Sectoral Duct Research Articles

Impact of Lorentz force on forced convective MHD Jeffrey fluid flow through annular sector duct

Present numerical simulation is to investigate the Lorentz force and constant axial pressure gradient effects on flow and heat transfer of electrically conducting magneto-hydrodynamic, [Formula: see text] Jeffrey fluid at fully developed region of annular sector duct. The law of conservation of energy is simulated by taking two thermally boundary conditions, known as [Formula: see text]1 thermally boundary condition (i.e. constant axial heat flux with uniform peripherally temperature in the annular sector duct’s cross section) and [Formula: see text] thermally boundary condition (i.e. constant temperature axially and peripherally). The numerical results are simulated in the following range of parameters: the ratio of radii, [Formula: see text], an apex angle of duct [Formula: see text] by using [Formula: see text] number of fins, Hartman number, [Formula: see text] and the ratio of relaxation time to retardation time, [Formula: see text]. During the simulation, it has been concluded that the other parameter corresponding to Jeffrey fluid (i.e. the retardation time, [Formula: see text]), has ignored due to minor attribution on flow and heat transfer by increasing the value from [Formula: see text] to [Formula: see text]. Hartman number, [Formula: see text], upgrades the [Formula: see text] up to 18.76% and 14.60%, while [Formula: see text] / [Formula: see text] up to 1.82% and 1.47%/1.55% and 1.29% for [Formula: see text] and [Formula: see text] respectively at [Formula: see text] and [Formula: see text] by increasing its value from 0 to 2. At higher [Formula: see text], the difference becomes ignored in the case of [Formula: see text] when we change the annular region along radial direction.

Laparoscopic management of variant ductal and vascular anatomy in children with choledochal cysts.

Variations in biliary ductal and hepatic vascular anatomy increase the complexity of surgery for choledochal cysts (CDC). The laparoscopic approach for the management of paediatric CDCs with variant anatomy is underreported. This study aimed to describe anatomical variations, operative techniques and early outcomes of laparoscopic hepaticojejunostomy (HJ) in children with CDCs and variant anatomy. We conducted a retrospective review of 40 children who underwent laparoscopic CDC excision with HJ between 2019 and 2024 in a single surgical unit. Patients were divided into Group I (with anatomical variations, n = 20) and Group II (without variations, n = 20). Data on demographic details, clinical presentation, imaging findings, pre-operative interventions, ductal and vascular anatomical variations, surgical techniques, intraoperative variables, post-operative complications and outcomes were collected and analysed. Ductal variations were found in 10 patients, with aberrant right posterior sectoral duct being the most common. Vascular variations were identified in 12 patients, with anteriorly crossing the right hepatic artery (RHA) being the most frequent. Group I had a higher mean age (7.32 vs. 3.57 years, P = 0.014) and longer operative times (415 vs. 364 min, P < 0.0001). Conversion to laparotomy was necessary in 10% of Group I and 15% of Group II patients ( P = 0.634). Post-operative complications, primarily minor (Clavien-Dindo Grade I or II), occurred in 40% of Group I and 30% of Group II ( P = 0.495). Group I had a significantly shorter time to full feeds (72 vs. 80 h, P = 0.015). Both groups had similar post-operative hospital stays and follow-up durations. At the last follow-up, all patients, except one with liver failure in Group II, were asymptomatic with no significant biliary dilatation or liver function abnormalities. Laparoscopic management of CDCs with variant ductal and vascular anatomy in children is feasible, safe and effective. Detailed pre-operative imaging, meticulous intraoperative assessment and tailored surgical techniques are crucial for successful outcomes.

