Objective To summarize the methods and experiences of surgical treatment of aortic arch diseases with four branches aortic graft under deep hypothermia circulatory arrest （DHCA） and antegrade selective cerebral perfusion （ASCP）. Methods In 2004 from September to December, surgical treatment of 12 patients with 7 aortic aneurysm（4 cases with ascending aorta and aortic arch aneurysm, 3 cases with aneurysm of aortic isthmus） and 5 aortic dissection（DeBakey Ⅰ 1 case, DeBakey Ⅱ 3 cases, DeBakey Ⅲ 1 case） were collected in Gunma Prefectural Cardiovascular Center. All operations were carried out under DHCA and ASCP, and four branches aortic graft were used to replace the aortic arch. The Bentall procedure, total and partial arch replacement and elephant trunk technique were undertaken in different patients. Results Total 12 patients recovered from the great vessel diseases smoothly without severe cerebral and other systematic complications, the time of operation was 5.5±1.7 h, the period of DHCA was 42.2±12.9min, 4 cases with no blood transfusion, the time of hospitalization was 22.3±7.2d. Conclusion ASCP is a safe. and effective method of cerebral protection during circulation arrest, and four branches aortic graft may shorten the time of DHCA and simplify the procedure of aortic arch replacement.
Objective To evaluate surgical treatment of infected femoral artery pseudoaneurysm. Methods The data on surgical treatment of 45 patients with infected femoral artery pseudoaneurysm admitted from January 2003 to June 2008 were analyzed retrospectively. Fourty-three patients underwent operative treatment including excision of infected femoral artery pseudoaneurysm, exhaustive debridement and bypass graft with vascular prosthesis. Two patients were unavoidable to undergo removing of infected femoral artery pseudoaneurysm and ligating the proximal and distal artery of pseudoaneurysm because of severe infection and large volume. Results The patients were followed up from 3 to 12 months (mean 7.82 months). The limbs of all the patients underwent bypass graft with vascular prosthesis were salvaged successfully, patients of which had secondary wound healing and had not intermittent lameness. One of two patients performed ligation of artery was salvaged successfully but had severe intermittent lameness, another patient underwent high amputation above knee because of ischemic gangrene. Conclusion For infected femoral artery pseudoaneurysm, the operative treatment including excision of infected femoral artery pseudoaneurysm, exhaustive debridement and bypass graft with vascular prosthesis is effective and safe.
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.
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.
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 discuss the endothelial cell which was modified by exogenous anticoagulant genes contribute to the increase of antithrombosis activity of lined vascular prosthesis and the influence to other physiological functions of endothelial cells. Methods This summarized paper was made on literature review of recent years. Results The transfection of genes, including plasminogen activator (tPA, uPA, Urokinase), thrombomoduline (TM) and hirudin, etc, to endothelial cells resulted in not only the increase of antithrombosis activity of local vascular, but also the decrease of endothelial cell function in adherence and proliferation. Conclusion The increase of antithrombosis activity of lined vascular prosthesis has been done by exogenous genes. However, this technique ought to be studied, intensively.
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.
