Egr-1DNA酶抑制自体移植静脉内膜增生的实验研究

目的 探讨早期生长反应基因-1 (Egr-1) DNA酶(Egr-1 DNA enzyme,EDRz)对血管平滑肌细胞(VSMC)增殖和内膜增生的抑制作用,从而证实基因治疗静脉移植后狭窄、闭塞的可行性.方法 构建EDRz,建立自体静脉移植模型,将大鼠右颈总静脉端-端吻合于肾下腹主动脉,EDRz转染移植静脉,分别于移植后1、2、6、24 h及3、7、14、28、42 d切取移植静脉标本,每个时相按随机数字表法随机抽取10只大鼠.荧光显微镜下观察EDRz转染移植静脉情况;应用原位杂交和RT-PCR方法检测Egr-1 mRNA的表达;应用Western蛋白印迹和免疫组织化学方法检测Egr-1蛋白表达情况;HE染色光镜下观察组织学形态.结果 ①EDRz转染移植静脉情况:移植后1h时,EDRz主要位于移植静脉的外膜、中膜和部分内皮细胞;2、6及24 h时,EDRz则主要位于移植静脉的中膜;7d时,EDRz主要位于移植静脉的内膜; 14、28及42 d时未检测到EDRz的表达.②Egr-1 mRNA表达结果.RT-PCR检测结果:转染EDRz后1h时,Egr-1 mRNA表达出现高峰,2、6及24 h表达下降,3d时表达微弱,移植后7、14、28及42 d未见Egr-1 mRNA的表达,转染EDRz后1h时Egr-1 mRNA表达明显高于其余各时相(P＜0.01).原位杂交检测Egr-1 mRNA表达的变化趋势与RT-PCR结果基本一致.③Egr-1蛋白表达结果.Western蛋白印迹结果:正常静脉中未检测到Egr-1蛋白阳性表达.转染EDRz后2h时,出现Egr-1蛋白阳性表达,6h、24 h及3d时其表达逐渐降低,移植后1h时和移植后7、14、28及42 d时未见Egr-1蛋白阳性表达.移植后2h时的Egr-1蛋白表达的吸光度值高于其他时相(P＜0.01).免疫组织化学方法检测的Egr1蛋白阳性表达的变化趋势与Western蛋白印迹结果基本一致.④EDRz转染移植静脉与未转染同期相比VSMC的增殖程度和内膜厚度明显减轻.结论 EDRz通过减少Egr1在自体移植静脉中的表达,可有效地抑制自体移植静脉中VSMC增殖和内膜增生,可用来防治自体静脉移植后所导致的血管狭窄、闭塞.     

反义寡核苷酸抑制早期生长反应基因1表达对移植静脉内膜增生的影响

目的 研究反义寡脱氧核苷酸(antisense oligodeoxynucleotides,ASODN)抑制早期生长反应基因1(early growth response gene-1,Egr-1)表达对移植静脉血管平滑肌细胞增殖和内膜增生的影响.方法构建Egr-1 ASODN,建立自体静脉移植模型,Egr-1 ASODN转染移植静脉,术后随机分为1、2、6、24 h,3、7、14、28、42 d组,以未应用Egr-1 ASODN的大鼠为对照组.荧光显微镜检测Egr-1 ASODN转染移植静脉情况;应用原位杂交和RT-PCR方法检测Egr-1 mRNA的表达;联合应用免疫组织化学方法和Western blot检测Egr-1蛋白表达情况.结果 实验组移植1 h,Egr-1 ASODN主要位于移植静脉的外膜、中膜和部分内皮细胞(荧光灰度值为67±11),移植2 h至24 h,Egr-1 ASODN则主要位于移植静脉的中膜,移植7 d,Egr-1 ASODN主要位于移植静脉的内膜.移植后期未检测到Egr-1 ASODN的表达.Egr-1 mRNA的表达只呈现一个高峰(基因表达值1.8±0.5).移植早期Egr-1蛋白表达主要位于中膜的VSMC、部分单核细胞和内皮细胞,而移植后期在中膜和新生内膜的VSMC都未检测到Egr-1蛋白的表达.与对照组相比VSMC的增殖程度和内膜厚度均明显减轻(P＜0.01).结论 Egr-1 ASODN可显著抑制移植静脉的内膜增生,其作用可能是通过抑制Egr-1基因及其蛋白产物表达,从而抑制VSMC增殖、促进其凋亡而实现的.     

