重组蛇毒纤溶因子修饰聚氨酯人工血管的犬颈动脉置换实验

目的通过动物实验评价重组蛇毒纤溶因子（recombinant fibrinolytic enzyme factor II，rF II）修饰聚氨酯（polyurethane，PU）人工血管的植入效果。方法采用浸渍．沥滤法制备口径4mmPU微孔人工血管，扫描电镜观察血管管壁微孔大小和形态，用rF II修饰人工血管内腔。取20只体重（20±1）kg的雄性杂种犬制作颈动脉2cm缺损模型，随机分为3组：rF II修饰PU组（n=8）、无rF II修饰PU组（n=6）和膨体聚四氟乙烯（expanded polytetrafluoroethlyene，ePTFE）组（n=6），植入相应人工血管以修复缺损。记录术后动物一般情况；计算术后30d和60d的血管通畅率；测量术后60d人工血管内径，并进行组织学检查和扫描电镜观察。结果制得的PU微孔人工血管内径（3．74±0．06）mm，壁厚0．4～0．6mm，密度0．25g／cm^3，孔隙率79．8％，径向动态顺应性为8．57％／100mmHg。人工血管管壁内，微孔分布均匀，呈开孔结构。外层孔径为（140±41）Ima，内层孔径为（100±3）μm，外层／内层的厚度比约2：1，内腔表面孔径为（40±16）μm。术后颈部切口愈合良好，动物均存活，无并发症发生。术后30d及60d血管通畅率：rF II修饰PU组分别为100％及66．7％，无rF II PU组为66．7％及33．3％，ePTFE组为66．7％及0，堵塞的人工血管在吻合处发现血栓。rFII修饰PU组、无rF II修饰PU组及ePTFE组植入前血管内径分别为（3．74±0．06）、（3．74±0．06）、（4．00±0．03）mm；术后60d内径分别为（4．51±0．05）、（4.31±0．24）、（4．43±0．12）mm；3组间植入前后比较差异均无统计学意义（P〉0．05）。rF II修饰PU组组织学观察，植入15d有血浆蛋白在内腔表面沉积；30d后有少量细胞黏附；60d后新内膜形成。新内膜厚度随植入时间增加而变厚；植入后60 d rF II修饰PU组人工血管近端、中点及远端的新内膜厚度分别为（560±22）、（78±5）、（323±31）μm（P〈0．05）。扫描电镜观察，rF II修饰PU组新内膜表面由扁长形细胞组成，其长轴顺着血流方向排列，与正常颈动脉内腔表面形貌相似。结论rF II修饰PU血管内腔可提高纤溶活性，减少血栓栓塞的发生，有利于提高植入血管的通畅率。     

犬骨髓CD34＋细胞种植人工血管置换后短期内皮化的实验研究

目的：探讨骨髓CD34＋细胞种植于常用膨体聚四氟乙烯（expanded polytera fluoroethylene，ePTFE）人工血管和涤纶人工血管后二者的内皮化程度。方法：选杂种犬8条，依支架覆膜不同分为ePTFE组和涤纶组，每组实验犬2条，对照犬2条。实验犬采自体骨髓，提取CD34＋细胞种植覆膜支架，对照犬采用单纯自体血预凝覆膜支架。将人工血管植入犬的下腔静脉和腹主动脉。在术后第10、30天观察植入的人工血管通畅情况，采用免疫组织化学方法鉴定内膜细胞来源，在光镜和电镜下观察人工血管新生内膜表面内皮化情况。结果：术后第10天实验组与对照组差异无统计学意义；术后第30天腔面新生内膜内皮细胞自人工血管吻合口向中间逐渐减少（P〈0．05）；而对照组内膜表面第10、30天均无内皮细胞覆盖。结论：经纯化的CD34＋细胞种植于ePTFE和涤纶人工血管，均获得理想的内皮化。     

犬失血性休克时的凝血纤溶活性变化

创伤、感染或失血的病人,凝血和纤溶系统的活性均会发生显著的变化。本组实验是对出血性休克的犬,在达到不可逆性休克时再静脉注射大肠杆菌内毒素,除观察常规凝血纤溶检查项目外,尚利用显色肽基质S—2238和S—2251测定休克前、休克达到不可逆后以及注射内毒素后,血液凝血纤溶系统活性的变化。     