A Monograph on Anatomy and Variants of Hepatic Resectional Surgery

BACKGROUND: The liver anatomy appears to be very complex due to the enormous number of vascular and biliary branches as well as the fact that the underlying pathology frequently distorts the anatomy. To prevent damage during surgical or invasive procedures, it is advised to be aware of the arteries’ typical structure and variations. Hepatic surgeons, general surgeons, transplant surgeons, interventional radiologists, and other medical specialists who treat liver problems must have this knowledge. MATERIALS AND METHODS: We have retrospectively evaluated the PubMed databases, Embase, and the Cochrane Library by applying various combinations of subject-related terms. The search terms identified with the medical subject heading were “Anatomy, right hepatectomy, resection, variants.” The databases were used to collect the literature published since 1991. RESULTS: Results delineated that 91.6% of patients had a single right hepatic vein, 81% shared a trunk with their middle hepatic vein (MHV) and left hepatic vein (LHV), and 19% had separate MHV and LHV drainage into the inferior vena cava. Overall prevalences of the abnormal hepatic artery, abnormal right hepatic artery (aRHA), abnormal left hepatic artery (aLHA), and combined aRHA/aLHA were found to be 27.41%, 15.63%, 16.32%, and 4.53%, respectively. The most common variation (type 2) is the so-called “portal vein (PV) trifurcation,” in which the main PV divides into the left PV, the right anterior PV, and the right posterior PV. The right posterior sectoral duct joins the left hepatic duct with a supraportal course, the right posterior sectoral duct joins the right anterior sectoral duct with an infraportal course, the trifurcation variation of the biliary tree, retroportal course, and the left lateral segmental ducts caudal to the umbilical portion of the PV are examples of variant biliary anatomy encountered in PV variations. Duplication of the common bile duct is a very uncommon congenital biliary system defect. CONCLUSION: It is very crucial for surgeon to have abreast knowledge of the tributaries, their anatomy, and variations to limit blood loss and operative morbidities.

Study of Anatomical Variation of Intrahepatic Biliary Tree by Magnetic Resonance Cholangiopancreatography in Patients Attending Tertiary Hospital of Eastern Nepal

Background: There are several variations in the complex anatomy of intrahepatic bile ducts. Magnetic resonance cholangiopancreatographyis a safer imaging modality that effectively shows these variations, aiding in surgical planning and preventing iatrogenic injuries. This study aims to evaluate these anatomical variations using magnetic resonance cholangiopancreatography. Materials and Methods: This cross-sectional prospective study was performed in the Radiology Department of Nobel Medical College for one year using a convenient sampling technique. A total of 165 cases meeting the inclusion criteriawere selected and magnetic resonance cholangiopancreatography was performed to evaluate the anatomical variations. Results: The mean age of patients was 34.32±10.22 years out of which 51.5%were male and 48.5%were female. The branching pattern of right hepatic duct was typical in 66.7% of cases. The right posterior sectoral duct joining left hepatic duct was the most common variation seen in 15.2%. Right posterior sectoral duct joining the common bile duct was present in 6.7%. 6.1% of cases had unclassified variation whereas a trifurcation pattern was found in 5.5%. Left hepatic duct showed the typical branching pattern in 70.9% of cases. Segment II duct draining into the common trunk of segments III and IV was seen in 20%. Triconfluence among segments II, III, and IV was seen in 8.5% and 0.6% of cases had unclassified variation. Conclusion: This study revealed wide variation in branching patterns of intrahepatic biliary ducts. The typical branching pattern of right and left hepatic ducts were seen in majority of cases.

Intrahepatic lithiasis managed with hepatectomy and anterograde cholangioscopy through the right posterior sectorial duct

Intrahepatic lithiasis managed with hepatectomy and anterograde cholangioscopy through the right posterior sectorial duct

Robotic Left Hepatectomy with En Bloc Biliary Resection and Roux-en-Y Hepaticojejunostomy: A Technique of Portal Venous Tangential Vascular Reconstruction.

