123 research outputs found

    Extended Reverse Superficial sural Artery Flaps: A Clinical Study

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    INTRODUCTION: Skin defects over the lower third leg, ankle , heel and Foot areas were always a challenging task to a reconstructive surgeon, since these areas are difficult to cover. These areas are easily susceptible to trauma and are the site of numerous trophic problems like pressure sores, chronic ulcers and penetrating injuries. The possibilities For coverage of such defects are Few and those that exist have complications. The Flap chosen should be easy to execute quickly with minimal discomfort to the patient and should provide durable coverage For the defect. Many studies have proven beyond doubt the versatility and reliability of the reverse superficial sural artery fascio-cutaneous flaps in covering these defects and a few studies have even concluded that the reverse sural flap is the flap of choice in covering defects of lower third of leg, foot, ankle and heel regardless of the local conditions. However, in many occasions, conventional reverse sural Flaps limited to middle third of leg, Falls short of the critical area to be covered, with the limitation being the location of the Flap (middle third of leg). Extending the Flap territory proximally into the upper third of the leg would have a versatile Flap with immense potential. Nevertheless, the critical questions remained “How Far?” and “How safe?” For which very little references exist in literature albeit with a very limited number of cases. AIM OF THE STUDY: • To study the versatility, reliability and safety of the extended reverse superficial sural artery fascio cutaneous Flaps in covering the lower third leg, ankle, heel and Foot defects. • To refine the surgical techniques with regard to safe elevation of large Flap dimensions and possible extension of territory in the light of proper understanding of relevant applied anatomy to ensure a reliable Flap. • To compare the conventional method of Flap markings and operative technique with a modified method of Flap markings and operative technique with regard to the reliability and Flap survival. MATERIALS AND METHODS: This study was done in our department From March 2005 to April 2007. This is a prospective comparative study of the reverse sural artery Fascio cutaneous Flaps, most of them with extensions into the upper third of leg done by conventional markings and method and modified markings and method which evolved as we were analysing the causes For Failure of the extended segments done by conventional method. A total number of 26 patients were included in this study with soft tissue defects exposing tendons or bone in the lower third of leg, malleolar area, tendo achilles area, heel, hind Foot and dorsum of the Foot due to various aetiologies. As the modified markings and method were evolved as we were analysing the Failure in our initial cases, randomisation of cases could not be done. Hence, initial l3 cases were done by the conventional method and subsequent l3 cases were done by the modified method. In an effort to minimize the bias, the same team of surgeons operated in all the 26 cases. Equal number (2 cases) of cases with Flaps confined to middle third of leg were used as control in both groups. As Far as possible, the cases with same aetiologies and similar Flap dimensions were taken for comparison in both groups. Inclusion Criteria: • Patients within the age group of l0 years to 60 years. • Patient with soft tissue defects in the lower third of leg, malleolar area, tendoachilles area, heel, hind Foot and dorsum of Foot due to Following aetiologies were included in the study. 