• Investigative Magnetic Resonance Imaging
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• v.16 no.2
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• pp.159-168
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• 2012

The proximity of thoracic aortic aneurysm to the left subclavian artery (LSA) has made the coverage of LSA during thoracic endovascular aortic repair (TEVAR) be essential. Despite controversy concerning the safety of LSA coverage and the indications for LSA revascularizations, the cerebral hemodynamic change after LSA coverage has not been demonstrated. We prospectively examined two patients who would undergo TEVAR with LSA coverage by using 2D cine phase contrast MR imaging. After LSA coverage, the left subclavian steal was properly compensated by the increased flow volumes of both carotid arteries and right vertebral artery, which is the major collateral supply. The total brain supply after TEVAR did not lessen, which showed good correlation with uneventful clinical outcome. Therefore, 2D phase contrast MR imaging can be recommended as a useful technique to evaluate the hemodynamic change of the LSA coverage during TEVAR and to triage the candidate for LSA revascularization.

• Clinics in Shoulder and Elbow
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• v.14 no.1
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• pp.117-124
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• 2011

Purpose: We reviewed arthroscopic reconstruction among the several treatment options for anterior shoulder instability with a bony Bankart lesion. Materials and Methods: Although open Bankart repair has long been considered the optimal surgical management of anterior shoulder instability, advancements in arthroscopic techniques have led to a recent shift to arthroscopic Bankart repair. However, for cases of a glenoid bony defect, several authors have reported various methods to accurately measure the amount of bony defect. Results: The arthroscopic technique of bony Bankart reconstruction continues to evolve and various methods have followed. To overcome the limitations of single fixation of a Bankart lesion, arthroscopic dual fixation (2 point fixation) has recently been tried to anatomically repair and restore the rigid fixation of a bony fragment. The concept of performing the Bristow-Latarjet transfer procedure under arthroscopy has also recently emerged. However, a large series of cases and long term follow up are required to prove the better results. Conclusion: To obtain a successful outcome for patients with anterior instability with a glenoid bony defect, it is imperative that the surgeon be aware of the accurate status of the bony defect and the intraoperative, postoperative factors associated with the proper treatment of this unstable pathology.

• Journal of Chest Surgery
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• v.44 no.6
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• pp.406-412
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• 2011

Background: Development of thoracic aortic aneurysms and aortic dissections (TAAD) is attributed to unbearable wall tension superimposed on defective aortic wall integrity and impaired aortic repair mechanisms. Central to this repair mechanisms are well-balanced and adequately functional cellular components of the aortic wall, including endothelial cells, smooth muscle cells (SMCs), inflammatory cells, and adventitial fibroblasts. Adventitial fibroblasts naturally produce aortic extracellular matrix (ECM), and, when aortic wall is injured, they can be transformed into SMCs, which in turn are involved in aortic remodeling. We postulated the hypothesis that adventitial fibroblasts in patients with TAAD may have defects in ECM production and SMC transformation. Materials and Methods: Adventitial fibroblasts were procured from the adventitial layer of fresh aortic tissues of patients with TAAD (Group I) and of multi-organ donors (Group II), and 4-passage cell culture was performed prior to the experiment. To assess ECM production, cells were treated with TNF-${\alpha}$ (50 pM) and the expression of MMP-2/MMP-3 was analyzed using western blot technique. To assess SMC transformation capacity, cells were treated with TGF-${\beta}1$ and expression of SM ${\alpha}$-actin, SM-MHC, Ki-67 and SM calponin was evaluated using western blot technique. Fibroblasts were then treated with TGF-${\beta}1$ (10 pM) for up to 10 days with TGF-${\beta}1$ supplementation every 2 days, and the proportion of transformed SMC in the cell line was measured using immunofluorescence assay for fibroblast surface antigen every 2 days. Results: MMP-3 expression was significantly lower in group I than in group II. TGF-${\beta}1$-stimulated adventitial fibroblasts in group I expressed less SM ${\alpha}$-actin, SM-MHC, and Ki-67 than in group II. SM-calponin expression was not different between the two groups. Presence of fibroblast was observed on immunofluorescence assay after more than 6 days of TGF-${\beta}1$ treatment in group I, while most fibroblasts were transformed to SMC within 4 days in group II. Conclusion: ECM production and SMC transformation are compromised in adventitial fibroblasts from patients with TAAD. This result suggests that functional restoration of adventitial fibroblasts could well be a novel approach for the prevention and treatment of TAAD.

