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Norberto Sánchez-fernandez - One of the best experts on this subject based on the ideXlab platform.
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Bile duct growing factor: An alternate technique for reconstruction of thin bile Ducts after iatrogenic injury
Journal of Gastrointestinal Surgery, 2006Co-Authors: M. A. Mercado, Carlos Chan, Alexandra Barajas-olivas, Daniel Borja-cacho, H. Orozco, Carlos Quezada, Norberto Sánchez-fernandezAbstract:A variant of bilioenteric anastomosis, laterolateral hepatojejunostomy, is described in which the opened anterior aspect of the common hepatic duct and left hepatic duct is anastomosed to a Roux jejunal limb. This technique is specially designed for thin, injured bile Ducts in which a conventional anastomosis is difficult due to the small diameter of the Ducts. A wide anastomosis is obtained, leaving the posterior wall as a conduit for bile, ensuring an adequate anastomotic diameter.
Hassan M Nagib - One of the best experts on this subject based on the ideXlab platform.
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convergence of numerical simulations of turbulent wall bounded flows and mean cross flow structure of rectangular Ducts
Meccanica, 2016Co-Authors: Ricardo Vinuesa, Cezary Prus, Philipp Schlatter, Hassan M NagibAbstract:Convergence criteria for direct numerical simulations of turbulent channel and duct flows are proposed. The convergence indicator for channels is defined as the deviation of the nondimensional total shear-stress profile with respect to a linear profile, whereas the one for the duct is based on a nondimensional streamwise momentum balance at the duct centerplane. We identify the starting (\(T_{S}\)) and averaging times (\(T_{A}\)) necessary to obtain sufficiently converged statistics, and also find that optimum convergence rates are achieved when the spacing in time between individual realizations is below \(\Delta t^{+}=17\). The in-plane structure of the flow in turbulent Ducts is also assessed by analyzing square Ducts at \(Re_{\tau ,c} \simeq 180\) and 360 and rectangular Ducts with aspect ratios 3 and 10 at \(Re_{\tau ,c} \simeq 180\). Identification of coherent vortices shows that near-wall streaks are located in all the duct cases at a wall-normal distance of \(y^{+} \simeq 40\) as in Pinelli et al. (J Fluid Mech 644:107–122, 2010). We also find that large-scale motions play a crucial role in the streamline pattern of the secondary flow, whereas near-wall structures highly influence the streamwise vorticity pattern. These conclusions extend the findings by Pinelli et al. to other kinds of large-scale motions in the flow through the consideration of wider Ducts. They also highlight the complex and multiscale nature of the secondary flow of second kind in turbulent duct flows.
Zdenĕk Lecjaks - One of the best experts on this subject based on the ideXlab platform.
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wall effect for a sphere falling through a non newtonian fluid in a rectangular duct
Chemical Engineering Science, 1995Co-Authors: Ivan Machač, Zdenĕk LecjaksAbstract:The wall effects on the terminal falling velocity of a sphere moving through power law liquids (1≥n≥0.36) contained in a rectangular duct have been examined in the creeping flow region. Defining an effective diameter De of the rectangular duct with a falling sphere, the experimental wall factor data have been correlated by means of a single relationship for rectangular Ducts of arbitrary geometry including the parallel plates and square Ducts.
Carlos Chan - One of the best experts on this subject based on the ideXlab platform.
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Bile duct growing factor: An alternate technique for reconstruction of thin bile Ducts after iatrogenic injury
Journal of Gastrointestinal Surgery, 2006Co-Authors: M. A. Mercado, Carlos Chan, Alexandra Barajas-olivas, Daniel Borja-cacho, H. Orozco, Carlos Quezada, Norberto Sánchez-fernandezAbstract:A variant of bilioenteric anastomosis, laterolateral hepatojejunostomy, is described in which the opened anterior aspect of the common hepatic duct and left hepatic duct is anastomosed to a Roux jejunal limb. This technique is specially designed for thin, injured bile Ducts in which a conventional anastomosis is difficult due to the small diameter of the Ducts. A wide anastomosis is obtained, leaving the posterior wall as a conduit for bile, ensuring an adequate anastomotic diameter.