1. Motor vehicle accidents 2. Closet injury 3. Wheel spokes injury 4. Unstable scar 5. Malignant melanoma and other malignancies 6. Electrical burns 7. Industrial accidents 8. Osteomyelitis. Patient with co-morbid conditions like Diabetes mellitus, hypertension and coronary artery diseases were not excluded From the study. Exclusion Criteria: • Patients with age less than l0 years and more than 60 years. • Patients with diabetic ulcers, venous ulcers, neuropathic and trophic ulcers were excluded From the study. OBSERVATION: In this study, a total number of 26 patients were inc1uded of which initial 13 cases were operated by conventional markings and method and the subsequent 13 cases were operated by modified method and markings. In this study, we came across various aeteo1ogies like motor vehicle accidents, unstab1e scar excision, c1oset injury, post-excisional defect of skin ma1ignancies and electrical burns. The majority of the cases were due to motor vehicle accidents. In this study, we came across dejects involving all the regions of the lower third of the leg, ankle and foot. In majority of the cases, two or more regions were involved. Out of 13 patients operated by conventional method, the flap was 1imited to the midd1e of third of leg in 2 cases. Remaining 11 cases, needed flap extension into upper third of leg ranging from 2cms to 13 cms. The smallest flap was 7x8 cms with a pedicle length of 26cms. The largest flap was 10 x 16cms with a pedic1e length of 24cms. In the 2 cases in which the flap was limited to the middle third of leg, there was no venous congestion or flap tip necrosis and both the flaps settled well. In the 10 cases which needed flap extension into the upper third of 1eg and elevated in a single stage, 2 cases developed venous congestion which sett1ed subsequently and 5 cases deve1oped distal tip necrosis which ranged from 1-3 cms. In the largest flap which was elevated in stages with a de1ay, dista1 tip necrosis of 4.5 cms occurred. In the other 13 patients operated by the modified method, the flap was 1imited to the middle third of the leg in 2 patients. Remaining 11 patients needed flap extension into upper third of the 1eg ranging from 3-8.5 cms. The smallest flap was 6 x 8 cms with a pedic1e length of 24 cms and the 1argest Flap was 10 x 18 cms with a pedicle length of 26 cms. In the 2 cases in which the flap was 1imited to the middle third of the leg, there were no comp1ications and both flaps sett1ed well. In 10 cases which needed flap extension into the upper third of the leg and elevated in a sing1e stage, venous congestion deve1oped in 2 cases which sett1ed subsequently and kea1ed uneventfully and one Flap deve1oped partia1 thickness flap tip necrosis of 1cms. In the largest flap in this group which measured 10x18cms which was e1evated in stages with a de1ay, distal tip necrosis of 2cms occurred. Post-operative wound infection occurred totally in 2 cases, which was treated by conservative measures and which did not affect the surviva1 of flap adversely. CONCLUSION: • Extended reverse superficial sural artery flaps are a versatile choice of reconstruction of difficult heel and foot dejects. • This flap rep1aces microsurgica1 reconstructions as a first choice in most cases of hee1 and foot dejects with the added advantages of not sacrificing a major artery, a reduced time factor and a 1ower required level of expertise and infrastructure. • The safety and re1iabi1ity of the flap, despite its 1arge dimensions, have been tkorougk1y verified in our experience. • The dissection is simple, and the morbidity, in terms of loss of sensation of sural area, is minimal, the advantages for out weight the compromises. • Dopp1er skou1d be used not on1y to mark the perforators, but a1so to mark the course of the 1esser saphenous vein for inc1usion of this structure a1ong the 1ie of the pedic1e which significantly reduces the venous congestion and increases the flap survival. • The modified sura1 nerve marking and the modified and careful operative technique significantly reduces the flap tip necrosis rate and increases the re1iabi1ity of the extended reverse sura1 flaps. • For high-risk patients, whose under1ying condition warrants a two-staged treatment approach, flap de1ay is a safer way to increase the re1iabi1ity of the extended reverse superficia1 sura1 artery flaps

