Comparative Analysis Between Thoracic Spinal Cord and Sacral Neuromodulation in a Rat Spinal Cord Injury Model: A Preliminary Report of a Rat Spinal Cord Stimulation Model

현승재,이창현,권지웅,윤철용,임재영,김기정,장태안,김현집 대한척추신경외과학회 2013 Neurospine Vol.10 No.1

Objective: The purpose of this study is to compare a neuroprotective effect of thoracic cord neuromodulation to that of sacral nerve neuromodulation in rat thoracic spinal cord injury (SCI) model. Methods: Twenty female Sprague Dawley rats were randomly divided into 4 groups: the normal control group (n=5), SCI with sham stimulation group (SCI, n=5), SCI with electrical stimulation at thoracic spinal cord (SCI + TES, n=5), and SCI with electrical stimulation at sacral nerve (SCI + SES, n=5). Spinal cord was injured by an impactor which dropped from 25mm height. Electrical stimulation was performed by the following protocol: pulse duration, 0.1ms; frequency, 20 Hz; stimulation time, 30 minutes; and stimulation duration at thoracic epidural space and S2 or 3 neural foramina for 4 weeks. Locomotor function, urodynamic study, muscle weights, and fiber cross sectional area (CSA) were investigated. Results: All rats of the SCI + TES group expired within 3 days after the injury. The locomotor function of all survived rats improved over time but there was no significant difference between the SCI and the SCI + SES group. All rats experienced urinary retention after the injury and recovered self-voiding after 3-9 days. Voiding contraction interval was 25.5±7.5 minutes in the SCI group, 16.5±5.3 minutes in the SCI+SES group, and 12.5±4.2 minutes in the control group. The recovery of voiding contraction interval was significant in the SCI + SES group comparing to the SCI group (p<0.05). Muscle weight and CSA were slightly greater in the SCI + SES than in the SCI group, but the difference was not significant. Conclusion: We failed to establish a rat spinal cord stimulation model. However, sacral neuromodulation have a therapeutic potential to improve neurogenic bladder and muscle atrophy.

Pedicle Screw Placement in the Thoracolumbar Spine Using a Novel, Simple, Safe, and Effective Guide-Pin : A Computerized Tomography Analysis

현승재,Yongjung J. Kim,임승철,Gene Cheh,Samuel K. Cho 대한신경외과학회 2015 Journal of Korean neurosurgical society Vol.58 No.1

Objective : To improve pedicle screw placement accuracy with minimal radiation and low cost, we developed specially designed K-wire with a marker. To evaluate the accuracy of thoracolumbar pedicle screws placed using the novel guide-pin and portable X-rays. Methods : Observational cohort study with computerized tomography (CT) analysis of in vivo and in vitro pedicle screw placement. Postoperative CT scans of 183 titanium pedicle screws (85 lumbar and 98 thoracic from T1 to L5) placed into 2 cadavers and 18 patients were assessed. A specially designed guide-pin with a marker was inserted into the pedicle to identify the correct starting point (2 mm lateral to the center of the pedicle) and aiming point (center of the pedicle isthmus) in posteroanterior and lateral X-rays. After radiographically confirming the exact starting and aiming points desired, a gearshift was inserted into the pedicle from the starting point into the vertebral body through the center of pedicle isthmus. Results : Ninety-nine percent (181/183) of screws were contained within the pedicle (total 183 pedicle screws : 98 thoracic pedicle screws and 85 lumbar screws). Only two of 183 (1.0%) thoracic pedicle screws demonstrated breach (1 lateral in a patient and 1 medial in a cadaver specimen). None of the pedicle breaches were associated with neurologic or other clinical sequelae. Conclusion : A simple, specially designed guide-pin with portable X-rays can provide correct starting and aiming points and allows for accurate pedicle screw placement without preoperative CT scan and intraoperative fluoroscopic assistance.

