• Archives of Plastic Surgery
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• v.36 no.4
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• pp.397-405
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• 2009

Purpose: Soft tissue defect of anterior chest wall is caused by trauma, infection, tumors and irradiation. To reconstruct damaged anterior chest wall does require to consider the patient's body condition, the cause, the location, the depth and the size of deletion, the circulation of surrounding tissue and minimization of functional and cosmetic disability. In this report, we suggest the algorithm of configuration for reconstruction methods. Methods: A retrospective study of 20 patients who underwent anterior chest wall reconstruction with pedicled musculocutaneous flap and fasciocutaneous flap was conducted. We collected the information of the patient's body condition, the cause, the size, the depth and the location of deletion, implemented flap and complication. We observed and evaluated flap compatibility, functional and cosmetic results. Patients completed survey about the extent to their satisfaction. Result: Follow up period after surgery was from 6 to 26 months, survival of flap were confirmed in all of patients' case. Two cases of local necrosis, one case of wound disruption were reported, but all these were cured by the debridement and primary closure. One hematoma and one seroma formation were observed in donor site. Longer surgery time, more bleeding amount and more transfusion volume were reported in the group of musculocutenous flap. Conclusion: Long term follow up result showed the successful reconstruction in all patients without recurrence and with minimal donor site morbidity. In addition, the patients' satisfaction for cosmetic and functional results were scaled relatively higher. This confirmed the importance of reconstruction algorithm for the chest wall reconstruction.

• Archives of Plastic Surgery
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• v.39 no.6
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• pp.643-648
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• 2012

Background Aggressive treatment of sternoclavicular joint (SCJ) infection involves systemic antibiotics, surgical drainage and resection if indicated. The purpose of this paper is to describe a classification of post resectional SCJ defects and highlight our reconstructive algorithm. Defects were classified into A, where closure was possible often with the aid of topical negative pressure dressing; B, where parts of the manubrium, calvicular head, and first rib were excised; and C, where both clavicular, first ribs and most of the manubrium were resected. Methods Twelve patients (age range, 42 to 72 years) over the last 8 years underwent reconstruction after SCJ infection. There was 1 case of a type A defect, 10 type B defects, and 1 type C defect. Reconstruction was performed using the pectoralis major flap in 6 cases (50%), the latissimus dorsi flap in 4 cases (33%), secondary closure in 1 case and; the latissimus and the rectus flap in 1 case. Results All wounds healed uneventfully with no flap failure. Nine patients had good shoulder motion. Three patients with extensive clavicular resection had restricted shoulder abduction and were unable to abduct their arm past $90^{\circ}$. Internal and external rotation were not affected. Conclusions We highlight our reconstructive algorithm which is summarised as follows: for an isolated type B SCJ defect we recommend the ipsilateral pectoralis major muscle for closure. For a type C bilateral defect, we suggest the latissimum dorsi flap. In cases of extensive infection where the thoracoacromial and internal mammary vessels are thrombosed, the pectoralis major and rectus abdominus cannot be used; and the latissimus dorsi flap is chosen.

• Archives of Plastic Surgery
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• v.33 no.3
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• pp.283-288
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• 2006

Various vascularized free flaps have been used for midfacial reconstruction after ablative head and neck cancer surgery. The most common donor sites for free flap include latissimus dorsi, rectus abdominis, and radial forearm. Between 1994 and 2004, 14 patients underwent free flap operation after head and neck cancer ablation, and were reviewed retrospectively. Among 14 free flaps, 8 were latissimus dorsi myocutaneous flaps, 3 rectus abdominis myocutaneous flaps and 3 radial forearm flaps, respectively. The overall survival rate of the flap was 100%. Complications were wound dehiscence(5 cases) and ptosis(1 case). We designed multiple dimensionally folded free flap for midfacial reconstruction. For 3-dimensional flap needs, we used latissimus dorsi myocutaneous flap. 2-Dimensional flap was latissimus dorsi or rectus abdominis myocutaneous flap and 1-dimensional flap was radial forearm flap. In this study we produced an algorithm for midfacial reconstruction. Large volume with many skin paddle defects were best reconstructed with latissimus dorsi myocutaneous flap or rectus abdominis myocutaneous flap. Radial forearm flap was used for reconstruction of small volume and little skin paddle defects.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.490-498
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• 2007

BGP route flap damping(RFD) was anecdotally considered to be a key contributor to the stability of the global Internet inter-domain routing system. However, it was recently shown that RFD can incorrectly suppress for substantially long periods of time relatively stable routes, i.e., routes that only fail occasionally. This phenomenon can be attributed to the complex interaction between BGP path exploration and how the RFD algorithm identifies route flaps. In this paper we identify a distinct characteristic of BGP path exploration following a single network event such as a link or router failure. Based on this characteristic, we distinguish BGP route updates during BGP path exploration from route flaps and propose a novel BGP route flap damping algorithm, RFD+. RFD+ has a number of attractive properties in improving Internet routing stability. In particular, it can correctly suppress persistent route flaps without affecting routes that only fail occasionally. In addition to presenting the new algorithm and analyzing its properties, we also perform simulation studies to illustrate the performance of the algorithm.

