracheostomy. Cricothyrotomy and tracheostomy should be performed without complications and as quickly as possible with regards the patients' clinical condition. Methods : A total of 40 cadaver necks were dissected in this study. The trachea and larynx and the relationship between the trachea and larynx and the surrounding structures was investigated. The tracheal cartilages and annular ligaments were counted and the relationship between tracheal cartilages and the thyroid gland and vascular structures was investigated. We performed cricothyrotomy and tracheostomy in eleven cadavers while simulating intensive care unit conditions to determine the duration of those procedures. Results : There were 11 tracheal cartilages and 10 annular ligaments between the cricoid cartilage and sternal notch. The average length of trachea between the cricoid cartilage and the suprasternal notch was 6.9 to 8.2 cm. The cricothyroid muscle and cricothyroid ligament were observed and dissected and no vital anatomic structure detected. The average length and width of the cricothyroid ligament was 8 to 12 mm and 8 to 10 mm, respectively. There was a statistically significant difference between the surgical time required for cricothyrotomy and tracheostomy (p < 0.0001). Conclusion : Tracheostomy and cricothyrotomy have a low complication rate if the person performing the procedure has thorough knowledge of the neck anatomy. The choice of tracheostomy or cricothyrotomy to establish an airway depends on the patients' clinical condition, for instance; cricothyrotomy should be preferred in patients with cervicothoracal injury or dislocation who suffer from respiratory dysfunction. Furthermore; if a patient is under risk of hypoxia or anoxia due to a difficult airway, cricothyrotomy should be preferred rather than tracheostomy.

• Journal of Korean Neurosurgical Society
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• v.39 no.2
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• pp.87-91
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• 2006

Objective : Management of recurrent vestibular schwannomas[VS] after microsurgery or radiosurgery is a complicated subject. However, few studies have documented the outcome of recurrent VS. The authorsreviewclinicalexperience of recurrent VS management and analyzed the efficacy of treatment modalities. Methods : Between 1990 and 2002, 293 patients harboring unilateral VS underwent, microsurgery, radiosurgery, microsurgery followed by radiosurgery. Of these, 26 procedures [in 20 patients] were performed to assessed from an increased tumor size by magnetic resonance imaging[MRI]. The mean age of patients with recurred VS was 46.9 years and the mean follow-up period was 68 months. Radiological characteristics were investigated and growth rates of recurred tumors were calculated by measuring changes in tumor diameter on MRI after treatment. Results : MRI characteristics revealed a lobulated contour in 75% and a cyst in 60% of the patients. Only 1 patient showed neither lobulation nor a cyst. The average diameter of the recurrent tumors were 36.9mm. The overall tumor control rate for initial management was 87.4%, 94.7%, and 98.5% for microsurgery, radiosurgery, and microsurgery plus radiosurgery, respectively. However, control rates for recurrent tumors were lower at 85%, 63%, and 80%, respectively. Conclusion : A cystic nature and a lobulated tumor contour are frequent clinical characteristics of recurrent VS. Microsurgery or microsurgery followed by radiosurgery shows little difference in tumor control rate for primary and recurrent VS. However, radiosurgery alone appears to be less beneficial for recurrent VS.

• Journal of Korean Neurosurgical Society
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• v.57 no.3
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• pp.192-196
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• 2015

Objective : Tremor is a common movement disorder that interferes with daily living. Since the medication for tremor has some limitations, surgical intervention is needed in many patients. In certain patients who cannot undergo aggressive surgical intervention, Gamma Knife thalamotomy (GKT) is a safe and effective alternative. Methods : From June 2012 to August 2013, 7 patients with an intractable tremor underwent GKT. Four of these 7 patients had medical comorbidities, and 3 patients refused to undergo traditional surgery. Each patient was evaluated with the modified Fahn-Tolosa-Marin tremor rating scale (TRS) along with analysis of handwriting samples. All of the patients underwent GKT with a maximal dose of 130 Gy to the left ventralis intermedius (VIM) nucleus of the thalamus. Follow-up brain MRI was performed after 3 to 8 months of GKT, and evaluation with the TRS was also performed. Results : Six patients showed objective improvement in the TRS score. Excluding one patient who demonstrated tremor progression, there was 28.9% improvement in the TRS score. However, five patients showed subjective improvement in their symptoms. On comparing the TRS scores between follow-up periods of more and less than 4 months, the follow-up TRS score at more than 4 months of GKT was significantly improved compared to that at less than 4 months of GKT. Follow-up MRI showed radiosurgical changes in 5 patients. Conclusion : GKT with a maximal dose of 130 Gy to the VIM is a safe procedure that can replace other surgical procedures.