    Measuring Absorptive Capacity: An Antecedent to Time-Based Manufacturing Practices

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    This study defines absorptive capacity, develops valid and reliable instruments to measure it, describes a framework to examine its impact on time-based manufacturing practices, and test the relationships between these variables

    The information systems environment of time-based competitors

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    Time-based competitors create product development and manufacturing practices that reduce response-time and enhance customization capabilities. These practices require an information-rich, internal environment capable of flexible resource deployment and direct and continuous feedback. These firms should have enhanced information systems planning capabilities, cross-functional involvement in information systems related activities, responsiveness to organizational computing demands, high levels of end-user development, and high levels of information systems performance. Data were collected from 265 manufacturers to develop measures for these information systems variables and to determine if there are relationships between the use of time-based practices and the levels of these variables. Results indicate that firms with high levels of time-based product development practices and time-based manufacturing practices have significantly higher scores across these information systems variables than firms with low levels of these time-based practices

    Impact Of SCM Practices Of A Firm On Supply Chain Responsiveness And Competitive Advantage Of A Firm

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    Today’s supply chains are expected to respond rapidly, effectively, and efficiently to changes in the marketplace to sustain, succeed and create competitive advantage in this increasingly global marketplace by focusing on time, flexibility, and speed of response. The focus of this study is the supply chain responsiveness construct and a firm’s practices to respond to customer’s demands and constantly changing market conditions to create competitive advantage. This research conceptualizes three dimensions of supply chain responsiveness and develops a reliable and valid instrument for measuring this construct. The study further tests the relationships between supply chain management (SCM) practices, supply chain responsiveness, and competitive advantage using structural equation modeling based on 294 responses from industry professionals in the manufacturing and supply chain area. Research findings point out that higher level of SCM practices can lead to improved supply chain responsiveness and enhanced competitive advantage of a firm. Also supply chain responsiveness can have a direct positive impact on competitive advantage of a firm

    Trust-Driven Joint Operations Practices to Achieve Mass Customization: A Comparative Study for U.S., Chinese and Japanese Companies

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    This study builds a model of trust, based on joint operational activities and mass customization using theories of social capital and the resource-based view of the firm. Based on 208 responses from suppliers in the U.S. and China, this study empirically supports the notion that trust positively drives manufacturer-supplier activities in operations. It also supports the claim that joint operations activities contribute to mass customization capabilities in a significant way. Moreover, the level of trust and the degree of joint activities are different for the four types of suppliers used in the study: U.S. brands produced in North America, Japanese brands produced in China, U.S. brands produced in China, and Chinese brands produced in China

    Identification of Glycochenodeoxycholate 3-O-glucuronide and Glycodeoxycholate 3-O-glucuronide as Highly Sensitive and Specific OATP1B1 Biomarkers

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    The aim of this study was to investigate the sensitivity and specificity of endogenous glycochenodeoxycholate and glycodeoxycholate 3-O-glucuronides (GCDCA-3G and GDCA-3G) as substrates for organic anion transporting polypeptide 1B1 (OATP1B1) in humans. We measured fasting levels of plasma GCDCA-3G and GDCA-3G using liquid chromatography-tandem mass spectrometry in 356 healthy volunteers. The mean plasma levels of both compounds were similar to 50% lower in women than in men (P = 2.25 x 10(-18) and P = 4.73 x 10(-9)). In a microarray-based genome-wide association study, theSLCO1B1rs4149056 (c.521T>C, p.Val174Ala) variation showed the strongest association with the plasma GCDCA-3G (P = 3.09 x 10(-30)) and GDCA-3G (P = 1.60 x 10(-17)) concentrations. The mean plasma concentration of GCDCA-3G was 9.2-fold (P = 8.77 x 10(-31)) and that of GDCA-3G was 6.4-fold (P = 2.45x10(-13)) higher in individuals with theSLCO1B1c.521C/C genotype than in those with the c.521T/T genotype. No other variants showed independent genome-wide significant associations with GCDCA-3G or GDCA-3G. GCDCA-3G was highly efficacious in detecting theSLCO1B1c.521C/C genotype with an area under the receiver operating characteristic curve of 0.996 (P <0.0001). The sensitivity (98-99%) and specificity (100%) peaked at a cutoff value of 180 ng/mL for men and 90 ng/mL for women. In a haplotype-based analysis,SLCO1B1*5and*15were associated with reduced, andSLCO1B1*1B, *14, and *35with increased OATP1B1 function.In vitro, both GCDCA-3G and GDCA-3G showed at least 6 times higher uptake by OATP1B1 than OATP1B3 or OATP2B1. These data indicate that the hepatic uptake of GCDCA-3G and GDCA-3G is predominantly mediated by OATP1B1. GCDCA-3G, in particular, is a highly sensitive and specific OATP1B1 biomarker in humans.Peer reviewe
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