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 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 construct vectors that express phosphatidylinositol-3-kinase, catalytic, beta polypeptide （PIK3cb） shRNA in eukaryon plasmid catalyzed by PI3K in rat, then test their effects on intimal hyperplasia in transplanted vein graft. Methods One hundred and fifty SD rats were randomly divided into six groups （n=25, in each group）: blank (25% Pluronic F-127), shRNA-1, shRNA-2, 1/2 （shRNA-1+shRNA-2）, negative control (pGenesil-1 scramble shRNA) and positive control （wortmannin） group. The jugular vein in rats were interpositioned autologously into the common carotid artery. shRNA and 25% Pluronic F-127 were mixed and coated around the transplanted vein in three PIK3cb shRNA groups. Every 5 samples were removed according to the time point (1, 3, 7, 14 and 28 days after operation), respectively. The thickness of intima and neointima area were calculated and analyzed by computer system. The PCNA expression was detected by Western blot and SP immunohistochemistry. Results The intimal thickness of three PIK3cb shRNA groups were lower than those in the blank group and negative control group on day 3, 7, 14, 28 after operation (P＜0.05); The neointima area in three PIK3cb shRNA groups (except shRNA-2 group on day 3, 7) began to decrease significantly from day one (P＜0.05). The protein expression of PCNA in three PIK3cb shRNA groups on day 3 after operation were decreased compared with blank group and negative group (P＜0.05). The percentage of the PCNA positive cells area in three PIK3cb shRNA groups were significantly lower than those in blank group and negative control group in each time point (Plt;0.05). There were no significant differences between blank and negative control group in different time points (Pgt;0.05). Conclusion The PIK3cb shRNA can effectively inhibit the proliferation of vascular smooth muscle cell, which may provide a new gene therapy for the prevention of vein graft restenosis after bypass grafting.
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.
Coronary artery bypass grafting (CABG) is an effective method for the treatment of coronary heart disease at present. However, there is still a high rate of vein graft occlusion after CABG, which has a serious impact on the short and long-term clinical results. Venous access technique has been considered as an important factor on affecting the long-term patency rate. Compared with harvesting technology of the open saphenous vein harvesting, no-touch technology retained the surrounding tissue and vascular adventitia of great saphenous vein, and it avoided the high pressure of expansion vein. After CABG was performed by using the no-touch technique, the vein grafts obtained a better short and long-term patency rate, but the effect still needs further clinical verification.
In order to prevent tendon adhesion following operation, autogenous great saphenous vein graft was used to reconstruct the tendon sheath. The operation was performed under microsurgical technique. This method was used to repair 23 tendons and 17 tendon sheaths. The early functional exercises were carried out after operation. Follow up from 10 months to 4 years, the prognosis was good except in 3 fingers, in which, the wounds were infected resulting the necrosis of the grafted veins and exposure of the repaired tendons. The details of the operation were introduced. It was emphasized that non-traumatic handling of the tissues was essential in preventing tendon from adhesion.
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.
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.
ObjectiveTo investigate the expression of extracellular signalregulated kinase (ERK) and p38 mitogenactivated protein kinase （p38 MAPK） in autogenous vein grafts during vascular remodeling.MethodsAn autogenous vein graft model was established by transplanting the right jugular vein to infrarenal abdominal aorta in 80 Wistar rats. Vein graft samples were harvested 6 hours, 24 hours, 3 days, 7 days, 2 weeks, 4 weeks, 6 weeks and 8 weeks after surgery. Gene expression of ERK and p38 MAPK was measured by reverse transcriptionPCR. Western blot was used to detect the expression of protein products and phosphorylation protein products of ERK and p38 MAPK. Apoptosis of vascular smooth muscle cells (VSMCs) was determined by TUNEL. Proliferating cell nuclear antigen(PCNA) of VSMCs also was studied.ResultsThe expression of ERK1 mRNA and p38 MAPK mRNA increased considerably after surgery. ERK1 mRNA reached the peak on the 7th day 〔（33.2±14.2）%, P＜0.01〕, but p38 MAPK mRNA reached the peak on the second week after surgery 〔(58.8±26.2）%, P＜0.01〕. The expression of ERK1/2 detected by western blot reached the peak during 1 to 2 weeks and decreased gradually to normal level 6 weeks after surgery. The expression of p38 MAPK reached the peak during 2 to 4 weeks and decreased to 1/4 to 1/2fold 8 weeks after surgery. There was a positive relationship between ERK1 and PCNA(r=0.759 6，P＜0.01) and a positive relationship between p38 MAPK and apoptosis(r=0.892 2，P＜0.01). ConclusionActivation of MAPK system exists in autogenous vein grafts and it may become a new target for the therapy of stenosis after vein grafts.
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.