大鼠肢体急性和慢性缺血病变特点的对照研究

目的 建立大鼠急性和慢性后肢缺血模型,研究两组大鼠病变特点及缺血代偿情况.方法 选择3 月龄成年、高脂血症SD 大鼠建立急性（n = 20）和慢性（n = 20）后肢缺血模型.采用实时荧光定量PCR 和2-△△Ct 法,检测股动脉闭塞后6 h 患肢股内收肌血管内皮生长因子（VEGF）和缺氧诱导因子（HIF-1α）的相对定量.股动脉闭塞1 周后取腓肠肌检查组织坏死及炎症浸润情况.股动脉闭塞后4 周后采用免疫组织化学染色法计算股内收肌毛细血管/肌纤维比例.术后记录患肢运动功能及患肢/健肢股骨中段周径比值.结果 急性组大鼠术后即刻表现严重肢体缺血.慢性组平均术后（8.2 ± 0.7）d 始表现严重肢体缺血.股动脉闭塞后6 h,急性组股内收肌目标基因VEGF和HIF-1α的相对定量均高于慢性缺血组[（5.57 ± 0.87） vs.（2.49 ± 0.85）和（10.28 ± 1.09） vs.（6.83 ±1.17）,P 〈 0.05].股动脉闭塞后1 周,急性组腓肠肌病理组织学检查显示较多坏死及炎症浸润.股动脉闭塞后4 周,急性组股内收肌毛细血管/肌纤维比例显著高于慢性组[（1.37 ± 0.14） vs.（1.18 ±0.12）,P 〈 0.05].缺血肢体功能评分结果 显示,急性缺血肢体运动功能早期受损甚于慢性组（P 〈0.05）,但后期恢复较优（P 均〈 0.05）.结论 急、慢性缺血具有不同的病理损伤特点,进而表现出不同的缺血代偿机制.急性大鼠缺血的代偿优于慢性缺血.     

大鼠后肢急性缺血模型的构建及评估

目的：探讨大鼠后肢急性缺血后血流、血压的动态变化及肌肉组织的变化,为进行后续干预实验摸索条件。方法：取Lewis大鼠10只采用切除左后肢股动脉及其分支至膝关节附近的方法制备急性后肢缺血模型,分别于术后2,7,14,28,42,49 d对患侧和健侧肢体进行血流、血压及血管造影分析。取材后行后肢肌肉HE常规染色,观察病理变化。结果：动物术后均成活,但部分出现后肢跛行(n=2),紫绀（n=2）,苍白(n=3),肌肉的萎缩(n=1)。急性缺血下肢部分肌肉坏死,大量炎性细胞浸润;后期出现纤维化。患肢血流在术后7 d明显下降,术后28 d下降至最低点,术后49 d基本恢复正常（正常肢体的90%）。患肢血压在术后2 d明显下降,14 d下降至最低点,后逐渐恢复,至49 d基本恢复正常。结论：结扎并切除大鼠后肢股动脉及分支可以成功制备下肢缺血模型,但血流及血压在术后42~49 d基本恢复正常,术后14~28 d是缺血最严重的阶段,适于进行各种干预实验研究。     

缺氧诱导因子转染内皮祖细胞治疗大鼠缺血后肢

目的 使用缺氧诱导因子-1α(HIF-1α)转染内皮祖细胞(EPC)治疗大鼠后肢缺血,观察EPC、HIF-1α转染EPC对大鼠缺血后肢血管新生和肢体成活的影响.方法 制作SD大鼠后肢缺血模型,将动物随机分为3组,每组6只.将构建的HIF-1α基因真核表达载体转染入EPCs后通过尾静脉注射入大鼠体内,并与注射磷酸盐缓冲液(PBS)或EPC的大鼠进行比较,观察转染HIF-1α对新生血管形成的影响.结果 (1)EPC组、HIF组较PBS组肢体恢复率明显增加(P<0.05),EPC组肢体恢复率较HIF组差(P<0.05).(2)与PBS组比较,各时间点中EPC、HIF组微血管密度(MVD)均明显增多(P<0.05),HIF组较EPC组明显增高(P<0.05).(3)HIF组的HIF与血管内皮生长因子(VEGF)蛋白表达较PBS组、EPC组明显增多(P<0.05).PBS组Capase-3的表达较EPC组、HIF组明显增多(P<0.05).(4)术后7 d,各组的大鼠肢体灌注均明显降低,但EPC、HIF组细胞的血流灌注较PBS组多(P<0.01).术后14、21 d,与PBS对照组比较,HIF组的血流灌注恢复明显(P<0.01),EPC组血流灌注较HIF组少(P<0.05).结论 EPCs对大鼠缺血后肢的局部血管新生有明显促进作用,联合应用HIF-1α和EPCs有更优的治疗效果.     

