• 제목/요약/키워드: Korean Flap

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복합재 유연보를 갖는 무베어링 로우터 시스템의 정지 비행시 공탄성 안정성 해석 (Aeroelastic Stability Analysis of Bearingless Rotors with Composite Flexbeam in Hover)

  • 임인규;최지훈;이인;한재흥
    • Composites Research
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    • 제17권3호
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    • pp.29-37
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    • 2004
  • 본 연구에서는 대변형 보이론을 이용하여 정지 비행 시 복합재 무베어링 로우터 시스템의 공력탄성학적 안정성 해석을 수행하였다. 무베어링 로우터 시스템은 유연보, 토오크 튜브, 피치 링크, 그리고 메인 블레이드로 구성된다. 유연보, 토오크 튜브, 그리고 메인 블레이드를 각각 플랩 굽힘, 리드-래그 굽힘, 비틀림 그리고 축 방향 변형의 탄성 운동을 하는 보로 가정하고, 1차원 보 요소로 모델링을 하였다. 또한, 유연보를 복합재료 적층판으로 구성된 비틀림에 유연한 직사각형 단면을 갖는 보로 모델링 하여, 1차원 보 해석에 필요한 유효 단면 상수를 얻었다. 외력으로는 2차원 준-정상 공기력 모델을 적용하였으며, 보의 유한 요소 지배방정식은 헤밀턴 원리(Hamilton's principle)를 이용하여 얻었다. 공력 탄성학적 안정성 해석을 수행하기 위하여 p-k 방법을 이용하였으며, 유연보의 적층각과 적층 순서에 따른 구조적 연성이 무베어링 로우터 시스템의 공란성 안정성에 미치는 영향을 알아보았다.

포가티 카테터를 이용한 유리조직 전이술 시 수술 중 혈전 및 연축의 치료 (Treatment of Intraoperative Thrombosis and Spasm in Free Tissue Transfers Using the Fogarty Catheter)

  • 이승렬;윤영묵;오상하
    • Archives of Plastic Surgery
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    • 제35권2호
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    • pp.159-164
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    • 2008
  • Purpose: Microvascular free tissue transfer has become a reliable technique for the reconstruction of complex wounds. Occasionally, unexpected intraoperative thrombosis and/or spasm of recipient artery might be annoying problems even for the technically competent microvascular surgeons. If such problems are not treated properly, they will inevitably cause to flap failure. Methods: From January 2006 to February 2007, soft tissue reconstructions by free tissue transfers were performed on 21 patients having complex defects in the lower extremity. Although segmental revision and various pharmacologic agents were repeatedly applied, arterial occlusions were not managed in 6 cases. For removal of thrombi and release of spasm, Fogarty No. 2 or No. 3 catheters were inserted into the lumen to the proximal recipient artery. Its balloon was then inflated after passing through a resistant area. Next, the catheter was gently withdrawn backward. Results: After the Fogarty catheter was inserted two or three times, the pulsatile arterial flow was restored. When the catheter was inserted into the lumen, a feeling of resistance existed in a 5-10cm more proximal portion that could not be easily accessed from the vascular end. After the reestablishment of blood flow, successful anastomoses were achieved and immediate rethrombosis or spasm did not occur. No long-term sequelae associated with balloon trauma to the arterial wall were observed. Conclusion: The use of the Fogarty catheter can be an effective method in treating pedicle thrombosis and spasm. This is a very simple and rapid technique that offers microvascular surgeons another option to increase the success rate of microvascular anastomosis in free tissue transfers.

Evaluating the Effectiveness of Cryopreserved Acellular Dermal Matrix in Immediate Expander-Based Breast Reconstruction: A Comparison Study

  • Kim, So-Young;Lim, So Young;Mun, Goo-Hyun;Bang, Sa-Ik;Oh, Kap Sung;Pyon, Jai-Kyong
    • Archives of Plastic Surgery
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    • 제42권3호
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    • pp.316-320
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    • 2015
  • Background CGCryoDerm was first introduced in 2010 and offers a different matrix preservation processes for freezing without drying preparation. From a theoretical perspective, CGCryoDerm has a more preserved dermal structure and more abundant growth factors for angiogenesis and recellularization. In the current study, the authors performed a retrospective study to evaluate freezing- and freeze-drying-processed acellular dermal matrix (ADM) to determine whether any differences were present in an early complication profile. Methods Patients who underwent ADM-assisted tissue expander placement for two stage breast reconstruction between January of 2013 and March of 2014 were retrospectively reviewed and divided into two groups based on the types of ADM-assisted expander reconstruction (CGDerm vs. CGCryoDerm). Complications were divided into four main categories and recorded as follows: seroma, hematoma, infection, and mastectomy skin flap necrosis. Results In a total of 82 consecutive patients, the CGCryoDerm group had lower rates of seroma when compared to the CGDerm group without statistical significance (3.0% vs. 10.2%, P=0.221), respectively. Other complications were similar in both groups. Reconstructions with CGCryoDerm were found to have a significantly longer period of drainage when compared to reconstructions with CGDerm (11.91 days vs. 10.41 days, P=0.043). Conclusions Preliminary findings indicate no significant differences in early complications between implant/expander-based reconstructions using CGCryoderm and those using CGDerm.

