• Journal of Chest Surgery
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• v.18 no.3
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• pp.371-382
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• 1985

Over the past 4 decades after World War II a great deal of data and clinical experiences have been accumulated relating to the diagnosis and surgical treatment of congenital and acquired cardiovascular diseases in Korea. Clinical data on cardiovascular surgical cases performed in all 22 hospitals for open heart surgery in Korea was collected from it`s starting up to December 1984. The first recorded open heart surgery for a young adult atrial septal defect was performed by Young Kyoon Lee, M.D. on August 7, 1959, Seoul National University Hospital, Korea. And, some scattered reports on cardiovascular surgical cases in it`s early period have changed recently the number of hospitals for open heart surgery and clinical cases enormously in total amount of 13, 100 cardiovascular operations performed on 12, 990 cases up to December 1984. Of the total 13, 100 cardiovascular operations, congenital cardiovascular anomaly occupied 70%. Of the congenital cases, 6, 580 operations for acyanotic group [operative mortality 4.5%], and 2, 489 operations for cyanotic group [operative mortality 20%]. The incidence of congenital cardiovascular anomaly in order of frequency was ventricular septal defect [29%], patent ductus arteriosus [26%], Tetralogy of Fallot [22%], atrial septal defect [8, 6%], pulmonary valve stenosis [3.0%], and endocardial cushion defect [1.1%]. Of the 3, 412 valvular heart disease cases, which occupied 85% of total 4, 031 acquired cardiovascular disease, individual incidence was in mitral 2, 565 [63.5%], double valve 451 [11.1%], and simple aortic valve 351 [8.7%]. Total number of valve replaced, mechanical and tissue, was 2, 795, and 1, 884 for mitral, 808 for aortic, and 103 for tricuspid in position. Operative mortality for prosthetic valve replacement in total was 9.8%. Remained acquired cardiovascular cases chronic constrictive pericarditis [7.9%], cardiac tumor [1.9%], coronary artery bypass [1.8%], cardiac trauma [1.2%] and less than 1% of thoracic aortic aneurysm. Overall operative mortality for open and non-open cardiovascular surgical operation was 7.7% [congenital acyanotic group 3.2%, congenital cyanotic group 19.4%, and acquired group 7.8%]. In conclusion, present status of cardiovascular surgery in Korea is stabilized with accumulation of clinical cases and experiences, and the future in the field of cardiovascular surgery is promising, especially in the infant cardiac surgery and aortocoronary bypass surgery, with abrupt increase of specialized cardiac centers, trained specialists, and expanding social health insurance.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.493-500
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• 2001

Objective : Anterior cervical locking plates are the devices for achieving anterior cervical spinal fusion. This study was conducted to evaluate the locking plate system regarding its long-term advantages and disadvantages in the view of interbody fusion rate, hardware-related failures, vertebral change close to the fusion segment and postoperative complications. Method : Eight-six patients, operated from Jan., 1996 to Jun. 1998, were followed-up for more than two years. All of the cases were fused with iliac bone graft and ORION locking plate(Sofamor Danek USA, Inc., Memphis, TN) fixation. The patients were discharged or transferred to rehabilitation department 2-7 days after operation. A comprehensive evaluation of the interbody fusion state, instrument failure, vertebral change and postoperative complications were made by direct interview and cervical flexion-extension lateral plain films. Results : There were 55 male and 31 female with a mean age of 45 years(18-75 years). The mean follow-up period was 29 months(24-43 months). Various disorders that were operated were 40 cervical discs, 6 cervical stenosis including OPLL, 2 infections, and 38 traumas. Fusion level was single in 59 cases, two levels of each disc space in 15 cases, and two levels after one corpectomy in 12 cases. There was no instrument failure. Pseudoarthrosis was observed in two cases(2%) without radiological instability. The other patients(98%) showed complete cervical fusion with stable instrument. Mild settling of interbody graft with upward migration of screws was found in 12 cases(14%). Anterior bony growth at the upper segment was found in 5 cases(6%). Postoperative foreign body sensation or dysphagia was observed in 12 cases(4%), and disappeared within one month in 7 cases and within six months in 4 cases. One patient complained for more than six months and required reoperation to remove paraesophageal granulation tissue. Conclusion : The results show that Orion cervical locking plate has some disadvantages of upward migration of screws, anterior bony growth at the upper segment, or possibility of esophageal compression even though it has advantages of high interbody fusion rate or low instrument failure. Author believe that anterior cervical locking plate in the future should be thinner, and should have short end from the screw hole, and movable screw with adequate stability.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1063-1068
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• 2000

