• Journal of Korean Neurosurgical Society
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• v.43 no.5
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• pp.232-236
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• 2008

Total laminectomy for the removal of intradural-extramedullary spinal cord tumors has been used widely, but postoperative complications often develop, such as kyphosis, spinal instability, and persistent back pain. In this study, we evaluated seven patients with intradural-extramedullary spinal cord tumors with respect to the value of unilateral limited laminectomy. Our cases included six schwannomas, and one meningioma. The cervical region was involved in four cases, the thoracolumbar region in two cases, and the lumbar region in one case. The rationale for choosing a unilateral approach is to preserve musculoligamentous attachments and posterior bony elements as much as possible. The patients were mobilized on the third postoperative day and preoperative neurological symptoms were recovered within a few weeks. We did not observe any complication relating to unilateral limited laminectomy and at follow-up evaluation (at 3 and 12 months postoperatively), none of the patients showed spinal deformity or spinal instability. We think that the unilateral limited laminectomy is a safe and efficient technique for the treatment of intradural-extramedullary spinal cord tumors. We suggest that this technique is one of the best treatments for these tumors.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.363-369
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• 2011

Objective : We investigated the clinical and radiological advantages of unilateral laminectomy in posterior lumbar interbody fusion (PLIF) procedure comparing with bilateral laminectomy, under the same procedural condition including bilateral instrumentation and insertion of two cages, in patients with degenerative lumbar disease with unilateral leg symptoms. Methods : We retrospectively reviewed 124 consecutive cases of PLIF via unilateral or bilateral approach between January 2006 and April 2010. In 80 cases (bilateral group), two cages were inserted via bilateral laminectomy, and in 44 cases (unilateral group), via unilateral laminectomy. The average follow-up duration was 29.5 months. The clinical outcomes were evaluated with the Visual Analogue Scale (VAS) and the Oswestry disability index (ODI). The fusion rates and disc space heights were determined by dynamic standing radiographs and/or computed tomography. Operative times, intra-operative and post-operative blood losses and hospitalization periods were also evaluated. Results : In clinical evaluation, the VAS and ODI scores showed excellent outcomes in both groups. There were no significant differences in term of fusion rate, but the perioperative blood loss and the operative time of the unilateral group were lower than that of the bilateral group. Conclusion : Unilateral laminectomy can minimize the operative time and perioperative blood loss in PLIF procedure. However, the different preoperative disc height between two groups is a limitation of this study. Despite this limitation, solid fusion and satisfactory symptomatic improvement could be achieved uniquely by our surgical method. This surgical method can be an alternative surgical technique in patients with unilateral leg pain.

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.65-71
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• 2015

Objective : Lumbar spinal stenosis is conventionally treated with surgical decompression. However, bilateral decompression and laminectomy is more invasive and may not be necessary for lumbar stenosis patients with unilateral radiculopathy. We aimed to report the outcomes of unilateral laminectomy and bilateral pedicle screw fixation with fusion for patients with lumbar spinal stenosis and unilateral radiculopathy. Methods : Patients with lumbar spinal stenosis with unilateral lower extremity radiculopathy who received limited unilateral decompression and bilateral pedicle screw fixation were included and evaluated using visual analog scale (VAS) pain and the Oswestry Disability Index (ODI) scores preoperatively and at follow-up visits. Ligamentum flavum thickness of the involved segments was measured on axial magnetic resonance images. Results : Twenty-five patients were included. The mean preoperative VAS score was $6.6{\pm}1.6$ and $4.6{\pm}3.1$ for leg and back pain, respectively. Ligamentum flavum thickness was comparable between the symptomatic and asymptomatic side (p=0.554). The mean follow-up duration was 29.2 months. The pain in the symptomatic side lower extremity (VAS score, $1.32{\pm}1.2$) and the back (VAS score, $1.75{\pm}1.73$) significantly improved (p=0.000 vs. baseline for both). The ODI improved significantly postoperatively ($6.60{\pm}6.5$; p=0.000 vs. baseline). Significant improvement in VAS pain and ODI scores were observed in patients receiving single or multi-segment decompression fusion with fixation (p<0.01). Conclusion : Limited laminectomy and unilateral spinal decompression followed by bilateral pedicle screw fixation with fusion achieves satisfactory outcomes in patients with spinal stenosis and unilateral radiculopathy. This procedure is less damaging to structures that are important for maintaining posterior stability of the spine.