A Revision Restoring Projection after Nipple Reconstruction by Burying Four Triangular Dermal Flaps

  • Kim, Ji Hun;Ahn, Hee Chang
    • Archives of Plastic Surgery
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    • 제43권4호
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    • pp.339-343
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    • 2016
  • Background Numerous techniques have been used to achieve long-term projection of the nipple following nipple-areola reconstruction. However, the reconstructed nipple loses projection over time. We describe a technique that uses local flaps to improve the lost projection of reconstructed nipples. Methods Between November 2013 and March 2015, nine patients (11 nipples) underwent revisional nipple reconstruction for lost projection. Only C-H nipple reconstructions were included in this study. The medical history of each patient was reviewed and photographs were taken in front and lateral views. All patients attended routine follow-up visits. Deepithelialized triangular flaps were made on all four sides of the nipple and buried in the opposite corners in order to augment the volume of the nipple. Anchoring sutures were used to attach each triangular flap on the side opposite their point of origin, and the resulting defects were closed directly. Results This procedure was used successfully in nine patients (11 nipples). Adequate projection was achieved in all patients and no complications occurred. The average nipple height was 3 mm before operation, 7 mm one day after operation, 5 mm at the six-month follow-up, and 5 mm at the 12-month follow-up. The average nipple-areolar angle was $164^{\circ}$ before the operation, $111^{\circ}$ one day after the operation, $130^{\circ}$ at the six-month follow-up, and $133^{\circ}$ at the 12-month follow-up. Conclusions The method described provides a solution to the loss of projection in reconstructed nipples. We recommend this technique because it leads to better projection, greater volume, and a more natural shape.

두피에 발생한 혈관 육종의 치험 2례 (Case Report of Angiosarcoma on Scalp (2 cases))

  • 양은진;김정태;김연환;이형중
    • Archives of Plastic Surgery
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    • 제36권1호
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    • pp.96-100
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    • 2009
  • Purpose: Angiosarcoma of the scalp is unusual vascular tumor originating from endothelial cell. Angiosarcoma is an aggressive tumor with high propensity for both local recurrence and distant metastasis. We report 2 cases of angiosarcoma having poor prognosis recently. Methods: Case 1 was a 67 - year - old male patient. He visited the hospital with a $3{\times}5cm$ sized discolored mass in forehead. It began at one month ago from coming to the hospital. Case 2 was a 64 - year - old male patient. He visited for our hospital to remove a $4{\times}5cm$ sized scalp mass. He had a pruritis on scalp from 9 months ago before coming to the hospital. Despite of the conservative treatments, the wound was not healed and advanced necrotic lesion with hemorrhage. Results: Case 1 diagnosed as an angiosarcoma. He underwent a radical operation 5 times. But the tumor expanded multiple area in dura & frontal area of the brain. The patient rejected the treatment any more. And he died one month later. Case 2 diagnosed as an angiosarcoma and metastased to skull in MRI. He got a radical resection including cranium. Three months later, it recurred to ipsilateral Sternocleidomastoideus muscle. He got a additional operation & started radiotherapy. And now he is receiving chemotherapy, but the recurred lesion is expanding. Conclusion: Angiosarcoma is a highly malignant tumor. Especially it arises in vascularized area, it easily metastases. So it is the best to treat angiosarcoma with surgery included wide margins. Despite of the lesion is small, we remember that angiosarcoma is a tumor that consider to metastases.

