Byung Kwan Choi

Pusan National University, Pusan, Busan, South Korea

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Publications (34)31.19 Total impact

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    ABSTRACT: Artificial nerve guidance conduits (aNGCs) prepared from polymer scaffolds and carbon nanotubes (CNTs) possess unique chemical and physical properties, and have been widely used in preclinical trials to promote neuronal differentiation and growth. However, there have been only a few reports on the clinical applicability of CNT sheets for proliferation of primary neuronal cells due to safety concerns. The present study assesses the ability and potential applicability of multi-wall CNTs (MWNTs) composited with polydimethylsiloxane (PDMS) sheets to promote and enhance the proliferation of primary neuronal cells. In this study, the aqueous MWNT dispersion was filtered, and the PDMS/MWNT sheets were prepared using a simple printing transfer method. Characterization of PDMS/MWNT sheets demonstrated their unique physical properties such as superior mechanical strength and electroconductivity compared with PDMS sheets. The effect of the PDMS/MWNT sheets on the neural cell proliferation and cytotoxicity was evaluated using MTT and alamar blue assays. Our results indicate the viability and proliferation of primary neuronal cells and Schwann cells in PDMS/MWNT sheets increased over twice compared with a non-coated dish that is not usual in the primary neuronal cell growth control (p < 0.05). In addition, PDMS/MWNT sheets enhanced the adhesion and viability of the cells compared with poly-L-lysine coated dishes, which are most commonly used for improving cell adherence. Additionally, the PDMS/MWNT sheets exhibited excellent biocompatibility for culturing neuronal and Schwann cells. Overall, all assessments indicate that PDMS/MWNT sheets are ideal candidates for the development of artificial nerve conduits for clinical use following peripheral nerve injury.
    Journal of Biomedical Materials Research Part A 08/2014; · 2.83 Impact Factor
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    ABSTRACT: Objectives Acupuncture is commonly used as a complimentary treatment for pain management. However, there has been no systematic review summarizing the current evidence concerning the effectiveness of acupuncture for acute postoperative pain after back surgery. This systematic review aimed at evaluating the effectiveness of acupuncture treatment for acute postoperative pain (≤1 week) after back surgery.Methods We searched 15 electronic databases without language restrictions. Two reviewers independently assessed studies for eligibility and extracted data, outcomes, and risk of bias. Random effect meta-analyses and subgroup analyses were performed.ResultsFive trials, including 3 of high quality, met our inclusion criteria. The meta-analysis showed positive results for acupuncture treatment of pain after surgery in terms of the visual analogue scale (VAS) for pain intensity 24 hours after surgery, when compared to sham acupuncture (standard mean difference −0.67 (−1.04 to −0.31), P = 0.0003), whereas the other meta-analysis did not show a positive effect of acupuncture on 24-hour opiate demands when compared to sham acupuncture (standard mean difference −0.23 (−0.58 to 0.13), P = 0.21).Conclusion Our systematic review finds encouraging but limited evidence for the effectiveness of acupuncture treatment for acute postoperative pain after back surgery. Further rigorously designed clinical trials are required.
    Pain Practice 04/2014; · 2.61 Impact Factor
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    ABSTRACT: Cerebrospinal fluid (CSF) diversion is an essential component of neurosurgical care, but the rates and significance of hemorrhage associated with external ventricular drainage (EVD) and ventriculoperitoneal (VP) shunt procedures have not been well quantified. In this retrospective study, the authors examined the frequencies of hemorrhagic complications associated with EVD and VP shunt procedures, and attempted to identify associated risk factors. The treatment records of 370 EVDs in 276 patients and 102 VP shunts in 96 patients performed between 2008 and 2010 were retrospectively reviewed. Post-insertion computed tomographic (CT) scans were analyzed for any new hemorrhage related to the ventricular catheter. The effects of diagnosis at admission, endovascular treatment, anti-platelet medication, and a concurrent craniotomy operation were included in the analysis conducted to identify risk factors of ventricular catheterrelated hemorrhage. Hemorrhage following EVD was detected on CT scans in 76 (20.5%) of the 370 cases. However, symptomatic hemorrhage occurred in only 5 cases (1.4% of all EVDs). VP shunt was associated with a higher incidence of ventricular catheter-related hemorrhage than EVD (hemorrhage rate: 43.1%) and the rate of detectable neurological change was 2.9%. Multivariate logistic-regression analysis of risk factors of EVD-related hemorrhage identified preoperative anti-platelet medication as the only significant factor (odds ratio, 3.583 [95% confidence interval, 1.353 to 9.486]; p = 0.010). Ventriculostomy-related hemorrhagic complications were more common than anticipated, especially for the VP shunt procedure. However, such hemorrhages are rarely large, rarely the cause of neurological deterioration, and rarely require surgical removal. Preoperative anti-platelet medication appears to affect EVD-related hemorrhage development.