• Journal of Korean Neurosurgical Society
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• v.59 no.5
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• pp.478-484
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• 2016

Objective : To assess the clinical and radiological factors as predictors for successful outcomes in lumbar disc herniation (LDH) treatment. Methods : Two groups of patients with single level LDH (L4-5) requiring treatment were retrospectively studied. The surgery group (SG) included 34 patients, and 30 patients who initially refused the surgery were included in the nerve blocks group (NG). A visual analogue scale (VAS) for leg and back pain and motor deficit were initially evaluated before procedures, and repeated at 1, 6, and 12 months. Radiological factors including the disc herniation length, disc herniation area, canal length-occupying ratio, and canal area-occupying ratio were measured and compared. Predicting factors of successful outcomes were determined with multivariate logistic regression analysis after the optimal cut off values were established with a receiver operating characteristic curve. Results : There was no significant demographic difference between two groups. A multivariate logistic regression analysis with radiological and clinical (12 months follow-up) data revealed that the high disc herniation length with cutoff value 6.31 mm [odds ratio (OR) 2.35; confidence interval (CI) 1.21-3.98] was a predictor of successful outcomes of leg pain relief in the SG. The low disc herniation length with cutoff value 6.23 mm (OR 0.05; CI 0.003-0.89) and high baseline VAS leg (OR 12.63; CI 1.64-97.45) were identified as predictors of successful outcomes of leg pain relief in the NG. Conclusion : The patients with the disc herniation length larger than 6.31 mm showed successful outcomes with surgery whereas the patients with the disc herniation length less than 6.23 mm showed successful outcomes with nerve block. These results could be considered as a radiological criteria in choosing optimal treatment options for LDH.

• Journal of Korean Neurosurgical Society
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• v.63 no.6
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• pp.723-729
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• 2020

Objective : The use of oblique lateral interbody fusion at the L5-S1 level (OLIF51) is increasing, but no study has directly compared OLIF51 and transforaminal lumbar interbody fusion (TLIF) at the L5-S1 level. We evaluated the usefulness of OLIF51 by comparing clinical and radiologic outcomes with those of TLIF at the same L5-S1 level. Methods : We retrospectively reviewed and compared 74 patients who underwent OLIF51 (OLIF51 group) and 74 who underwent TLIF at the L5-S1 level (TLIF51 group). Clinical outcomes were assessed with the visual analogue scale for back pain and leg pain and the Oswestry Disability Index. Mean disc height (MDH), foraminal height (FH), disc angle (DA), fusion rate, and subsidence rate were measured for radiologic outcomes. Results : The OLIF51 group used significantly higher, wider, and larger-angled cages than the TLIF51 group (p<0.001). The postoperative MDH and FH were significantly greater in the OLIF51 group than in the TLIF51 group (p<0.001). The postoperative DA was significantly larger in the OLIF51 group than in the TLIF51 group by more than 10º (p<0.001). The fusion rate was 81.1% and 87.8% at postoperative 6 months in the OLIF51 and TLIF51 groups, respectively, and the TLIF51 group showed a higher fusion rate (p<0.05). The subsidence rate was 16.2% and 25.3% in the OLIF51 and TLIF51 groups, respectively, and the OLIF51 group showed a lower subsidence rate (p<0.05). Conclusion : OLIF51 was more effective for the indirect decompression of foraminal stenosis, providing strong mechanical support with a larger cage, and making a greater lordotic angle with a high-angle cage than with TLIF.