• Advances in aircraft and spacecraft science
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• v.2 no.3
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• pp.329-343
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• 2015

This study aimed to observe the effect of a novel concept (referred to as the flap extension) implemented on the leading edge of the flap of a three element high lift device. The high lift device, consisting of a flap, main element and slat is designed around an Airbus research profile for sufficient take off and landing performance of a large commercial aircraft. The concept is realised on the profile and numerically optimised to achieve an optimum geometry. Two different optimisation approaches based on Genetic Algorithm optimisations are used: a zero order approach which makes simplifying assumptions to achieve an optimised solution: as well as a direct approach which employs an optimisation in ANSYS DesignXplorer using RANS calculations. Both methods converge to different optimised solutions due to simplifying assumptions. The solution to the zero order optimisation showed a decreased stall angle and decreased maximum lift coefficient against angle of attack due to early stall onset at the flap. The DesignXplorer optimised solution matched that of the baseline solution very closely. The concept was seen to increase lift locally at the flap for both optimisation methods.

• Archives of Plastic Surgery
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• v.48 no.5
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• pp.511-517
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• 2021

The use of free flaps is an essential and reliable method of reconstruction in complex head and neck defects. Flap failure remains the most feared complication, the most common cause being pedicle thrombosis. Among other measures, thrombolysis is useful when manual thrombectomy has failed to restore flap perfusion, in the setting of late or established thrombosis, or in arterial thrombosis with distal clot propagation. We report a case of pedicle arterial thrombosis with distal clot propagation which occurred during reconstruction of a maxillectomy defect, and was successfully treated with thrombolysis using recombinant tissue plasminogen activator. We also review the literature regarding the use of thrombolysis in free flap surgery, and propose an algorithm for the salvage of free flaps in head and neck reconstruction.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.649-656
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• 2013

High-lift devices have a major influence on takeoff, landing and stall performance of an aircraft. Therefore, a slotted flap design optimization process is proposed in this paper to obtain the most effective flap configuration from supported 2D flap configuration. Flap deflection, Gap and Overlap are considered as main contributors to flap lift increment. ANSYS Fluent 13.0.0$^{(R)}$ is used as aerodynamic analysis software that provides accurate solution at given flight conditions. Optimum configuration is obtained by Sequential Quadratic Programing (SQP) algorithm. Performance of the aircraft with optimized flap is estimated using Aircraft Design Synthesis Program (ADSP), the in-house performance analysis code. Obtained parameters such as takeoff, landing distance and stall speed met KAS-VLA airworthiness requirements.

• Advances in aircraft and spacecraft science
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• v.4 no.1
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• pp.81-91
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• 2017

The performances of lifting surfaces are particularly critical in specific flight conditions like takeoff and landing. Different systems can be used to increase the lift and drag coefficients in such conditions like slat, flap or ailerons. Nevertheless they increase the losses and make difficult the mechanical design of wing structures. Morphing surfaces are a compromise between a right increase in lift and a reduction of parts movements involved in the actuation. Furthermore these systems are suitable for more than one flight condition with low inertia problems. So, flap and slats can be easily substituted by the corresponding morphing shapes. This paper deals with a genetic optimization of an airfoil with morphing flap with an already optimized nose. Indeed, two different codes are used to solve the equations, a finite volume code suitable for structured grids named ZEN and the EulerBoundary Layer Drela's code MSES. First a number of different preliminary design tests were done considering a specific set of design variables in order to restrict the design region. Then a RANS optimization with a single design point related to the take-off flight condition has been carried out in order to refine the previous design. Results are shown using the characteristic curves of the best and of the baseline reported to outline the computed performances enhancements. They reveal how the contemporary use of a morphing acting on the nose of the main component and the trailing edge of the flap drive towards a total not negligible increment in lift.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.1
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• pp.58-65
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• 2020

Oroantral fistula (OAF), also termed oroantral communication, is an abnormal condition in which there is a communicating tract between the maxillary sinus and the oral cavity. The most common causes of this pathological communication are known to be dental implant surgery and extraction of posterior maxillary teeth. The purpose of this article is to describe OAF; introduce the approach algorithm for the treatment of OAF; and review the fundamental surgical techniques for fistula closure with their advantages and disadvantages. The author included a thorough review of the previous studies acquired from the PubMed database. Based on this review, this article presents cases of OAF patients treated with buccal flap, buccal fat pad (BFP), and palatal rotational flap techniques.

• Archives of Craniofacial Surgery
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• v.21 no.4
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• pp.237-243
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• 2020

Background: The scalp is an important functional and aesthetic structure that protects the cranial bone. Due to its inelastic characteristics, soft-tissue defects of the scalp make reconstruction surgery difficult. This study aims to provide an improved scalp reconstruction decision making algorithm for surgeons. Methods: This study examined patients who underwent scalp reconstruction within the last 10 years. The study evaluated several factors that surgeons use to select a given reconstruction method such as etiology, defect location, size, depth, and complications. An algorithmic approach was then suggested based on an analysis of these factors. Results: Ninety-four patients were selected in total and 98 cases, including revision surgery, were performed for scalp reconstruction. Scalp reconstruction was performed by primary closure (36.73%), skin graft (27.55%), local flap (17.34%), pedicled regional flap (15.30%), and free flap (3.06%). The ratio of primary closure to more complex procedure on loose scalps (51.11%) was significantly higher than on tight scalps (24.52%) (p=0.011). The choice of scalp reconstruction method was affected significantly by the defect size (R=0.479, p<0.001) and depth (p<0.001). There were five major complications which were three cases of flap necrosis and two cases of skin necrosis. Hematoma was the most common of the 29 minor complications reported, followed by skin necrosis. Conclusion: There are multiple factors affecting the choice of scalp reconstruction method. We suggest an algorithm based on 10 years of experience that will help surgeons establish successful surgical management for their patients.