生肌玉红胶原促进大鼠后肢缺血组织血管新生的实验研究

目的探讨生肌玉红胶原在缺血组织中促进血管新生的作用效果及其作用机理。方法 Wistar大鼠48只按随机配对方法随机均分为空白组、对照组（胶原）及实验组（生肌玉红胶原）3组;在大鼠后肢缺血模型基础上于大鼠右后肢缺血组织中植入不同的胶原制剂,分别于模型制作术后3,7、14及28 d取埋植的胶原制剂标本及标本周围约0.5 cm范围的缺血肌肉组织。通过激光散斑成像系统观察大鼠右后肢缺血模型制作术后各时点的血流灌注情况,采用光度计法测定胶原制剂（生肌玉红胶原）内的血红蛋白含量,采用免疫组化染色方法检测标本周围肉芽组织中的微血管计数,采用实时荧光定量RT-PCR方法检测缺血肌肉组织中各时点低氧诱导因子（HIF）-1αmRNA以及血管内皮生长因子（VEGF）mRNA的表达。结果大鼠右后肢缺血模型制作成功即刻大鼠患肢呈现明显的缺血状态,其血流灌注值明显低于术前（P〈0.01）;在术后3 d却呈明显的充血状态,其血流灌注值明显升高,且略高于术前水平,但差异无统计学意义（P〉0.05）;在术后7～14 d大鼠患肢的血流灌注值呈逐渐下降趋势,至术后28 d又开始回升,该3个时点实验组大鼠患肢的血流灌注值均高于空白组（P〈0.05）,对照组与空白组比较其差异均无统计学意义（P〉0.05）;术后7及14 d实验组大鼠肢体的血流灌注值高于对照组（P〈0.05）。各时点实验组胶原标本内血红蛋白含量均高于对照组（P〈0.01）。实验组微血管计数于术后7及14 d高于对照组（P〈0.05）;实验组术后各时点HIF-1αmRNA及VEGF mRNA的表达水平均高于对照组和空白组（P〈0.05）,而对照组与空白组间比较差异无统计学意义（P〉0.05）。结论生肌玉红胶原通过诱导HIF-1αmRNA及VEGF mRNA血管新生相关基因的表达而改善缺血组织的血流灌注,促进微血管新生,从而达到促进组织修复的功效。     

应用激光多普勒血流仪对大鼠后肢缺血模型血流动力学的观察

目的应用激光多普勒血流探测仪(LDF)和激光多普勒血流成像仪(LDPI)监测Lewis大鼠后肢急性缺血模型血流和血压的动态变化,探讨大鼠后肢急性缺血后血流变化特点。方法切除大鼠左后肢股动脉制备急性后肢缺血模型,于术后2、7、14、28及49 d对手术侧和非手术侧肢体采用LDF进行血流、血压检测,于术后7 d采用LDPI进行血流检测。结果所有大鼠术后均成活,未发现后肢坏死;在术后14 d内手术侧后肢平均分为2分,在49 d平均分为1分。大鼠手术侧和非手术侧肢体血流比值在术后2 d由术前的1上升至1.31±0.439(P=0.021),术后7 d和14 d分别为0.82±0.538和0.93±0.294,两者比较差异无统计学意义(P=0.502),但均明显低于术后2 d的值(P=0.032和P=0.019);术后28 d下降到最低点(0.41±1.970),明显低于术后2、7和14 d值(P=0.004、P=0.007和P=0.006);在术后49 d手术侧后肢血流恢复到接近术前值(0.98±0.093),明显低于术后2 d(P=0.010)而高于术后28 d值(P=0.005),与术后7 d和14 d的差异无统计学意义(P=0.126和P=0.382)。大鼠手术侧和非手术侧肢体血压比值术后2 d由术前的1明显下降至0.47±0.375(P=0.031);术后7 d继续下降至0.44±0.118,与术后2 d比较差异无统计学意义(P=0.203);术后14 d下降到最低点(0.35±0.115),明显低于术后2 d和7 d值(P=0.001和P=0.036);术后28 d开始上升(0.54±0.146),明显高于术后14 d值(P=0.008),但与术后2 d(P=0.493)和7 d(P=0.551)的差异无统计学意义;术后49 d恢复接近术前值(0.97±0.094),明显高于术后2、7、14和28 d值(P=0.013、P=0.021、P=0.002和P=0.031)。结论切除大鼠后肢股动脉及分支的方法制备后肢急性缺血模型,在术后14~28 d患肢缺血处于最严重阶段。LDF和LDPI可以动态监测肢体血流及血压的变化,对监测大鼠后肢术后缺血的动态演变过程有着重要的作用。     

