多层裸支架腔内隔绝动脉瘤的研究现状及存在问题

多层裸支架隔绝动脉瘤瘤腔的同时,能保持支架覆盖区域分支动脉的通畅,解决了覆膜支架不能保留支架覆盖区重要分支的问题。笔者就多层裸支架治疗动脉瘤的现状及其机制进行综述,并总结其存在的问题,为临床治疗提供依据。     

输尿管支架管在腔内泌尿外科的应用进展

输尿管支架管已在泌尿外科临床应用多年，即可用于疾病的诊断也可用于临床治疗，并且常作为腔内检查和微创操作的辅助手段。本文就输尿管支架管的发展、腔内泌尿外科中的应用指征及其并发症作一综述。     

输尿管支架管在腔内泌尿外科的应用进展

输尿管支架管已在泌尿外科临床应用多年 ,即可用于疾病的诊断也可用于临床治疗 ,并且常作为腔内检查和微创操作的辅助手段。本文就输尿管支架管的发展、腔内泌尿外科中的应用指征及其并发症作一综述     

镍钛记忆合金气管腔内支架的实验研究

报告采用记忆合金支架治疗气管软化的实验研究，７条犬造成气管软化模型后，将支架置入软化部位。气道阻力测定结果表明，该支架能有效地克服气道软化，观察２～６个月，支架全部发生移位。向近端移位的３条犬，最终全部出现肉芽组织增生，阻塞管腔，向远端移位的４条犬中有３条出现理想的结果，即正常气管上皮爬过重建光滑的气管腔，支架的合金丝逐渐被纤维包膜所包绕，作者认为：对于临床上没有理想治疗方法的远端气管软化，该方法     

应用输尿管镜腔内碎石取出长期存留输尿管支架管

输尿管支架管长期存留在泌尿外科临床中并不罕见 ,支架管留置过久 ,其上可有结石壳形成 ,结石镶嵌在输尿管壁上 ,治疗十分困难。我们曾对 1例左肾慢性感染性萎缩 ,功能丧失 ,右侧输尿管支架管留置 30个月 ,支架管完全结壳钙化 ,导致慢性梗阻性肾功能不全的患者 ,通过输尿管镜下气压弹道碎石术 ,将已钙化结壳的输尿管支架管成功取出。现结合文献复习报道如下。1　病例报告患者 ,男 ,66岁。以恶心 ,乏力 ,持续性右侧腰背部疼痛 ,反复尿路感染 ,间歇性发热 ,体温波动在38.9～ 39.5 0℃之间 ,持续达 1个月入院。患者有左肾萎缩病史 ,1 999年 4月…     

包埋后的几丁质与软骨细胞体外培养的实验研究

目的 探讨几丁质作为组织工程技术中细胞培养支架的可行性。方法 采用聚乳酸、卵磷脂及多聚赖氨酸分别或工同包埋几丁质与软骨细胞体外培养,观察其产亲水性的改变、对细胞吸附力和细胞功能的影响。结果 以聚乳酸包埋的几丁质对细胞的生长有抵制作用;以卵磷脂包埋的几柄质亲水性增强;以多聚赖氨酸包埋的几丁质对细胞吸附力增强;以卵磷脂和多聚赖氨酸共同包埋的几丁质具有良好的亲水性和对细胞吸附力,并可使细胞更好地发挥功能     

自制国产化支架-移植物腔内治疗腹主动脉瘤的实验研究

目的 探讨自制国产化支架、移植物在治疗犬腹主动脉瘤中的作用。方法 以国产镍钛合金丝纺织成网状管型支架,外套以国产真丝涤纶交织人造血管,装入导鞘制成支架-移植物系统;用胰蛋白酶灌注犬肾下腹主动脉段形成动脉瘤模型;用血管腔内技术将支架-移植物置入腹主动脉内,隔绝血流分别于第1周、1个月、3个月和6个月末观察通畅度及新生内膜生长。结果 20条模型犬接受手术,成功19条,支架置入后能充分展开并恢复形状,1个月末,支架内表面90%被新生内膜覆盖,3个月末几达100%,6个月末,79%的支架保持通畅,无移位、内漏等并发症。结论 自制国产化支架、移植物有良好的生物相容性和较高的通畅率,可用于腹主动脉瘤的治疗。     

