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 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.
Objective To observe the occurrence condition of endoleak after endovascular aneurysm repair (EVAR) operation for abdominal aortic aneurysm (AAA), and to analyze the factors of the endoleak. Methods Between July 2005 and June 2013, 210 cases of AAA were treated with EVAR. Of 210 patients, 175 were male and 35 were female, aging 42-89 years (mean, 65.7 years). The patients were all proved to have infrarenal AAA by computed tomography angiography (CTA). The disease duration ranged from 1 week to 2 years (median, 11.3 weeks). The maximum diameter of the aneurysms was 44-72 mm (mean, 57.3 mm). The proximal landing zone was longer than 1.5 cm. CTA was performed routinely at 2 months after operation to detect the endoleak of contrast agent. If endoleak was found, CTA was performed again at 6 months. If obvious endoleak still existed, digital subtraction angiography (DSA) would be performed to clarify the character and the degree of the endoleak, and EVAR should be done if necessary. Results Endoleak occurred in 31 cases (14.8%) during operation, including 11 cases of type I endoleak (8 cases of type IA and 3 cases of type IB), 18 cases of type II endoleak, and 2 cases of type III endoleak (type IIIB). The patients were followed up 2-8 months (mean, 3.1 months). At 2 months after operation, contrast agent endoleak was found in the remnant aneurysm cavity of 12 cases (5.7%). At 6 months after eperation, contrast agent endoleak was found in 10 cases (4.8%) by CTA. In 8 patients receiving DSA, there were 4 cases of type I endoleak (3 cases of type IA and 1 case of type IB), 3 cases of type II endoleak, and 1 case of type III (type IIIB) endoleak. In 5 patients having type I and type III endoleak, collateral movement of stent graft was observed in different degree; after increased stent graft was implanted, the endoleak disappeared after 2-4 months. The patients having type II endoleak were not given special treatment, endoleak still existed at 2 months after reexamination of CTA, but the maximum diameter of AAA had no enlargement. Conclusion The collateral movement of stent graft is a very important factor to cause type I and type III endoleak in the patients of AAA after EVAR, and endoleak can be plugged by EVAR again.
Objective To select levorotatory polylactic acid (PLLA) and polycaprolactone (PCL) as the main materials, use electrostatic spinning and ultrasonic broaching processing technique to prepare a similar to natural vascular diameter gradient structure of large diameter artificial blood vessels, and evaluate its potential applications. Methods Using PLLA and PCL as raw materials, through the electrospinning process, using core shafts of different diameters as collection devices, artificial vascular materials with a natural-like structure were constructed. Using end to end anastomosis method to experimental pig thoracic descending aorta replacement of artificial blood vessels. Results Computed tomography angiography (CTA) results showed that the artificial vascular graft was patent at 1 week and 6 weeks after operation. Animal experimental pathology examination revealed, artificial blood vessels unobstructed, the lining of endothelial cells, and elastic fiber, roughly three layer structure formed similar natural aorta. Artificial blood vessel wall visible elastic fibers, elastic fibers and collagen fibers with natural blood vessels distribution was similar. Immunohistochemical examination showed that the artificial blood vessels had a strong immune response to ERG staining, Actin staining, and Vementin staining. Scanning electron microscopy showed that endothelial cells were formed in the inner layer of the artificial blood vessel. Conclusion PLLA and photo as raw material, the use of electrostatic spinning and ultrasonic reaming technology preparation of large diameter artificial blood vessels, imitation of natural structure may have potential good flow resistance, good endothelial and may have induced in-situ natural function of angiogenesis.
Objective To study the effect of preparation conditions for small-diameter polyurethane(PU) vascular graft on microstructure and mechanical properties. Methods The small-diameter microporous PU artificial vascular grafts were prepared by dipping and leaching method. The dimension and microstructure were controlled by changing mold diameter, PU materials, salt sizes, salt to polymer ratio, times of dipping layers etc. The mechanical properties of PU grafts including radical compliance, water permeability, longitudinal strength, burst strength, and suture tearing strength were measured and the effect of the graft dimension and microstructure on their properties were studied. Results The internal diameter of grafts prepared was 2-4 mm depending on mold diameter. The wall thickness was 0.6-1.2 mmafter dipping 4-8 layers. The density was 0.23-0.49 g/cm3. The pore was 42-95 μm in diameter. The porosity was 56%80%. The radical compliance was 1.2%-7.4%·13.3 kPa-1 and higher compliances could be obtained by using moreelastic polyurethane, higher salt to polymer ratio, longer diameter and less wall thickness. The water permeability, mainly depending on salt to polymer ratio,diameter, and wall thickness, was 0.29-12.44 g／(cm2·min). The longitudinal strength was 1.55-4.36 MPa correlating with tensile strength of polyurethane and salt to polymer ratio. The burst strength was 60-300 kPa also depending on tensile strength of polyurethane and salt to polymer ratio. The suture tearing strength was 19.5-96.2 N／cm2 depending on tensile strength of polyurethanebut not on the angle of tearing and graft axial directions. The compliance and water permeability of Chronoflex grafts were higher than those of PCU1500 grafts, but longitudinal strength, burst strength, and suture tearing strength of PCU1500 grafts were better than those of Chronoflex grafts. Conclusion Small-diameter grafts with proper pore sizes, porosity, matching compliance can be obtained by selecting PU materials and optimizing the preparation conditions.