早期生长反应基因-1在自体移植静脉中的表达研究

目的研究自体静脉移植后早期生长反应基因-1(Egr-1)表达的动态变化,探讨其在内膜增生(IH)中的作用。方法 Wistar大鼠90只,建立自体静脉移植模型。术后分为1、2、6、24 h,3、 7、14、28、42 d组,取正常静脉作为对照。应用原位杂交和RT-PCR方法检测Egr-1 mRNA的表达,联合应用Western blot蛋白印迹和免疫组织化学方法检测Egr-1的蛋白表达。结果自体静脉移植后, Egr-1 mRNA和Egr-1蛋白的表达具有双相变化。移植后1 h,Egr-1 mRNA基因表达值为2．21±0．85。 6-24 h时下降,7 d时重新升高,28 d达高峰为3．16±1．14。移植早期2 h:Egr-1蛋白的表达阳性率为 31％±6％,24 h至3 d下降,28 d达高峰为41％±8％。免疫组化显示:移植早期Egr-1蛋白阳性表达主要位于中膜血管平滑肌细胞(VSMCs)和单核细胞／巨噬细胞;移植后期Egr-1蛋白阳性表达主要位于新生内膜和中膜的VSMCs,同时部分内皮细胞也有表达。结论移植静脉内膜增生与Egr-1的激活及表达关系密切,因而与移植静脉内膜增生及狭窄有关。     

Egr-1在自体移植静脉中的表达及意义

目的研究自体静脉移植后早期生长反应基因-1(Egr-1)表达的动态变化,探讨其在内膜增生中的作用。方法Wistar大鼠90只,将大鼠右颈总静脉端-端吻合于肾下腹主动脉建立自体静脉移植模型。术后随机分别于1、2、6和24h,3、7、14、28及42d相应时间处死动物取移植静脉,同时取正常静脉作对照。应用原位杂交和RT-PCR方法检测Egr-1mRNA的表达,联合应用Western蛋白印迹和免疫组织化学方法检测Egr-1蛋白表达情况,同时进行组织形态学观察。结果自体静脉移植后,Egr-1mRNA和Egr-1蛋白的表达呈双相变化,即移植后1h,Egr-1mRNA表达迅速升高,阳性率为(35±7)%,6h、24h及3d时下降到较低水平,阳性率分别为(8±2)%、(8±6)%和(8±4)%,7d时又再升高,28d时达高峰,阳性率为(45±6)%,此与其余各时点比较差异均有统计学意义(P<0.01),42d时,Egr-1mRNA的表达再次下降;移植早期(2h)即有Egr-1蛋白的表达,阳性率为(30±5)%,并持续至6h,24h~3d表达下降到较低水平,阳性率分别为(7±3)%和(7±8)%,7d时又再升高,至移植后28d,Egr-1蛋白的表达阳性率达到高峰,为(40±9)%,此与其余各时点比较差异有统计学意义(P<0.01)。移植后7d,免疫组化结果显示,Egr-1蛋白表达主要位于中膜血管平滑肌细胞(VSMCs)和单核细胞/巨噬细胞,移植后期28d,Egr-1蛋白表达主要位于新生内膜和中膜的VSMCs,同时部分内皮细胞也有Egr-1蛋白的表达。结论移植静脉内膜增生与Egr-1的激活及表达关系密切,Egr-1可能成为防治移植静脉内膜增生、狭窄及闭塞的一个新的干预靶点。     