    Neurologia medico-chirurgica 02/2014; · 0.49 Impact Factor
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    ABSTRACT: A 47-year-old woman visited with lumbago and severe left leg pain that had been presented for 1 week. The patient complained of severe radiating pain on left L3 sensory dermatome area and reported aggravation of leg pain at 20 degrees of hip flexion by straight leg raising test (SLRT). However, there was no motor weakness on neurological examination. Magnetic resonance imaging (MRI) demonstrated contrast enhancing spinal extradural mass at L2-3 level that was iso-signal intensity (SI) on T1-weighted images (WI), hypo-SI on T2WI. She was not able to walk and sleep due to incapacitating pain. Thus, surgical removal was performed via left partial laminectomy. Postoperatively, the radiating pain was relieved completely. Histopathologic examination revealed that the tumor consisted of chondroma, which had mature hyaline cartilage with nests of benign-appearing cells and calcium deposits in lacunae.
    Korean Journal of Spine. 12/2013; 10(4):252-4.
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    ABSTRACT: The purpose of this study is to evaluate the efficacy of laminoplasty in the treatment of spinal cord injury (SCI) without instability. 79 patients with SCI without instability who underwent surgical treatment in our institute between January 2005 and September 2012 were retrospectively reviewed. Twenty nine patients fulfilled the inclusion criteria as follows: SCI without instability, spinal cord contusion in MRI, cervical stenosis more than 20%, follow up at least 6 months. Preoperative neurological state, clinical outcome and neurological function was measured using the American Spinal Injury Association (ASIA) impairment scale, modified Japanese Orthopedic Association (mJOA) grading scale and Hirabayashi recovering rate. Seventeen patients showed improvement in ASIA grade and twenty six patients showed improvement in mJOA scale at 6 month follow up. However, all patients with ASIA grade B and C have shown improvement of one or more ASIA grade. Mean Hirabayashi recovery rate was 47.4±23.7%. There was better neurologic recovery in those who had cervical spondylosis without ossification of posterior longitudinal ligament (OPLL) (p<0.05, χ(2) test). It is different in B, C, D with ASIA A that there are debates going on about the application of surgical treatment in ASIA A, and surgical treatment is helpful in B, C, D since it contributes to neurologic improvement. We concluded that laminoplasty provided good neurologic recovery in SCI without instability that cervical canal stenosis, especially spondylosis without OPLL and neurologic deterioration in ASIA B, C and D.
    Korean Journal of Spine. 09/2013; 10(3):133-7.
  • Kyoung Hyup Nam, In Ho Han, Won Ho Cho, Byung Kwan Choi
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    ABSTRACT: Lumbar intradural disc herniation (IDH) is rare, and intradural cyst associated with IDH is quite rare. Only seven cases of an intradural cyst associated with lumbar disc herniation have been reported, and all were gas-filled cysts. We report the first case, to our knowledge, of a fluid-filled intradural cyst associated with IDH. To report an extremely rare case of a fluid-filled intradural cyst associated with lumbar IDH and suggests the possible pathogenesis. Case report. An 82-year-old woman presented with right leg pain and motor weakness. Computed tomography and magnetic resonance imaging (MRI) scans showed calcified lumbar disc herniation and an intradural cystic mass at the L1-L2 level. An MRI, which was performed 2 years before admission, showed an IDH without a cyst at the same level. Surgical resection of the intradural cyst was performed. Intraoperative finding showed a fluid-filled intradural cyst with 1-cm diameter of displacing nerve rootlets. The cyst was connected with extradural cystic components through a ventral dural hole, but the tract was blocked by fibrous septum. Histopathologic examination showed a pseudocyst that consisted of degenerative cartilaginous and fibrous tissues, including degenerative disc materials. We concluded that the cyst was an intradural cyst transformed from the intradural disc fragment. The current case is the first report to our knowlege of a fluid-filled intradural cyst associated with IDH. The possible mechanism may be focal degeneration and spontaneous absorption of the intradural disc with fluid production. Unlike the gas-filled intradural cysts, the cause of the pure fluid-filled cyst may be disconnection from the intervertebral vacuum because of a calcified disc and septation of the cyst.