主动脉弓三分支型移植物在血管模拟装置中的腔内修复实验

目的:研究一体化三分支型主动脉弓腔内移植物在新型血管模拟装置中模拟腔内修复主动脉弓的可行性。方法:设计并制作主动脉弓一体化三分支型覆膜支架,其分支针对主动脉弓上的3个分支动脉;用新型血管模拟装置测试此种移植物,优化移植物的腔内操作,评估移植物在模拟装置内释放的可行性。结果:新型血管模拟装置运作正常,移植物可顺利装载入输送系统并导入血管模拟装置内释放,其主体和分支在位良好。结论:设计制作了新型主动脉弓分支型移植物,其输送系统能顺利将移植物送达靶血管准确位置;新型体外血管模拟装置能模拟人体血管腔内环境并对上述移植物进行体外测试。     

血管腔内支架植入术的临床应用

目的 评价应用血管内支架治疗血管性疾病的临床价值。方法 对36例患有血管性疾病的患者施行了血管内支架植入术，包括胸主动脉夹层动脉瘤24例，腹主动脉真性动脉瘤3例，腹主动脉夹层动脉瘤1例，颈动脉动静脉瘘1例，左锁骨下动脉狭窄1例，左锁骨下动静脉瘘1例，髂动脉假性动脉瘤4例及股动脉狭窄1例。除1例左锁骨下动脉狭窄患者、1例股动脉狭窄患者使用了裸支架外，其余34例患者均采用带膜支架进行血管内治疗。结果 术中所有患者均未出现特殊不适，术后随访期间未见明显合并症发生。所有患者均完全消除了临床症状。结论 应用血管内支架治疗血管性疾病是一种实用且效果较好的治疗方法。     

聚二元共聚物多孔支架活性真皮替代物的体外构建

活性皮肤替代物是指含有活细胞成分的皮肤组织工程产品 ,是皮肤组织工程研究的热点。由于人工合成的生物可降解材料具有生物相容性、加工性能良好以及降解速度可控等优点 ,已被广泛用作细胞支架。然而 ,在多孔的人工材料中种植细胞还存在很多问题。本文应用成纤维细胞胶原凝胶 (fibroblastspopulatedcollagenlattice ,FPCL)的制作方法 ,成功地将人成纤维细胞种植于聚二元共聚物 (乙交酯 /丙交酯polylacticacid/ polyglycolicacidcopolymers ,PLGA)多孔真皮支架中 ,体外培养出一种新型的活性真皮替代物。材　料　与　方　法1.胶原和细胞 …     

Sequential changes in the mechanical properties of viable articular cartilage stored in vitro

Viable articular cartilage from the medial femoral condyles of rabbits was stored in vitro in tissue culture medium with various additives and the same site of each specimen was mechanically tested sequentially throughout a 12-day storage period. Indentation testing was performed with instantaneous and sustained loads. Preservation of sustained-load carrying capacity was observed in the condyles stored with additives, indicating maintenance of an intact cartilage matrix. However, initial testing with small sustained loads (preload) showed changes not observed at higher load levels. The changes noted at small sustained initial loads may reflect alterations in cartilage surface structure and may be an early indicator of its mechanical integrity. Chondrocyte viability and proteoglycan content, as measured by ³⁵S incorporation and hexosamine concentration, were unchanged in comparison to fresh articular cartilage.     

