Objective To study the feasibility of transplanting human saphanous vein endothelial cells to luminal surface of blood vessel prosthesis and to play a theoretical foundation for the clinical application of autologous endothelial cell transplantation. Methods Human saphanous vein endothelial cells were harvested with 0.1% collagenase and cultivated in vitro for 13.08±1.24 days. The cultures were confirmed as endothelial cells with the fourescent linked anti-Ⅷ antigen antibodies. The content of both 6-keto-PGF1α and Von Willebrand factor (vWF) in the supernatant were detected with ELISA and radioimmunoassay. The multiplied cells were lined in vitro onto the luminal surface of expanded polytetraflouroethylene (ePTFE) grafts precoated with fibrin glue and fibronectin, then cultivated again for 9 days. Results 11.46±2.69×１０６ of available endothelial cells could be regularly obtained, the number of endothelial cells increased 147.93±88.68 times when culture were terminated. All the cells diploid cells with a purity of 99%. The content of both 6-keto-PGF1α and vWF in the media showed no significant difference between the primary and subculture passages. The luminal surface of grafts was covered completely by a spindlelike endothelial monolayer and an even fibrin glue matrix could be seen underneath. Conclusion Endothelial cells derived from human saphanous veins might be feasible to be transplanted onto the luminal surface of ePTFE and present a potential clinical application.
Objective To summarize the current progress in the genetic modification of vascular prostheses and to look forward to the future of genetic modification in vascular prostheses. Methods PubMed onl ine search with the key words of “vascular prostheses, gene” was undertaken to identify articles about the genetic modification of vascular prostheses. Then these articles were reviewed and summarized. Results To improve long-term patency of vascular prostheses, various genes were transfected into seeded cells. The antithrombosis activity of local vessels increased. Conclusion Progresses in tissue engineering and molecular biology make possible endothel ial ization and genetic modification of vascular prostheses. However, because most relevant researches are still basic experiments, further study is needed before cl inical appl ication.
Objective To summarize the experience of extraanatomic aortic bypass grafting through median sternotomy for onestage treatment of aortic coarctation and associated cardiac diseases, and to improve surgical effect of the diseases. Methods Between July 1997 and July 2008, 31 consecutive patients(20 male,11 female; age 31.9±11.7 years) with aortic coarctation and associated cardiac anomalies underwent onestage surgical repair through median sternotomy. The associated cardiac anomalies included: aortic valve insufficiency or stenosis(n=22); mitral valve insufficiency or stenosis (n=9); patent ductus arteriosus (n=5); ascending aortic aneurysm (n=4); ventricular septal defect (n=3); coronary artery disease (n=2). Extra-anatomic aortic bypass grafting was used to repair the coarctation. Routing of the grafts was: ascendingto posterior pericardial descending aorta (n=9) and ascendingtoinfrarenal abdominal aorta (n=22). Concomitant cardiac procedures included: aortic valve replacement in 16; Bentall procedures in 6; mitral valve repair or replacement in 9; ascending aortic replacement or aortoplasty in 4; patent ductus arteriosus closure in 5; ventricular septal defect closure in 3 and coronary artery bypass grafting in 2. Results One patient died of septic shock 39 days after operation with an inhospital mortality of 3.2%. Mean systolic blood pressure gradient between upper and lower extremities decreased from 64.2±25.3 mm Hg preoperatively to 13.7±10.2 mm Hg postoperatively (Plt;0.05). Twentyseven patients were followed up from 4 to 73 months, there were no late deaths，reoperations or graftrelated complications. Conclusion Extraanatomic aortic bypass grafting can be performed simultaneously through median approach in patients with aortic coarctation and associated cardiac diseases. It is an effective and safe treatment option for onestage surgical repair in adults and adolescents. Both ascendingto posterior pericardial descending aorta and ascendingtoinfrarenal abdominal aorta bypass have favorable results.
To evaluate the implantation effect of artificial vascular grafts with recombinant fibrinolytic enzyme factor II (rF II)-immobil ized lumina in animal test. Methods Four mm internal diameter (ID) polyurethane (PU) artificial vascular grafts were prepared by di pping and leaching method. The micro-pore size and morphology of the graft walls were observed by SEM. The graft lumina were immobil ized with rF II. Twenty hybrid male dogs [weighing (20 ± 1) kg] were used for animal model of carotid artery defect and were randomly divided into 3 groups: rF II -immobil ized PU group, no rF II -immobil ized PU group and expanded polytetrafluoroethylene (ePTFE) group. The vascular grafts were implanted for repairing injured segments of carotid artery in dogs. The general health state of animals was recorded. At 30 days and 60 days,the patency rate of every group was calculated. At 60 days IDs were measured, cell prol iferation in neointima was inspected by l ight microscope, morphology on neointima was observed by SEM. Results The ID of the PU vascular grafts was (3.74 ± 0.06) mm, wall thickness was 0.4-0.6 mm, the wall density was 0.25 g/cm3, the porosity was 79.8%, racical compl iance was 8.57%/100 mmHg. In the wall, micropores were well distributed and opened-pores structure was observed. Pore size was (140 ± 41) μm in the outside layer, pore size was (100 ± 3) μm in the inside layer, thickness ratio of outside / inside layers was 2 ∶ 1, the pore size was (40 ± 16) μm on the lumina surface. After operation the wounds on neck healed, all the animals survived and had no compl ication. At 30 days and 60 days after implantation, the patency rate for rF II -immobil ized PU group were 100% and 66.7%, for no rF II -immobil ized PU group were 66.7% and 33.3%, and for ePTFE group were 67.7% and 0 respectively, but at 60 days there were thrombosis at anastamotic sites of some grafts occluded. Before operation the IDs for rF II-immobil ized PU group, no rF II -immobil ized PU group and ePTFE group were (3.74 ± 0.06), (3.74 ± 0.06) and (4.00 ± 0.03) mm, at 60 days after operation the IDs were (4.51 ± 0.05), (4.31 ± 0.24) and (4.43 ± 0.12) mm respectively, showing no statistically significant differences between 3 groups (P gt; 0.05). Histological inspection indicated that at 15 days a layer of plasma protein deposited on the lumina, at 30 days some cells adhered to the lumina, at 60 days neointima could be observed on the lumina. Thickness of the neointima became larger with implantation time. At 60 days neointima thickness at proximal end, middle site and distal end ofgraft were (560 ± 22), (78 ± 5) and (323 ± 31) μm respectively for rF II -immobil ized PU group. The results of SEM showed that neointima surface consisted of flat and long cells which long axes ranged with blood flow direction and was similar to lumina morphology of carotid artery of dog. Conclusion Immobil ization of rF II to lumina of grafts could enhance fibrinolytic activity and inhibited formation of thrombo-embol ia which led to an increase in patency rate after implantation.