Lewis大鼠慢性后肢缺血模型的制备与评价

目的通过线栓法制备大鼠慢性后肢缺血模型,将其与急性后肢缺血模型进行比较研究。方法采用线栓法制备Lewis大鼠慢性后肢缺血模型,分别于术后第7、14、28、42及49天进行激光多普勒血流分析及血管造影。每组动物在血管造影后处死,分别取其健侧和患侧股四头肌和腓肠肌行HE染色及α-actin免疫组织化学染色,并计算小动脉密度。结果慢性后肢缺血模型组动物术后未出现明显的跛行和肢体坏死。血流分析发现,慢性后肢缺血模型在术后第49天仍处于缺血状态。后肢肌肉组织病理学检查未发现急性坏死和肌肉纤维化的表现。术后第7天,慢性缺血组股四头肌的小动脉密度低于急性缺血组(0.015 2比0.036 4)。结论线栓法制备大鼠慢性后肢缺血模型与目前采用的急性动物后肢缺血模型制备方法有显著的不同,其缺血肢体较少受到代偿机制的影响且缺血时间维持较长,此为进一步研究缺血后血管新生的机理和治疗严重的下肢缺血提供了一种新的动物模型。     

两种急性大鼠后肢动脉缺血模型的DSA表现

目的观察采用两种不同方法建立的急性大鼠后肢动脉缺血动物模型的DSA表现。方法雌性SD大鼠60只,采用随机数字表分为A、B组,每组30只。A组结扎离断右侧股动脉,B组结扎离断右侧髂总动脉,建立急性大鼠后肢动脉缺血模型。结果术后4周,A组4只大鼠右侧股动脉远端完全未见显影,模型复制成功率14．81％（4／27）;14只可见少量至中等量侧支循环建立;9只可见大量侧支循环建立和开放。B组3只大鼠右侧髂总动脉结扎离断远端血管未显影,模型复制成功率12．00％（3／25）;10只可见少量侧支至中等量侧支循环建立;12只可见大量侧支循环建立和开放。两组大鼠模型复制成功率差异无统计学意义（P〉0．05）。结论使用DSA可清晰、准确地了解大鼠后肢动脉缺血模型循环建立开放的情况。结扎单侧股动脉及髂总动脉均可建立后肢动脉缺血大鼠模型。     

