In order to develope a new method to overcome the difficulties in anastomosis of blood vessels with different diameter, phleboplasty was utilized at the join-point to expand the diameter of branched vein graft, with a funnel-shaped stoma formed consequently. After successfully experimented in fresh blood vessels in vitro, the method was practised clinically to repair injured arteries in extremities, with the outcome that phleboplasty of branched vein graft could enlarge the diameter by 1-1.25 times, and with satisfied effects in 3 clinic cases. So, the conclusion was that: phleboplasty of branched vein graft was a new effective and convinient method to repair injured arteries with different diameters
OBJECTIVE: To investigate the relationship between the different defect length of vessels and the options of vascular repair, and to compare the different options of repair because of the longitudinal biomechanical effect. METHODS: A clinical analysis was undertaken to evaluate the major arterial and venous injuries in human extremities repaired by end-to-end anastomoses or venous autograft(177 cases, 185 vessels). Compared the defect length of the same kind of vessels repaired by different options (Student-t test). Evaluated the defect length to repair arterial injuries between by end-to-end anastomoses and by vein graft by means of 95% confidence interval. RESULTS: There was significant difference between the defect length of brachial artery repaired by end-to-end anastomosis and femoral artery and popliteal artery repaired by autogenous vein graft (P lt; 0.01). The upper limit of confidence interval in the defect length of brachial artery, femoral artery and popliteal artery was 3.17 cm, 2.81 cm and 2.44 cm respectively by end-to-end anastomosis by means of 95% confidence interval. The lower limit of confidence interval in the defect length of brachial artery, femoral artery and popliteal artery was 2.82 cm, 2.41 cm and 2.17 cm respectively by vein graft by means of 95% confidence interval. The defect length of brachial artery, femoral artery and popliteal artery repaired by vein graft was linear correlation with the length of graft. CONCLUSION: Because of the longitudinal biomechanical difference of arteries and veins in human extremities, different options of repair are necessary to different arterial injuries.
Objective To study the mechanism of restenosis of the vein graft and the effect of the grafting injury to the vein graft. Methods One side of the 36 healthy rabbits was randomly chosen as the V-A group, and on the side a 1.5cmlong femoral vein was obtained, and an 0.5-cm-long segment of the obtained femoral vein was separated as the control group. The remaining 1-cm-long femoral vein was inverted and was autogenously implanted into the femoral artery on the same side of the rabbit. The other side of the rabbits was chosen as the V-V group, and on this side a 1-cm-long femoral vein was obtained ex vivo and then was sutured in situ. The vein grafts on both sides were harvested 4 weeks after operation. The specimens from the harvested vein grafts were stained with HE and theelastic fiber Victoria blue for an observation on the histological changes in the walls of the vein grafts, and the specimens were also stained by the immunohistochemistry of the proliferating cell nuclear antigen (PCNA) for an observation on the wall cell proliferation of the vein grafts. The changes in the ultrastructure of the proliferated wall cells of the vein grafts were observed under electron microscope. The two sides of the rabbits were compared. Results The smooth muscle cells of the media developed hyperplasia, but theintima and the media remained unchanged in their thickness (3.50±0.41 μm, 12.23±1.59 μm) in the V-V group, with no difference when compared with the control group (3.40±0.37 μm, 12.14±1.62 μm); however, when compared with the V-A group (25.60±3.21 μm, 21.30±2.47 μm),there was a significant difference in the thickness (Plt;0.01). There were no cells positive for PCNA by the immunohistochemistry examination in the control group. The cells positive for PCNA were found in the intima and the media in both the V-V group and the V-A group; however, the percentageof the cells positive for PCNA in the intima and the media was significantly greater in the V-A group than in the V-V group (16.4%±1.9% and 36.5%±3.7% vs 5.9%±1.3% and 23.4%±3.4%, Plt;0.01). In the V-V group, the endothelial cell could be observed under transmis-sion electron microscope, which was flat and had a processlike villus at its free end, and the endothelial cells were closely arranged andhad hyperplasia of the smooth muscle cells in the media. But in the V-A group,the endothelial cells had an obvious hyperplasia with an irregular shape and a widened space between the cells, and in the intima a great amount of the smooth muscle cells could be observed, which had a broken basement membrane. The smooth muscle cells also had an obvious hyperplasia in the media. The shape and alignment of the endothelial cells in the control group were similar to those in the V-V group, but the hyperplasia of the smooth muscle cells was not observed in the media. Conclusion The grafting injury can cause hyperplasia ofthe vascular wall cells, and if the hemodynamics is changed simultaneously, more serious hyperplasia and cell migration can be observed from the media to the intima, resultingin restenosis of the blood vessels. So, if we can reduce the grafting injury and improve the microcirculation of the vein graft, we may find out the methods ofpreventing restenosis of the vein graft. The animal model of the V-V graftcan help to understand the mechanism of restenosis of the vein graft.
