BACKGROUND:The piggy-back caval anastomosis technique is widely used in orthotopic liver transplantation although it carries an increased risk of complications,including outflow obstruction and Budd-Chiari syndrome.Th...BACKGROUND:The piggy-back caval anastomosis technique is widely used in orthotopic liver transplantation although it carries an increased risk of complications,including outflow obstruction and Budd-Chiari syndrome.The aim of this study is to clarify the anatomy and variations of hepatic veins(HVs)draining into the inferior vena cava(IVC),and to classify the surgical techniques of piggy-back liver transplantation(PBLT)based on the anatomy of HVs which can reduce the occurrence of complications.METHODS:PBLT was performed in 248 consecutive cases at our hospital from January 2004 to August 2011.The anatomy of recipients’HVs was determined when removing the native diseased livers.Both anatomy of HVs and short HVs draining into the IVC were recorded.These data were collected and analyzed.RESULTS:We classified anatomic variations of HVs in the 248 livers into five types according to the way of drainage into the IVC:type I(trunk type of left and middle HVs),142(57.3%)patients;type II(trunk type of right and middle HVs),54(21.8%);type III(trunk type of left,middle and right HVs),14(5.6%);type IV(non-trunk type of left,middle and right HVs),of which,type IVa,16(6.5%),in the same horizontal plane;type IVb,18(7.3%),in different horizontal planes;and type V(segment type),4(1.6%).The patients whose HVs anatomy belonged to types I,II and III underwent classical piggy-back liver transplantation.Type IVa patients had classical PBLT via HV venoplasty prior to piggy-back anastomosis,while type IVb patients and type V patients could only have modified PBLT.CONCLUSION:This study demonstrates that HVs can be classified according to the anatomy of their drainage into the IVC and we can use this classification to choose the best operative approach to PBLT.展开更多
Wadi Fatima fold-thrust (FAT) belt is a distinctive foreland FAT belt in the Arabian-Nubian Shield (ANS) involving unmetamorphosed to slightly metamorphosed sedimentary sequence of Fatima Group, deposited over a metam...Wadi Fatima fold-thrust (FAT) belt is a distinctive foreland FAT belt in the Arabian-Nubian Shield (ANS) involving unmetamorphosed to slightly metamorphosed sedimentary sequence of Fatima Group, deposited over a metamorphic/igneous basement, comprising ortho-amphibolites, orthoand para-schists (with chaotic unmappable blocks of marbles, pyroxenites and metagabbros), older granite (773 ± 16 Ma) and younger granite. The basement exhibits structural fabrics, such as attenuated tight isoclinal folds, sheared-out hinges, NE-SW penetrative foliation and subhorizontal stretched and mineral lineations, related to an oldest prominent dextral shearing phase affected the main Wadi Fatima during the Neoproterozoic. In Wadi Fatima FAT belt, the style of deformation encompasses flexural-slip folding forming mesoscopicand map-scales NE to ENE plunging overturned antiforms and synforms, and a thrust duplex system bounded by floor thrust and sole thrust (basal detachment) dipping gently towards the hinterland (SE to SSE direction) and rises stratigraphically upwards towards the foreland. Such style is affiliated to thin-skinned deformation. Several lines of evidence, such as geometry of interacting outcropand map-scale folds and thrusts, patterns of thrust displacement variations and indications for hinge migration during fold growth, strongly suggest that folding and thrusting in Wadi Fatima FAT belt are geometrically and kinematically linked and that thrusting initiated as a consequence of folding (fold-first kinematics). Thrusts frequently show flat-ramp-flat geometry, and every so often give an impression that they are formed during two main sub-stages;an older sub-stage during which bedding sub-parallel thrusts were formed, and a younger sub-stage which generated younger ramps oblique to bedding. Thrust ramps with SE to SSE dipping regularly show sequential decrease in dip or inclination (due to piggy-back imbrication) into their transport direction which is proposed to be towards NW to NNW. Evidence indicating this transport direction of Wadi Fatima FAT belt embrace NW to NNW oriented stretching lineations recorded along thrust planes, NW to NNW folding vergence, and diminishing of the intensity of deformation and thrust stacking and imbrication from SE to NW;i.e. from hinterland to foreland. The tectonic transport vector is congruent with the mean orientation of slickenline striae formed by layer-parallel slipping along folded bedding planes. The mean orientation of slickenline lineations, after their host beds were rotated to horizontal about their strikes, is found to be N25°W - S25°E. Two tectonic models are proposed to unravel the structural history of the study area and to illustrate the tectonic evolution of Wadi Fatima FAT belt which represents one of interesting foreland FAT belts recorded worldwide. In the first model, the area was evolved from dextral shearing during the early convergence and amalgamation between East and West Gondwana, to emplacement of the older granite during a period of crustal cessation and relaxation, NNW SSE extension and extrusion of dyke swarms, emplacement of younger granite, deposition of Fatima Group over an ancient peneplain, layer parallel shortening, folding and fold tightening and overturning, thrusting, NE-SW (to NNE-SSW) shortening, and eventually NE tilting accompanied with Red Sea rifting (?). The second model suggests the presence of basement ramps (pre-existing normal faults), with NW to NNW dipping, have a strong effect on overlying Fatima Group which was evolved throughout gravitational, soft-sediment slumping and deformation.展开更多