An in vitro methodology for evaluating the mechanical properties of aortic vascular prostheses

The main problem in the replacement of pathological segments of the aorta with vascular prostheses consists of matching the fluid admittance of the host artery and the graft. This mismatch results from the different compliance between natural and prosthetic vessels and from the plastic dilatation of the prosthesis diameter that occurs after implantation. An experimental procedure was set up for evaluating the mechanical properties of aortic vascular prostheses. An MTS 858 MiniBionix testing machine was equipped with a purposely designed testing apparatus, which allows loading a ring-shaped prosthesis specimen with forces that can be related easily to the transmural pressure acting on the prostheses in vivo. The reference pressure waveforms are simulated from a lumped parameter model of the cardiovascular system. Preliminary tests on 3 different (woven, warp knitted, and carbon-coated warp knitted fabric) aortic prostheses point out a good reproducibility of the results. The fabric strongly affects the circumferential elasticity and the dimensional stability of the graft. Simulation of hypertension promotes larger diameter dilatation and reduction in compliance. Agreement between in vitro and clinical diameter measurements has been assessed for 8 prosthesis samples and found to be adequate. This method is thus a potentially useful means for preclinical evaluation of compliance of vascular prostheses for the purpose of matching to native vessels.     

全覆膜自膨胀金属支架治疗胆胰管良性狭窄的现状与进展

全覆膜自膨胀金属支架（FCSEMS）治疗肝移植术后胆管吻合口狭窄和慢性胰腺炎等因素导致的胆管良性狭窄的初步结果令人鼓舞,但在FCSEMS完全取代塑料支架成为胆管良性狭窄的治疗首选之前,应充分评估支架移位、胆道感染、胰腺炎和支架无法移除等并发症的发生率.对于良性的主胰管狭窄,FCSEMS是一种有效的治疗方法,但支架移位率较高,需要更好顺应性和末端喇叭口的支架设计.理论上讲,FCSEMS会堵塞分支胰管导致胰管感染,但目前并没有这些并发症的报道.由于FCSEMS治疗主胰管狭窄的长期有效性和安全性尚不清楚,FCSEMS使用应限制在治疗复发性和有症状的胰管良性狭窄.     

Evaluation of the long-term effectiveness of extraluminal and intraluminal vasodilators in an in vitro porcine model of arterial graft spasm

Objective.

Postoperative graft spasm is a concern when arterial conduits are used because there may be insufficient arterial graft flow. Intraoperatively, vasodilators are used to increase flow and prevent spasm, but little is known about their duration of effectiveness.

Methods.

To examine this we attached porcine gastroepiploic and internal thoracic arteries (GEA, n=48; ITA, n=24, 10–12 cm long) to a computer-controlled perfusion system (constant inflow pressure 80 mmHg) with a fixed outflow resistance. Norepinephrine (10⁻⁹ – 10⁻⁵ M) was incrementally added to the perfusate at baseline (B), then immediately (h+0) and 2 h (h+2) after the vessels were treated with 30 min of extraluminal or intraluminal nitroglycerin, nitroprusside, verapamil or papaverine.

Results.

At (B), norepinephrine caused a dose-dependent decrease in flow in both the ITAs and GEAs. In the ITAs, at (h+0), both extraluminal and intraluminal papaverine and, to a lesser extent nitroprusside, increased initial flow and decreased graft sensitivity to norepinephrine. At (h+2), only extraluminal papaverine sustained this maximal effect (ED₅₀ for extraluminal papaverine at (B) 2.6 E⁻⁷ vs (h+2) 1.3 E⁻⁶, P=0.01). For the GEAs, at (h+0), both extraluminal and intraluminal verapamil, papaverine, nitroprusside and nitroglycerin attenuated flow reduction due to norepinephrine. At (h+2), only extraluminal papaverine, extraluminal verapamil and intraluminal verapamil were effective in preventing norepinephrine-induced spasm (ED₅₀ for extraluminal papaverine at (B) 1.0 E⁻⁷ vs (h+2) 6.4 E⁻⁶ (P=0.004); extraluminal verapamil at (B) 1.2 E⁻⁷ vs (h+2) 4.0 E⁻⁶; intraluminal verapamil at (B) 5.8 E⁻⁷ vs (h+2) 5.7 E⁻⁶, P=0.005).

Conclusion.

Verapamil-and papaverine-treated arteries have a greater duration of efficacy in resisting spasm than arteries treated with nitroglycerin and nitroprusside. In the ITA, extraluminal administration of papaverine is most efficacious, possibly due to the prolonged exposure afforded by this route of administration. The effects of verapamil and papaverine are more prolonged in the GEA when administered extraluminally, potentially due to absorption in the perivascular fat-pad and subsequent slow release. The results of this study suggest that extraluminally administered verapamil and papaverine appear to be the preferred vasodilators for preventing arterial graft spasm in the postoperative period. This may be especially important when multiple arterial grafts are used.     