Adolescent Idiopathic Scoliosis Treatment by a Korean Neurosurgeon : The Changing Role for Neurosurgeons

현승재,Woong-Beom Kim,Young-Seop Park,Ki-Jeong Kim,장태안,Yongjung J. Kim 대한신경외과학회 2015 Journal of Korean neurosurgical society Vol.58 No.1

Objective : The purpose of this study was to evaluate radiographic/clinical outcomes of adolescent idiopathic scoliosis (AIS) patients treated by a Korean neurosurgeon. Methods : Ten AIS patients were treated by a single neurosurgeon between January 2011 and September 2013 utilizing segmental instrumentation with pedicle screws. Basic demographic information, curve pattern by Lenke classification, number of levels treated, amount of correction achieved, radiographic/clinical outcomes [by Scolisis Resarch Society (SRS-22r) questionnaire] and complications were evaluated to determine the surgical results. Pulmonary function test was utilized to assess forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) before and after surgery. Results : The average percentage of correction of the major structural curve was 73.6% (ranged from 64% to 81.5%). Preoperative and final postoperative absolute FVC averaged 3.03 L and 3.76 L (0.73 L increase, p=0.046), and absolute FEV1 averaged 2.63 L and 3.49 L (0.86 L increase, p=0.021). Preoperative and final postoperative average self-image and function scores of SRS-22r were, 2.6±0.5, 3.3±0.1, 4.0±0.5, and 4.6±0.0, respectively. There was a significant improvement of the self-image and function scores of SRS-22r questionnaires before and after surgery (p<0.05). There was no case of neurological deficit, infection and revision for screw malposition. One patient underwent a fusion extension surgery for shoulder asymmetry. Conclusion : Radiographic/clinical outcomes of AIS patients treated by a Korean neurosurgeon were acceptable. Fundamental understanding of pediatric spinal deformity is essential for the practice of AIS surgery.

The Effect of Preoperative Short-term Use of Tranexamic Acid in Patients with Aneurysmal Subarachnoid Hemorrhage

현승재,황성남,박승원,남택균,이영석 대한뇌혈관외과학회 2010 Journal of Cerebrovascular and Endovascular Neuros Vol.12 No.1

Objective : The goal of this study was to determine the effect of short-term usage of tranexamic acid (TXA), which is an antifibrinolytic agent, on patients with aneurysmal subarachnoid hemorrhage (aSAH). Methods:Weprospectivelyanalyzed80consecutivepatientswho had undergone surgery for aSAH between January 2004 and December 2006. The patients were placed either in the TXA group for those who were treated with TXA (N=38) or in the n-TXA group for those who were not (N=42). The incidences of rebleeding and vasospasm (with using the transcranial Doppler (TCD) criteria), symptomatic vasospasm and hydrocephalus were compared between the two groups. Results : Preoperative rebleeding occurred only in one patient in each group (2.6% of the TXA group and 2.3% of the n-TXA group (p>0.05). Vasospasm developed in 18 (47.4%) of the TXA patients and in 20 (47.6%) of the n-TXA patients (p>0.05). Among the patients with vasospasm, the number of symptomatic vasospasms was 16 (89%) in the TXA group and 11 (55%) in the n-TXA group (p<0.05). The patients with symptomatic vasospasm in the TXA group seemed to have worse outcomes than those in the n-TXA group (p>0.05). The incidence of hydrocephalus was not different between the two groups. Conclusion:Weconcludethatthepreoperativeshort-termuse of TXA can increase the risk of postoperative symptomatic vasospasm, although the incidence of vasospasm was not different between the two groups. According to our results, we recommend being very cautious of vasospasm and ischemic events when TXA is used preoperatively in patients with aSAH. (KorJCerebrovascularSurgery12(1):5-9,2010)

Proximal Junctional Kyphosis and Proximal Junctional Failure Following Adult Spinal Deformity Surgery

현승재,이병헌,박종화,김기정,장태안,김현집 대한척추신경외과학회 2017 Neurospine Vol.14 No.4

The purpose of this review is the current understanding of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) following adult spinal deformity (ASD) surgery. We carried out a systematic search of PubMed for literatures published up to September 2017 with “proximal junctional kyphosis,” “proximal junctional failure,” and “adult spinal deformity” as search terms. A total of 98 literatures were searched. The 37 articles were included in this review. PJK is multifactorial in origin and likely results from variable risk factors. PJF is a progressive form of the PJK spectrum including bony fracture, subluxation between UIV and UIV+1, failure of fixation, neurological deficit, which may require revision surgery for proximal extension of fusion. Soft tissue protections, adequate selection of the UIV, prophylactic rib fixation, hybrid instrumentation such as hooks, vertebral cement augmentation at UIV and UIV+1, adequate selection material of rods and age-appropriate spinopelvic alignment goals are strategies to minimize PJK and PJF. The ability to perform aggressive global realignment of spinal deformities has also led to the discovery of new complications such as the PJK and PJF. Continuous research on PJK and PJF should be proceeded in order to comprehend the pathophysiology of these complications.