Robotic technology is increasingly utilized in perihilar cholangiocarcinoma treatments, requiring expertise in minimally invasive liver surgeries and biliary reconstructions. These resections often involve vascular and multiple sectoral bile duct reconstructions. Minimally invasive vascular repairs are now emerging with promising outcomes, potentially altering criteria for selecting minimally invasive hepatobiliary tumor resections. In this multimedia article, we describe our technique of robotic portal venous tangential primary reconstruction with right sectoral bile duct unification ductoplasty for the treatment of perihilar cholangiocarcinoma using the robotic approach. The robotic technique was chosen in this operation with preoperative anticipation of needing vascular resection and reconstruction due to left portal vein tumor involvement. Additionally, a Roux-en-Y hepaticojejunostomy to the right anterior and posterior sectoral duct was planned for biliary reconstruction. Proximal and distal vascular control of the portal vein bifurcation was obtained by placing vascular bulldog clamps across the main and right portal veins. Once an R0 vascular margin was obtained on the left portal vein, portal bifurcation was tangentially repaired. Perfusion to the liver was then restored, and left hemihepatectomy with enbloc extrahepatic biliary resection was carried out, followed by Roux-en-Y hepaticojejunostomy reconstruction to the right anterior and posterior sectoral bile ducts, as a single anastomosis. The operation was uneventful without vascular or biliary complications. Robotic unification ductoplasty circumvented the need for multiple anastomoses. The robotic approach for left-sided perihilar cholangiocarcinoma resections, requiring precise biliovascular management, is safe, feasible, and efficient. This method demonstrates the potential of robotic techniques as an alternative to traditional open surgery.

Right posterior sectoral duct draining into the common bile duct: the discovery of a new anatomical biliary variant

Right posterior sectoral duct draining into the common bile duct: the discovery of a new anatomical biliary variant

Biliary Ablation for Sectoral Duct Injury to Avoid Surgery

AbstractBile duct injury is a common and serious complication of both laparoscopic and open cholecystectomy. The conventional treatment for isolated bile duct injury is hepaticojejunostomy or hepatectomy. We present a case of biliary leak from an isolated right posterior sectoral duct after cholecystectomy treated with percutaneous sclerotherapy using alcohol. Approval and consent waiver were obtained from the Institutional Review Board (IRB 2023-CR-18).

Convective heat transfer of electrically conducting MHD power law fluid through annular sector duct

This study deals with the effect of Lorentz force on forced convection flow of electrically conducting magneto-hydrodynamic, (MHD) power law fluid through the annular sector duct by using finite volume method. In existence literature, hydro-thermal flow of MHD power law fluid within an annular sector duct has not been reported. The effect of Lorentz force on hydro-thermal power law fluid flow makes it very much novel in its own right. Here the main objective is to explore the effect of Lorentz force on hydro-thermal flow characteristics. The influence of uniform magnetic field is taken parallel to the radial direction. The effects of Hartman parameter, [Formula: see text] and power law index, [Formula: see text], corresponding to Lorentz force and power law fluid respectively, on the quantities of interest such as velocity and temperature profiles, friction factor and average Nusselt number [Formula: see text] are discussed for different geometric configuration parameters’ values of the annular sector duct. Computer code is developed and validated by comparing the results of limiting cases with the available literature. It has been observed that [Formula: see text] increases with the increase in [Formula: see text]. This trend is prevalent in both pseudo-plastic and dilatant fluids. The impact of [Formula: see text] is pronounced in the later case.

Numerically hydrothermal fully developed forced convective hybrid nanofluid flow through annular sector duct

In this paper, fully developed forced convective flow properties of hybrid nanofluid through annular sector duct are discussed. The studies of hybrid nanofluid, i.e. the combination of a nanofluid (nanoparticles plus water) with another nanoparticles’ volume fraction, are considered. Hybrid nanofluids become most important due to enhancement in the heat transfer rate. Copper oxide (CuO)–water is taken as the nanofluid. The volume fraction of CuO nanoparticles in water is kept fixed at 4%, whereas the volume fractions of Cu nanoparticles are taken in the range of 0–4% in this study. Under the assumption of hydrodynamically and thermally fully developed flow, the deviation in the velocity components along the axial direction vanishes in the case of momentum equations; however, the deviation in the temperature becomes constant in the case of energy equation. After dimensionless analysis, the finite volume method is applied to find the numerical solutions for velocity, temperature, heat transfer rate and fanning friction factor. During physical analysis, it has been concluded that the percentage enhancement in heat transfer rate is comparably more than fanning friction factor when we increase the volume fraction of Cu nanoparticles in the CuO–water nanofluid. Furthermore, the same observation has been noticed in the case of heat transfer rate when the platelet shape factor of the nanoparticles has been used instead of brick and cylinder shape factors. Increase in fRe is 8.01% when we increase the Cu nanoparticles’ volume fraction from 1% to 4%, whereas the increments in Nu are 15.09%, 18.56% and 20.81% for the brick-, cylinder- and platelet-shaped nanoparticles, respectively, for all values of the ratio of radii, [Formula: see text], and apex angle, [Formula: see text], in both thermal cases.