Objectives : To determine the contribution of cranial magnetic resonance angiography(MRA) for the evaluation of patients with ischemic cerebrovascular accident. Methods : Magnetic resonance image(MRI) and MRA studies performed on 34 patients with ischemic stroke were retrospectively reviewed with the clinical records. Results : There were 9 transient ischemic attacks and 25 completed strokes in our series. Twenty-three of 34 MRA examinations(68%) were positive for stenosis or occlusion. The distribution of stenotic or occlusive vascular lesions were correlated with the location of infarction in 22 of the 23 positive cases(96%). MRA provided additional information not obtained from the MRI in 19 cases(56%). Conclusions : Vascular lesions demonstrated on intracranial MRA show a high correlation with infarct distribution. MRA provided information adjunctive to conventional MRI in a majority of cases. We conclude that MRA is an important noninvasive component of the complete evaluation of ischemic stroke.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.904-909
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• 2000

Objectives : Most cases of cervical ossification of the posterior longitudinal ligament(OPLL) present with myelopathy or myeloradiculopathy, which sometimes is further complicated by minor trauma to the spinal cord. The main purpose of surgery in these patients is the alleviation symptoms but also as protection against further deterioration. The purpose of this study is to analyze the influence of trauma on the surgical outcome in patients with cervical OPLL. Methods : Over the past 13 years, we have operated on 123 patients with myelopathy associated with cevical OPLL. Among these, thirty patients had cervical cord injury associated with major or minor trauma and their clinical and radiographic data were reviewed retrosepctively. Results : As to cause of trauma, seventeen were related with traffic accident and 13 were related with minor slipping injury. The pre- and post-operative motor power were significantly weaker in the patients with trauma, but the degree of motor improvement was significantly higher(trauma group : $0.90{\pm}1.49$, non-trauma group : $0.41{\pm}0.80$). Conclusion : These results indicate that even indirect minor trauma to the cervical spine can cause irreversible changes to the spinal cord if this is associated with underlying cervical stenosis with OPLL. Although less favorable results may be anticipated in patients with trauma, operative decompression could improve motor power and protect further deterioration.

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.43-49
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• 2015

Objective : $Dynesys^{(R)}$ is one of the pedicle-based dynamic lumbar stabilization systems and good clinical outcome has been reported. However, the cylindrical spacer between the heads of the screws undergoes deformation during assembly of the system. The pre-strain probably change the angle of instrumented spine with time and oblique-shaped spacer may reduce the pre-strain. We analyzed patients with single-level stabilization with $Dynesys^{(R)}$ and simulated oblique-shaped spacer with finite element (FE) model analysis. Methods : Consecutive 14 patients, who underwent surgery for single-level lumbar spinal stenosis and were followed-up more than 24 months (M : F=6 : 8; age, $58.7{\pm}8.0$ years), were analyzed. Lumbar lordosis and segmental angle at the index level were compared between preoperation and postoperative month 24. The von Mises stresses on the obliquely-cut spacer ($5^{\circ}$, $10^{\circ}$, $15^{\circ}$, $20^{\circ}$, $25^{\circ}$, and $30^{\circ}$) were calculated under the compressive force of 400 N and 10 Nm of moment with validated FE model of the L4-5 spinal motion segment with segmental angle of $16^{\circ}$. Results : Lumbar lordosis was not changed, while segmental angle was changed significantly from $-8.1{\pm}7.2^{\circ}$ to $-5.9{\pm}6.7^{\circ}$ (p<0.01) at postoperative month 24. The maximum von Mises stresses were markedly decreased with increased angle of the spacer up to $20^{\circ}$. The stress on the spacer was uneven with cylindrical spacer but it became even with the $15^{\circ}$ oblique spacer. Conclusion : The decreased segmental lordosis may be partially related to the pre-strain of Dynesys. Further clinical and biomechanical studies are required for relevant use of the system.

• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.217-221
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• 2011

Objective : This paper presents data from a retrospective study of endoscopic third ventriculostomy (ETV) in patients with shunt malfunction and proposes a simple and reasonable post-operative protocol that can detect ETV failure. Methods : We enrolled 19 consecutive hydrocephalus patients (11 male and 8 female) who were treated with ETV between April 2001 and July 2010 after failure of previously placed shunts. We evaluated for correlations between the success rate of ETV and the following parameters : age at the time of surgery, etiology of hydrocephalus, number of shunt revisions, interval between the initial diagnosis of hydrocephalus or the last shunt placement and ETV, and the indwelling time of external ventricular drainage. Results : At the time of ETV after shunt failure, 14 of the 19 patients were in the pediatric age group and 5 were adults, with ages ranging from 14 months to 42 years (median age, 12 years). The patients had initially been diagnosed with hydrocephalus between the ages of 1 month 24 days and 32 years (median age, 6 years 3 months). The etiology of hydrocephalus was neoplasm in 7 patients; infection in 5; malformation, such as aqueductal stenosis or megacisterna magna in 3; trauma in 1; and unknown in 3. The overall success rate during the median follow-up duration of 1.4 years (9 days to 8.7 years) after secondary ETV was 68.4%. None of the possible contributing factors for successful ETV, including age (p=0.97) and the etiology of hydrocephalus (p=0.79), were statistically correlated with outcomes in our series. Conclusion: The use of ETV in patients with shunt malfunction resulted in shunt independence in 68.4% of cases. Age, etiology of hydrocephalus, and other contributing factors were not statistically correlated with ETV success. External ventricular drainage management during the immediate post-ETV period is a good means of detecting ETV failure.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.431-436
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• 2009

Objective : This study examines whether functional motion is present at one or more years after Bioflex System placement. BioFlex System is a flexible rod system which has been used to preserve motion at the area of implantation. There has not been a scientific study showing how much motion is preserved after implantation. Methods : A total of 12 consecutive patients underwent posterior dynamic stabilization using the BioFlex System. Six patients were treated using a L3-4-5 construct and other six patients using a L4-5-S1 construct. Follow-up ranged from 12 to 33 months and standing neutral lateral, extension, flexion and posteroanterior (PA) radiographs were obtained at 3, 6, 9, and 12 months and at more than 12 months postoperatively. Range of motion (ROM), whole lumbar lordosis, and ROMs of motion segments from L2 to S1 were determined. Results : Patients with a L3-4-5 construct demonstrated a decrease in mean ROM for whole lumbar decreased from 40.08 to 30.77. Mean ROM for L3-4 (6.12 to 2.20) and L4-5 (6.55 to 1.67) also decreased after one year. Patients with a L4-5-S1 construct demonstrated L4-5 (8.75 to 2.70) and L5-S1 (9.97 to 3.25) decrease of mean ROM at one year postoperatively. Lumbar lordosis was preservep at both L3-4-5 and L4-5-S1 constructs. Clinical results showed significant improvements in both study groups. Conclusion : The present study provides preliminary information regarding the BioFlex motion preservation system. We conclude that the BioFlex System preserves functional motion to some degree at instrumented levels. However, although total lumbar lordosis was preserved, ROMs at implantation segments were lower than preoperative values.