• Journal of Korean Neurosurgical Society
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• v.37 no.6
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• pp.410-415
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• 2005

Objective: The aim of our study is to evaluate the effectiveness of unilateral hemilaminectomy for bilateral decompression in elderly patients with degenerative spinal stenosis. For this purpose, we studied the co-morbid condition and clinical outcome of patients who underwent decompressive surgery using the unilateral approach technique. Methods: Thirty-four patients over 65years of age who underwent unilateral partial laminectomy for bilateral decompression from January 2000 to October 2003 were analyzed. These patients were studied for preoperative co-morbid condition and physical status according to the American Society of Anesthesiologists(ASA) classification, postoperative morphometrical change, and clinical outcomes, including visual analogue scale(VAS) score. The mean follow-up was 23months (range 6 - 48months). Results: A patient's physical status was recorded as class I, II, or III by ASA classification, which correlated to 41.2%, 44.1%, and 14.7% of patients, respectively. The cross-sectional area of the pre- and postoperative dural sac at the level of the stenosis was $52.5{\pm}19.9mm^2$ and $110.6{\pm}18.2mm^2$, respectively. The outcome was excellent in 8.8%, good in 58.8%, fair in 23.6%, and poor in 8.8% of the patients. The VAS was changed postoperatively to $3.1{\pm}1.2$. There was no operation-related transfusion yet there was no evidence of postoperative instability at the follow-up examination. Conclusion: Unilateral laminectomy for bilateral decompression, in spite of the limited exposure, can result in satisfactory decompression of the lumbar spinal stenosis and tolerable clinical outcome. This approach is thought to be appropriate for elderly patients who have a greater surgical burden.

• Journal of Korean Neurosurgical Society
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• v.40 no.1
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• pp.35-37
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• 2006

We present a case of acute spinal epidural hematoma[EDH] following unilateral laminectomy for bilateral decompression[ULBD]. A 45-year-old male presented with severe multi-level spinal stenosis underwent ULBD on the left side at the L2-3 and L3-4 level. Five hours after operation, paraparesis developed along with severe bilateral buttock pain. The CT scan showed an acute spinal EDH at the L2-3 level. The acute spinal EDH was successfully decompressed after emergency decompressive surgery with performing an additional laminectomy on the contralateral side at the L2-3 level. Although ULBD is an effective minimally invasive surgical technique for treating spinal stenosis, the possibility of acute spinal EDH should be kept in mind, as happened in our case.

• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.537-543
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• 2002

The purpose of the present study was to investigate structural stability of extensive laminectomy and the effect of subcutaneous fat autograft on restricting formation of postlaminectomy membrane (fibrous tissue). Eighteen healthy dogs of both sexes and of mixed breeding were divided into 6 groups : (1) unilateral hemilaminectomy (group H) on 3rd, 4th and 7th vertebrae ; (2) modified dorsal laminectomy (group D) on 3rd, 4th and 7th vertebrae. Hemilaminectomies were carried out incontinuously at 16 sites in 4 dogs, then subcutaneous fat autografts (group F) were applied to 8 laminectomy sites and no treatment (group C) was assigned to 8 laminectomy sites, too. Operating time of group H ($30.9{\pm}10.4$ minutes) was significantly shorter (p<0.05) than that of group D ($43.1{\pm}12.2$ minutes), but surgical hemorrhage of group H is severer than that of group D. General states, such as standing, gait, defecation and urination, were normal. Upper motor neuron/lower motor neuron signs were not found and superficial/deep pain, proprioception and anal sphincter tone were normal. Gross postmortem findings were similar in all groups. The laminectomy sites of groups H and D were filled with fibous connective tissue at 4 months after operation and histopathological abnormalities of spinal cord were not found. One of eight laminectomy sites in group F was filled with fibrous tissue at 2 months after operation, but all operating sites of group C were covered with fibrous tissue. The present study indicated that extensive laminectomy on 7 vertebrae, using unilateral hemilaminectomy and modified dorsal laminectomy technique, maintained structural stability and subcutaneous fat autograft was effective on reducing the formation of fibrous membrane in laminectomy sites.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.680-688
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• 2018

Objective : To mitigate the risk of iatrogenic instability, new posterior decompression techniques able to preserve musculoskeletal structures have been introduced but never extensively investigated from a biomechanical point of view. This study was aimed to investigate the impact on spinal flexibility caused by a unilateral laminotomy for bilateral decompression, in comparison to the intact condition and a laminectomy with preservation of a bony bridge at the vertebral arch. Secondary aims were to investigate the biomechanical effects of two-level decompression and the quantification of the restoration of stability after posterior fixation. Methods : A universal spine tester was used to measure the flexibility of six L2-L5 human spine specimens in intact conditions and after decompression and fixation surgeries. An incremental damage protocol was applied : 1) unilateral laminotomy for bilateral decompression at L3-L4; 2) on three specimens, the unilateral laminotomy was extended to L4-L5; 3) laminectomy with preservation of a bony bridge at the vertebral arch (at L3-L4 in the first three specimens and at L4-L5 in the rest); and 4) pedicle screw fixation at the involved levels. Results : Unilateral laminotomy for bilateral decompression had a minor influence on the lumbar flexibility. In flexion-extension, the median range of motion increased by 8%. The bone-preserving laminectomy did not cause major changes in spinal flexibility. Two-level decompression approximately induced a twofold destabilization compared to the single-level treatment, with greater effect on the lower level. Posterior fixation reduced the flexibility to values lower than in the intact conditions in all cases. Conclusion : In vitro testing of human lumbar specimens revealed that unilateral laminotomy for bilateral decompression and bone-preserving laminectomy induced a minor destabilization at the operated level. In absence of other pathological factors (e.g., clinical instability, spondylolisthesis), both techniques appear to be safe from a biomechanical point of view.