Darcy–Brinkman–Forchheimer forced convective pseudo-plastic nanofluid flow through annular sector duct

In this research paper, we numerically analyze the flow and heat transfer rate of non-Newtonian pseudo-plastic nanofluid with variable apparent viscosity and thermal conductivity effects, respectively, through annular sector duct. Concentric pipes annular sector duct of an apex angle, [Formula: see text] and ratio of radii, [Formula: see text], is filled with saturated porous media. For this purpose, we utilize the power law Darcy–Brinkman flow model along with Forchheimer term. Also, the contribution of nanoparticles is accounted in carboxy methyl cellulose (CMC)-water, which has been taken as base fluid. Finite volume method (FVM) is utilized to discretize the governing mathematical model, whereas algebraic equations are solved numerically by using strongly implicit procedure (SIP). With the help of graphs, the impacts of nanoparticles’ contribution and porosity factor have been discussed by giving physical interpretation. Results are also found in the limiting sense and show the good agreement with already published data. At [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], we can observe down in [Formula: see text] and Nu upto [Formula: see text] and [Formula: see text], respectively, when n decreases from 1 to [Formula: see text], whereas [Formula: see text] and [Formula: see text], respectively, by decreasing the value of n from 1 to [Formula: see text]. For both cases of nanoparticles’ contribution, the downs in Nu have been observed same by decreasing the value of n.

Forced convective power-law fluid flow through porous annular sector duct

In this paper, we discuss the forced convective heat transfer of power-law fluid flow through porous annular sector duct by applying the Brinkman-extended Darcy flow model. A strongly implicit procedure (SIP) is utilized to solve the algebraic momentum and energy equations which was discretized by using the finite volume method (FVM). The effects of permeability factor and power-law index corresponding to the Brinkman-extended Darcy flow model and power-law fluid, respectively, on flow and heat transfer rate are carried out numerically and graphically against different values of parameters corresponding to geometrical configuration. In the pseudo-plastic fluids, a maximum decrease of more than [Formula: see text] has been observed in [Formula: see text], whereas maximum decrease in dilatant fluid is around [Formula: see text], when we increase the values of k. A decrease of 16.02% in Nu has been carried out in pseudo-plastic fluid, whereas unforeseen decrease in Nu has been observed in both Newtonian and dilatant fluids comparably pseudo-plastic fluid for particular values of k.

Temperature-dependent viscosity effect on forced convective CH3OH–Fe3O4 nanofluid flow through annular duct

The importance of Methanol can be guessed from its usage as in the preparation of methyl tertiary butyl ether (MTBE) fuel, ascetic acid, formaldehyde, metabolize food, biodiesel, pharmaceutical ingredients and products, energy related applications and many more. In this research work, we numerically analyze the impact of temperature-dependent viscosity on flow and heat transfer of Methanol Iron oxide, CH3OH–Fe3O4 nanofluid through annular sector duct. The effects of pertinent parameters corresponding to temperature-dependent viscosity, m, Fe3O4 nanoparticles’ contribution, n and geometrical configuration (i.e. [Formula: see text] and N), are revealed graphically by velocity contours, isotherms, velocity and temperature profiles, and discussed physically. Both parameters m and n suppress the velocity and temperature profiles by increasing the friction factor [Formula: see text] and average Nusselt number [Formula: see text]. Same impacts of m and n have been observed for all values of [Formula: see text] and N.