• Journal of the Korea Concrete Institute
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• v.19 no.4
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• pp.421-431
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• 2007

The main purpose of this study is to develop a sprayed FRP repair and strengthening method, which is a new technique for strengthening the existing concrete structures by mixing one of the carbon or glass chopped fibers and one of the epoxy or vinyl ester resins with high-speed compressed air in open air and randomly spraying the mixture onto the concrete surface. At present, the sprayed FRP repair and strengthening method using the epoxy resin has not been fully discussed. In order to investigate the material property of the sprayed FRP, this study carried out tensile tests of the material specimens, which were changed with the combinations of various variables including the length of chopped fiber and the mixture ratio of chopped fiber and resin. These variables were set to have the equal material strength, compared with that of one layer of the FRP sheet. As a result, the optimal length of glass and carbon chopped fibers was fumed out to be 38 mm, and the optimal mixture ratio between chopped fiber and resin was also turned out to be 1 : 2 from each variable. And also, the thickness of the sprayed FRP to have the equal strength to one layer of the FRP sheet was finally calculated. In is study, a series of experiments were carried out to evaluate the strengthening effects of flexural beams, shear beams and damaged beams strengthened with the sprayed FRP method, respectively. The results revealed that the strengthening effects of the flexural and shear specimens were reasonably similar to those of the FRP sheet, and the developed Sprayed FRP technique is able to be used as a strengthening scheme of existing RC building.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.340-349
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• 2007

Free flap transplantation with microvascular anastomosis has been successfully performed by development of surgical technique, materials and postoperative monitoring equipments of flap. But success rate of microvascular anastomosis is influenced by various factors, and failure rate is about 5-10%. The most influential factor for success rate is surgical technique and other factors that influence failure of microvascular anastomosis are ischemic time of free flap, thrombus formation of anastomosis region and vascular spasm. In this study, vascular patency and thrombus formation in experimental micro-venous anastomosis, and endothelial repair were observed with histologic analysis, scanning electron microscopy, transmission electron microscopic examination. The results were obtained as follows: 1. In vascular patency test in 30 minute and 7 days after micro-venous anastomosis with heparin irrigation, all of 12 anastomosis site were good vascular patency. 2. In thrombus formation in 2 weeks group(Experimental I), 2 site of 6 cases were observed thrombus, and in 4 weeks group(Experimental II), 1 site of 6 cases were observed thrombus. 3. In histologic examination, normal vein(Control Group) showed continued internal elastic lamina, well formed thick smooth muscle layer and connective tissue. The group of 2 weeks after microvenous anastomosis(Experimental I) showd locally recovered internal lamina, discontinued internal lamina, disorganized smooth muscle cells and granulation tissue around suture silk. In the group of 4 weeks after micro-venous anastomosis(Experimental II), anastomosis site showed almostly continued internal lamina, disorganized smooth muscle cells and cicartrized tissue around suture silk. 4. In scanning electron microscope examination in 2 weeks(Experimental I) after micro-venous anastomosis, mesh fibrin formation showed near to endothelial cells, and in 4 weeks after micro-venous anastomosis(EXperimental II), numerous blood cells and fibrin mesh formation was seen associated with irregular endothelial cell arrangement. 5. In transmission electron microscope examination in 2 weeks after micro-venous anastomosis(Experimental I), irregular arrangement of smooth muscle cells was seen adjacent to collagenized tissue around suture silk. In 4 weeks after micro-venous anastomosis(Experimental II), denuded venous wall composed of relatively well arranged smooth muscle cells was covered by endothelial cells, but fibroblast cells and foreign body giant cells near to suture silk was remained. From the results obtained in this study, results of good vascular patiency and anti-thrombotic effect of heparin were obtained as a local irrigation solution, and repair of venous endothelial cell was observed in 2 weeks after micro-venous anastomosis.