In order to solve the defect of blood vessel in tissue transplantation and complicated palmar amputation, bridge by "Y" type vein had been used from Jan. 1990 to Jul. 1996. Twenty-three cases were treated. In this series, there were 16 males and 7 females, with ages ranged from 10 to 42 years old. Six cases were the defect of lower legs anterior skin and tibia, 3 cases were the femur fracture with injury of femoral artery and tissue’s defect, 2 cases were defect of five fingers, 12 cases were complicated palmar amputation. RESULT: 15 cases with tissue transplantation and 12 cases with limb replantation were all survival without infection or necrosis. After the following-up for 3 years (ranged from 1 to 5 years), the function of injured limbs were satisfactory, 19 patients had resumed their original work. So, to bridge by "Y" type vein is a good method for repairing the defect of blood vessels in tissue transplantation and complicated palmar amputation, but skilled microsurgery technique is required.
【Abstract】ObjectiveSome studies have demonstrated that recombinant adenoviruses are efficient vectors for gene transfer to the venous wall and AdCMV.tk encoded thymidine kinase can be used to reduce restenosis. In this study AdCMV.tk was apply to human vein smooth muscle cells (SMC) and organ cultured saphenous veins to study its effects on proliferation of SMCs and reduction of intimal hyperplasia. MethodsThe adenovirus vector transferred tk gene and mark gene lacZ to the SMC of human saphenous veins and organ cultured vein segments. Various concentrations ganciclovir (GCV) were contained in culture media. The efficiency of gene transfer was studied by using Xgal staining. The proliferation of SMC was monitored by the method of trypan blue exclusion. The bystander effect was observed by mixed cell culture. After vein segments treated by AdCMV.tk+GCV and cultured for 14 days, HE and VG staining were carried out and intimal thickness was analysis by computer image system. ResultsAdenovirus vector could infect saphenous vein SMC efficiently both in cultured SMCs and organ cultured vein segments. Gene expression sustained 14 d at least. The inhibition of SMCs proliferation in vitro was a positive correlation in GCV concentrations and the levels of tk expression. The proliferation of SMCs transfectered lacZ wasn’t restrained by GCV (P＜0.05). In mixed cell experiment there was at least 55% reduction in total cell number when as few as 10% of the cells express tk. Assessment of this “suicide gene strategy” in saphenous vein organ culture model demonstrated that veins treated with AdCMV.tk+GCV had a significant reduction at 14 days in the intimal thickness compared to control group (P＜0.01). ConclusionThe results suggest that adenovirusmediated gene transfer of tk along with GCV administration may be a useful strategy to treat the proliferation of intimal hyperplasia of transplanting saphenous veins. Bystander effects are amplified by AdCMV.tk/GCV gene therapy system.
