【作者】 罗明尧；

【导师】 舒畅； 周晓；

【作者基本信息】 中南大学 ， 外科学， 2011， 博士

【摘要】 第一章肿瘤侵犯大血管根治术后人工血管重建腹主动脉模型的建立目的：建立模拟恶性肿瘤侵犯腹主动脉的根治手术后、ePTFE人工血管植入重建腹主动脉的动物模型。方法：取长沙地区健康杂种犬40只,体重8-12kg,雌雄不限。全麻,取腹正中切口入腹,暴露、游离肾下段腹主动脉,肝素化后阻断之,切除游离段约1.5-2.0cm,以6mm直径的ePTFE人工血管行端端吻合置换。手术当天禁食、补液,术中术后预防感染、抗凝、抗血小板治疗。结果：40只实验犬模型制备手术均获得成功。术中术后5只犬(12.5%,5/40)发生了包括乳糜管损伤、腹部伤口化脓性感染、呼吸道感染、消化道感染等并发症,其中1只在术后5天死亡,其余均存活,术后存活率97.5%(39/40)。结论：直接行“肾下段腹主动脉部分切除+人工血管置换术”构建杂种犬实验模型技术成熟,成功率高,并发症发生率较低,性能稳定可靠,可用于模拟恶性肿瘤侵犯大血管根治性切除术后的相关研究。第二章术后体外放疗对犬腹主动脉人工血管移植物的影响目的：研究大剂量体外分割放疗对人工血管移植物的影响,探讨放疗对吻合口、人工血管内壁的内皮细胞覆盖、内膜增生状态等的影响,以及是否导致严重并发症。方法：取26只ePTFE人工血管重建腹主动脉的杂种犬模型,随机分为对照组(D组)和放疗组(F组)。F组于术后第二周予以体外分割放疗(7Gy×5d),D组同期全麻输液,但不予照射。D、F两组再各分为D1组、D2组,F1组、F2组。其中D1组和F1组于放疗后4周取标本；D2组和F2组于放疗后12周取标本。记录分析实验犬在干预期间的生理指标,HE染色后,通过IPP软件测量人工血管各断面内膜厚度,通过免疫组化染色比较CD34. PCNA的表达。结果：F组体重下降0.8±0.5kg,D组下降0.3±0.2kg；F组死亡率15.4%(2/13),D组无死亡。F1、F2、D1、D2组分别可见1(1/5)、1(1/6)、0、2(2/7)例人工血管存在少量附壁血栓,但保持通畅。F组人工血管周边组织炎性反应明显,末观察到吻合口假性动脉瘤、人工血管破裂、闭塞或感染。内膜厚度：D1、Fl两组的人工血管各断面的内膜厚度无统计学意义(p>0.05),D2组各断面的新生内膜厚度值均大于F2组(p<0.01)。内皮细胞覆盖：除人工血管中段外,D1组、F1组标本其余平面的新生内膜CD34阳性细胞率无统计差异(P>0.05)；而D2组、F2组在所有平面均无显著差异(P>0.05)。人工血管新生内膜的增殖状态：F1组PCNA阳性表达在各平面均较D1组低,其中吻合口部位的差异具有统计学意义(P<0.05)；与D2组相比,F2组的PCNA阳性表达在各平面均较低,均有统计学意义(P<0.05); PCNA表达最低部位均为人工血管中段。结论：总剂量35Gy的体外分割放疗,可导致人工血管周边组织炎性反应加重,但不增加吻合口假性动脉瘤、人工血管破裂、闭塞或感染的发生率；对人工血管中段的内皮细胞覆盖率可能存在一过性影响；可抑制人工血管内膜增生。第三章术后静脉化疗对犬腹主动脉人工血管移植物的影响目的：研究静脉联合化疗对人工血管移植物的影响,探讨其对吻合口、人工血管内壁的内皮细胞覆盖、内膜增生状态等的影响,以及是否导致严重并发症。方法：取26只ePTFE人工血管重建腹主动脉的杂种犬模型,随机分为对照组(D组)和化疗组(H组),D组与第二章共用。H组于术后第二周予5-氟尿嘧啶(5-FU,10mg/kg)和顺铂(DDP,1mg/kg)静脉联合化疗,D组同期予以全麻输液,但不予化疗。D、H两组再各分为D1、D2, H1、H2亚组,其中D1组和H1组于化疗后4周获取标本,D2组和H2组于化疗后12周获取标本。记录分析实验犬在干预期间的生理指标,HE染色后,通过IPP软件测量人工血管各断面内膜厚度,通过免疫组化染色比较CD34、PCNA的表达。结果：H组体重平均下降1.0±0.7kg,D组下降0.3±0.2kg；H组死亡率23.1%(3/13),D组无死亡。H1、H2、D1、D2组分别可见2(2/5)、3(3/5)、0(0/6)、2(2/7)例人工血管少量附壁血栓形成,但均保持通畅,未见吻合口假性动脉瘤、人工血管破裂、闭塞或感染。内膜厚度：D1组和H1组、D2组和H2组标本的内膜厚度均不具有统计差异(p>0.05)；各组内,人工血管中段的内膜厚度低于两端吻合口,有统计学意义(P<0.05)。内皮细胞覆盖：除H1组人工血管中段的CD34阳性细胞率显著低于D1组外,在其余平面的差异无统计学意义(P>0.05)；H2组、D2组标本的CD34阳性细胞率无显著差异(P>0.05)；各组内,人工血管中段CD34阳性细胞率(个/100μm)均低于吻合口。人工血管新生内膜的增殖状态：H1组与D1组、H2组与D2组相比,各平面内膜的PCNA的表达均不具有统计差异(P>0.05)；组内比较,各小组标本均为远端吻合口PCNA表达量较近端吻合口高,两端吻合口较人工血管中段高(P<0.05)。结论：5-FU和DDP静脉联合化疗可能一过性影响动脉人工血管中段的内皮细胞覆盖,可能增加人工血管附壁血栓形成几率,在12周内对人工血管吻合口愈合无显著影响,对人工血管内膜生成和PCNA表达无显著影响,不增加移植物感染、闭塞、破裂的几率。更多还原

【Abstract】 Objective:To establish canine models after reconstruction of infrarenal abdominal aorta by expanded Polytetrafluoroethylene (ePTFE) grafts, in order to mimic reconstruction of abdominal aorta after combined resection of malignant tumor and vital vessels which have been involved.Methods:Operations were performed in 40 mongrel canines with the body weight of 8～12 kg. By a median abdominal incision, the infrarenal abdominal aorta was exposed carefully. After intravenous administration of heparin (0.5mg/kg), both proximal and distal sides