人arresten基因转染对自体移植静脉内膜增生的影响

目的:探讨体内转染arresten基因对自体移植静脉内膜增生的影响。方法:建立大鼠自体静脉移植模型。血管吻合术前，用脂质体介导重组质粒pSecTag2-AT（Ⅰ组），空载体pSecTag2转染（Ⅱ组）移植血管，等体积脂质体溶液处理移植血管(空白对照组，Ⅲ组）。各组动物均于4周后切取移植血管，RT-PCR检测移植血管中arresten mRNA的表达；常规HE，Verhoeff弹力纤维染色；计算机图象分析检测移植静脉血管内膜及中膜面积、厚度；免疫组化检测移植血管内膜α-SMA及PCNA的表达；Western blot检测TGF-β1蛋白的表达。结果:Ⅰ组转染的移植静脉中有目的基因mRNA的表达, 而Ⅱ、Ⅲ组无Ⅰ组内膜、中膜面积小均于Ⅱ组和Ⅲ组，差异有显著性（P<0.05）。而内膜面积/中膜面积3组间无统计学差异（P>0.05）；Ⅰ组内膜厚度小于Ⅱ组和Ⅲ组，组间比较有统计学差异（P<0.01）；α-SMA染色表明增生内膜中的细胞是血管平滑肌细胞；PCNA阳性细胞数及表达指数Ⅰ组均低于Ⅱ组和Ⅲ组（P<0.05）；Ⅰ组TGF-β1蛋白的表达明显低于Ⅱ组和Ⅲ组。结论:移植血管转染arresten基因，可有效抑制自体移植静脉内膜的增生，在防治血管移植术后再狭窄方面显示出良好的临床应用前景。     

缺氧诱导基因-1α和gax基因共转染对移植静脉内膜重塑态的效应与分子机制

目的 探讨缺氧诱导基因(HIF-1α)和同源盒基因(gax)过表达对移植静脉内膜过度增生的影响及其机制.方法 自体静脉移植术大鼠28只均分为基因转染组和非基因转染组.于核酸、蛋白、细胞超微结构及细胞形态层次分析移植静脉中HIF-1α和gax基因表达与血管平滑肌细胞(VSMC)表型、中膜厚度等指标.结果 基因转染组与非基因转染组比较:HIF-1α和gax的mRNA及其蛋白表达增强(P＜0.05);增殖型VSMC和增殖细胞核抗原(PCNA)阳性细胞减少(P＜0.05);TUNEL阳性细胞增多(P＜0.05);内皮修复较显著,较多肌-内皮连接结构形成;内膜过度增生程度有所减弱.结论 HIF-1α和gax基因联合转染对移植静脉内膜过度增生具有一定的抑制作用.     

野生型p53基因转染和低能量激光照射防治移植静脉再狭窄的实验研究

目的：探索转基因疗法和激光疗法防治移植静脉远期再狭窄的可行性及作用机制。方法：建立兔颈外静脉颈总动脉移植模型，分为（1）对照组，（2）绿色荧光蛋白（GFP）基因转染组，（3）p53基因转染组，（4）低能量激光照射组，（5）p53基因转染并低能量激光照射组。术后4周，免疫组织化学方法检测外源p53基因的表达及增殖细胞核抗原（PCNA），应用DNA片段末端标记法（TUNEL）标记凋亡细胞。HE、Masson及维多利亚兰染色后，应用计算机图像分析系统检测移植静脉内膜、中膜增生情况。结果：术后4周，与对照组相比，GFP基因转染组移植静脉血管平滑肌细胞（VSMC）增殖率、凋亡率差异无显著性，移植静脉内膜和中膜厚度无明显变化；p53基因转染组VSMC增殖率降低61％，凋亡率增加25％，移植静脉内膜和中膜厚度分别减少60％、33％，内膜厚度/中膜厚度比值(I/M)减少37％；应用低能量激光照射组VSMC增殖率降低41.5％，细胞凋亡率增加40.9％，移植静脉内膜和中膜厚度分别减少了58.5％、18.0％，I/M比值减少47.2％；转染p53基因同时应用低能量激光照射组VSMC增殖率较对照组降低61.7％，细胞凋亡率增高47.0％，移植静脉内膜和中膜厚度分别减少69.7％、44.4％，I/M比值减少44.5％。结论：转染野生型p53基因和低能量激光血管外照射可以抑制静脉VSMC增殖，促进移植静脉VSMC凋亡，使移植静脉内膜和中膜的增生减轻，具有防治移植静脉远期再狭窄的作用。     