Alar Extension Graft를 이용한 콧방울뒤당김의 교정 (The Alar Extension Graft for Retracted Ala)

  • 김현수;노시균
    • Archives of Plastic Surgery
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    • 제36권1호
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    • pp.66-74
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    • 2009
  • Purpose: The importance of the deformities in alar - columellar complex has been underestimated in Asian ethnic groups for the last decades. Fortunately, with increasing familiarity of the open rhinoplasty techniques, the anatomic details of the nasal tip have been pointed up. Definitely, having an interest and demand for improving the sub - normal relationship between the alar rim and columella are indebted for such growing of knowledge about nasal tip anatomy. However, it is true that any single procedure is not settled as versatile and fully confident modality to correct the retracted notching of the alar rim. With this article, I should like to propose another useful option for treating retracted ala. Methods: The author has tried to correct alar rim retraction by means of: (1) Triangular onlay septal cartilage graft on the lower lateral cartilage with the medial end fixed to the anterior surface of the lateral crus(Alar extension graft), (2) Inserting lateral end of the alar extension graft to the vestibular skin pocket in the form of a finger - in - groove, (3) using the vestibular skin in the form of an advancement flap, and (4) using the soft shield graft to prevent possible visible step - off of the alar margin. Results: The author applied an alar extension graft to 16 patients in order to correct a retracted ala for the last 27 months (August, 2003 - October, 2005). The distances from alar rim to long axis of nostril were improved to be within 2 mm in all of the cases, and also the shape of the alar rim changed to a round form. Nostril asymmetry (6%) in one case, temporary palpable step - off (18%) in three cases, temporary visible step - off (6%) in one case, and temporary paresthesia of the tip (25%) in four cases were observed. Conclusion: The alar extension graft is simple and efficacious. It does not need donor sites other than the operative field, and its results are predictable. In particular, since it may give structural intensity to a weak lower lateral cartilage, it may be preferentially used for the correction of a retracted ala that arises from hypoplastic lower lateral cartilage. Moreover intensified lower lateral cartilage also improves the esthetic shape of lobule.

역 L 형 절골술과 Liou 신연기를 이용한 넓은 치조열의 교정 (Correction of a Wide Alveolar Cleft with Reverse L osteotomy and Liou Alveolar Distractor)

  • 이명철;유대현;박병윤;권순만
    • Archives of Plastic Surgery
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    • 제36권4호
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    • pp.445-449
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    • 2009
  • Purpose: A successful surgical treatment for a wide alveolar cleft with bone graft is difficult to achieve due to several factors such as the limitation of gingivoperiosteal flap, the presence of large scar tissues, and the poor blood circulation. To overcome these problems, alveolar distraction osteogenesis using Liou alveolar distraction device was applied. We analyzed the consequences of this surgical treatment. Method: Between 2006 January and 2007 August, we have conducted analysis on the methods and consequences of Liou alveolar distraction osteogenesis for 6 patients. The age of patients was 12 years and 6 months in average. The follow up period was 19 months in average. The Reverse L osteotomy followed by the placement of the Liou alveolar distraction device was performed. After serial distraction, the distractor was removed after 5 months of the process of osteogenesis, and the result was analyzed using the computed tomography and the x-ray films of the alveolar bone and the teeth. Results: The alveolar cleft with 12.5 mm in average width was filled with 8.5 mm of newly formed bone tissue in average width after 5 months of osteogenesis. Among the 6 cases, 5 required the additional bone graft and 1 case only required the gingivoperioplasty. The newly formed bone tissues did not show any signs of bone resorption. However, a considerable degree of teeth displacement was shown. Conclusion: For the alveolar cleft too wide to be reconstructed by a general bone graft, it is strongly recommended to perform the reverse L osteotomy of the cleft side with Liou alveolar distraction device to initiate the alveolar osteogenesis. However, the migrated teeth showed some degree of relapse, thus, the orthodontic treatment is essential following the distraction osteogenesis treatment.

Prevention of Implant Malposition in Inframammary Augmentation Mammaplasty

  • Kim, Yoon Ji;Kim, Yang Woo;Cheon, Young Woo
    • Archives of Plastic Surgery
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    • 제41권4호
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    • pp.407-413
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    • 2014
  • Background Implant malposition can produce unsatisfactory aesthetic results after breast augmentation. The goal of this article is to identify aspects of the preoperative surgical planning and intraoperative flap fixation that can prevent implant malposition. Methods This study examined 36 patients who underwent primary dual plane breast augmentation through an inframammary incision between September 1, 2012 and January 31, 2013. Before the surgery, preoperative evaluation and design using the Randquist formula were performed. Each patient was evaluated retrospectively for nipple position relative to the breast implant and breast contour, using standardized preoperative and postoperative photographs. The average follow-up period was 10 months. Results Seven of 72 breasts were identified as having implant malposition. These malpositions were divided into two groups. In relation to the new breast mound, six breasts had an inferiorly positioned and one breast had a superiorly positioned nipple-areolar complex. Two of these seven breasts were accompanied with an unsatisfactory breast contour. Conclusions We identified two main causes of implant malposition after inframammary augmentation mammaplasty. One cause was an incorrect preoperatively designed nipple to inframammary fold (N-IMF) distance. The breast skin and parenchyma quality, such as an extremely tight envelope, should be considered. If an extremely tight envelope is found, the preoperatively designed new N-IMF distance should be increased. The other main cause of malposition is failure of the fascial suture from Scarpa's fascia to the perichondrium through an inframammary incision. As well, when this fixation is performed, it should be performed directly downward to the perichondrium, rather than slanted in a cranial or caudal direction.