2型糖尿病大鼠后肢缺血模型的建立及评价

目的建立2型糖尿病大鼠后肢缺血模型并进行评价,为后续的干预实验提供研究平台。方法将15只SD大鼠随机分为正常对照组、糖尿病组及糖尿病后肢缺血组,每组5只。糖尿病组及糖尿病后肢缺血组的10只大鼠均给予高脂饮食喂养4周后,腹腔注射链脲佐菌素（STZ,40mg／kg）以建立2型糖尿病模型。糖尿病后肢缺血组大鼠建模成功后行双侧髂总动脉结扎术以建立后肢缺血模型,正常对照组和糖尿病组大鼠仅分离髂总动脉,不予结扎。2周后对3组大鼠股动脉的起始段行彩色多普勒超声检查,以检测股动脉的血流峰值速度和血流加速时间;取缺血部位的小腿三头肌及大腿股四头肌组织,分别行HE染色及免疫组化SP染色,以观察3组大鼠肌细胞的营养状况及血管再生情况。结果后肢缺血模型建模2周后,正常对照组、糖尿病组和糖尿病后肢缺血组大鼠的血流峰值速度分别为（22．49±3．02）cm／s、（17．36±2．60）cm／s和（11．23±1．26）cm／s,血流加速时间分别为（0．080±0．009）S、（0．120±0．009）S和（0．160±0．020）s,糖尿病后肢缺血组大鼠的股动脉血流峰值速度小于正常对照组和糖尿病组（P〈0．05）,而血流加速时间较长（P〈0．05）。HE染色结果显示：糖尿病后肢缺血组大鼠小腿三头肌的结构破坏,有大量炎症细胞浸润,肌肉损伤程度重于正常对照组和糖尿病组。免疫组化sP染色结果显示：糖尿病后肢缺血组大鼠大腿股四头肌的毛细血管密度[（1．40±0．55）个／HPF]小于正常对照组[（6．80±0．84）个／HPF]及糖尿病组[（4．60±0．55）个／HPF],差异均有统计学意义伊〈O．05）。结论对SD大鼠给予高脂饮食联合小剂量STZ注射可以成功诱导2型糖尿病模型,在此模型基础上结扎髂总动脉可以成功制备糖尿病后肢缺血模型。     

胰岛素干预对糖尿病大鼠后肢缺血的作用及意义

目的研究外源性胰岛素对糖尿病大鼠缺血后肢血管内皮生长因子(VEGF)表达的影响及其促血管新生的作用。方法取20只健康雄性SD大鼠,将其右后肢股动、静脉及其分支和属支结扎,制成糖尿病大鼠后肢缺血模型,然后将其用简单随机化方法随机平均分为模型组与治疗组,另取10只正常大鼠作为对照组。14 d后处死大鼠,应用Western blot法检测大鼠后肢肌肉组织中VEGF蛋白表达水平,并采用碱性磷酸酶(AKP)染色法测定大鼠后肢肌肉组织中毛细血管密度。结果对照组大鼠术前和术后7 d体重和血糖水平比较差异无统计学意义(P>0.05);模型组大鼠术后7 d与术前比较,体重明显下降(P<0.05),但血糖水平差异无统计学意义(P>0.05);而治疗组给予皮下注射胰岛素注射液术后7 d较术前体重明显下降,并且血糖水平较术前也明显下降,差异均有统计学意义(P<0.05)。与对照组比较,治疗组及模型组大鼠术后7 d体重明显下降、血糖明显升高(P<0.05,P<0.01);治疗组与模型组比较,体重差异无统计学意义(P>0.05),但治疗组大鼠术后7 d血糖水平较模型组明显降低(P<0.05)。治疗组大鼠缺血肢体肌肉组织中VEGF蛋白相对表达量(155.06±10.26)明显高于模型组(94.30±11.23),P<0.05;对照组大鼠未检测到VEGF蛋白表达。对照组大鼠右后肢肌肉组织中毛细血管密度明显高于模型组和治疗组(P<0.05),而治疗组又明显高于模型组(P<0.05)。3组大鼠左后肢毛细血管密度差异无统计学意义(P>0.05);对照组大鼠左、右后肢毛细血管密度差异无统计学意义(P>0.05);模型组和治疗组大鼠右后肢毛细血管密度均明显低于左后肢(P<0.05)。结论胰岛素可以增强糖尿病大鼠后肢缺血肌肉组织中VEGF蛋白表达,促进毛细血管生成,发挥保护作用。     

血管内皮生长因子转染内皮祖细胞治疗大鼠缺血后肢的研究

目的 使用血管内皮生长因子(VEGF)转染内皮祖细胞(EPC)治疗大鼠缺血后肢,观察EPC、VEGF转染EPC对大鼠缺血后肢的新生血管和肢体成活的影响.方法 制作SD大鼠后肢缺血模型,将动物随机分为3组,每组6只.将构建的VEGF基因真核表达载体转染入骨髓来源的EPCs后通过尾静脉注射人大鼠体内,并与使用磷酸盐缓冲液(PBS)或EPC的动物进行比较,观察转染VEGF的EPCs在缺血部位的聚集和形成新生血管的情况.结果 (1)动物总残肢率比较,CELL组、VEGF组较PBS组明显增加的肢体恢复率(P<0.05),CELL组肢体恢复率较VEGF组差(P<0.05).(2)毛细血管密度与PBS组比较,各时间点中CELL、VEGF组MVD均明显增多(P<0.05).(3)缺血肢体VEGFa的表达:VEGF组的VEGF蛋白表达较PBS组、CELL组、明显增多(P<0.05);(4)手术后7、14、28 d,与PBS对照组比较,CELL、VEGF组细胞的血流灌注有较大程度的恢复(P<0.01).结论 VEGFa基因转染EPCs对缺血部位的血管新生有重要影响,联合应用VEGFa基因和EPCs治疗缺血后肢有较好的协同作用.     