• Journal of Korean Neurosurgical Society
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• v.39 no.1
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• pp.40-45
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• 2006

Objective : To determine the relationship between the clinical outcome and the extent of surgical laminectomy for adequate decompression on the cases of cauda equina syndrome, the authors review and analyze their cases and compared with those of literatures. Methods : The authors reviewed 655 patients retrospectively who had underwent surgery on the cases of lumbar disc herniation from January 2000 to December 2004. There were 19 patients [2.9%] who presented for clinical cauda equina syndrome. Among them, we selected and analyzed 15 patients who were treated by unilateral partial hemilaminectomy with discectomy or bilateral partial laminectomy with discectomy, and they had been followed from 5 weeks to 47 months postoperatively [mean, 13.47 months]. The levels of the disc herniations were L4-5 in 8 patients, following L5-S1 in 4 patients and 2 levels [L4-5 and L5-S1] in 3 patients. Motor and sensory recoveries were recorded. Postoperative urinary function recovery Was defined according to Gleave and Macfarlane. Results : In 12 months postoperatively, the bladder function was obtained in 14 of 15 patients[93%] with regaining urinary continence. Thirteen of 15 patients[86%] with preoperative motor weakness of lower extremities were recovered. Sensory deficit of lower extremities, perianal and saddle anesthesia were all recovered. Patients had recovered on lumbosciatic pain and saddle hypesthesia, in turn, motor function and urinary incontinence. Conclusion : In treating cauda equina syndrome, the authors did less extensive surgery, such as unilateral partial hemilaminectomy with discectomy or bilateral partial laminectomy with discectomy for adequate decompression. The outcome is satisfactory and comparable with those of subtotal or total laminectomy.

• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.119-124
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• 2010

Objective : Disc herniations at the L1-L2 and L2-L3 levels are different from those at lower levels of the lumbar spine with regard to clinical characteristics and surgical outcome. Spinal canals are narrower than those of lower levels, which may compromise multiple spinal nerve roots or conus medullaris. The aim of this study was to evaluate the clinical features and surgical outcomes of upper lumbar disc herniations. Methods : We retrospectively reviewed the clinical features of 41 patients who had undergone surgery for single disc herniations at the L1-L2 and L2-3 levels from 1998 to 2007. The affected levels were L1-L2 in 14 patients and L2-L3 in 27 patients. Presenting symptoms and signs, patient characteristics, radiologic findings, operative methods, and surgical outcomes were investigated. Results : The mean age of patients with upper lumbar disc was 55.5 years (ranged 31 to 78). The mean follow-up period was 16.6 months. Most patients complained of back and buttock pain (38 patients, 92%), and radiating pain in areas such as the anterior or anterolateral aspect of the thigh (32 patients, 78%). Weakness of lower extremities was observed in 16 patients (39%) and sensory disturbance was presented in 19 patients (46%). Only 6 patients (14%) had undergone previous lumbar disc surgery. Discectomy was performed using three methods : unilateral laminectomy in 27 cases, bilateral laminectomy in 3 cases, and the transdural approach in 11 cases, which were performed through total laminectomy in 10 cases and unilateral laminectomy in 1 case. With regard to surgical outcomes, preoperative symptoms improved significantly in 33 patients (80.5%), partially in 7 patients (17%), and were aggravated in 1 patient (2.5%). Conclusion : Clinical features of disc herniations at the L1-L2 and L2-L3 levels were variable, and localized sensory change or pain was rarely demonstrated. In most cases, the discectomy was performed successfully by conventional posterior laminectomy. On the other hand, in large central broad based disc herniation, when the neural elements are severely compromised, the posterior transdural approach could be an alternative.

• Journal of Chest Surgery
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• v.27 no.6
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• pp.502-505
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• 1994

Neurogenic tumors of the mediastinum may have an intraspinal component connected by a narrowed segment of tumor in the intervertebral foramen,hence the descriptive term dumbbell.Recently we had an occasion to remove a dumbbell neurilemmoma in a 62 years old woman using an approach designed to allow wide posterolateral thoracotomy and concomitant laminectomy for a single stage removal of the entire tumor. The mass in the posterior mediastinum was discovered on routine chest roentgenography. CT scan demonstrated a dumbbell shaped soft tissue mass density compressing spinal canal but preserving spinal cord. There were no neurologic signs. A standard posterolateral thoracotomy incision was made to remove tumor mass and then T5 unilateral laminectomy has done by Neurosurgeon. 7 x 7 cm sized extrapleural neurilemmoma was round, cystic, soft mass which covered parietal pleural with invaded regional vertebrae. There was no postoperative neurological complication.