BACKGROUND: Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. To overcome the problem of graft size insufficiency, living donor liver transplantation (LDLT) using the...BACKGROUND: Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. To overcome the problem of graft size insufficiency, living donor liver transplantation (LDLT) using the right lobe has become a standard method for adult patients. As the drainage of the median sector (segments V, VIII and IV) is mainly by the middle hepatic vein (MHV), the issue of whether the MHV should or should not be taken with the graft or whether the MHV tributaries (V5, V8) should be reconstructed in the recipient remains to be settled. DATA SOURCES: An English-language literature search was conducted using MEDLINE (1985-2006) on right lobe living donor liver transplantation, middle hepatic vein, vein graft, hepatic venoplasty and other related subjects. RESULTS: Some institutions had proposed their policy for the management of the MHV and its tributaries. Dominancy of the hepatic vein, graft-to-recipient weight ratio, and remnant liver volume as well as the donor-to-recipient body weight ratio, the volume of the donor's right lobe to the recipient's standard liver volume and the size of MHV tributaries are the major elements for the criteria of inclusion of the MHV, while for the policy of MHV tributaries reconstruction, the proportion of congestive area and the diameter of the tributaries are the critical elements. Optimal vein grafts such as recipient's portal vein and hepatic venoplasty technique have been used to obviate hepatic congestion and venous drainage disturbance. CONCLUSIONS: Taking right liver grafts with the MHV trunk (extended right lobe grafts) or performing the MHV tributaries reconstruction in modified right lobe grafts, according to the criteria proposed by the institutions with rich experience, can solve the congestion problem of the right paramedian sector and help to improve the outcomes of the patients. The additional use of optimal vein grafts and hepatic venoplasty also can guarantee excellent venous drainage.展开更多
Background External stents have been used to reduce intimal hyperplasia of vein grafts. The aim of the present study was to define the size of an external stent appropriate for a particular graft by comparing vein gra...Background External stents have been used to reduce intimal hyperplasia of vein grafts. The aim of the present study was to define the size of an external stent appropriate for a particular graft by comparing vein grafts with different sizes of external stents. Methods A series of paired trials was performed to compare femoral vein grafts with different sizes of external stents, where 30 modeled canines were equally divided into three groups： 6-mm external stent vs non-stent control, 4-mm vs 6-mm external stent, and 4-mm vs 8-ram external stent. At day 3 after operation, color Doppler flow imaging （CDFI） was done to observe blood flow in the lumen. Four weeks later, CDFI was re-checked and the veins were harvested, stained and measured. Results All grafts were patent without formation of thrombosis. External stents significantly reduced intimal thickness of the vein grafts with a 6-mm external stent compared with the vein grafts without external stents （P〈0.05）.The vein grafts with the 4-mm external stent had similar intimal, medial and adventitial thicknesses compared with those with the 6-mm external stent and the 8-mm external stent. Conclusions External stents can reduce intimal hyperplasia of vein grafts. Stents of different diameters exert the similar effect on prevention of intimal hyperplasia.展开更多
BACKGROUND： In the repair of nerve defects, collapse of the venous wall, as a result of vein grafting alone, could impede nerve regeneration. Therefore, vein lumens filled with muscle and nerve segments have been use...BACKGROUND： In the repair of nerve defects, collapse of the venous wall, as a result of vein grafting alone, could impede nerve regeneration. Therefore, vein lumens filled with muscle and nerve segments have been used to bridge nerve defects. OBJECTIVE： To compare the effects of autogenous, inside-out, vein-skeletal, muscle-combined grafting versus standard, vein-skeletal, muscle-combined grafting for the repair of facial nerve defects. DESIGN, TIME AND SETTING： A randomized, controlled, neuroanatomical, animal study was performed at the Animal Experimental Center and Laboratories of the Capital Medical University Xuanwu Hospital and the Peking Union Medical College Hospital from September 2007 to October 2008.MATERIALS： A total of 10 healthy, male, New Zealand rabbits, aged 6 months, were randomly assigned to