p27kip1基因表达对大鼠移植静脉内膜平滑肌细胞增殖与凋亡的影响

目的观察以聚乳酸聚乙醇酸（PLGA）纳米粒子为载体的人p27^kip1基因局部转染自体移植静脉后，对大鼠静脉内膜平滑肌细胞增殖及凋亡的影响。方法Wistar大鼠120只建立自体静脉移植模型，随机分成3组。转基因组：移植静脉转染以PLGA纳米粒子为载体的p27^kip1基因；空白对照组：转染不含有p27^kip1基因的单纯PLGA纳米粒子；单纯静脉移植组：使用生理盐水。分别于术后3、7、14、28d取材，常规HE、Verhoeff弹力纤维染色，Western blot检测p27^kip1蛋白的表达，免疫组化（SABC）法检测增殖细胞核抗原（PCNA）的表达、TUNEL法观察内膜平滑肌细胞凋亡的动态变化。结果转基因组内膜中p27^kip1蛋白表达水平高于其他组；内膜平均厚度7、14、28d低于其他2组（P〈0．01）；转基因组内膜PCNA的表达7、14d明显受到抑制（P〈0．01），平滑肌细胞的凋亡细胞百分比于7、14d较对照组明显增加（P〈0．01），单纯静脉移植组与空白对照组之间各项监测指标差异无统计学意义。结论p27^kip1基因的过表达能够有效抑制自体静脉移植后的内膜增生（IH），促进平滑肌细胞的凋亡。     

转染survivin反义寡脱氧核苷酸对移植血管内膜增生的影响

目的研究survivin基因的反义寡脱氧核苷酸（ASODN）对移植血管内膜增生的影响。方法Wistar大鼠60只，建立自体静脉移植模型，术后随机分为5组：对照组，survivin ASODN 50μg组，200μg组，正义对照组，lipoectin＋pluronic组。分别施加不同的处理因素，在移植后1，2周取材。用组织形态学方法比较内膜增生程度；用半定量RT-PCR检测survivin基因的mRNA表达；Western blot检测survivin基因的蛋白产物表达；免疫组化方法检测survivin及增殖细胞核抗原（PCNA）的表达，TUNEL法检测血管平滑肌细胞（VSMC）凋亡。结果静脉移植1～2周内膜增生明显，局部转染50μg survivin ASODN后明显抑制内膜增生（P〈0．05），200μg组受抑制程度较50μg组更为显著（P〈0．05）。静脉移植后，对照组survivin的mRNA及蛋白产物表达显著增加，而survivin ASODN组却显著减少（P〈0．05），VSMC中PCNA表达也同时减少，而TUNEL阳性细胞明显增加。结论survivin ASODNs可显著抑制移植静脉的内膜增生；其作用可能是通过抑制survivin的基因及蛋白产物表达，促进VSMC凋亡而实现的。     

联合转染eNOS基因反义ET核酸对自体移植静脉内膜增生的影响

目的;探讨联合转染eNOS基因和反义ET核酸对自体移植静脉内膜增生的影响。方法：制作20只自体颈静脉腹主动脉移植Wistar大鼠模型,实验组,对照组各10只,实验组移植血管行腺病毒介导的eNOS溶液浸泡和反义ET核酸凝胶涂布,对照组仅行空载腺病毒溶液浸泡和凝胶兴布。术后2周取出移植血管,利用病理学,免疫组织化学,RT－PCR方法检测移植血管内膜厚度,管腔狭窄度,内膜VSMC数及PCNA阳性表达,血管ETmRNA,eNOSmRNA表达情况。结果：实验组移植血管内膜厚度,管腔狭窄及VSMC数均较对照组减小或减少,PCNA阳性表达及ETmRNA表达较对照组减少,而eNOSmRNA表达则明显增加。结论;联合转染NOS基因和反义ET核酸可有效地抑制移植静脉内膜的增生,是一种有效地防治移植静脉再狭窄的基因疗法。     

碱性成纤维细胞生长因子结合静脉套接法修复周围神经缺损的实验研究

目的 探讨碱性成纤维细胞生长因子（ｂＦＧＦ）与静脉套接法修复神经缺损的作用。方法 新西兰大白兔５４只,分成三组,切断兔一侧坐骨神经,用自体静脉桥接。Ａ组于静脉段内注入ｂＦＧＦ溶液０．２ｍｌ（浓度４０００Ｕ／ｍｌ）,Ｂ组注入等量的生理盐水,Ｃ组不注入任何物质。分别于术后１０、３０及１００天取标本行ＨＥ染色,光镜检查。其中１００天组先做传导速度测定,远端再生神经做髓鞘染色,轴突断面做图像分析并与健侧比     