文摘BACKGROUND:The piggy-back caval anastomosis technique is widely used in orthotopic liver transplantation although it carries an increased risk of complications,including outflow obstruction and Budd-Chiari syndrome.The aim of this study is to clarify the anatomy and variations of hepatic veins(HVs)draining into the inferior vena cava(IVC),and to classify the surgical techniques of piggy-back liver transplantation(PBLT)based on the anatomy of HVs which can reduce the occurrence of complications.METHODS:PBLT was performed in 248 consecutive cases at our hospital from January 2004 to August 2011.The anatomy of recipients’HVs was determined when removing the native diseased livers.Both anatomy of HVs and short HVs draining into the IVC were recorded.These data were collected and analyzed.RESULTS:We classified anatomic variations of HVs in the 248 livers into five types according to the way of drainage into the IVC:type I(trunk type of left and middle HVs),142(57.3%)patients;type II(trunk type of right and middle HVs),54(21.8%);type III(trunk type of left,middle and right HVs),14(5.6%);type IV(non-trunk type of left,middle and right HVs),of which,type IVa,16(6.5%),in the same horizontal plane;type IVb,18(7.3%),in different horizontal planes;and type V(segment type),4(1.6%).The patients whose HVs anatomy belonged to types I,II and III underwent classical piggy-back liver transplantation.Type IVa patients had classical PBLT via HV venoplasty prior to piggy-back anastomosis,while type IVb patients and type V patients could only have modified PBLT.CONCLUSION:This study demonstrates that HVs can be classified according to the anatomy of their drainage into the IVC and we can use this classification to choose the best operative approach to PBLT.
文摘Wadi Fatima fold-thrust (FAT) belt is a distinctive foreland FAT belt in the Arabian-Nubian Shield (ANS) involving unmetamorphosed to slightly metamorphosed sedimentary sequence of Fatima Group, deposited over a metamorphic/igneous basement, comprising ortho-amphibolites, orthoand para-schists (with chaotic unmappable blocks of marbles, pyroxenites and metagabbros), older granite (773 ± 16 Ma) and younger granite. The basement exhibits structural fabrics, such as attenuated tight isoclinal folds, sheared-out hinges, NE-SW penetrative foliation and subhorizontal stretched and mineral lineations, related to an oldest prominent dextral shearing phase affected the main Wadi Fatima during the Neoproterozoic. In Wadi Fatima FAT belt, the style of deformation encompasses flexural-slip folding forming mesoscopicand map-scales NE to ENE plunging overturned antiforms and synforms, and a thrust duplex system bounded by floor thrust and sole thrust (basal detachment) dipping gently towards the hinterland (SE to SSE direction) and rises stratigraphically upwards towards the foreland. Such style is affiliated to thin-skinned deformation. Several lines of evidence, such as geometry of interacting outcropand map-scale folds and thrusts, patterns of thrust displacement variations and indications for hinge migration during fold growth, strongly suggest that folding and thrusting in Wadi Fatima FAT belt are geometrically and kinematically linked and that thrusting initiated as a consequence of folding (fold-first kinematics). Thrusts frequently show flat-ramp-flat geometry, and every so often give an impression that they are formed during two main sub-stages;an older sub-stage during which bedding sub-parallel thrusts were formed, and a younger sub-stage which generated younger ramps oblique to bedding. Thrust ramps with SE to SSE dipping regularly show sequential decrease in dip or inclination (due to piggy-back imbrication) into their transport direction which is proposed to be towards NW to NNW. Evidence indicating this transport direction of Wadi Fatima FAT belt embrace NW to NNW oriented stretching lineations recorded along thrust planes, NW to NNW folding vergence, and diminishing of the intensity of deformation and thrust stacking and imbrication from SE to NW;i.e. from hinterland to foreland. The tectonic transport vector is congruent with the mean orientation of slickenline striae formed by layer-parallel slipping along folded bedding planes. The mean orientation of slickenline lineations, after their host beds were rotated to horizontal about their strikes, is found to be N25°W - S25°E. Two tectonic models are proposed to unravel the structural history of the study area and to illustrate the tectonic evolution of Wadi Fatima FAT belt which represents one of interesting foreland FAT belts recorded worldwide. In the first model, the area was evolved from dextral shearing during the early convergence and amalgamation between East and West Gondwana, to emplacement of the older granite during a period of crustal cessation and relaxation, NNW SSE extension and extrusion of dyke swarms, emplacement of younger granite, deposition of Fatima Group over an ancient peneplain, layer parallel shortening, folding and fold tightening and overturning, thrusting, NE-SW (to NNE-SSW) shortening, and eventually NE tilting accompanied with Red Sea rifting (?). The second model suggests the presence of basement ramps (pre-existing normal faults), with NW to NNW dipping, have a strong effect on overlying Fatima Group which was evolved throughout gravitational, soft-sediment slumping and deformation.