A New Approach to Objective Evaluation of the Success of Nasal Septum Perforation

  • Ozturk, Sinan;Zor, Fatih;Ozturk, Serdar;Kartal, Ozgur;Alhan, Dogan;Isik, Selcuk
    • Archives of Plastic Surgery
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    • 제41권4호
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    • pp.403-406
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    • 2014
  • Background Perforations in the nasal septum (NSP) give rise not only to disintegration of the septum anatomy but also impairment in normal nasal physiology. The successes of these surgical techniques are usually equated to anatomical closure of the perforation. The goal of this study is to evaluate the subjective and objective results of our surgical technique for septal perforation surgery. Methods All NSPs in the six patients were closed by inferior turbinate flap. The Nasal Obstruction Symptom Evaluation (NOSE) instrument was used to evaluate the preoperative and postoperative subjective sensation of nasal obstruction. Measurement of preoperative and postoperative nasal airway resistance was performed using active anterior rhinomanometry which is an objective test. Wilcoxson signed rank test and Spearman correlation test were used to analyze correlation between NOSE scores and rhinomanometric measurements. Results The full closure of the septal perforations was noted in 100% of patients. The total NOSE score was 14 preoperatively and one postoperatively. The improvement in NOSE scores was statistically significant ($P{\leq}0.002$). The mean preoperative total resistance (ResT150) value was $0.13Pa/cm^3s^{-1}$, which is below the normal range ($0.16-0.31Pa/cm^3s^{-1}$), while the mean postoperative ResT150 value was $0.27Pa/cm^3s^{-1}$. The correlation between the improvement in NOSE scores and improvements in ResT150 values was statistically significant. Conclusions Surgical approaches should aim to solve both the anatomical and physiological problems of NSP. The application of subjective and objective tests in the postoperative period will help surgeons assess the applied techniques.

Indications, Outcomes, and Complications of Pedicled Propeller Perforator Flaps for Upper Body Defects: A Systematic Review

  • Lazzeri, Davide;Huemer, Georg M.;Nicoli, Fabio;Larcher, Lorenz;Dashti, Talal;Grassetti, Luca;Li, Qingfeng;Zhang, Yixin;Spinelli, Giuseppe;Agostini, Tommaso
    • Archives of Plastic Surgery
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    • 제40권1호
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    • pp.44-50
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    • 2013
  • Background The aim of this investigation was to systematically review the current literature to provide the best data for indications, outcomes, survival, and complication rates of pedicled propeller perforator flaps for upper body defects. Methods A comprehensive literature review for articles published from January 1991 to December 2011 was performed using the PubMed, Medline, and Cochrane Databases. Articles without available full-text, single case reports or papers with excessive missing data were excluded. Papers reporting pedicle-perforator (propeller) flaps used for lower extremity reconstruction were excluded from meta-analysis. Results From the initial 1,736 studies our search yielded, 343 studies qualified for the second stage of selection. Of 117 full-text reports screened, 41 studies, met the definitive inclusion and exclusion criteria. Of the selected 41 articles, 26 were case series, original papers or retrospective reviews and were included, whereas 15 were case report papers and therefore were excluded. Two hundred ninety-five propeller flaps were reported to have been used in a total of 283 patients. Indications include repair of trauma-induced injuries, post-trauma revision surgery, cancer resection, chronic infection, pressure sores, and chronic ulcers with a major complication rate (3.3%) comparable to that of free flaps. No specific exclusion criteria for the procedure were presented in the studies reviewed. Conclusions Pedicled propeller flaps are a versatile and safe reconstructive option that are easy and quick to raise and that provide unlimited clinical solutions because of the theoretical possibility of harvesting them based on any perforator chosen among those classified in the body.