肢体负压对后肢动脉闭塞犬纤溶酶原激活物及其抑制因子1？…

目的 探讨肢体负压对犬纤溶系统的影响。方法 通过建立后肢动脉闭塞犬模型，检测肢体负压（ＬＮＰ）前后外周血纤溶酶原激活物（ｔ－ＰＡ）及其抑制物（ＰＡＩ－１）活性、静脉血氧分压（ＰＯ２）和ＰＨ值的变化。结果 ＬＮＰ治疗后实验组ｔ－ＰＡ活性、ＰＯ２、ＰＨ值较治疗前明显升高，ＰＡＩ－１活性显著下降（Ｐ〈０．０１），与对照组比较也有显著性差异（Ｐ〈０．０１）。结论 ＬＮＰ可提高局部纤溶活性，促进血栓溶解和再     

磁压榨吻合技术实现犬腹主动脉人工血管置换快速无缝线吻合

目的  探讨利用磁压榨吻合（MCA）技术实现犬腹主动脉人工血管置换快速无缝线吻合的可行性。方法  选择成年健康杂交犬12只,按腹主动脉与人工血管吻合方式分为MCA组和手工缝合（HS）组,每组6只。比较两组术中腹主动脉阻断时间、术中吻合口情况与术后吻合口影像学检查情况。结果  MCA组腹主动脉阻断时间短于HS组[（5.2±2.3）min比（24.4±4.3）min],差异有统计学意义（P < 0.001）。MCA组术中吻合口无渗漏血及狭窄情况发生;HS组术中6只犬均发生吻合口渗漏血,其中1只犬因失血过多死亡,2只犬因反复修补而出现吻合口轻度狭窄。MCA组术后彩色多普勒超声与血管造影检查显示吻合口血流通畅,无狭窄及血栓形成,HS组术后4周时血管造影检查共发现4只犬吻合口狭窄。结论  利用MCA技术可实现犬腹主动脉人工血管置换快速无缝线吻合,减少吻合口并发症的发生,有利于术后恢复。     

纤溶酶原激活因子及其抑制因子与睾丸支持细胞

纤溶酶原激活因子 (PA)及其抑制因子 (PAI)参与机体的多种生理、病理活动。支持细胞是睾丸精曲小管的重要组成部分 ,其正常功能的发挥对精子发生等生物学行为的正常进行具有非常重要的意义。睾丸支持细胞在激素及其他因子的作用下 ,分泌PA及PAI,发挥生物学作用 ,维持正常的精子发生、精子活力及受精过程 ,两者之间的关系正日益受到人们的重视     

蛇毒因子、全身照射、胸腺修饰预处理受者对异种小动物心脏移植的作用

目的　利用眼镜蛇蛇毒因子 (CVF)、全身照射 (WBI)、异基因胸腺修饰等途径预处理受者 ,探讨这些处理对非协调性异种心脏移植物存活期及免疫排斥反应的影响。方法　供者为三色豚鼠 ,受者为SD大鼠 ,随机配对分成空白组 (O组 ) ;单用CVF的对照组 (A组 ) ;CVF +全身照射组 (B组 ) ;CVF +全身照射 +胸腺注射组 (C组 )。各组分别行大鼠腹腔内异位异种心脏移植术。观察各组供心存活时间及排斥后的光镜及电镜表现。结果　 (1)存活时间 :B组、C组和A组均较O组明显延长 (P <0 .0 1) ;B组和C组又较A组明显延长 (P <0 .0 5 ) ;但C组与B组比较 ,差异无显著性 (P >0 .0 5 )。 (2 )病理表现 :O组呈超急性排斥反应 ,另三组均呈延迟性异种排斥改变。结论　在本模型中 ,使用CVF可克服超急性排斥反应 ,联用全身照射可进一步延长供心存活时间 ;但在此基础上加用异基因胸腺修饰对延长供心存活时间无显著意义。     

胰腺癌根治术联合血管切除中人造血管的采用

近年胰腺癌手术切除率得到明显提高。以往当胰腺癌侵及门静脉（PV）／肠系膜上静脉（SMV）时，常被视为手术切除的禁忌证。但大量研究表明，如果胰腺癌侵犯PV／SMV而无其他远处脏器转移．行联合血管切除的胰头癌扩大根治术仍可获得较好的治疗效果．并对改善病人术后生活质量有一定益处。一般认为，当血管切除长度不超过3～4cm时，可直接行血管吻合。但如果PV切除范围较长而难以直接行端端吻合时。就需应用替代血管进行重建，包括自体血管或人造血管。     

Endothelialization of polyurethane vascular prostheses implanted in the dog carotid and femoral artery