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Long-term evaluation of biliary reconstruction after partial resection of segments IV and V in iatrogenic injuries
Journal of Gastrointestinal Surgery, 2006Co-Authors: Miguel Ángel Mercado, Carlos Chan, Alexandra Barajas-olivas, Héctor Orozco, José M. Villalta, Javier Eraña, Ismael DomínguezAbstract:Roux-en-Y hepatojejunostomy is the procedure of choice for biliary reconstruction after complex iatrogenic injury that is usually associated with vascular injuries and concomitant ischemia of the Ducts. To avoid the ischemic component, our group routinely performs a high repair to assure an anastomosis in noninflamed, nonscarred, and nonischemic Ducts. If the duct bifurcation is preserved, the Hepp-Couinaud approach for reconstruction is an excellent choice. Partial liver resection of segments IV and V allows adequate exposure of the bile duct at its bifurcation with an anterior approach of the Ducts (therefore not jeopardizing the circulation), allowing a high quality anastomosis. Long-term results of bile duct reconstruction using this approach are described. Two hundred eighty-five bile duct reconstructions were done between 1989 and 2004 in a tertiary care university hospital. The first partial-segment IV resection was done in 1994; 94 cases have been reconstructed since then using this approach. All of them had a complex injury (Strasberg E1-E5), and although in many cases the bifurcation was preserved (E1-E3), a high bilioenteric anastomosis was done to facilitate the reconstruction. In 70 cases, the bifurcation was identified, and in the 24 in which the confluence was not preserved, the right and left Ducts were found except in one case. In three patients, the right duct was found unsuitable for anastomosis, and a liver resection was done. In the remaining 21, an anastomosis was done using a stent (transhepatic, transanastomotic) through the right duct. According to Lillemoe’s criteria, 86 cases had good results (91%). In four of the eight remaining patients, there was the need to operate again due to the presence of an obstruction and/or cholangitis. In the rest, radiological instrumentation was done. Four of these cases have developed secondary biliary cirrhosis, two of which have died while waiting for a liver transplant, four and six years after reconstruction. Partial segments IV and V resection allows adequate exposure of the confluence and the isolated left or right hepatic Ducts. Anterior exposure of the Ducts allows an anastomosis in well-preserved, nonischemic, nonscarred, or noninflamed Ducts. Parenchyma removal also allows the free placement of the jejunal limb, without external compression and tension, obtaining a high quality anastomosis with excellent long-term results.
Alexandra Barajas-olivas - One of the best experts on this subject based on the ideXlab platform.
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Bile duct growing factor: An alternate technique for reconstruction of thin bile Ducts after iatrogenic injury
Journal of Gastrointestinal Surgery, 2006Co-Authors: M. A. Mercado, Carlos Chan, Alexandra Barajas-olivas, Daniel Borja-cacho, H. Orozco, Carlos Quezada, Norberto Sánchez-fernandezAbstract:A variant of bilioenteric anastomosis, laterolateral hepatojejunostomy, is described in which the opened anterior aspect of the common hepatic duct and left hepatic duct is anastomosed to a Roux jejunal limb. This technique is specially designed for thin, injured bile Ducts in which a conventional anastomosis is difficult due to the small diameter of the Ducts. A wide anastomosis is obtained, leaving the posterior wall as a conduit for bile, ensuring an adequate anastomotic diameter.
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Long-term evaluation of biliary reconstruction after partial resection of segments IV and V in iatrogenic injuries
Journal of Gastrointestinal Surgery, 2006Co-Authors: Miguel Ángel Mercado, Carlos Chan, Alexandra Barajas-olivas, Héctor Orozco, José M. Villalta, Javier Eraña, Ismael DomínguezAbstract:Roux-en-Y hepatojejunostomy is the procedure of choice for biliary reconstruction after complex iatrogenic injury that is usually associated with vascular injuries and concomitant ischemia of the Ducts. To avoid the ischemic component, our group routinely performs a high repair to assure an anastomosis in noninflamed, nonscarred, and nonischemic Ducts. If the duct bifurcation is preserved, the Hepp-Couinaud approach for reconstruction is an excellent choice. Partial liver resection of segments IV and V allows adequate exposure of the bile duct at its bifurcation with an anterior approach of the Ducts (therefore not jeopardizing the circulation), allowing a high quality anastomosis. Long-term results of bile duct reconstruction using this approach are described. Two hundred eighty-five bile duct reconstructions were done between 1989 and 2004 in a tertiary care university hospital. The first partial-segment IV resection was done in 1994; 94 cases have been reconstructed since then using this approach. All of them had a complex injury (Strasberg E1-E5), and although in many cases the bifurcation was preserved (E1-E3), a high bilioenteric anastomosis was done to facilitate the reconstruction. In 70 cases, the bifurcation was identified, and in the 24 in which the confluence was not preserved, the right and left Ducts were found except in one case. In three patients, the right duct was found unsuitable for anastomosis, and a liver resection was done. In the remaining 21, an anastomosis was done using a stent (transhepatic, transanastomotic) through the right duct. According to Lillemoe’s criteria, 86 cases had good results (91%). In four of the eight remaining patients, there was the need to operate again due to the presence of an obstruction and/or cholangitis. In the rest, radiological instrumentation was done. Four of these cases have developed secondary biliary cirrhosis, two of which have died while waiting for a liver transplant, four and six years after reconstruction. Partial segments IV and V resection allows adequate exposure of the confluence and the isolated left or right hepatic Ducts. Anterior exposure of the Ducts allows an anastomosis in well-preserved, nonischemic, nonscarred, or noninflamed Ducts. Parenchyma removal also allows the free placement of the jejunal limb, without external compression and tension, obtaining a high quality anastomosis with excellent long-term results.