纳米血管内皮生长因子在治疗下肢缺血促进血管再生成中的作用

目的　利用家兔后肢缺血模型 ,观察纳米材料聚乳酸聚乙醇酸共聚物 (poly dl lactic co glycolicacid ,PLGA) ,包载血管内皮生长因子 (VEGF16 5 )基因 ,经局部肌肉注射后 ,外源基因在局部缺血组织中的转染及强度 ,以及缺血部位的血管新生状况。　方法　制备VEGF16 5 真核表达质粒 ,制备包载VEGF16 5 基因的纳米粒子 ,并检测其理化性质和体外释放曲线。建立家兔后肢缺血模型 2 4只 ,其中4只为对照组 ,只行股动脉及其分支结扎切断术 ;2只为空白纳米粒子组 ,局部缺血肌肉注射空白纳米粒子 ;10只应用裸质粒VEGF16 5 转染 ,8只采用纳米技术包载VEGF16 5 转染。直接缺血部位肌肉内多点注射 ,进行局部定位基因转染。术后 14d行血管造影 ,了解缺血部位侧枝形成情况。处死兔子 ,取股二头肌 ,内收大肌 ,做病理切片 ,免疫组化染色 ,观察VEGF16 5 的表达 ,测定毛细血管密度。应用逆转录 聚合酶链反应了解VEGF16 5 在骨骼肌中的表达 ,并对不同的转染技术进行半定量分析。　结果　转基因治疗 14d后 ,转染VEGF基因组血管造影可见明显新生血管和侧枝循环形成 ,免疫组化染色可见VEGF16 5 蛋白表达水平增高 ,缺血肌肉血管数增多 ,纳米VEGF16 5 治疗组与裸质粒VEGF16 5 治疗组的毛细血管密度明显高于对照组 ,有显著性差异 (P     

Correlation of a simple direct measurement of muscle pO(2) to a clinical ischemia index and histology in a rat model of chronic severe hindlimb ischemia

PURPOSE: The lack of suitable experimental models of chronic severe limb ischemia and deficiencies in the available methods that allow for direct intermittent measurement of regional limb perfusion are obstacles to the evaluation of recently developed molecular strategies to reverse severe limb ischemia. Our aim was to develop a model of clinically relevant severe limb ischemia and correlate a simple direct measurement of muscle pO(2) to a clinical ischemia index, muscle mass, and capillary density. METHODS: Severe hindlimb ischemia was induced in 44 adult rats with ligation of the left common iliac artery, the femoral artery, and their branches. The effect of ischemia on muscle pO(2) was measured in the left gastrocnemius with room air and with 100% oxygen at 3, 10, 24, and 40 days after ischemia was induced. Clinical ischemia index, muscle mass, cellular proliferation, and capillary density also were assessed. RESULTS: The clinical ischemia index of the left limb was most severe at day 10, with evidence of pressure sores, a pale and dusky limb, and abnormal gait. With the rats breathing room air, muscle pO(2) was significantly lower in the left limbs than in the right limbs at days 3, 10, 24, and 40. After an oxygen challenge (100% O(2)), muscle pO(2) was significantly lower at 3, 10, and 40 days. At 3 days, the fraction of muscle mass per total body weight of the left tibialis anterior (TA) was significantly greater than the right TA as a result of edema and inflammation. By days 10, 24, and 40, the left gastrocnemius and TA masses were significantly less than the right as a result of muscle atrophy. Histopathology showed severe necrosis in the left gastrocnemius and TA on day 3. Inflammation was greatest by day 10. Necrotic muscle regenerated but remained atrophic at 40 days. The TA was slower to recover than the gastrocnemius. Capillary densities and capillary-to-muscle fiber ratios were greater in the ischemic limb than in the normal limb at day 24. Cellular proliferation as determined with bromodeoxyuridine labeling reagent staining was maximal in the ischemic limb at day 3. CONCLUSION: We have developed a rat model of chronic severe hindlimb ischemia with persistent ischemia as shown with a simple direct measurement of muscle pO(2) for up to 40 days. This model of severe hindlimb ischemia may be applicable for future studies of molecular strategies to treat severe limb ischemia in humans.     