Comparison of initial limb salvage in 98 consecutive patients with either reversed autogenous or in situ vein bypass graft procedures

A retrospective review of 98 consecutive patients undergoing femoropopliteal or distal bypass procedures was conducted to determine whether in situ bypass grafting offers statistically significant initial limb salvage over reversed autogenous techniques. Over a 40 month period, 98 consecutive patients received either in situ or reversed autogenous vein grafts to effect limb salvage. The groups were similar in incidences of diabetes and previous myocardial infarctions, as well as in site of distal anastomosis (beneath the tibial peroneal trunk in more than 80 percent). The in situ vein graft group had an overall limb salvage rate of 92 percent with an 88 percent cumulative patency rate at 4 to 18 month follow-up, whereas the reversed autogenous vein graft group had a limb salvage rate of 86 percent with a 79 percent cumulative patency rate at up to 18 months. Results after 30 days showed 47 patients had improvement and 3 patients (6 percent) had died in the in situ vein graft group. In the reversed autogenous vein graft group, 44 patients improved, 4 did not improve and required amputations, and 2 (1 percent) died. Our study supports the use of in situ vein bypass grafting for limb salvage.     

Comparative electrophysiologic evaluation of nerve grafts and autogenous vein grafts as nerve conduits: an experimental study

This study was carried out to compare electrophysiologically the efficacy of autogenous vein grafts, with autogenous nerve grafts as conduits for nerve regeneration. A 0.75-cm segment of sciatic nerve was resected in two groups of Sprague-Dawley rats of equivalent maturity. The nerve gaps were bridged with an autogenous vein graft in the first group (31 rats), and an autogenous nerve graft in the second group (24 rats). Serial in vivo nerve conduction velocity studies and terminal in vitro nerve conduction velocity and nerve action potential measurements were performed. An additional group of 21 animals who had undergone no surgical procedures, were similarly studied to establish an age-adjusted baseline for comparison. Twelve animals in the first group, 14 in the second group, and 13 in the baseline group survived the full year of study. In vivo conduction velocities between the two experimental groups compared favorably. Nerve conduction velocity determined by in vitro technique confirmed this finding and measured similarly at about 78 percent of the baseline. Nerve action potential amplitude in the vein-grafted group was 12.0 percent of the baseline, while the nerve-grafted group was 23.9 percent of the baseline. This study demonstrated that the vein graft compares well with the nerve graft in nerve conduction velocity, but only one-half as well in nerve action potential.     

Comparison of regeneration results of prefabricated nerve graft, autogenous nerve graft, and vein graft in repair of nerve defects

The purpose of this study was to evaluate the effectivity of prefabricated nerve grafts in the repairing nerve defect and to compare them with the autogenous nerve graft and vein graft. Four groups were created, each containing 10 rats. First, nerve prefabrication was carried out in groups I and II during 8 weeks. For this purpose, jugular vein graft was sutured to the epineural windows on the peroneal and tibial nerve at the right side in an end-to-side fashion. To create neurotrophic stimulus, partial incision was performed on the nerves in group I, and gene therapy was performed by plasmid injecting to the adjacent muscles in group II. At the end of the eighth week, prefabricated nerve grafts, jugular vein, and the axons passing through it were taken. Then, gap was created on the left peroneal nerve in all groups. Defect on the peroneal nerve was repaired by using the prefabricated nerve grafts in groups I and II, the autogenous nerve graft in group III, and the vein in group IV. Assessment of nerve regeneration was performed by using electromyography. Morphological assessment was performed after follow-up period. According to electrophysiological and morphological results, the results of first three groups were similar. There was no statistically significant difference between three groups. Prefabricated nerve graft is as effective as autogenous nerve graft, and it can be used in the repair of nerve defects as autogenous nerve graft as an alternative.     