• Journal of the Korean GEO-environmental Society
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• v.22 no.6
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• pp.27-32
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• 2021

Due to heavy rainfall and typhoons caused by climate change, it has become common to witness heavy rain that exceeds the design frequency of agricultural reservoirs. This has brought greater attention to the safety of irrigation facilities including agricultural reservoirs. Out of approximately 17,740 reservoirs available in Korea, 83.87% were built before 1970. To ensure the safety of these old reservoirs, their embankments are being repaired and reinforced using various techniques. Among these techniques, using the cement-bentonite cutoff wall makes it possible to construct diaphragm walls with slurry composed of cement and bentonite, while excavation. The advantages of this technique include that it is simple and fast, and ensures the uniformity of cutoff walls by enabling the immediate application of the replacement method to excavation areas; thus excellent performance is guaranteed. However, despite these advantages, the technique is not commonly used in Korea. Thus, this study investigated the changes in strength and permeability by varying the mix ratio of cement and bentonite. As a major experimental results, when the cement of 200 kg/m³ and the bentonite of 60 to 80 kg/m³ is most suitable for the repair and reinforcement of the reservoir embankments.

• Journal of Korean Foot and Ankle Society
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• v.26 no.1
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• pp.40-47
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• 2022

Purpose: The modified Broström repair (BR) technique has yielded good outcomes in patients with chronic ankle instability. This study compared clinical and radiological outcomes between two groups of patients who underwent modified BR or lateral ligament augmentation using suture tapes (ST). Materials and Methods: Seventy-seven patients (ST group [n=47], BR group [n=30]; body mass index <26.61 kg/m²; mean age, 30.7±11.0 years [range, 17~39 years]; mean follow-up, 34.0±12.0 months [range, 24~59 months]) were retrospectively reviewed between January 2014 and July 2017. The Foot and Ankle Outcome Score (FAOS), American Orthopedic Foot and Ankle Score (AOFAS), Foot and Ankle Ability Measure (FAAM), visual analogue scale (VAS) score, and Sefton grading system were used for clinical assessment. The talar tilt angle and anterior talar translation were measured using the Telos stress device (Telos GmbH, Marburg, Germany) at 150 N for radiological evaluation. Results: FAOS, AOFAS, FAAM, and VAS scores improved in both groups at final follow-up (ST, 91.1±5.2, 93±2, 88.1±4.5, 1.5±0.7 vs. BR, 91.3±5.4, 93±3, 83.3±4.8, 1.2±0.7, respectively; p=0.854, 0.971, <0.001, 0.04, respectively). According to the FAOS, mean sports activity scores for the ST and BR groups at the final follow-up were 90.3±3.2 and 76.6±4.2, respectively, reflecting superior outcomes in the ST group (p<0.001). Sefton grading revealed satisfactory functional outcomes (ST, 91.5% vs. BR, 90.0%). There was significant improvement in the talar tilt angle and anterior talar translation in both the ST and BR groups (7.6°±1.2°, 10.5±1.8 mm vs. 4.9°±1.1°, 7.9±1.5 mm, respectively; p<0.001). Conclusion: The ST group demonstrated comparable clinical but better improvement in mechanical stability and FAOS sports scores than the BR group.

• Journal of Korean Foot and Ankle Society
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• v.26 no.1
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• pp.22-29
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• 2022

Purpose: Despite continuous updates of standard treatment guidelines for acute ankle sprain and chronic ankle instability (CAI), in practice preferred treatment protocols vary widely. Based on a Korean Foot and Ankle Society (KFAS) member survey, this study reports current trends in the management of ankle ligament injuries. Materials and Methods: A web-based questionnaire containing 34 questions was sent to all KFAS members in September 2021. Questions mainly addressed clinical experience and preferences for the diagnosis and treatment of ankle ligament injuries. Answers with a prevalence of ≥50% among respondents were considered to reflect tendencies. Results: Eighty-four of the 550 members (15.3%) responded. Answers that showed a tendency were as follows: commonest additional image study (ultrasound), conservative treatment modality (immobilization, oral medication), frequency of surgical treatment (<5 cases per annum), most important factor when deciding on surgical treatment (activity level, e.g., occupation or sport), and commonest surgical procedure (open ligament repair). Answers that showed a tendency for CAI were as follows: most important symptom (repeated sprain, giving way), radiological factors (talar tilt, osteochondral lesion, anterior talar translation), and patient factors (occupation, sports activities, recurrent instability after surgery, etc.). For decision making regarding surgical treatment and method, the most preferred surgical procedure was the modified Broström procedure, and the most common repair technique was suture anchor technique. The following were considered poor prognostic factors; generalized laxity, failed previous surgery, cavovarus, severe mechanical instability, heavy work, obesity, and dissatisfaction after surgery because of residual pain. Conclusion: This study updates information regarding current trends in the management of ankle ligament injuries in Korea, and reveals consensus opinions and variations in approaches to patients with an acute or chronic injury. The divergence of approaches identified indicates the need for further studies to determine standard guidelines and long-term results.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.434-439
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• 2006