The effect of gradual or acute arterial occlusion on skeletal muscle blood flow, arteriogenesis, and inflammation in rat hindlimb ischemia

BACKGROUND: Current experimental models of critical limb ischemia are based on acute ischemia rather than on chronic ischemia. Human peripheral vascular disease is largely a result of chromic ischemia. We hypothesized that a model of chronic hindlimb ischemia would develop more collateral arteries, more blood flow, and less necrosis and inflammation than would acute hindlimb ischemia. We therefore developed a rat model of chronic hindlimb ischemia and compared the effects of chronic ischemia with those of acute ischemia on hindlimb skeletal muscle. METHODS: Acute or chronic ischemia was induced in 36 male Sprague-Dawley rats. Chronic ischemia caused blood flow, as measured by laser Doppler scanning and confirmed by muscle oxygen tension measurements, to gradually decrease over 1 to 2 weeks after operation. RESULTS: Histologic analysis showed chronic hindlimb ischemia better preserved muscle mass and architecture and stimulated capillary angiogenesis, while lacking the muscle necrosis and inflammatory cell infiltrate seen after acute ischemia. Surprisingly, the chronic ischemia group recovered dermal blood flow more slowly and less completely than did the acute ischemia group, as measured by laser Doppler (0.66 +/- 0.02 vs 0.76 +/- 0.04, P < .05) and tissue oxygen tension (0.61 +/- 0.06 vs 0.81 +/- 0.05, P < .05) at 40 days postoperatively. Consistent with poorer blood flow recovery, chronic ischemia resulted in smaller diameter collateral arteries (average diameter of the five largest collaterals on angiogram was 0.01 +/- 0.0003 mm vs 0.013 +/- 0.0007 mm for acute, P < .005 at 40 days postoperatively). Acute ischemia resulted in decreased tissue concentrations of vascular endothelial growth factor (VEGF) (0.96 +/- 0.23 pg/mg of muscle for acute vs 4.4 +/- 0.75 and 4.8 +/- 0.75 pg/mg of muscle for unoperated and chronic, respectively, P < .05 acute vs unoperated), and in increased tissue concentrations of interleukin (IL)-1beta (7.3 +/- 4.0 pg/mg of muscle for acute vs undetectable and 1.7 +/- 1.6 pg/mg of muscle for unoperated and chronic, respectively, P < 0.05 acute vs unoperated). CONCLUSIONS: We describe here the first model of chronic hindlimb ischemia in the rat. Restoration of blood flow after induction of hindlimb ischemia is dependent on the rate of arterial occlusion. This difference in blood flow recovery correlates with distinct patterns of muscle necrosis, inflammatory cell infiltration, and cytokine induction in the ischemic muscle. Differences between models of acute and chronic hindlimb ischemia may have important consequences for future studies of mechanisms regulating arteriogenesis and for therapeutic approaches aimed at promoting arteriogenesis in humans suffering from critical limb ischemia. CLINICAL RELEVANCE: Despite the substantial clinical differences between acute and chronic ischemia, researchers attempting to develop molecular therapies to treat critical limb ischemia have only tested those therapies in experimental models of acute hindlimb ischemia. We present here a novel model of chronic hindlimb ischemia in the rat. We further demonstrate that when hindlimb ischemia is developed chronically, collateral artery development is poorer than when hindlimb ischemia is developed acutely. These findings suggest that further tests of molecular therapies for critical limb ischemia should be performed in chronic hindlimb ischemia models rather than in acute hindlimb ischemia models.     