Autogenous venous graft with one-stage prepared Schwann cells as a conduit for repair of long segmental nerve defects

The use of autogenous venous graft with intraluminal injection of Schwann cells to enhance nerve regeneration of long segmental nerve defects was evaluated in a rabbit tibial nerve-repair model. Schwann cells were isolated from the excised rabbit tibial nerve by using the polylysine differential adhesion method. The cultured cells were identified by immunocytochemical labeling for S-100 protein. Tibial nerve defects in 4-cm segments were created in 24 animals, which were then divided into three groups. In Group 1, the tibial nerve defect was repaired with interposition vein graft alone; in Group 2, the nerve defect was repaired with a vein graft with intraluminal injection of Schwann-cell suspension; in Group 3, the nerve defect was repaired by autogenous nerve graft alone. At 2 months postoperatively, electrophysiologic evaluation showed that an evoked muscle action potential was recorded for the animals in Group 2, with vein grafting plus Schwann cells, and for those in Group 3, with autogenous nerve grafting, but not for those in Group 1, where vein grafting alone was used. The average motor nerve conduction velocity in the group with vein grafting and Schwann cells was 3.4 +/- 1.5 m/sec, which was slower than the nerve grafting group (7.8 +/- 1.8 m/sec). Histologic analysis confirmed there was formation of new nerve fascicles with myelination in the vein graft filled with Schwann cells. No nerve regrowth was found in the vein grafts without Schwann cells. These results suggested that isolated Schwann cells are able to survive in a vein graft, and that the vein graft with intraluminal seeded Schwann cells could be an alternative for repairing injured nerves with long gaps.     

伊马替尼抑制大鼠静脉移植物内膜增生

目的 观察伊马替尼对自体移植静脉内膜增生的影响.方法 建立大鼠自体颈外静脉移植模型,实验分为4组:移植组、低剂量给药组、高剂量给药组及对照组.移植4周后取移植静脉,行病理学检查观察内膜增生情况,免疫组织化学及Western blot法检测PDGFRβ、ERK及P-PDGFRβ、P-ERK蛋白表达情况.结果与对照组比较,移植组和低剂量给药组内皮下平滑肌细胞大量增生,静脉内膜显著增厚,管腔明显狭窄,高剂量给药组内膜无明显增厚.Western blot结果显示,移植组血管P-PDGFRβ蛋白含量(P-PDGFRβ/GAPDH)较对照组明显增加(0.81±0.06比0.18±0.02,P<0.05),而高剂量给药组较移植组明显减少(0.32±0.03比0.81±0.06,P<0.05),低剂量给药组与移植组比较差异无统计学意义(P>0.05),P-ERK蛋白表达亦呈同样趋势变化.结论 高剂量伊马替尼能有效抑制自体移植静脉内膜增生,其机制可能与抑制PDGF信号通路蛋白磷酸化,从而抑制平滑肌细胞增殖有关.     

Infrainguinal arterial reconstructions with vein grafts in patients with prior aortic procedures: the influence of aneurysm and occlusive disease

PURPOSE: This study assessed whether infrainguinal reconstructions with autogenous vein (IR) performed in patients with prior abdominal aortic aneurysm (AAA) repairs have altered graft patency, compared with those in patients who have undergone prior aortobifemoral bypass grafting procedures (ABF) for aortoiliac occlusive disease. METHODS: From 1979 to 1998, 54 patients with prior aortic reconstructions underwent 64 autogenous single-segment saphenous IRs solely for infrainguinal occlusive disease. Included in this cohort were 30 IRs with an earlier AAA repair and 34 IRs with an earlier ABF repair. During the same period, 1274 patients underwent 1642 autogenous vein lower-extremity bypass grafting procedures (LEB). Lower-extremity native arterial (AAA, n = 6; ABF, n = 11) and vein graft diameters (AAA, n = 6; ABF, n = 6) were determined by means of angiography and duplex ultrasonography, respectively. The three reconstruction groups (AAA, ABF, LEB) were compared. RESULTS: The patients in the three groups were similar in sex, indication for operation, proximal and distal anastomotic site, and number of distal runoff vessels. The cumulative 5-year primary graft patency rate in the AAA group (92% +/- 5%) was significantly higher (P <. 001) than that in the LEB group (63% +/- 2%) and the ABF group (44% +/- 11%). Furthermore, cumulative 5-year primary patency was decreased in the ABF group compared with the LEB group (P =.05). A significant increase in both native arterial (P =.001) and vein graft diameter (P <.05) was demonstrated by using linear regression and a Student t test, respectively, in the AAA group compared with the ABF group. CONCLUSION: These data demonstrate that, compared with those in patients without a previous aortic procedure, IRs in patients with prior AAA repairs have significantly improved graft patency, and IRs in patients with prior ABF reconstructions for aortoiliac occlusive disease have significantly decreased graft patency. Larger arterial diameter and altered vein graft adaptation may contribute to the superior long-term outcomes of IRs in patients with prior AAA repairs.     

