• 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 Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.117-128
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• 2006

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. Many studies has been published in microvascular anastomosis with histologic effect for irrigating solution. But local irrigation solution has been used clinically in microvascular anastomosis, the comparison with each solution, microhistological study for endothelial cell repair and vascular patency has not been reported. The heparin which is anti-thrombotic agent, and urokinase which is fibrinolytic agent are used for this study. Vascular patency and thrombus formation in experimental micro-arterial 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-arterial anastomosis, equal effects of good vascular patency were obtained in group of local irrigation with heparin and urokinase. 2. In thrombus formation in 7 days after micro-arterial anastomosis, equal effects of minimal thrombus formation were obtained in group of local irrigation with heparin and urokinase. 3. In toluidin blue staining in 7 days after micro-arterial anastomosis, local destruction of endothelial cell and inner elastic lamina were seen and endothelial repair was not seen. 4. In scanning electron microscope examination in 7 days after micro-arterial anastomosis, endothelial cell was not seen in peripheral to suture materials, thrombus associated fibrin network was observed. 5. In transmission electron microscope examination in 7 days after micro-arterial anastomosis, inflammatory cell was seen within smooth muscle cells in site of endothelial cell destruction, smooth muscle cell around suture material were arranged irregularly, some collagenous change were seen. From the results obtained in this study, same results of good vascular patency and anti-thrombotic effect of heparin and urokinase were obtained as a local irrigation solution, and repair of endothelial cell was not seen in 7 days after micro-arterial anastomosis.

• Journal of Chest Surgery
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• v.18 no.1
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• pp.36-45
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• 1985

During the twelve-year period from March 1973 through July 1984, 23 consecutive operations for coarctation of the aorta were performed at Seoul National University Hospital. The patients included 19 male and 4 female in the range of 4 months and 16 years old. Associated cardiac anomalies were present in 19 patients [70%] and they were VSD+PDA [9 patients], VSD[2], PDA[1], VSD+ASD+PDA[1], VSD+MS+AS+PDA[1], D-TGA+VSD+PDA[1], P-ECD[1], MS[1], Al[1], and DORV+PDA[1]. The preoperative main symptoms included congestive heat failure, hypertension, subacute bacterial endocarditis and nonspecific symptoms. Congestive heart failure was the most common symptom in the group younger than 2 years and hypertension in the adult group. Operative techniques for coarctation of the aorta were resection and end to end anastomosis in 10 patients, prosthetic patch aortoplasty in 8, subclavian flap aortoplasty in 4, and LSCA-aortic anastomosis in 1. There were 4 operative deaths among the nine patients less than 2 years old[44.4% mortality]: all of these patients had associated cardiac anomalies. And only one operative death occurred in patients older then 2 years old[7.1% mortality]. No hospital death occurred in patients with isolated coarctation of the aorta. Operation of the coarctation was performed primarily in 6 patients associated with ventricular septal defect and subsequently underwent successful VSD closure except one operative death.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.54.1-54.3
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• 2019

Background: The presence of septa increases the risk of Schneiderian membrane perforation during sinus lift procedure, and therefore, the chance of graft failure increases. We present a safe method of managing septa and, in particular, overcoming small and palatally located septa. Methods: After the elevation of the flap and the creation of a small bony window positioned anterior to the septum, the Schneiderian membrane is lifted carefully. A thin and narrow osteotome is then placed at the indentation created at the base of the septum, and mobilization of the septum is achieved by gentle malleting. The membrane is again carefully lifted up behind the septum. Results: There was one small membrane perforation case in all 16 cases, and none of these patients showed postoperative complications such as implant failure, infection, or maxillary sinusitis. Conclusions: This technique is useful for overcoming the problem of maxillary sinus septa hindering the sinus floor elevation procedure, leading to fewer complications.

• Journal of Chest Surgery
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• v.23 no.6
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• pp.1213-1220
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• 1990

During the period of January 1979 to December 1988, 220 patients with empyema thoracis were treated in the department of Thoracic and Cardiovascular Surgery, Chonnam National University Medical School Hospital. There were 167 males[75.9%] and 53 females[24.1%] ranging from 18 days to 76 years of age. Occurrence ratio of left and right empyema was 1 : 1.9. The underlying pathologic lesions of empyema were pneumonia[30.9%], pulmonary tuberculosis[22.7%], chest trauma[8.6%] and postoperative complications. In bacteriologic study, staphylococcus, pseudomonas and streptococcus accounted for 26.4%, 11.8% and 9% respectively, and 25% were not identified. Surgical treatment modalities were thoracentesis[10 patients, 4.5%], closed thoracostomy[132, 60%], closed rib resection drainage[4.2, 6%], modified Eloesser’s operation[37, 16.8%], decortication[27, 12.3%], decortication with pulmonary resection[6, 2.7%], thoracoplasty[2, 0.9%], muscle flap closure [1, 0.5%], and staged pneumonectomy[1, 0.5%], The mortality rate was 2.3% and the complications were sepsis[9 patients]. acute renal failure[4], and paralytic ileus[3].