A rat model for severe limb ischemia at rest

We sought an animal model able to discriminate metabolic and angiogenic processes in limb ischemia. For that we modified and evaluated a rat model of severe unilateral limb ischemia at rest. A two-stage surgical procedure entailing left femoral artery ligation preceded by interruption of collateral vessels originating from the infra-renal aorta and left iliac arteries was performed in Sprague-Dawley rats. The model was evaluated for up to 8 weeks with a transit-time flow meter, a laser Doppler perfusion imager, microspheres, arteriography and histology. It was found to be well tolerated with low mortality and perfusion in the foot skin was reduced up to 8 weeks, while collaterals were visible after 2 weeks. Histologic signs of ischemia were seen for up to 4 weeks. This rat model of severe limb ischemia at rest lasts up to 8 weeks and seems well suited for longitudinal studies of the pathophysiology of limb ischemia and healing mechanisms like angio- and arteriogenesis.     

下肢慢性缺血合并急性血栓形成的外科治疗

目的 探讨治疗下肢慢性缺血合并急性血栓形成的最佳外科治疗手段.方法 回顾性分析2000年1月～2010年10月我科收治的26例下肢慢性缺血合并急性血栓形成患者的临床资料,比较单纯采用股动脉切开导管取栓术组(10例)与股-腘动脉切开取栓联合动脉重建手术组(16例)的疗效.结果随访时间1～114个月,单纯股动脉切开术组中的...     

缺血预处理对鼠后肢缺血再灌注下脊髓腰骶膨大运动神经元的保护作用

[目的]对大鼠一侧后肢的缺血再灌注损伤行不同条件缺血预处理,观察脊髓腰骶膨大处运动神经元超微结构的变化,探讨其保护作用.[方法]通过血管夹暂时阻断大鼠左侧髂总、髂内和髂外动脉,建立大鼠后肢缺血模型.以缺血6h再灌注2h和12 h分为A、B两组,预处理方式为缺血10 min血液复流10 min,按无预处理、预处理1次、无时间间隔预处理2、3次,分成A0、A1、A2、A3;B0、B1、B2、B3组.取材腰骶膨大处脊髓灰质前角,光镜及透射电镜下观察不同条件预处理对缺血再灌注损伤中脊髓前角超微结构变化.[结果]组织形态观察结果显示A0组缺血再灌注损伤后神经元细胞减少,核溶解消失,损伤明显,预处理后神经元细胞增多,可见部分细胞核存在;B0组缺血再灌注损伤后神经元细胞大部分坏死溶解,预处理后坏死溶解现象减轻.超微结构观察显示A0和B0组脊髓前角神经兀细胞不同程度核周器扩张损伤,出现内质网扩张、大量线粒体空泡以及核膜溶解消失.预处理后损伤程度有所减轻,叠加预处理后损伤进一步减轻.[结论]缺血预处理能减轻大鼠肢体缺血再灌注下脊髓腰骶膨大运动神经元的损伤,对脊髓具有保护作用.反复3次预处理产生的保护作用优于2次预处理及1次预处理.     

血管生长素治疗家兔肢体缺血的实验研究

目的观察动脉内注射重组人血管生长素（rhANG）对家兔缺血肢体血管再生的影响。方法将28只家兔随机均分为空白对照组、小剂量组、中剂量组、大剂量组。手术结扎、切断家兔股动脉各分支,插入硅塑导管至髂内、髂外动脉处。于术后第11天经动脉内导管注射不同剂量的rhANG。分别作肢体血压测定、动脉造影、放射性核素血流测定及计算肢体肌肉毛细血管密度。结果中剂量组、大剂量组与对照组、小剂量组各项指标于术后20、30、40d时差异有非常显著性（P<0.01）,尤以大剂量组变化最为明显。结论家兔动脉内注射rhANG治疗肢体缺血,在用药（20～40μg）后10～40d可观察到明显的促血管新生作用,此作用随rhANG的剂量增大而明显。     

Reconstructive surgeries on deep femoral artery in chronic critical limb ischemia

Possibilities of revascularisation of the lower extremity through the deep femoral artery in elderly and aged patients with chronic critical limb ischemia were evaluated. Forty-nine patients with high surgical risk were studied. Safety of the extremity, decrease of ischemia degree and level of amputation were the main problems in surgical treatment. Deep-femoral-popliteal index was very important. If this index was less 0.3 surgeries on deep femoral artery were effective. If index was 0.3-0.5 results of surgery were questionable. Index more than 0.5 is the factor of unsuccessful revascularisation through the deep femoral artery.