    The spine journal: official journal of the North American Spine Society 08/2013; · 2.90 Impact Factor
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    ABSTRACT: The purposes of this study were to evaluate the prevalence, types, and locations of Modic changes (MCs) in the thoracic spine in a large number of subjects, and to investigate the relation between the distributions of MCs and disc herniations (DHs) in the thoracic spine. Two experienced musculoskeletal radiologists assessed the presence of MCs and DHs by consensus in the thoracic MRIs of 144 patients with non-specific back pain. Patient ages ranged from 22 to 88 years (mean=53.3±14.66 years), and 72 were female (50%). The prevalence, distribution, relation of MCs and DHs was recorded. MC was observed in 8 of the 144 patients (5.6%) and 10 of 1728 segments (0.58%). The most common MC was type II. Of the 8 patients exhibiting MC, 6 had type II (75.0%), and 2 had mixed MCs (type I/II or type II/III). MCs were distributed mainly at the mid-thoracic level (from T5/6 to T9/10). DH was detected in 18 patients (12.5%), 36 of 1728 segments (2.1%). Of the 10 segments exhibiting MC, 5 had DHs at the same level (50.0%). Accordingly, DH was strongly associated with MC (p=0.000). A low prevalence of MC was observed in the thoracic spine, and type II MC predominated. The low prevalence of MC in the thoracic spine suggests that it was caused by a relative lack of mobility as compared with the cervical and lumbar spines. And DHs were found to be strongly associated with MCs even in the thoracic spine.
    Journal of Korean Neurosurgical Society 07/2013; 54(1):34-7. · 0.56 Impact Factor
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    ABSTRACT: Ginsenoside is known to have potential cancer-preventive activities. The major active components in red ginseng consist of a variety of ginsenosides including Rg3, Rg5 and Rk1, each of which has different pharmacological activities. Among these, Rg3 has been reported to exert anticancer activities through inhibition of angiogenesis and cell proliferation. However, the effects of Rg3 and its molecular mechanism on glioblastoma multiforme (GBM) remain unclear. Therefore, it is essential to develop a greater understanding of this novel compound. In the present study, we investigated the effects of Rg3 on a human glioblastoma cell line and its molecular signaling mechanism. The mechanisms of apoptosis by ginsenoside Rg3 were related with the MEK signaling pathway and reactive oxygen species. Our data suggest that ginsenoside Rg3 is a novel agent for the chemotherapy of GBM.
    Oncology Reports 06/2013; · 2.30 Impact Factor
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    Hwa Joong Lee, Won Ho Cho, In Ho Han, Byung Kwan Choi
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    ABSTRACT: The standard treatment for symptomatic spinal extradural arachnoid cyst (SEAC) is complete surgical removal of cyst and closure of the dural defect. In most cases, total laminectomy has been performed at affected vertebra for complete removal of the SEAC. However, this invasive surgery may result in postoperative kyphosis and back pain. We report a case of large SEAC involving T10-L1 which was excised through the minimal skipped hemilaminectomy, to minimize the risk of postoperative kyphotic deformity. Simultaneously, we closed the dural defect after preoperative precise identification of the site through several radiological studies.
    Korean Journal of Spine. 03/2013; 10(1):28-31.