Open right hepatectomy post tace in a patient of hepatocellular carcinoma in segment 6 and 7 with aberrant right sectoral duct in common hepatic duct

Open right hepatectomy post tace in a patient of hepatocellular carcinoma in segment 6 and 7 with aberrant right sectoral duct in common hepatic duct

Hydro-dynamically and thermally fully developed flow analysis of magneto-hydrodynamic fluid through annular duct

A hydro-dynamic thermal fully developed forced convective heat transfer analysis of magneto-hydrodynamics fluid flow through an annular sector duct is presented in this paper. Two types of thermal boundary conditions i.e., axially uniform heat flux along with peripherally uniform temperature (known as H1-condition) and, axially and peripherally uniform temperature (known as T condition), have been considered to carry out the thermal analysis of fluid. The velocity components along r and [Formula: see text] direction are transformed into algebraic form by using power law discretized scheme, whereas cross-sectional pressure [Formula: see text] is estimated with the help of well know technique [Formula: see text]. The governing partial differential equations are solved by numerically with the help of [Formula: see text] code. Furthermore, simulated results have been compared with the existing results of literature to validate the results. From the results, it is noted that hydro-dynamically and thermally impacts relate directly by increasing the Hartman number, (M). It is further reported that the effect of magnetic field becomes insignificant for the higher number of fins, N. The findings of the present analysis will be applicable in various types of thermal systems.

Viscous dissipation and Joule heating effects on hydro-thermal power law nanofluid through annular duct

This study presents a mathematical model along with numerical simulation to investigate the viscous dissipation and Joule heating effects on electrically conducting magnetohydrodynamics (MHD) forced convection non-Newtonian power law nanofluid flow through annular sector duct. Hydro-thermal power law nanofluid flow through annular sector duct is not investigated in the presence of Joule heating and viscous dissipation effects. The consideration of Joule heating and viscous dissipation effects makes it very much novel in its own right. The main objective of this work is to explore the Joule heating and viscous dissipation effects on hydro-thermal power law nanofluid. Both Copper, Cu/Titanium oxide, TiO2 nanoparticles with base fluid water have been taken as a power law model. Numerically simulation is carried out for viscous, incompressible and steady laminar fully developed fluid flow with constant properties, by using the finite volume method (FVM) and strongly implicit procedure (SIP). It has been observed that viscous dissipation effect on temperature profiles is enhanced in the absence of magnetic field/at lower value of Ha, however, when nanoparticles’ concentration is increased, the effect of magnetic field slightly decreases. Furthermore, by adding Cu nanoparticles from 0% to 5%, we observe the increment in average Nusselt number, Nu up to 16.01% and 16.07% in pseudo-plastic and dilatant fluids, respectively, at [Formula: see text].

A unique case of combined variations of the cystic artery and biliary tree complicating the management of acute cholecystitis

Anatomic variations of the biliary tree and/or the vascular supply of the gallbladder pose challenges in the surgical management of diseases and conditions of the liver-biliary tree and the pancreas. A patient with acute cholecystitis underwent imaging investigation preoperatively with computed tomography of the abdomen and magnetic resonance cholangiopancreatography, which revealed a unique combination of variations: the cystic artery originated from the superior mesenteric artery and the right posterior sectoral duct drained at the same point with cystic duct to the common hepatic duct. The patient underwent open cholecystectomy and her postoperative period was uneventful. The surgeon should be aware of these variations in order to avoid intra- or post-operative complications, and the radiologists should report these variations because they could have a significant clinical impact.

Our Experience in Tracking the Tract: Normal Biliary Anatomy and Variants on Magnetic Resonance Cholangiopancreatography in Living Donor Liver Transplantation.