inside-out, vein-skeletal, muscle-combined grafting and standard, vein-skeletal, muscle-combined grafting groups, with 5 rabbits in each group. METHODS： A 20-mm gap in the buccal branch of the right facial nerve was made in each animal, which was respectively repaired with inside-out, vein-skeletal, muscle-combined grafts or standard vein-skeletal muscle-combined grafts.MAIN OUTCOME MEASURES： At 6 months after implantation, evoked maximal compound muscle action potentials were recorded on bilateral facial nerves using electromyogram. Myelinated nerve fibers of the regenerating nerves were quantified using myelin sheath osmic acid staining. RESULTS： There was no significant difference between the groups in terms of ratios of bilateral amplitude and latency of compound muscle action potential （P 〉 0.05）. Moreover, morphology of regenerating nerves and quantity of myelinated nerve fibers were similar between the groups （P 〉 0.05）. CONCLUTION： Compared with standard vein grafting, the inside-out vein grafting did not significantly improve nerve regeneration. Therefore, it is not necessary to utilize inside-out vein grafting for the repair of nerve defects, in particular with the comb展开更多
Background Placement of an external support has been reported to prevent intimal hyperplasia of vein grafts. However, it is limited by potential complications. In the present study, we investigated the effect of fibri...Background Placement of an external support has been reported to prevent intimal hyperplasia of vein grafts. However, it is limited by potential complications. In the present study, we investigated the effect of fibrin glue on preventing vein graft failure as perivenous application. Methods Twenty-four rabbits were divided into non-supported group （n=12） and fibrin glue group （n=12）. All animals underwent unilateral jugular vein into common carotid artery interposition grafting and then fibrin glue was applied as perivenous support. Samples of tissues were harvested after 4 weeks. Results The vein grafts with fibrin glue demonstrated a statistically significant decrease in proliferating cell nuclear antigen in the medial/intimal region [13.38% （11.26%-15.11%）] compared with non-supported vein grafts [31.22% （27.15%-35.98%）] （P〈0.001）. Light microscopy showed remarkable attenuation of endothelial cell loss and numerous microvessels in neoadventitia in the fibrin glue group compared with the non-supported group. The smooth muscle cells migrated into adventitia significantly in fibrin glue group, whereas the smooth muscle ceils migrated into intima in non-supported group. Conclusion Perivenous support of vein graft with fibrin glue in vivo can attenuate the severe injury encountered in the non-supported vein grafts exposed to artery.展开更多
<abstract>Abstract Aim: To evaluate the degree of corporal fibrosis in rats with cadaveric pericardium or vein as grafting materials for tunica albuginea substitution. Materials and methods: Thirty male Sprague-...<abstract>Abstract Aim: To evaluate the degree of corporal fibrosis in rats with cadaveric pericardium or vein as grafting materials for tunica albuginea substitution. Materials and methods: Thirty male Sprague-Dawley rats (300 g-325 g) were divided at random into 3 groups of 10 animals each: group 1 was the sham-operated controls and groups 2 and 3 underwent wedge excision of tunica albuginea and replacement with cadaveric pericardium and vein grafts, respectively. Four months later, rats were sacrificed and the penis removed to assess the degree of fibrosis using RT PCR technique for TGP-β1 mRNA expression. The tissues were fixed in 10 % formalin, paraffin-embedded and stained with Masson's trichrome and Verhoff's van Giesen for collagen and elastic fibers. Results: Four months after grafting, there was minimal fibrosis surrounding the patch in the vein graft rats and moderate fibrosis in the pericardial graft rats. The degree of penile fibrosis in the pericardial graft rats was significantly higher than that in the controls (P<0.01), but in the vein graft rats it was not significantly different from that of the controls (P>0.05). Conclusion: The degree of penile fibrosis of cadaveric pericardial graft was significantly higher than that of the control group, while in the vein graft group it was comparable to the latter. The authors believe that the vein graft may be a more ideal substance to be used as the tunica albuginea substitute than the pericardial graft in the surgical treatment of Peyronie's disease.展开更多
基金This study was supported by a grant from the National Key Basic Research Program (973) of China (No. 2003 CB515501) Important Project from Science and Technology Department of Zhejiang Province (No. 021103699).