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    ABSTRACT: The Leksell Gamma Knife® (LGK) is based on a single-fraction high dose treatment strategy. Therefore, independent verification of the Leksell GammaPlan® (LGP) is important for ensuring patient safety and minimizing the risk of treatment errors. Although several verification techniques have been previously developed and reported, no method has ever been tested statistically on multiple LGK target treatments. The purpose of this study was to perform and to evaluate the accuracy of a verification method (modified variable ellipsoid modeling technique, MVEMT) for multiple target treatments. A total of 500 locations in 10 consecutive patients with multiple brain tumor targets were included in this study. We compared the data from an LGP planning system and MVEMT in terms of dose at random points, maximal dose points, and target volumes. All data was analyzed by t-test and the Bland-Altman plot, which are statistical methods used to compare two different measurement techniques. No statistical difference in dose at the 500 random points was observed between LGP and MVEMT. Differences in maximal dose ranged from -2.4% to 6.1%. An average distance of 1.6 mm between the maximal dose points was observed when comparing the two methods. Statistical analyses demonstrated that MVEMT was in excellent agreement with LGP when planning for radiosurgery involving multiple target treatments. MVEMT is a useful, independent tool for planning multiple target treatment that provides statistically identical data to that produced by LGP. Findings from the present study indicate that MVEMT can be used as a reference dose verification system for multiple tumors.
    Journal of Korean Neurosurgical Society 02/2013; 53(2):102-7. · 0.56 Impact Factor
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    ABSTRACT: Study Design. A case report of anaerobic vertebral osteomyelitis after percutaneous epidural adhesiolysis.Objective. To present a case of Bacteroides fragilis spondylodiscitis (BFS) secondary to percutaneous epidural adhesiolysis in 38-year-old woman without predisposing factors.Summary of Background Data. Most cases of BFS result from hematogenous spread from a perianal abscess or sigmoidoscopy or local spread from an adjacent infection. However, BFS due to direct inoculation after percutaneous epidural adhesiolysis has not been previously reported.Methods. A 38-year-old woman presented with spondylodiscitis at the L4-5 level 2 weeks after percutaneous epidural adhesiolysis. Despite empirical antibiotherapy, the spondylodiscitis and an epidural abscess became much aggravated. Open biopsy and curettage was performed, and metronidazole sensitive Bacteroides fragilis was identified by tissue culture.Results. Metronidazole was administrated for 5 weeks and symptoms were completely resolved. Follow-up MRI showed that the spondylodiscitis was completely cured.Conclusion. This is the first report to be issued regarding BFS secondary to percutaneous epidural adhesiolysis. In our case, the pathogenesis may have been direct inoculation of Bacteroides fragilis into the epidural space and disc during percutaneous epidural adhesiolysis because the procedural approach used was adjacent to the anus.
    Spine 01/2013; · 2.16 Impact Factor
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    ABSTRACT: Coding Systematized Nomenclature of Medicine, Clinical Terms (SNOMED CT) with complex and polysemy clinical terms may ask coder to have a high level of knowledge of clinical domains, but with simpler clinical terms, coding may require only simpler knowledge. However, there are few studies quantitatively showing the relation between domain knowledge and coding ability. So, we tried to show the relationship between those two areas. We extracted diagnosis and operation names from electronic medical records of a university hospital for 500 ophthalmology and 500 neurosurgery patients. The coding process involved one ophthalmologist, one neurosurgeon, and one medical record technician who had no experience of SNOMED coding, without limitation to accessing of data for coding. The coding results and domain knowledge were compared. 705 and 576 diagnoses, and 500 and 629 operation names from ophthalmology and neurosurgery, were enrolled, respectively. The physicians showed higher performance in coding than in MRT for all domains; all specialist physicians showed the highest performance in domains of their own departments. All three coders showed statistically better coding rates in diagnosis than in operation names (p < 0.001). Performance of SNOMED coding with clinical terms is strongly related to the knowledge level of the domain and the complexity of the clinical terms. Physicians who generate clinical data can be the best potential candidates as excellent coders from the aspect of coding performance.
    Healthcare informatics research. 09/2012; 18(3):186-90.
