• Proceedings of the KSME Conference
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• 2004.11a
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• pp.823-828
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• 2004

Minimally Invasive Surgery (MIS) is surgery of the chest, abdomen, spine and pelvis, done with the aid of a viewing scope, and specially designed instruments. Benefits of minimally invasive surgery are less pain, less need for post-surgical pain medication, less scarring and less likelihood for incisional complications. Since the late 1980's, minimally invasive surgery has gained widespread acceptance because of the such advantages. However there are significant disadvantages which have, to date, limited the applications for these promising techniques. The reasons are limited degree-of-freedom, reduced dexterity and the lack of tactile feeling. To overcome such disadvantages many researchers have endeavored to develop robotic systems. Even though some robot aided systems achieved success and commercialized, there still remain many thing to be improved. In this paper, the robotic system which can mimic whole motions of a human arm by adding additional DOF is presented. The suggested design is expected to provide surgeons with improved dexterity during minimally invasive surgery.

• Journal of Korean Neurosurgical Society
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• v.40 no.4
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• pp.296-299
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• 2006

Recently the trend of surgical procedure for treatment of lumbar benign disease is a minimally invasive surgery due to small incision, minimal blood loss, and a short hospital day. By using a microscope or an endoscope, and other surgical equipment, a delicate manipulation in a narrow space became feasible, consequently, to secure a wider view with small incision, appropriate retractors are required. But the various tubular retractor systems are expensive and have some problems. We modified Thoracoport [Auto Suture Co., Norwalk, CT] by making a window at the distal end of trocar and used it as a tubular retractor in surgical procedure for treatment of lumbar benign disease. This modified tubular retractor is docked closely on the curved lamina and provides a wider view. We used it as a tubular retractor also in lumbar bilateral decompression involving a unilateral approach. But this trocar has the limited sizes [diameter and length], and also it is difficult to fix the retractor or change the direction of retractor. And then, we propose a more modified Thoracoport with various sizes and attaching the settling holders to the head of tubular retractor to be able to fix the retractor.

• Journal of Korean Neurosurgical Society
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• v.63 no.6
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• pp.767-776
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• 2020

Objective : The aim of this study is to evaluate the feasibility of posterior cervical foraminotomy (PCF) for adjacent segmental disease (ASD) after anterior cervical fusion (ACF). As ACF is accepted as the standard treatment for cervical spondylosis, many studies have been conducted to evaluate the efficacy of various surgical techniques to overcome symptomatic ASD after the previous surgery. Herein, PCF was performed for the treatment of symptomatic ASD and the feasibility of the surgery was evaluated. Methods : Forty nine patients who underwent PCF due to symptomatic ASD from August 2008 to November 2017 were identified. For demographic and perioperative data, the sex, age, types of previous surgery, ASD levels, operation times, and bleeding amount were recorded. The clinical outcome was assessed using the visual analogue scale for the neck and arm, the modified Odom's criteria as well as neck disability index. Radiologic evaluations were performed by measuring disc softness, disc height, the cervical 2-7 sagittal vertical axis, cervical cobb angle, and facet violation. Results : Thirty-seven patients were enrolled in this study. The patients were divided into two groups based on the location of the pathology; paracentral (group P) or foramina (group F). Both groups showed significant clinical improvement (p<0.05). The proportion of calcified disc and facet violations was significantly larger in group F (p<0.05). The minimal disc height decrease with mild improvement on sagittal alignment and cervical lordosis was radiologically measured without statistical significance in both groups (p>0.05). Conclusion : PCF showed satisfactory clinical and radiologic outcomes for both paracentral and foraminal pathologies of ASD after ACF. Complications related to anterior revision were also avoided. PCF can be considered a feasible and safe surgical option for ASD after ACF.

• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.248-251
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• 2011

Objective : In the field of spinal surgery, a few laboratory results or clinical cases about robotic spinal surgery have been reported. In vivo trials and development of related surgical instruments for spinal surgery are required before its clinical application. We investigated the use of the da $Vinci^{(R)}$ Surgical System in spinal surgery at the craniovertebral junction in a human cadaver to demonstrate the efficacy and pitfalls of robotic surgery. Methods : Dissection of pharyngeal wall to the exposure of C1 and odontoid process was performed with full robotic procedure. Although assistance of another surgeon was necessary for drilling and removal of odontoid process due to the lack of appropriate end-effectors, successful robotic procedures for dural sutures and exposing spinal cord proved its safety and dexterity. Results : Robot-assisted odontoidectomy was successfully performed in a human cadaver using the da $Vinci^{(R)}$ Surgical System with few robotic arm collisions and minimal soft tissue damages. Da $Vinci^{(R)}$ Surgical System manifested more dexterous movement than human hands in the deep and narrow oral cavity. Furthermore, sutures with robotic procedure in the oral cavity demonstrated the advantage over conventional procedure. Conclusion : Presenting cadaveric study proved the probability of robot-assisted transoral approach. However, the development of robotic instruments specific to spinal surgery must first precede its clinical application.