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.430-435
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• 2014

This paper presents the case study of the airworthiness certification for the flight control system of tactical UAV. Airworthiness regulations for flight characteristics and design and construction based on the STANAG 4671 are selected, and safety assessment is performed. Stall protection on wing level and turning flight criteria, and flap interconnection system failures were analyzed and applied to the flight control system design. The Hardware-in-the-loop simulation including math model, integrated system verification and validation test and failure mode and effects test were also performed and they are used to validate the means of compliance of the proposed airworthiness.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.3
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• pp.233-236
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• 2021

A mandibular continuity defect can be repaired using either a prosthetic device or autogenous bone. A titanium reconstruction plate can be used with a localized or vascularized flap over the defect of the mandible. Unfortunately, the plate may fail due to plate exposure, screw loosening, fracture, or infection, and will need to be removed. Plate exposure though the skin or mucosa is one of the main reasons for failure. In the present work, the authors introduced a lingually positioned reconstruction plate fabricated via three-dimensional printed bending support. This custom reconstruction plate can avoid plate re-exposure as well as reduce surgical errors and operation time.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.461-466
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• 2005

Despite the major advances in the microvascular surgery with success rates of up to 98%, failure and vascular complications still remain even in the experienced hands. Failure of blood to flow across an anastomosis is usually caused by three factors: (1) Technical errors; (2) Undetected damage more proximally or via vasospasm; or (3) A clot or a thrombus. The success of a microvascular surgery depends on the severity of the vascular injury and, proper debridement of an injured vessel, and the failure rate of microvascular anastomosis in cases of trauma is higher as the thrombogenic possibility is increased by the endothelial damage. From January to November in 2003, 460 patients were underwent microvascular surgery(270 replantations and 190 free flap transfers) and re-operations were performed in 15 cases. Cases were reviewed by clinical and operative records. In these cases, causes of post-operative circulation insufficiency were identified as 9 vascular spasms and 6 thromboses at the previous anastomotic site. The average of re-operative success rate was 73%(60% in replantations and 100% in free flaps). In conclusion, through precise postoperative monitoring and assessment, immediate surgical re-exploration could be performed when a vascular complication is suspicious, the success rate of microvascular surgery would be increased more.

• Archives of Plastic Surgery
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• v.32 no.6
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• pp.753-756
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• 2005

In the cases of severe arrythmia and conduction failure, a permanent implanted pacemaker is considered an essential treatment modality with less complication rate, broad indications and low morbidity. However, some pacemakers needs to be removed or replaced due to infection, in need of a lead upgrade, elective replacement, conduction failure or insulation failure. The most common indication for pacemaker extraction is infection. Conservative treatments such as administration of intravenous antibiotics and limitation of debridement are not effective and the removal of the entire pacing system is considered to be the best approach to pacemaker pocket infection. Although a locking stylet, a laser sheath and other newer methods of transvenous lead extraction have been proven to be effective, all leads cannot be removed. Moreover, major complications such as, cardiac tamponade and respiratory arrest during leads extraction procedure should not be ignored. We experienced two cases of exposed pacemakers in the subclavicular region. After removing the pacemaker body, exposed proximal lead was pulled out and cut off. The end of remnant external insulation tube was tied to prevent infection propagation between external insulation tube and inner metalic coil. Wounds were covered by local flap coverage. No other problems were detected during the one-year follow-up. Since there are few reports on lead-preserving method of treating limited infection of exposed pacemakers, we would like to present our new method for treating exposed pacemakers.

• Archives of Plastic Surgery
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• v.46 no.6
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• pp.550-557
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• 2019

Background In recent years, breast implants have been frequently placed in the subcutaneous pocket, in the so-called prepectoral approach. We report our technique of prepectoral implant-based breast reconstruction (IBR), as well as its surgical and aesthetic outcomes, in comparison with subpectoral IBR. We also discuss relevant considerations and pitfalls in prepectoral IBR and suggest an algorithm for the selection of patients for IBR based on our experiences. Methods We performed 79 immediate breast reconstructions with a breast implant and an acellular dermal matrix (ADM) sling, of which 47 were subpectoral IBRs and 32 were prepectoral IBRs. Two-stage IBR was performed in 36 cases (20 subpectoral, 16 prepectoral), and direct-to-implant IBR in 43 cases (27 prepectoral, 16 subpectoral). The ADM sling supplemented the inferolateral side of the breast prosthesis in the subpectoral group and covered the entire anterior surface of the breast prosthesis in the prepectoral group. Results The postoperative pain score was much lower in the prepectoral group than in the subpectoral group (1.78 vs. 7.17). The incidence of seroma was higher in the prepectoral group (31.3% vs. 6.4%). Other postoperative complications, such as surgical site infection, flap necrosis, implant failure, and wound dehiscence, occurred at similar rates in both groups. Animation deformities developed in 8.5% of patients in the subpectoral group and rippling deformities were more common in the prepectoral group (21.9% vs. 12.8%). Conclusions The indications for prepectoral IBR include moderately-sized breasts with a thick well-vascularized mastectomy flap and concomitant bilateral breast reconstruction with prophylactic mastectomy.