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    ABSTRACT: The purpose of this study was to present the MRI and CT findings of solitary spinal bone lesions (SSBLs) with the aims of aiding the differential diagnoses of malignant tumors and benign lesions, and proposing a diagnostic strategy for obscure SSBLs. The authors retrospectively reviewed the imaging findings of 19 patients with an obscure SSBL on MRI at our hospital from January 1994 to April 2011. The 19 patients were divided to benign groups and malignant groups according to final diagnosis. MRI and CT findings were evaluated and the results of additional work-up studies were conducted to achieve a differential diagnosis. At final diagnoses, 10 (52.6%) of the 19 SSBLs were malignant tumors and 9 (47.4%) were benign lesions. The malignant tumors included 6 metastatic cancers, 3 multiple myelomas, and 1 chordoma, and the benign lesions included 4 osteomyelitis, 2 hemangiomas, 2 nonspecific chronic inflammations, and 1 giant cell tumor. No MRI characteristics examined was found to be significantly different in the benign and malignant groups. Reactive sclerotic change was observed by CT in 1 (10.0%) of the 10 malignant lesions and in 7 (77.8%) of the 9 benign lesions (p=0.005). Approximately half of the obscure SSBLs were malignant tumors. CT and MRI findings in combination may aid the differential diagnosis of obscure SSBLs. In particular, sclerotic change on CT images was an important finding implying benign lesion. Finally, we suggest a possible diagnostic strategy for obscure SSBLs on MRI.
    Journal of Korean Neurosurgical Society 08/2012; 52(2):126-32. · 0.60 Impact Factor
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    ABSTRACT: The intracranial stent functions primarily to prevent protrusion of coils into the parent vessel during the embolization of wide-necked cerebral aneurysms and might also reduce aneurysm recanalization rate. In spite of these advantages, little is known about the long-term interaction of the stent with the parent vessel wall. We present a rare case of severe in-stent stenosis occurring as a delayed complication of Neuroform stent-assisted coil embolization of an unruptured intracranial aneurysm.
    Journal of Korean Neurosurgical Society 06/2012; 51(6):370-3. · 0.60 Impact Factor
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    In Ho Han, Byung Kwan Choi, Won Ho Cho, Kyoung Hyup Nam
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    ABSTRACT: In conventional percutaneous disc surgery, introducing instruments into disc space starts by inserting a guide needle into the triangular working zone. However, landing the guide needle tip on the annular window is a challenging step in endoscopic discectomy. Surgeons tend to repeat the needling procedure to reach an optimal position on the annular target. Obturator guiding technique is a modification of standard endoscopic lumbar discectomy, in which, obturator is used to access triangular working zone instead of a guide needle. Obturator guiding technique provides more vivid feedback and easy manipulation. This technique decreases the steps of inserting instruments and takes safer route from the peritoneum.
    Journal of Korean Neurosurgical Society 03/2012; 51(3):182-6. · 0.60 Impact Factor
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    ABSTRACT: The purpose of this prospective study was to evaluate the effects of body mass index (BMI) on intra-abdominal pressure (IAP) and intraoperative blood loss (IBL) during lumbar spinal surgery. Thirty patients scheduled for single level posterior lumbar interbody fusion were allocated equally to a normal group (Group 1, BMI;18.5-22.9 kg/m(2)), an overweight group (Group 2, BMI; 23-24.9 kg/m(2)), and an obese group (Group 3, BMI; 25.0-29.9 kg/m(2)) according to BMI. IAP was measured using a urinary bladder catheter; 1) supine after anesthesia induction, 2) prone at skin incision, 3) prone at the end of surgery. In addition, IBL was also measured in the three groups. IAP in the supine position was not significantly different in groups 1, 2, and 3 (2.7 mm Hg, 3.0 mm Hg, and 4.2 mm Hg, respectively) (p=0.258), and IAP in the prone position at incision increased to 7.8 mm Hg, 8.2 mm Hg, and 10.4 mm Hg, respectively, in the three groups, and these intergroup differences were significant, especially for Group 3 (p=0.000). IAP at the end of surgery was slightly lower (7.0 mm Hg, 7.7 mm Hg, and 9.2 mm Hg, respectively). IBLs were not significantly different between the three groups. However, IBLs were found to increase with IAP in the prone position (p=0.022) and BMI (p<0.05). These results show that BMI affects IAP in the prone position more than in the supine position during lumbar spinal surgery. In addition, IBLs were found to increase with IAP in the prone position and with BMI. Thus, IBLs can be expected to be higher in morbidly obese patients due to an increased IAP.