A new type of vascular prosthesis made of polyurethane with a fibrous structure of the wall was implanted in the carotid and/or femoral artery of dogs. The healing process and neo-intima formation after implantation of this type of prosthesis was followed with light- and scanning electron microscopy. A total of 18 prostheses, which had been implanted for 1, 3, 6, 9 or 20 weeks were studied. Endothelial like cells invaded the prosthesis over the anastomoses, starting the first week after implantation. The growth zones advanced steadily, and prostheses measuring 3 cm in length were completely endothelialized by 20 weeks after implantation, a mean growth rate of the endothelial like cells of 0.09 mm/day. Subsequently, fibroblasts and smooth muscle cells grew between the neoendothelial layer and the prosthetic inner surface, forming a new multi-layered neo-intima. Cellular elements of the neo-intima were firmly anchored onto the inner wall of the prosthesis by cells with extending cytoplasmic protrusions between the fibers of the prosthetic wall. Since in this type of fibrous polyurethane prosthesis, endothelial like cells continually grew until a new lining was formed, apparently facilitated by the fibrous structure of the wall, further investigations are indicated for progression toward clinical implantation of this type of prosthesis.     

Establishment of a vascular graft infection model in the sheep carotid artery

A study was performed to assess whether a model of vascular graft infection could be established in sheep carotid artery. Either a protein sealed Dacron or a polytetrafluoroethylene (PTFE) graft was used in 22 sheep while a control operation was performed on 4 animals. Staphylococcus aureus in concentrations of 10(2), 10(4), 10(6) or 10(8) colony-forming units (CFU) was inoculated into the wound before closure. No infection occurred with an inoculum of 10(2). The lowest concentration of organism producing infection was 10(4) for PTFE, 10(6) for Dacron and 10(8) for controls. Six of eleven Dacron grafts and seven of ten PTFE grafts became infected. The sheep carotid artery has proven a satisfactory model for studies of vascular graft infection.     

Treatment of vascular graft infection by in situ replacement with a rifampin-bonded gelatin-sealed Dacron graft

Purpose: The purpose of this study was to treat an established prosthetic vascular graft infection by in situ replacement with a rifampin-bonded gelatin-sealed Dacron graft in an animal model.Methods: The infrarenal aorta of 18 dogs was replaced with a gelatin-sealed graft contaminated in vitro by soaking it in a solution with Staphylococcus epidermidis. One week later, animals were randomized into three groups. In group I (control, (n = 6), the dogs did not undergo repeat operations. The dogs in groups II and III underwent repeat operation. In these animals the infected grafts were removed for bacteriologic analysis and replaced in situ with one of two types of grafts: group II (n = 6) received an untreated, gelatin-sealed graft; group III (n = 6) received a rifampin-bonded, gelatin-sealed graft. Antibiotic bonding was obtained by soaking grafts for 15 minutes in a 60 mg/ml saline solution of rifampin at 37° C. All 18 dogs received no systemic adjunct antibiotic therapy. Control grafts and replacement grafts were removed 4 weeks after the initial implantation for bacteriologic analysis. When harvested, all the grafts were cut into two fragments, and quantitative bacterial cultures were obtained from all the fragments. Results were expressed as colony-forming units (CFU)/cm² of graft material.Results: All 18 initially implanted grafts and all the untreated replacement grafts were grossly infected at the time of removal, whereas all the rifampin-bonded replacement grafts had normal incorporation. None of the rifampin-bonded grafts grew bacteria, whereas all the initially implanted and all the untreated replacement grafts were infected (p < 0.01). Bacterial counts from the infected fragments were similar in control grafts (2.6 ± 1.9 × 10⁶ CFU/cm²), in initially implanted grafts of groups II (9 ± 1.1 × 10⁵ CFU/cm²) and III (1.3 ± 1.5 × 10⁶ CFU/cm²), and in untreated replacement grafts of group II (1.7 ± 2.5 × 10⁶ CFU/cm²). Blood culture results and culture results of liver, spleen, kidney, and lung specimens at the time of sacrifice were negative.Conclusion: This study demonstrates that rifampin-bonded gelatin-sealed Dacron grafts are resistant to infection when used for in situ replacement of an infected graft in the dog. (J VASC SURG 1994;19:739-44.)     