The autograft and non-autograft cannot meet the needs of clinical vascular surgery. Since there are possibilities of thrombus formation in artificial vascular grafts, the methods for deposing the graft using physical and chemical ways or simply seeding with endothelial cells cannot produce satisfactory grafts for vascular operations until now. In order to increase the anticoagulative capacity of artificial vascular graft, it is rational to use genetic engineering methods modifying the endothelial cells to make it express anticoagulative factors stably. Although seeding artificial graft with the genetically engineered endothelial cells can possibly produce a satisfactory graft for vascular surgery, some problems still need to be solved.
Abstract： Objective To evaluate the surgical effect of ring annuloplasty using prosthetic vascular graft for the treatment of tricuspid regurgitation. Methods From July 2000 to July 2010, ring annuloplasty using prosthetic vascular graft was performed to a total of 56 patients with tricuspid regurgitation in Changhai Hospital of Second Military Medical University. There were 24 male patients and 32 female patients. Their mean age was（45.7±21.8）years (ranging from 14 to 73 years). All the patients were diagnosed as moderate to severe tricuspid regurgitation by color Doppler echocardiography examination, including 47 patients with rheumatic heart valve diseases, and 9 patients with congenital heart disease (Ebstein’s anomaly). All the 56 patients underwent ring annuloplasty using prosthetic vascular graft instead of Carpentier annuloplasty ring for the treatment of tricuspid regurgitation. Results There was no in-hospital death. Postoperatively, one patient had acute respiratory failure, one patient had acute kidney failure, and one patient had re-exploration for bleeding. All patients had none or mild tricuspid regurgitation by echocardiography examination one month after surgery. Forty eight patients were followed up from 1.0 to 9.5 years with a median follow-up time of 3.8 years. During follow-up, there was no late death, but one patient had brain embolism as an anticoagulation complication. Sixteen patients were in New York Heart Association (NYHA) functional classⅠ, 26 patients in NYHA classⅡ, and 6 patients in NYHA class Ⅲ. Thirty six patients had no tricuspid regurgitation, 10 patients had mild tricuspid regurgitation, and 2 patients had moderate tricuspid regurgitation by echocardiography examination during follow-up. Conclusion The early and mid-term follow-up results of ring annuloplasty using prosthetic vascular graft instead of Carpentier annuloplasty ring for the treatment of tricuspid regurgitation are satisfactory. It is a good choice for the surgical treatment of tricuspid regurgitation.
Objective To understand the value of pre-coating in artificial vessel endothelialization. Methods Literature concerning precoating in artificial vessel endothelialization was extensively reviewed. Results Pre-coating included chemical coatings(collagen, fibronectin, laminin, poly-l-lysin, gelatin andextracellular matrix), pre-clotting(plasma, blood, serum and fibrin glue), chemical bonding (heparin, RGD and lectins) and surface modification. Most of them could enhance the adhesion of the endothelial cells. Conclusion Pre-coating couldimprove endothelialization, but further research is needed to search for the appropriate concentration and incubation time.
OBJECTIVE: To investigate the clinical effects of revascularization in lower extremity for severe ischemia. METHODS: Fifty-six lower limbs with severe ischemia in 49 patients were evaluated retrospectively, who underwent surgical intervention from January of 1995 to December of 2000. By arteriography, the actual anatomic distributions of occlusive disease included infrarenal aorta-bicommon iliac arteries, abdominal aorta-bicommon iliac arteries, iliac artery, and femoral artery or femoropopliteal artery. The indication for surgery was disabling claudication, rest pain and gangrene. Fourteen limbs in 12 cases received arterialization of femoral venous system by artificial venous-arterial fistula. Artificial vascular grafts were implanted in 33 limbs of 28 cases, endarterectomy and patch profundaplasty were performed in 5 limbs of 5 cases, and primary amputation was carried out in 4 cases. RESULTS: During 38 months follow-up in average, 4 limbs were amputated within 52 revascularizated limbs, and accumulated amputation rate was 14.3%. Patency rate was 68.4% in arterial revascularization limbs (26/38 limbs), and limb survival rate was 94.7%(36/38 limbs) by procedure of artificial vascular grafts, endarterectomy and patch profundaplasty. Limb survival rate in procedure of artificial venous-arterial fistula was 85.7%(12/14 limbs). CONCLUSION: In treatment of severe lower extremity ischemia, the effective revascularization can be achieved by artificial vascular bypass, endarterectomy and patch profundaplasty, or arterialization of femoral venous system. Options in the surgical management should depend on individual. Arteriography is essential for revascularization and properly planning a practicable surgical approach.