Background: Deep hypothermic circulatory arrest during repair of aortic arch anomalies may induce neurological complications or myocardial injury. So we surveyed if the regional cerebral and myocardial perfusion might eliminate those potential side effects. Material and Method: From March 2000 to December 2004, 62 neonates or infants with aortic arch anomaly underwent one stage biventricular repair using the regional perfusion technique by single surgeon. Preoperative diagnosis of the arch anomaly consisted of coarctation (n=46), interruption of the aorta (n=12), hypoplastic left heart syndrome (n=2) and truncus areteriosus (n=2). Combined anomalies were ventricular septal defect (n=51), TAPVR (n=1), PAPVR (n=1) and atrioventricular septal defect (n=2). Arterial cannula was inserted at the innominate artery. Result: The mean regional perfusion time of brain was $28{\pm}10min$. Operative mortality rates was 0 (0/62). Late death was 1 (1/62) during $11{\pm}7$ months of follow-up. Neurologic complications consisted of transient chorea in 1 case. There was no reoperation associated with arch anolamy. Pulmonary complication associated with arch repair occurred in f case which was managed by aortopexy. Conclusion: One-tage rch repair using the regional profusion is safe and effective in minimizing the neurologic and myocardial complications.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.237-248
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• 1999

Background: The late results of repair of tetralogy of Fallot(TOF) are favorable in most patients. Some portion of the patients with tetralogy, however, require reoperation for residual lesions or result in late death. The outcome of patients after tetralogy repair performed during the past 13 years was studied, with an emphasis on postrepair survival and problems including reoperations. Material and Method: A retrospective review of clinical, echocardiographic and catheterization data was performed in 569 of 775 patients with TOF who underwent corrective repair between 1983 and 1995 at Sejong General Hospital, Buchon, Korea. Result: Of 28(4.9%) early deaths(defined as 30 days postrepair), 12 deaths(42.9%) were <1 year of age, with an operative mortality of 15.4%. The surviving 541 patients(age 2.8 months to 43.4 years, median 23 months) have been followed up from 1 month to 12.6 years(median 35 months) postoperatively. Most patients were in good functional class and had normal right ventricular(RV) function. Postrepair results were compared between the transatrial-transpulmonary approach and the conventional right ventriculotomy. The former technique provided a lesser incidence of significant pulmonary regurgitation(P<0.001) and alesser degree of RV dysfunction(P<0.05) compared with those in the latter. There were 10(1.8%) late deaths during the follow-up period and 6 of the deaths were directly related to reoperation or ventricular dysfunction. The 10-year actuarial survival rate was 96.7%. There were 44 reoperations(8.1%) in 39 patients(7.2%), with an operative mortality of 10.3%. The main indications or reoperation included residual ventricular septal defect(VSD) (n=6), pulmonary stenosis(PS) (n=11), VSD with PS(n=17), pulmonary regurgitation(n=7), and tricuspid regurgitation(n=2). The 5- and 10-year freedom from reoperation were 89.4% and 76.1%, respectively. Conclusion: Although the majority of patients with repaired TOF are clinically well, with a high rate of survival, approximately 7% of patients have residual lesions that require surgical therapy. Therefore, the timely and meticulous corrective repair is mandatory to avoid reoperation, and continued close surveillance is also needed for the early detection of residual problems.