Posterior Trans-Dural Repair of Iatrogenic Spinal Cord Herniation after Resection of Ossification of Posterior Longitudinal Ligament

현승재,김홍기,김기정,장태안,김현집 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.2

Iatrogenic spinal cord herniation is a rare complication following spinal surgery. We introduce a posterior trans-dural repair technique used in a case of thoracic spinal cord herniation through a ventral dural defect following resection of ossification of the posterior longitudinal ligament (OPLL) in the cervicothoracic spine. A 51-year-old female was suffering from paraplegia after laminectomy alone for cervicothoracic OPLL. Magnetic resonance imaging revealed a severely compressed spinal cord with pseudomeningocele identified postoperatively. Cerebrospinal fluid leak and iatrogenic spinal cord herniation persisted despite several operations with duroplasty and sealing agent. Finally, the problems were treated by repair of the ventral dural defect with posterior trans-dural duroplasty. Several months after surgery, the patient could walk independently. This surgical technique can be applied to treat ventral dural defect and spinal cord herniation.

Let’s Not Miss the Forest for the Trees

현승재 대한척추신경외과학회 2019 Neurospine Vol.16 No.2

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Postoperative Changes in Paraspinal Muscle Volume: Comparisonbetween Paramedian Interfascial and Midline Approaches for LumbarFusion

현승재,김영백,김양수,Seung Won Park,남택균,Hyun Jong Hong,권정택 대한의학회 2007 Journal of Korean medical science Vol.22 No.4

In this study, we compared the paramedian interfascial approach (PIA) and the traditional midline approach (MA) for lumbar fusion to determine which approach resulted in the least amount of postoperative back muscle atrophy. We performed unilateral transforaminal posterior lumbar interbody fusion via MA on the symptomatic side and pedicle screw fixation via PIA on the other side in the same patient. We evaluated the damage to the paraspinal muscle after MA and PIA by measuring the preoperative and postoperative paraspinal muscle volume in 26 patients. The preoperative and postoperative cross-sectional area, thickness, and width of the multifidus muscle were measured by computed tomography. The degree of postoperative paraspinal muscle atrophy was significantly greater on the MA side than on the contralateral PIA side (-20.7% and -4.8%, respectively, p<0.01). In conclusion, the PIA for lumbar fusion yielded successful outcomes for the preservation of paraspinal muscle in these 26 patients. We suggest that the success of PIA is due to less manipulation and retraction of the paraspinal muscle and further studies on this technique may help confirm whether less muscle injury has positive effects on the long-term clinical outcome.

The Incidence of Adding-On or Distal Junctional Kyphosis in Adolescent Idiopathic Scoliosis Treated by Anterior Spinal Fusion to L3 Was Significantly Higher Than by Posterior Spinal Fusion to L3

현승재,Lawrence G. Lenke,김용정,Keith H. Bridwell,Meghan Cerpa,Kathy M. Blanke 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

Objective: To compare and identify risk factors for distal adding-on (AO) or distal junctional kyphosis (DJK) in adolescent idiopathic scoliosis (AIS) treated by anterior- (ASF) and posterior spinal fusion (PSF) to L3. Methods: AIS patients undergoing ASF versus PSF to L3 from 2000–2010 were analyzed. Distal AO and DJK were deemed poor radiographic results. New stable (SV) and neutral vertebra (NV) scores were defined for this study. The total stability (TS) score was the sum of the SV and NV scores. Results: Twenty of 42 (ASF group: 47.6%) and 8 of 72 patients (PSF group: 11.1%) showed poor radiographic outcome. Fused vertebrae, correction rate of main curve, coronal reduction rate of L3 were significantly higher in PSF group. Multiple logistic regression results indicated that preoperative SV-3 at L3 in standing and side benders (odds ratio [OR], 2.7 and 3.7, respectively), TS score -5, -6 at L3 (OR, 4.9), rigid disc at L3–4 (OR, 3.7), lowest instrumented vertebra (LIV) rotation >15° (OR, 3.3), LIV deviation >2 cm from center sacral vertical line (OR, 3.1) and ASF (OR, 13.4; p<0.001) were independent predictive factors. There was significant improvement of the Scoliosis Research Society (SRS)-22 average scores only in PSF group. Furthermore, the ultimate scores of PSF group were significantly superior to ASF group. Conclusion: The prevalence of AO or DJK at ultimate follow-up for AIS with LIV at L3 was significantly higher in ASF group. Ultimate SRS-22 scores were significantly better in PSF group.

Commentary on “Emerging Technologies in the Treatment of Adult Spinal Deformity”

현승재 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

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