Objective Biliary anatomy is of paramount importance for hepatobiliary pancreatic surgeons for operative planning. Preoperative assessment with magnetic resonance cholangiopancreatography (MRCP) to evaluate the biliary anatomy plays a vital role, especially for prospective liver donors in living donor liver transplantation (LDLT). Our objective was to evaluate the diagnostic accuracy of MRCP in assessing the anatomical variations of the biliary system and the frequency of biliary variation in the donors of LDLT. Materials and Methods Sixty-five donors of living donor liver transplantation in the age range of 20 to 51 years were studied retrospectively to evaluate the anatomical variations of the biliary tree. As a part of the pre-transplantation donor workup, MRI with MRCP was performed in a 1.5T machine for all these candidates. MRCP source data sets were processed with maximum intensity projections, surface shading, and multi-planar reconstructions. Images were reviewed by two radiologists, and the classification system of Huang et al. was utilized to evaluate the biliary anatomy. The results were compared with the intraoperative cholangiogram, considered the gold standard. Results We identified standard biliary anatomy in 34 candidates (52.3%), and variant biliary anatomy was observed in 31 candidates (47.7%) on MRCP. An intraoperative cholangiogram showed standard anatomy in 36 candidates (55.4%) and biliary variation in 29 candidates (44.6%). Our study showed a sensitivity of 100% and a specificity of 94.5% for identifying biliary variant anatomy on MRCP in comparison with the gold standard intraoperative cholangiogram. The accuracy of MRCP in detecting the variant biliary anatomy in our study was 96.9%. The most common biliary variation was the right posterior sectoral duct draining into the left hepatic duct, Huang type A3. Conclusion The frequency of biliary variations is high in potential liver donors. MRCP is sensitive and highly accurate in identifying the biliary variations of surgical significance.

Fully developed forced convection H2O-CuO nanofluid flow through concentric pipes annular sector duct by using KKL model

Fully developed hydro-thermal H2 O- CuO nanofluid flow through concentric pipes annular sector duct is carried out. Koo–Kleinstreuer–Li ( KKL) model correlations are taken into account to discuss the forced convection flow under the effect of Brownian motion. For discretizing and numerical simulation of governing mathematical problem, finite volume based method, ( FVBM) and well known technique “semi implicit procedure for pressure linked equations, ( SIMPLE) revised” are utilized, whereas constant axial wall heat flux with uniform peripheral wall temperature and, constant and uniform wall temperature known as H1 and T thermally fully developed conditions respectively, are used to discuss the heat transfer rate for different contribution of “Copper Oxide ( CuO)” nanoparticles, n, in base fluid “pure water”. By adding the contribution of nanoparticles, the enhancement in fanning friction factor, fRe, and average Nusselt number, Nu, has been estimated upto 7.72% and 7.54% respectively, in H1 thermal case, whereas 7.71% and 7.16% respectively, in T thermal case.

Application of three-dimensional visualization technology in the anatomical variations of hilar bile ducts in Chinese population.

This study aimed to establish three-dimensional models of the biliary tract of Chinese people using the Hisense computer-aided surgery (CAS) system and to explore the branching patterns and variation types of the biliary system under the study of 3D reconstruction of the biliary tract. Three-dimensional models of the biliary tract were reconstructed in 50 patients using the Hisense CAS system. The branching patterns of intrahepatic bile ducts were observed. The biliary tract was classified according to the confluence of the right posterior sectoral duct (RPSD), right anterior sectoral duct (RASD) and left hepatic duct (LHD), and the presence or absence of accessory hepatic ducts. The 3D models of the bile ducts were successfully reconstructed in 50 Chinese patients. The branching patterns of the bile ducts were classified into seven types. The anatomy of the bile ducts was typical in 54% of cases (n = 27), showed triple confluence in 10% (n = 5), and crossover anomaly in 14% (n = 7), which means anomalous drainage of the RPSD into the LHD, anomalous drainage of the RPSD into the common hepatic duct (CHD) in 10% (n = 5), anomalous drainage of the RPSD into the cystic duct (CD) in 2% (n = 1), absence of left main hepatic duct in 1% (n = 1), presence of accessory duct in 8% (n = 4). Among them, there were three cases of accessory hepatic ducts coexisting with other variation types. By using the Hisense CAS system to establish 3D models of the biliary tract of the Chinese people, we established the branching model of the second-order bile ducts, which has important value for the classification of the biliary system and its variation types.