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.
The Dacron grafts seeded with autologous venous fragments were implanted into IVC of 13 canines as seeded group and the control grafts (8 cases), which were only preclotted with fresh blood. The amounts of cAMP and cGMP in serum and within platelet were measured. All of the specimens explanted at exsaguination were observed morphologically. The results shown that the total patency rate were 61.5% in seeded group, but 25.0% in control one and new endothelial lining formed at two weeks after implantation of the seeded grafts. The amounts of cAMP in serum and within platelet were higher in seeded group, but the amounts of cGMP were lower in serum and within platelet. These were in accordance with the results that the endothelialization of the grafts were complete in seeded group but not complete in control one. The results indicate that seeding Dacron with autologous venous fragment makes new endothelium formed at two weeks after implantation, increases the amounts of cAMP in serum and within platelet, but reduces the amounts of cGMP and thus improves graft patency rate.
ObjectiveTo analyze the causes and preventions of stent graft induced new entry (SINE) after thoracic endovascular aortic repair (TEVAR) for Stanford type B dissection, particularly from the standpoint of biomechanical behavior of stent graft. MethodsSINE was defined as the new tear caused by the stent graft itself, excluding those arising from natural disease progression or any iatrogenic injury from the endovascular manipulation. Twentytwo patients with SINE were retrospectively collected and analyzed out of 650 cases undergoing TEVAR for type B dissection from August 2000 to June 2008 in our center. An additional case included was referred to our center in 14 months after TEVAR performed in another hospital. ResultsTotally, there were 24 SINEs found in 23 cases, including SINE at the proximal end in 15 cases, at the distal end in 7, and at both in 1, and 6 patients died. The incidence was 3.4% ( 22/650) in our hospital, and the mortality was 26.1% (6/23). All 16 proximal SINEs was located at the greater curve of the arch and caused retrograde type A dissection. All 8 distal SINEs occurred at the dissected flap, and 5 of them caused enlarging aneurysm while 3 remained stable. All 23 cases had the endograft placed across the distal aortic arch during the primary TEVAR. ConclusionsSINE is not rare following TEVAR for type B dissection, and associates with a high substantial mortality. The stress yielded by the endograft seems to play a predominant role in its occurrence. It is of significance to take the stressinduced injury into account during both design and placement of the endograft.
ObjectiveTo investigate whether the recombinant human growth hormone (rhGH) can promote endothelialization, inhibit vascular intimal hyperplasia, and improve long-term patency rate by the treatment of rhGH after vascular prostheses bypass. MethodsBetween August 2007 and January 2009, 94 patients with lower extremity arteriosclerotic occlusive disease were treated. Among them, 32 patients (34 limbs) who met the selection criteria were enrolled in this study. All cases were randomly divided into study group (16 cases, 18 limbs) and control group (16 cases, 16 limbs). There was no significant difference (P>0.05) in gender, age, disease time, location of lesions, the Trans-Atlantic Inter-Society Consensus (TASC) grade, and basic diseases between 2 groups. The patients with superficial femoral artery disease received above-knee femoro-popliteal prostheses bypass. The patients who had combined abdominal-iliac artery disease received concurrent abdominal-femoral and femoro-popliteal prostheses bypass. Subcutaneous injection of 9 U rhGH was given every night for 7 days in study group, and saline was applied in control group. Ultrasonography was taken after 2 weeks and 3 months of operation to observe the patency and measure the wall thickness of vascular prostheses. ResultsAfter operation, 1 patient of control group died of renal failure caused by acute thrombosis. After 2 weeks, ultrasonography showed no obvious intimal hyperplasia in 2 groups; the wall thickness was (0.13±0.02) cm in study group and (0.15±0.03) cm in control group, showing no significant difference (t=-1.720, P=0.108). After 3 months, the wall thickness was (0.17±0.06) cm in study group and was (0.26±0.09) cm in control group, showing significant difference (t=-2.240, P=0.045). All cases were followed up 36-60 months (mean, 56.4 months). The 5-year primary patency rate was 52.5% in study group and 35.7% in control group, showing no significant difference (χ2=1.470, P=0.225). ConclusionThe rhGH can improve endothelialization in vascular prostheses and can inhibit postoperative vascular intimal hyperplasia in clinical application.
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.
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 assess clinical results of three different conduit materials （Gore-Tex synthetic graft，bovinejugular vein and autologous pericardium）for palliative right ventricle-to-pulmonary artery （RV-PA） shunt，and explore the correlation between suitable conduit size and patients’ body weight and McGoon ratio. Methods We retrospectively analyzed clinical data of 24 patients with congenital heart diseases who underwent palliative RV-PA shunt in Department of Pediatric Cardiovascular Surgery of Fu Wai Cardiovascular Hospital from July 2010 to July 2012. There were 11 males and 13 females with their age ranging from 60 days to 6 years and body weight of 10.22±7.41 kg. There were 22 patients with pulmonary atresia and ventricular septal defect （PAVSD），1 patient with tetralogy of Fallot （TOF） and 1 patient with doubleoutlet right ventricle （DORV）. Among different conduit materials，autologous pericardium was used for 17 patients，Gore-Texsynthetic graft was used for 5 patients，and bovine jugular vein was used for 2 patients. Conduit size and children’s body weight were analyzed with linear regression，then the equation was corrected with McGoon ratio. Results There was no perioperative death. Postoperative percutaneous saturation （SpO2）of the 24 children was 20.37%±28.33% higher than preoperative SpO2 . Electrocardiogram showed sinus rhythm in all the patients. Twenty-three patients were NYHA classⅡ，and 1 patient was NYHA classⅢ. Postoperative mechanical ventilation time of patients with autologous pericardium were significantly shorter than those of patients with other 2 materials （P=0.017）. Sixteen patients were followed up from 10 months to 2 years after discharge，including 12 patients with autologous pericardium，3 patients with Gore-Tex synthetic graft and 1 patient with bovine jugular vein. During follow-up，McGoon ratio of patients with autologous pericardium，Gore-Tex synthetic graft and bovine jugular vein were 1.98±0.46，1.83±0.33 and 1.68 respectively，all of which weresignificantly higher than preoperative McGoon ratio （P＜0.05）. Six patients underwent radical corrective surgery，including5 patients with autologous pericardium and 1 patient with Gore-Tex synthetic graft. There was no complication directly related to surgery during follow-up. Linear regression was performed to form an equation between suitable conduit size and patients’ body weight：conduit diameter （mm）=0.327×body weight （kg）＋4.599. McGoon ratio，conduit size and equationresult were compared to find a practical choice of conduit size. If McGoon ratio＜0.8，the first integer greater than the equation result could be chosen. If McGoon ratio＞1.2，the first integer less than the equation result could be chosen. If 1.2＞McGoon ratio＞0.8，the first integer either less or greater than the equation result could be chosen. Group analysis showed that patients who recovered better postoperatively were those whose conduit sizes were closer to equation results as well as equation results corrected with McGoon ratio. Conclusion All the 3 materials can be conventionally chosen for RV-PA shunt. Appropriate conduit size can be decided upon patients’ body weight and McGoon ratio for RV-PA shunt.
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.