脱细胞血管基质制备和异体移植的实验研究

目的研究建立无细胞血管基质制备的新方法,并探讨脱细胞血管异体移植的可行性。方法采用不同去垢剂[1％Triton X-100、1％十二烷基磺酸钠(SDS)]多步骤对血管进行脱细胞处理,并通过组织学和力学观测,建立兔动脉血管脱细胞的方法;并进行脱细胞血管的异体移植。结果经低渗溶液和去垢剂1％TritonX-100、1％SDS等多步骤处理,兔胸主动脉血管的细胞基本脱除,细胞外基质保持完好,血管的弹性、韧性和力学强度仅轻度降低;用该法制备的兔颈动脉(直径约2．0mm)进行异体移植,经2个月观察,全部通畅。结论经去垢剂TritonX-100、SDS加低渗溶液和蛋白酶抑制剂处理的多步法,可以脱除血管的细胞成分,细胞外基质和力学特性保持完好,是一种较好的方法;用该法制备的兔颈动脉(直径约2．0mm)进行异体移植,初步取得成功。     

Subclavian artery to external carotid artery bypass with saphenous vein graft in the treatment of common carotid artery stenosis

A case of TIAs due to proximal common carotid artery stenosis which was successfully treated with autogenous saphenous vein graft between the subclavian artery and the external carotid artery is presented. A 57-year-old, right handed female was admitted to our hospital for the treatment of left common carotid artery stenosis which was pointed out at a local hospital. She had a 7-years' history of repeated transient right hemiparesis and/or left amaurosis fugax. No neurological deficit was revealed on admission. Angiography showed an 80% irregular stenosis of the left common carotid artery at its origin, hypoplastic A1-portion of the left anterior cerebral artery and hypoplasia of the left posterior communicating artery. No other stenotic lesions were disclosed in a four-vessel study. Several kinds of surgical procedures have been reported for the treatment of common carotid stenotic lesion, in accordance with the site and extension of the lesion and hemodynamic factors. To maintain a sufficient blood flow of the left internal carotid artery, we considered four different operative methods such as (1) endarterectomy of the common carotid artery, (2) subclavian to common carotid artery bypass, (3) subclavian to external carotid artery bypass and (4) subclavian to middle cerebral artery bypass. The first two operative procedures force to clamp the common carotid artery which was the only one feeding artery of the left middle cerebral artery because of poor cross flow in this case. These procedures were thought highly possibly to give rise to cerebral infarction on the left side. The fourth method needs a long graft which has higher risk of bypass occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

A case of iatrogenic carotid artery dissection treated with radial artery graft

A case of iatrogenic intracranial artery dissection is reported. A 52-year-old female developed severe headache and nausea. Brain CT showed diffuse subarachnoid hemorrhage. On admission, carotid angiography revealed an aneurysm in the right middle cerebral artery and the intact right internal carotid artery. The aneurysm was clipped successfully. Carotid angiography on day 7 revealed dissection in the right internal carotid artery. Repeated angiograms at 10 and 31 days showed progression of the carotid artery dissection. Findings of ECD-SPECT on day 31 (Balloon occlusion test) suggested low perfusion of the right internal carotid artery territory. The patient underwent surgical reconstruction of the right internal carotid artery using a radial artery. She presented with right abducens nerve palsy three days after the radial artery graft. The patency of the radial artery graft was proved by the post-operative angiography. Internal carotid artery dissection may occur spontaneously or as a result of trauma. An iatrogenic dissection is an uncommon complication of cerebral angiography. There are no evidence-based guidelines for the treatment although anticoagulation therapy is most commonly used. The present case emphasizes the usefulness of radial artery graft for traumatic carotid artery dissection.     

In vivo evaluation of lumbrokinase,a fibrinolytic enzyme extracted from Lumbricus rubellus,in a prosthetic vascular graft

BACKGROUND: Lumbrokinase (LK) is a fibrinolytic enzyme purified from the earthworm Lumbricus rubellus. To investigate the fibrinolytic and antithrombotic effects of lumbrokinase, a series of animal experiments were performed. METHODS: The Dacron graft (3 mm in diameter, 3 cm in length) were treated with LK via two different methods, simple dipping and covalent bonding METHODS: Covalent bonding was performed by UV reaction to polyacrylic acid. The grafts were interposed into the inferior vena cava of the rabbits and harvested for 5 hours, 1, 2 and 4 weeks after the implantation. RESULTS: The LK non-treated graft (n=4) were totally occluded with thrombus 5 hours after the implantation. Both types of LK treated graft (n=8) were patent 1 week after the implantation. The grafts treated with the simple dipping method (n=4) were occluded with thrombus 2 weeks after the implantation. The grafts treated with covalent bonding (n=4) were patent 4 weeks after the implantation. Ultrastructural analysis of the luminal surface of the patent grafts by scanning electron microscopy revealed the thin plasma protein layer to be about 5 micro in thickness with platelet adhesions. CONCLUSIONS: Lumbrokinase has potential antithrombotic effects in a small diameter vascular prosthesis. The covalent bonding method proved to be more effective than the simple dipping method.