Objective To assess the effect of topical appl ication of 5-fluorouracil (5-FU) on intimal hyperplasia in rabbit vein graft. Methods Sixty-four male New Zealand white rabbits, aged 5 months and weighing 2.8-3.0 kg, were randomly divided into group A, B, C, and D (n=16 rabbits per group). Artery defect model was establ ished by cutting about 1 cm artery from the middle part of the dissociated left common carotid artery. A section about 3 cm was cut from the right external jugular vein, and the harvested vein was inverted and end-to-end anastomosed to the artery defect with 9-0 non-traumatic suture. After anastomosis, the extima of the grafted veins in group A, B, and C was completely wrapped with cotton sheet (12 mm × 30 mm × 1 mm in size) immersed by 5-FU at a concentration of 50.0, 25.0, and 12.5 mg/mL, respectively, and eachvein was treated 5 times (1 minute at a time). In group D, the extima of the graft veins was treated with normal sal ine instead of 5-FU. The grafted veins were obtained 1, 2, 4, and 6 weeks after operation, HE staining and Masson staining were preformed for histological changes of grafted vein wall, prol iferating cell nuclear antigen (PCNA) immunohistochemistry staining and TUNEL label ing staining were conducted for prol iferation and apoptosis of smooth muscle cell of the grafted vein, and transmission electron microscope observation was performed for cellular ultrastructure. Results The HE staining, Masson staining, and PCNA immunohistochemistry staining showed that the thickness of intima in group A and B was obviously less than that in group C and D at 1, 2, 4, and 6 weeks after operation, and the prol iferation cells in group A and B were less than that in group C and D at 1, 2, and 4 weeks after operation. The thickness of the intima, the degree of intima hyperplasia, the degree of vessel lumen stenosis of four groups at different time points were as follows: at 1 week after operation, group A [(12.69 ± 1.68) μm, 0.73 ± 0.05, 0.025 ± 0.003], group B [(17.52 ± 2.01) μm, 0.86 ± 0.06, 0.027 ± 0.004], group C [(21.92 ± 1.85) μm, 1.06 ± 0.09, 0.036 ± 0.006] and group D [(26.45 ± 3.86) μm, 1.18 ± 0.08, 0.041 ± 0.005]; at 2 weeks after operation, group A [(24.61 ± 2.91) μm, 0.86 ± 0.06, 0.047 ± 0.003], group B [(37.28 ± 2.78) μm, 1.17 ± 0.09, 0.060 ± 0.004], group C [(46.52 ± 2.25) μm, 1.44 ± 0.08, 0.073 ± 0.003], and group D [(52.07 ± 3.29) μm, 1.45 ± 0.05, 0.081 ± 0.006]; at 4 weeks after operation, group A [(61.09 ± 6.84) μm, 1.38 ± 0.08, 0.106 ± 0.007], group B [(63.61 ± 8.25) μm, 1.40 ± 0.07, 0.107 ± 0.010], group C [(80.04 ± 7.65) μm, 1.64 ± 0.07, 0.129 ± 0.011], and group D [(84.45 ± 9.39) μm, 1.68 ± 0.10, 0.139 ± 0.014]; at 6 weeks after operation, group A [(65.27 ± 5.25) μm, 1.46 ± 0.07, 0.113 ± 0.005], group B [(65.82 ± 7.12) μm, 1.45 ± 0.05, 0.112 ± 0.011], group C [(84.45 ± 9.39) μm, 1.69 ± 0.09, 0.135 ± 0.007], and group D [(87.27 ± 8.96) μm, 1.76 ± 0.05, 0.140 ± 0.012]. Group A and B were inferior to group C and D in terms of the above three parameters and cell prol iferation index 1, 2 and 4 weeks after operation (P lt; 0.05). Group A and B were superior to group C and D in terms of cell apoptosis index of intima and media 1 and 2 weeks after operation (P lt; 0.05). Transmission electron microscope observation showed that the synthetic cell organelles such as rough endoplasmic reticulum, golgi apparatus, and ribosome in group A and B were obviously less than those in group C and D (P lt; 0.05). Conclusion Topicalappl ication of 5-FU can effectively inhibit intima hyperplasia of the vein grafts.