体外受精-胚胎移植中选择性单胚胎移植的现状及新进展

随着辅助生殖技术的不断发展,生殖医学领域已不再单纯追求临床妊娠率的提高.越来越多的学者认为选择性单胚胎移植(eSET)既不影响整体成功率,又可以显著降低多胎妊娠.应用eSET已成为全球的发展趋势,但仍有诸多阻碍如患者偏好、胚胎筛选、经济因素等.本文将对选择性单胚胎移植的研究现状进行综述,为推动其广泛应用提供参考.     

新型冠状动脉支架应用现状及展望

采用裸金属支架植入治疗冠心病疗效显著,但内膜增生引起支架内再狭窄风险高。采用药物洗脱支架可降低支架内再狭窄发生率,但患者需长期接受双联抗血小板治疗来预防血管愈合延迟和内皮功能紊乱引起的支架内血栓形成。第二代药物洗脱支架和无载药涂层洗脱支架、载药涂层可降解支架、完全可降解支架等新概念支架已投入临床应用。这些新型支架具有良好的安全性和有效性。本文对新型冠状动脉支架的临床应用、研究现状及发展方向进行综述。     

The mineral and mechanical properties of bone in chronic experimental diabetes

The long-term effects of experimentally induced diabetes on bone were studied in eight male Lewis rats, intravenously (i.v.) injected with 65 mg/kg of streptozocin (STZ) and maintained for 12 months. Eight untreated age-matched rats served as controls. In the STZ-treated rats, experimentally induced diabetes was documented by the presence of hyperglycemia at 24 h and at 3 and 12 months. Significantly less weight was gained and less growth occurred in the STZ-treated rats despite careful attention to feeding and hydration. Mineral alterations were detected in the bones of the animals with experimental diabetes. Decreased hydroxyapatite crystal perfection, decreased Ca/P of the ash, and decreased ash content in the tibial metaphyses with increased ash content in the tibial diaphyses, was noted relative to controls. Bone osteocalcin content was increased in the metaphyses of the STZ-treated rats. While absolute measures of stiffness, torsional strength and energy absorption were decreased in the bones of the STZ-treated animals, when torsional strength and stiffness were normalized for differences in both growth and geometry, the normalized stiffness values for the diabetic bones were increased. The results suggest that in experimental diabetes certain aspects of bone mineralization are adversely affected and lead to reduced strength-related properties. However, a compensatory increase in stiffness occurs. The reason for this increase, although not known, may be related to changes in bone crystal structure.     

胆道支架覆膜研究现状

目前，胆道支架覆膜在保持胆道管腔通畅、提高引流效果和改善生存质量方面具有重要意义。本文就支架覆膜材料的发展，覆膜与抗癌、抑癌，覆膜与胆泥形成及支架覆膜后的利弊进行了综述。     

Bacterial adherence to silver nitrate coated poly-L-lactic acid urological stents in vitro

The purpose of this study was to see whether it is possible to prevent bacterial adherence to bioabsorbable self-reinforced l-lactic acid polymer (SR-PLLA) urological stents. The SR-PLLA stents were coated with silver nitrate blended ɛ-caprolactone/l-lactide copolymer. The adherence of five bacterial strains (Pseudomonas aeruginosa, Enterococcus faecalis, Proteus mirabilis and two strains of Escherichia coli) to coated and non-coated SR-PLLA wires were tested. It was found that silver nitrate coating prevented the adherence of bacteria (except E. faecalis) to SR-PLLA stents. The preventive effect correlated with the silver nitrate concentration. It was also found that silver nitrate coating reduced the amount of bacteria in ambient urine. In conclusion, silver nitrate coating may reduce stent-associated bacterial infections by preventing the adherence of bacteria. Further studies are needed to confirm its efficacy and safety in clinical practice. Received: 4 January 2000 / Accepted: 20 June 2000