文摘BACKGROUND: Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. To overcome the problem of graft size insufficiency, living donor liver transplantation (LDLT) using the right lobe has become a standard method for adult patients. As the drainage of the median sector (segments V, VIII and IV) is mainly by the middle hepatic vein (MHV), the issue of whether the MHV should or should not be taken with the graft or whether the MHV tributaries (V5, V8) should be reconstructed in the recipient remains to be settled. DATA SOURCES: An English-language literature search was conducted using MEDLINE (1985-2006) on right lobe living donor liver transplantation, middle hepatic vein, vein graft, hepatic venoplasty and other related subjects. RESULTS: Some institutions had proposed their policy for the management of the MHV and its tributaries. Dominancy of the hepatic vein, graft-to-recipient weight ratio, and remnant liver volume as well as the donor-to-recipient body weight ratio, the volume of the donor's right lobe to the recipient's standard liver volume and the size of MHV tributaries are the major elements for the criteria of inclusion of the MHV, while for the policy of MHV tributaries reconstruction, the proportion of congestive area and the diameter of the tributaries are the critical elements. Optimal vein grafts such as recipient's portal vein and hepatic venoplasty technique have been used to obviate hepatic congestion and venous drainage disturbance. CONCLUSIONS: Taking right liver grafts with the MHV trunk (extended right lobe grafts) or performing the MHV tributaries reconstruction in modified right lobe grafts, according to the criteria proposed by the institutions with rich experience, can solve the congestion problem of the right paramedian sector and help to improve the outcomes of the patients. The additional use of optimal vein grafts and hepatic venoplasty also can guarantee excellent venous drainage.
文摘Background External stents have been used to reduce intimal hyperplasia of vein grafts. The aim of the present study was to define the size of an external stent appropriate for a particular graft by comparing vein grafts with different sizes of external stents. Methods A series of paired trials was performed to compare femoral vein grafts with different sizes of external stents, where 30 modeled canines were equally divided into three groups： 6-mm external stent vs non-stent control, 4-mm vs 6-mm external stent, and 4-mm vs 8-ram external stent. At day 3 after operation, color Doppler flow imaging （CDFI） was done to observe blood flow in the lumen. Four weeks later, CDFI was re-checked and the veins were harvested, stained and measured. Results All grafts were patent without formation of thrombosis. External stents significantly reduced intimal thickness of the vein grafts with a 6-mm external stent compared with the vein grafts without external stents （P〈0.05）.The vein grafts with the 4-mm external stent had similar intimal, medial and adventitial thicknesses compared with those with the 6-mm external stent and the 8-mm external stent. Conclusions External stents can reduce intimal hyperplasia of vein grafts. Stents of different diameters exert the similar effect on prevention of intimal hyperplasia.