of the infrarenal abdominal aorta were clamped, thereafter a segment of about 2.5 cm was resected and quickly reconstructed with an ePTFE graft (diameter:6 mm) by running suture. After operation, medical treatment including antibiotics, anticoagulation and anti-platelet measures were routinely carried out.Results:All the surgical procedures were completed successfully. During and after operation,5 cases suffered from chyle vessel injury, operative incision infection, respiratory tract infection or diarrhea, of which 1 case died 5 days postoperatively, and the others recovered quickly. The survive rate is 97.5%(39/40).Conclusions:Reconstruction of infrarenal abdominal aorta by ePTFE grafts is a good method to establish canine models to mimic the settings after combined resection of malignant tumor and vital vessels involved, with a high rate of success, low incidence of complications, stable performance and satisfying quality. This canine model can be used for further researches.Objective:To study the effect of postoperative external fractionated irradiation on the ePTFE vascular grafts in mongrel canine models.Methods:After the infrarenal abdominal aorta was replaced by ePTFE prosthesis graft, twenty-six canine models were randomly divided into radiotherapy group (group F, n=13) and control group (group D, n=13), according to which the postoperative external fractionated irradiation (7Gy×5d) was administrated or not. The animals were sacrificed and graft specimens were harvested at 4 weeks (subgroup F1 and D1) or 12 weeks (subgroup F2 and D2) after radiotherapy. Physiological parameters during radiotherapy were recorded and H-E staining of the neointima inside the grafts, immunohistochemistry test of CD34 and PCNA were carried out.Results:The average body weight of each group decreased more or less (group F:0.8±0.5kg; group D:0.3±0.2kg). Two cases died in group F (2/13,15.4%), while all survived in group D. Inflammation of the tissues around the grafts was more severe in group F, but no evidence of increasing possibility of graft obstruction, infection or anastomotic pseudoaneurysm was observed. There is no statistical significance about difference of the intima thickness between subgroup D1 and F1 (p>0.05), while significant difference exists between subgroup D2 and F2. Except the middle segment of the grafts, no statistical difference exists on the coverage of vascular endothelial cells (percentage of CD34+ cells) between group F and group D (P>0.05). Comparing to group D, lower expression of PCNA in group F was observed, especially in subgroup F2 (p<0.05).Conclusions:Postoperative external fractionated irradiation (7Gy×5d) after prosthetic vessel replacement of abdominal aorta may result in severe inflammation of tissues around the grafts, but does not increase the