    Journal of Korean Neurosurgical Society 02/2012; 51(2):81-5. · 0.60 Impact Factor
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    In Ho Han, Young Jun Seo, Won Ho Cho, Byung Kwan Choi
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    ABSTRACT: A 67-year-old woman presented for evaluation of severe coccygeal pain. The computed tomography scans and magnetic resonance imaging showed an asymmetric midline sacral tumor invading the right lower portion of S2. To preserve both S2 nerve roots and to obtain negative surgical margins, a modified mid-sacrectomy with an aid of a computed navigation system was performed. The sacral tumor was excised en bloc with negative tumor margins. Both S2 nerve roots were preserved and additional reconstruction was not necessary because of minimal resection of the sacroiliac joint. We report a case of a sacral chordoma which was excised en bloc with adequate surgical margins by a computer-assisted modified mid-sacrectomy. The computed navigation system may be a useful tool for tumor targeting and safe osteotomies in sacral tumor surgery via the posterior only approach.
    Journal of Korean Neurosurgical Society 12/2011; 50(6):523-7. · 0.60 Impact Factor
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    ABSTRACT: A 64-year-old man, 7 years after cervical trauma, presented with severe dysphagia of 3-month duration. Computed tomography showed an unusual synostosis between the thyroid cartilage and the cervical spine at C5-6-7 on the right side. A barium swallow study revealed no laryngeal elevation during swallowing. Surgical resection of the bony fusion was performed, and the patient's dysphagia immediately improved without any complications. We report a case of delayed synostosis between the thyroid cartilage and the cervical spine causing severe dysphagia 7 years after cervical trauma. Surgical resection of the bony fusion resulted in immediate improvement of the dysphagia.
    American journal of otolaryngology 09/2011; 33(3):358-60. · 0.77 Impact Factor
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    Su Heon Lee, In Ho Han, Dong Wan Kang, Byung Kwan Choi
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    ABSTRACT: Vertebral involvement of fibrous dysplasia (FD) is rare, especially in the cervical spine. Moreover, cervical FD presenting as a pathologic fracture in older patients is extremely rare. We report a case of symptomatic cervical FD associated with pathologic fracture in a 63-year-old man. The patient presented with progressive weakness of the left arm and pain in the shoulder and arm. Radiologic studies revealed a collapsed and typical 'ground glass' radiolucency of C4. Multiple lytic lesions involved the odontoid process of C2 and the body, left pedicle, and posterior elements of C4. Combined anterior and posterior decompression and reconstruction were performed. Post-operatively, the histopathologic examination confirmed FD. On the post-operative follow-up examination, the neurologic deficits had completely resolved.
    Journal of Korean Neurosurgical Society 08/2011; 50(2):139-42. · 0.60 Impact Factor
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    ABSTRACT: Intradural extramedullary (IDEM) ependymomas occur very rarely and little has been reported about their clinical characteristics. The authors present a case of a 57-year-old woman with an IDEM ependymoma. She was referred for the evaluation of a 4-month history of increasing neck pain and muscular weakness of the left extremities. Magnetic resonance imaging (MRI) of the cervical spine demonstrated an IDEM tumor with spinal cord compression. At the time of surgery, an encapsulated IDEM tumor without a dural attachment or medullary infiltration was noted, but the tumor capsule adherent to the spinal cord and root was left in place to minimize the risk of neurological sequelae. Histologic examination revealed a benign classic ependymoma. The post-operative course was uneventful and radiotherapy was performed. The patient showed an excellent clinical recovery, with no recurrence after 5 years of follow-up.
    Journal of Korean Neurosurgical Society 07/2011; 50(1):57-9. · 0.60 Impact Factor