• Journal of Korean Neurosurgical Society
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• v.41 no.4
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• pp.241-245
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• 2007

Objective : So called "minimally invasive procedures" have evolved from chemonucleolysis, automated percutaneous discectomy, arthroscopic microdiscectomy that are mainly working within the confines of intradiscal space to transforaminal endoscopic technique to remove herniated epidural disc materials directly. The purpose of this study is to assess the result of endoscopic spinal surgery and favorable indication in the thoracolumbar spine. Methods : The records of 71 patients, 73 endoscopic procedures, were retrospectively analysed. Yeung Endoscopic Spine Surgery system with 7 mm working sleeve and $25^{\circ}$ viewing angle was used. The mean follow up period was 6 months [range, 3-9]. Results : Operated levels were from T12-L1 disc down to L5-L6 of S1 disc. Of 71 cases, 2 patients underwent transforaminal endoscopic surgery twice due to recurrence after initial operation. MacNab's criteria was used to assess the outcome. Favorable outcome, excellent of good, was seen in 78% [57 procedures] of the patients. Among 11 fair outcomes, only 1 procedure was followed by secondary open procedure, laminectomy with discectomy. Two of 5 poor outcomes were operated again by same procedure which resulted in fair outcomes. One patient with aggravated cauda equina syndrome remained poor and a lumbar fusion procedure was performed in other patient with poor outcome. There were 2 postoperative discitis that were treated with conservative care in one and anterior lumbar interbody fusion in the other. Conclusion : Evolving technology of mechanical, visual instrument enables minimal invasive procedure possible and effective. The transforaminal endoscopic spinal surgery can reach as high as T12-L1 disc level. The rate of favorable outcome is mid-range among reported endoscopic lumbar surgery series. Authors believe that the outcome will be better as cases accumulate and will be able to reach the fate of standard open microsurgery.

• Journal of Korean Neurosurgical Society
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• v.60 no.5
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• pp.597-603
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• 2017

Objective : Several surgical methods have been reported for treatment of ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine. Despite rapid innovation of instruments and techniques for spinal surgery, the postoperative outcomes are not always favorable. This article reports a minimally invasive anterior decompression technique without instrumented fusion, which was modified from the conventional procedure. The authors present 2 cases of huge beak-type OPLL. Patients underwent minimally invasive anterior decompression without fusion. This method created a space on the ventral side of the OPLL without violating global thoracic spinal stability. Via this space, the OPLL and anterior lateral side of the dural sac can be seen and manipulated directly. Then, total removal of the OPLL was accomplished. No orthosis was needed. In this article, we share our key technique and concepts for treatment of huge thoracic OPLL. Methods : Case 1. 51-year-old female was referred to our hospital with right lower limb radiating pain and paresis. Thoracic OPLL at T6-7 had been identified at our hospital, and conservative treatment had been tried without success. Case 2. This 54-year-old female with a 6-month history of progressive gait disturbance and bilateral lower extremity radiating pain (right>left) was admitted to our institute. She also had hypoesthesia in both lower legs. Her symptoms had been gradually progressing. Computed tomography scans showed massive OPLL at the T9-10 level. Magnetic resonance imaging of the thoracolumbar spine demonstrated ventral bony masses with severe anterior compression of the spinal cord at the same level. Results : We used this surgical method in 2 patients with a huge beaked-type OPLL in the thoracic level. Complete removal of the OPLL via anterior decompression without instrumented fusion was accomplished. The 1st case had no intraoperative or postoperative complications, and the 2nd case had 1 intraoperative complication (dural tear) and no postoperative complications. There were no residual symptoms of the lower extremities. Conclusion : This surgical technique allows the surgeon to safely and effectively perform minimally invasive anterior decompression without instrumented fusion via a transthoracic approach for thoracic OPLL. It can be applied at the mid and lower level of the thoracic spine and could become a standard procedure for treatment of huge beak-type thoracic OPLL.

• Journal of Korean Neurosurgical Society
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• v.60 no.3
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• pp.322-326
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• 2017

Neuroendoscopic surgery is performed because it causes minimal damage to normal structures, carries a lower rate of complications, and achieves excellent outcomes. Surgeons using an endoscope and related instruments can perform complex operations through very small incisions, which is especially useful for minimally invasive procedures for the brain and spine. Neuroendoscopic surgery is now performed in cases of obstructive hydrocephalus, various intraventricular lesions, hypothalamic hamartomas, craniosynostosis, skull base tumors, and spinal lesions. This review discusses the brief history of neuroendoscopy and the current state and future perspectives of endoscopic surgery.