The use of autogenous vein for nerve grafting

The use of autogenous femoral vein to graft a resected segment of sciatic nerve in 10 rats suggests that autogenous vein can serve as a satisfactory nerve graft conduit. Scar tissue within the vein or distal nerve was minimal.     

Autogenous vein graft repair of injured extremity arteries: early and late results with 134 consecutive patients

Autogenous vein tissue is recognized as the preferred material for extremity revascularizations that require the use of a conduit. However, the results after vascular repair of injured extremity arteries with autogenous vein interposition or bypass grafts have not been well defined. This study was done to determine both the early and late patency and limb salvage rates as well as the graft infection rate of autogenous vein repairs of injured extremity arteries. The records of 134 consecutive patients with acute extremity arterial injuries requiring repair with a reversed autogenous vein graft over a recent 5-year period were reviewed. Follow-up graft patency was defined by the presence of a palpable pulse and an extremity Doppler-derived pressure index of greater than or equal to 0.9 distal to the arterial repair. Cumulative patency was assessed by the life-table method. Acute graft thrombosis occurred in two patients, one of whom underwent successful graft thrombectomy. Four patients (3%) required extremity amputation: one patient with a thrombosed vein graft and three patients with patent vein grafts but nonsalvageable limbs as a result of myonecrosis (2) or osteomyelitis (1). No perioperative graft infections occurred. One hundred twenty-eight patients (97%) had an intact extremity and a patent vein graft at the time of hospital discharge. One hundred three patients (80%) were examined at 30 days, and all grafts were patent. Seventy-three patients (57%) were available for follow-up at intervals exceeding 6 months, and 40 patients (31%) were followed-up for periods exceeding 24 months.(ABSTRACT TRUNCATED AT 250 WORDS)     

Regional nerve block allows for optimization of planning in the creation of arteriovenous access for hemodialysis by improving superficial venous dilatation

Durable vascular access for hemodialysis remains a critical issue in end-stage renal disease patients. Creation of an autogenous arteriovenous (AV) fistula in the most distal location of the nondominant extremity is the preferred technique and provides superior patency over an AV graft. Others have shown that regional anesthesia in the form of axillary block results in the dilatation of the native veins and allows for their increased utilization in creating AV fistulae. We report on 26 patients undergoing creation of a vascular access for hemodialysis. Regional anesthesia consisting of axillary nerve block was used in all cases. All surgical plans with regard to the site and type of access were made based on the physical exam and ultrasound vein measurements taken prior to surgery. On the day of surgery patients were reevaluated with venous ultrasound using tourniquet before and after administration of the regional block. The previously determined operative plan either remained unchanged or was modified depending on the venous dilatation noted after administration of regional block. Among 26 patients, average vein diameter increased from 0.29 +/- 0.12 cm to 0.34 +/- 0.11 cm (P = 0.008). Twenty-one of 26 patients had no modification in operative plan (group 1). Five had some modification of the original operative plan (group 2): AV graft to a brachial vein transposition (n = 2), AV graft to a Cimino fistula (n = 2), and brachiocephalic to a Cimino (n = 1). The average follow-up for all patients was 82.6 +/- 75.6 days and did not differ between the groups. There was one failure in a patient from group 1, and there was no significant difference in the patency rate between study groups (P = 0.29). Following regional nerve block, operative plans in patients undergoing AV access surgery were modified in 29.4% of patients undergoing creation of an AV access for hemodialysis; either from graft to fistula creation or from the proximal to more distal fistula site. The routine use of regional anesthesia as well as intraoperative ultrasound during AV access surgery can lead to improved site selection and increased opportunity for AV fistula creation.