基金the Postdoctoral Science Foundation of China,No.20070420402
文摘BACKGROUND： In the repair of nerve defects, collapse of the venous wall, as a result of vein grafting alone, could impede nerve regeneration. Therefore, vein lumens filled with muscle and nerve segments have been used to bridge nerve defects. OBJECTIVE： To compare the effects of autogenous, inside-out, vein-skeletal, muscle-combined grafting versus standard, vein-skeletal, muscle-combined grafting for the repair of facial nerve defects. DESIGN, TIME AND SETTING： A randomized, controlled, neuroanatomical, animal study was performed at the Animal Experimental Center and Laboratories of the Capital Medical University Xuanwu Hospital and the Peking Union Medical College Hospital from September 2007 to October 2008.MATERIALS： A total of 10 healthy, male, New Zealand rabbits, aged 6 months, were randomly assigned to inside-out, vein-skeletal, muscle-combined grafting and standard, vein-skeletal, muscle-combined grafting groups, with 5 rabbits in each group. METHODS： A 20-mm gap in the buccal branch of the right facial nerve was made in each animal, which was respectively repaired with inside-out, vein-skeletal, muscle-combined grafts or standard vein-skeletal muscle-combined grafts.MAIN OUTCOME MEASURES： At 6 months after implantation, evoked maximal compound muscle action potentials were recorded on bilateral facial nerves using electromyogram. Myelinated nerve fibers of the regenerating nerves were quantified using myelin sheath osmic acid staining. RESULTS： There was no significant difference between the groups in terms of ratios of bilateral amplitude and latency of compound muscle action potential （P 〉 0.05）. Moreover, morphology of regenerating nerves and quantity of myelinated nerve fibers were similar between the groups （P 〉 0.05）. CONCLUTION： Compared with standard vein grafting, the inside-out vein grafting did not significantly improve nerve regeneration. Therefore, it is not necessary to utilize inside-out vein grafting for the repair of nerve defects, in particular with the comb
基金This study was supported by National Natural Science Foundation of China (No. 30371408).
文摘Background Placement of an external support has been reported to prevent intimal hyperplasia of vein grafts. However, it is limited by potential complications. In the present study, we investigated the effect of fibrin glue on preventing vein graft failure as perivenous application. Methods Twenty-four rabbits were divided into non-supported group （n=12） and fibrin glue group （n=12）. All animals underwent unilateral jugular vein into common carotid artery interposition grafting and then fibrin glue was applied as perivenous support. Samples of tissues were harvested after 4 weeks. Results The vein grafts with fibrin glue demonstrated a statistically significant decrease in proliferating cell nuclear antigen in the medial/intimal region [13.38% （11.26%-15.11%）] compared with non-supported vein grafts [31.22% （27.15%-35.98%）] （P〈0.001）. Light microscopy showed remarkable attenuation of endothelial cell loss and numerous microvessels in neoadventitia in the fibrin glue group compared with the non-supported group. The smooth muscle cells migrated into adventitia significantly in fibrin glue group, whereas the smooth muscle ceils migrated into intima in non-supported group. Conclusion Perivenous support of vein graft with fibrin glue in vivo can attenuate the severe injury encountered in the non-supported vein grafts exposed to artery.
文摘<abstract>Abstract Aim: To evaluate the degree of corporal fibrosis in rats with cadaveric pericardium or vein as grafting materials for tunica albuginea substitution. Materials and methods: Thirty male Sprague-Dawley rats (300 g-325 g) were divided at random into 3 groups of 10 animals each: group 1 was the sham-operated controls and groups 2 and 3 underwent wedge excision of tunica albuginea and replacement with cadaveric pericardium and vein grafts, respectively. Four months later, rats were sacrificed and the penis removed to assess the degree of fibrosis using RT PCR technique for TGP-β1 mRNA expression. The tissues were fixed in 10 % formalin, paraffin-embedded and stained with Masson's trichrome and Verhoff's van Giesen for collagen and elastic fibers. Results: Four months after grafting, there was minimal fibrosis surrounding the patch in the vein graft rats and moderate fibrosis in the pericardial graft rats. The degree of penile fibrosis in the pericardial graft rats was significantly higher than that in the controls (P<0.01), but in the vein graft rats it was not significantly different from that of the controls (P>0.05). Conclusion: The degree of penile fibrosis of cadaveric pericardial graft was significantly higher than that of the control group, while in the vein graft group it was comparable to the latter. The authors believe that the vein graft may be a more ideal substance to be used as the tunica albuginea substitute than the pericardial graft in the surgical treatment of Peyronie's disease.