• Journal of Korean Neurosurgical Society
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• v.55 no.5
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• pp.248-254
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• 2014

Objective : According to the recent development of minimally invasive spinal surgery, direct lumbar interbody fusion (DLIF) was introduced as an effective option to treat lumbar degenerative diseases. However, comprehensive results of DLIF have not been reported in Korea yet. The object of this study is to summarize radiological and clinical outcomes of our DLIF experience. Methods : We performed DLIF for 130 patients from May 2011 to June 2013. Among them, 90 patients, who could be followed up for more than 6 months, were analyzed retrospectively. Clinical outcomes were compared using visual analog scale (VAS) score and Oswestry Disability Index (ODI). Bilateral foramen areas, disc height, segmental coronal and sagittal angle, and regional sagittal angle were measured. Additionally, fusion rate was assessed. Results : A total of 90 patients, 116 levels, were underwent DLIF. The VAS and ODI improved statistically significant after surgery. All the approaches for DLIF were done on the left side. The left and right side foramen area changed from $99.5mm^2$ and $102.9mm^2$ to $159.2mm^2$ and $151.2mm^2$ postoperatively (p<0.001). Pre- and postoperative segmental coronal and sagittal angles changed statistically significant from $4.1^{\circ}$ and $9.9^{\circ}$ to $1.1^{\circ}$ and $11.1^{\circ}$. Fusion rates of 6 and 12 months were 60.9% and 87.8%. Complications occurred in 17 patients (18.9%). However, most of the complications were resolved within 2 months. Conclusion : DLIF is not only effective for indirect decompression and deformity correction but also shows satisfactory mechanical stability and fusion rate.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.225-229
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• 2010

Objective : The authors introduce a minimally invasive muscle sparing transmuscular microdiscectomy (MSTM) to treat herniated lumbar disc disease. Its results are compared with conventional subperiosteal microdiscectomy (CSM) to validate the effectiveness. Methods : Muscle sparing transmuscular microdiscectomy, which involves muscle dissection approach using the natural fat cleavage plane between the multifidus to expose the interlaminar space, was performed in 23 patients to treat a single level unilateral lumbar radiculopathy. The creatine phosphokinase (CPK)-MM serum levels were measured on admission and at 1, 3, and 5 days postoperatively. Postoperative pain was evaluated using a 10-point visual analogue scale (VAS) and recorded on admission and at 1, 3, and 5 days postoperatively. The results were compared to those from the conventional subperiosteal microdiscectomy (43 patients). Results : The CPK-MM levels were significantly lower in the serum of the MSTM group compared to the CSM group on postoperative days three and five (p = 0.03 and p = 0.02, respectively). The clinical scales for back pain using VAS were significantly lower in the MSTM group than in the CSM group on postoperative days three (p = 0.04). The mean VAS scores for leg pain in both groups showed no significant differences during the early postoperative period. Conclusion : Muscle sparing transmuscular microdiscectomy is a minimally invasive surgical option to treat lumbar radiculopathy due to herniated disc. The approach affected minimal injury to posterior lumbar supporting structures with alleviated postoperative back pain.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.332-340
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• 2011

Objective : Pyogenic spondylitis often results in acute neurological deterioration requiring adequate surgical intervention and appropriate antibiotic treatment. The purpose of this study was to conduct an analysis of the clinical effect of continuous irrigation via laminotomy in a series of patients with pyogenic spondylitis in thoracic and lumbar spine. Methods : The authors conducted a retrospective investigation of 31 consecutive patients with pyogenic thoracic and lumbar spondylitis who underwent continuous irrigation through laminotomy from 2004 to 2008. The study included 22 men and 9 women, ranging in age from 38 to 78 years (mean 58.1 years). The average follow-up duration was 13.4 months (range, 8-34 months). We performed debridement and abscess removal after simple laminotomy, and then washed out epidural and disc space using a continuous irrigation system. Broad spectrum antibiotics were administered empirically and changed according to the subsequent culture result. Clinical outcomes were based on the low back outcome scale (LBOS), visual analogue scale (VAS) score, and Frankel grade at the last follow-up. Radiological assessment involved plain radiographs, including functional views. Results : Common predisposing factors included local injection for pain therapy, diabetes mellitus, chronic renal failure, and liver cirrhosis. Causative microorganisms were identified in 22 cases (70.9%) : Staphylococcus aureus and Streptococcus spp. were the main organisms. After surgery, LBOS, VAS score, and Frankel grade showed significant improvement in most patients. Spinal stability was maintained during the follow-up period, making secondary reconstructive surgery unnecessary for all patients, except one. Conclusion : Simple laminotomy with continuous irrigation by insertion of a catheter into intervertebral disc space or epidural space was minimally invasive and effective in the treatment of pyogenic spondylitis. This procedure could be a beneficial treatment option in patients with thoracolumbar spondylitis combined with minimal or moderate destructive change of vertebrae.