• Journal of Korean Neurosurgical Society
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• v.61 no.1
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• pp.114-119
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• 2018

Objective : The purpose of this study was to determine the feasibility of screw fixation in previously augmented vertebrae with bone cement. We also investigated the influence of cement distribution pattern on the surgical technique. Methods : Fourteen patients who required screw fixation at the level of the previous percutaneous vertebroplasty or balloon kyphoplasty were enrolled in this study. The indications for screw fixation in the previously augmented vertebrae with bone cement included delayed complications, such as cement dislodgement, cement leakage with neurologic deficits, and various degenerative spinal diseases, such as spondylolisthesis or foraminal stenosis. Clinical outcomes, including pain scale scores, cement distribution pattern, and procedure-related complications were assessed. Results : Three patients underwent posterior screw fixation in previously cemented vertebrae due to cement dislodgement or progressive kyphosis. Three patients required posterior screw fixation for cement leakage or displacement of fracture fragments with neurologic deficits. Eight patients underwent posterior screw fixation due to various degenerative spinal diseases. It was possible to insert screws in the previously augmented vertebrae regardless of the cement distribution pattern; however, screw insertion was more difficult and changed directions in the patients with cemented vertebrae exhibiting a solid pattern rather than a trabecular pattern. All patients showed significant improvements in pain compared with the preoperative levels, and no patient experienced neurologic deterioration as seen at the final follow-up. Conclusion : For patients with vertebrae previously augmented with bone cement, posterior screw fixation is not a contraindication, but is a feasible option.

• Journal of Korean Neurosurgical Society
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• v.61 no.4
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• pp.458-466
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• 2018

Objective : To compare peri-operative any symptomatic stroke after carotid angioplasty and stenting (CAS), based on the application or absence of a cerebral protection device. Methods : A systematic literature review using PubMed, Embase, and the Cochrane Central was done across an online data base from January 1995 to October 2016. Procedures which were performed due to carotid dissection or aneurysm, procedures using covered stents or conducted in an emergency, were excluded. The primary endpoint was perioperative any symptomatic stroke within 30 days after the procedure. A fixed effect model was used in cases of heterogeneity less than 50%. Results : In the 25 articles included in this study, the number of stroke events was 326 (2.0%) in protected CAS and 142 (3.4%) in unprotected CAS. The use of cerebral protection device significantly decreased stroke after CAS (odds ratio [OR] 0.633, 95% confidence interval [CI] 0.479-0.837, p=0.001). In the publication bias analysis, Egger's regression test disclosed that the intercept was -0.317 (95% CI -1.015-0.382, p=0.358). Regarding symptomatic patients (four studies, 539 CAS procedures), the number of stroke was six (1.7%) in protected CAS and 11 (5.7%) in unprotected CAS. The protective effect against stroke events by cerebral protection device did not have a statistical significance (OR 0.455, 95% CI 0.151-1.366, p=0.160). Conclusion : The use of protection device significantly decreased stroke after CAS. However, its efficacy was not demonstrated in symptomatic patients. Routine use of protection device during CAS should be critically assessed before mandatory use.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.951-956
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• 2011

Coronary angiography technology is usually used for examining or treating coronary artery stenosis. Especially, when a cardiologist inserts catheter into the heart blood vessel, the catheter path detection system is needed because the cardiologist has difficulty in not damaging vessel. Recently, to reduce this difficulty, many searchers have been working for the various image processing technologies, such as vessel edge detection, optimal threshold method, etc. However the results of these searches are showing different performances depend on the contrast and quality of images. Therefore, this study for the coronary angiography suggests a novel algorithm to avoid these problems. The suggested algorithm consists of multi-sampling, interpolation, threshold method, and fault points elimination. To evaluate the performance of the proposed method, we used several angiographic images in experimentation, and we found that the proposed method is effective for detecting the catheter insertion path.