incidence of graft obstruction, infection or anastomotic pseudoaneurysm in 12 weeks. It does not significantly influence the growth and coverage of vascular endothelial cells, but can inhibit neointima proliferation and PCNA expression inside the grafts.Chapter 3. Effect of Adjuvant Chemotherapy on Vascular Graft After Prosthetic Replacement of the Abdominal Aorta in CanineObjective:To study the effect of postoperative combined intravenous chemotherapy on the ePTFE vascular grafts in mongrel canine models.Methods:After the infrarenal abdominal aorta was replaced by ePTFE prosthesis graft, twenty-six canine models were randomly divided into chemotherapy group (group H, n=13) and control group (group D, n=13), according to which the postoperative intravenous combined chemotherapy (5-FU:10mg/kg, cis-platinum:1mg/kg) was administrated or not. The animals were sacrificed and graft specimens were harvested at 4 weeks (subgroup H1 and D1) or 12 weeks (subgroup H2 and D2) after chemotherapy. Physiological parameters during chemotherapy were recorded, and H-E staining of the neointima inside the grafts, immunohistochemistry test of CD34 and PCNA were carried out and analysed. Results:The average body weight decreased in each group (group H: 1.0±0.7kg; group D:0.3±0.2kg). Three cases died in group H (3/13, 23.1%), while no one died in group D. No evidence of increasing the possibility for blood vessel prosthesis obstruction, infection or anastomotic pseudoaneurysm was observed, but inflammatory response of the tissues around the grafts was more obvious in group H. Small amount of mural thrombus formation were observed in some grafts (H1: 2/5; H2:3/5; D1:0/6; D2:2/7). There is no statistical significance about the intima thickness difference between subgroup D1 and F1 (p>0.05), or between subgroup D2 and F2. No statistical difference exists on the coverage of vascular endothelial cells (percentage of CD34+cells) between group H and group D, except the very middle segment of the grafts in subgroup D1 and H1. No statistical difference exists on the expression of PCNA between group F and D (p>0.05). However, in each subgroup, the percentage of CD34+ cells and expression of PCNA were the lowest in the middle of the grafts.Conclusions:Postoperative combined intravenous chemotherapy (5-FU and cis-platinum) after prosthetic vessel replacement of abdominal aorta may result in obvious inflammatory response of tissues around the prosthesis, without increasing the incidence of graft obstruction, infection or anastomotic pseudoaneurysm in 12 weeks. It may increase the possibility of mural thrombus formation, while not significantly influence the vascular endothelial cells coverage, neointima proliferation or PCNA expression inside the grafts. Further researches are needed for long-term results.更多还原