Objective To study the expression of receptor of advanced glycation end products (RAGE) in autogenous vein graft of streptozotocin induced diabetic rats and the inhibitory effects of aminoguanidine on intimal hyperplasia. Methods Sixty male Sprague-Dawley rats were randomly divided into three groups: aminoguanidine group, distilled water group and control group. Autogenous vein graft models were established in all groups. Streptozotocin was injected into abdominal cavity to induce diabetes in both aminoguanidine group and distilled water group, and they were intragastric administrated with aminoguanidine or distilled water, respectively before and after transplantation. Specimens were collected from autogenous vein graft 7 days and 14 days after surgery to undergo histological examination. At the same time, the level of serum advanced glycation end products (AGE) was tested. Western blotting and immunohistochemistry were used to detect the protein expression of RAGE and NF-κB p65. RAGE and NF-κB p65 mRNA were measured by reverse transcription-PCR. Results The mRNA and protein expressions of RAGE, NF-κB p65, the level of serum AGE and the intimal thickness of vein graft in distilled water group increased in comparison with those in control group 7 days and 14 days after surgery （P＜0.05). The level of serum AGE, mRNA and protein expressions of NF-κB p65 and the intimal thickness of vein graft in aminoguanidine group were lower than those in distilled water group （P＜0.05), and showed no significant difference compared with control group （P＞0.05). Conclusion The over-expression of RAGE in vein graft activats NF-κB in streptozotocin-induced diabetic rat, which has a close relation with intimal hyperplasia. Aminoguanidine can block the binding of AGE and RAGE by inhibiting the production of AGE, which will prevent intimal hyperplasia of vein graft.
OBJECTIVE To explore the effect of basic fibroblast growth factor (bFGF) combined with autogenous vein graft conduit on peripheral nerve regeneration. METHODS Fifty four New Zealand rabbits were divided into three groups. The main trunk of sciatic nerve of rabbit in one side was severed and bridged by autogenous vein. 0.2 ml bFGF solution (4,000 U/ml) was intravenously injected to the vein graft conduit as group A, the same amount of saline solution as group B, and no solution injection as group C. Microscopic examination, axon video analysis and nerve conduct velocity were performed at the 10th, 30th, and 100th day after operation. RESULTS The nerve fibers were grown into vein graft conduit in all groups at 30th after operation, they were more and regular in group A than that of group B and C, and the axon regeneration rate in group A was more than that of group B and C. CONCLUSION bFGF combined with autogenous vein graft conduit can markedly promote nerve regeneration.
Abstract:Objective To evaluate the effect of external stents on preventing vein graft neointima formation and medial thickening with non-restrictive macro porous polyester stent around porcine vein grafts. Methods Studies were performed by using ＂white race＂ pigs （n= 10） weight 25-30 kg. All the animals underwent bilateral saphenous vein into carotid artery bypass grafting. In each animal, a maeroporous stent was placed around a graft on one side and a control （unstented） graft on the opposite side. The polyester stent was shaped to cover both anastomoses completely. The size of the stem allowed unrestricted expansion of the graft in initial response to arterial pressure. After 35 days of surgery,all animals were taken to remove the grafts. Graft wall dimensions, platelet- derived growth factor （PDGF） expression and cell proliferation using proliferating cell nuclear antigen （PCNA） were measured on histological sections. Results Stents significantly reduced neointimal thickening （0. 4872 ± 0. 0706 mm vs. 0. 2259± 0. 0553mm,P〈0. 01）and medial thickening （0. 6246±0. 0859mm vs. 0. 4201±0. 0615mm,P〈0. 01）. Stents significantly reduced the percentage of cells expressing PDGF and PCNA. Media, intimal PCNA index was reduced from 7. 980/00± 4. 060/00 to 3.35±0.95%（P〈0.01）, PDGF index was reduced from 9.47%±5.35% to 2.67%± 0.97% （P 〈0. 01）. Conclusion External non-restrictive polyester stent can significantly inhibit neointimal formation and medial thickening, and may prevent late vein grafts restenosis.
This study was performed on canine femoral veins which were interpositionally implanted into the femoral arteries and the investigation was in terms of zero-stress state, compliance and hemodynamic assessment. The results revealed that the vein grafts had the similar characteristics of compliance with the normal veins. Using Doppler ultrasonography to monitor the blood flow velocity through the vein grafts, the hemodynamic parameters such as pulsatility index (PI) and blood flow volume were evaluated consecutively within one month after the operations .No significant differences were found between these parameters at different time points. It was suggested that autogenous vein graft had an adaptive course when operating in an arterial hemodynamic circumstances and It’s mechanical changes did not bear upon the hemodynamics through the vein graft.