Self-Expanding Nitinol Stent for Treatment of Tracheal Stenosis Caused by Pulmonary Hypertension:1 case report

A 38 year-old man was admitted because of half a year of recurrent bouts of eough and shortness of breath and 20 days of hemoptysis. He had been apparently healthy until the illness. In the recent 6 months, the dyspnea and fatigue gradually onset and became more severe, the hemoptysis being 100-200 mL per day. Spells of chest pain are associated with coughing. Despite accepting antibiotic and antispasmodic therapy in a hospital, there was no obvious improvement and he was transferred to our hospital. Physical examination on admission: He was in acute distress and anemic face With P 110/min., R 30/min., T36. 8oC and Bp 100/60 mmHg. There were Wheezes, medium and fine

Nitinol Stenting in Post-Traumatic Pseudo-Aneurysm of Internal Carotid Artery

Background: A pseudoaneurysm of the internal carotid artery (ICA) at its cervicl part, is a rare and often lethal com-plication after cervical trauma. The treatment of choice is anticoagulation. Patients with a contraindication for anticoagulation or those who do not improve with standard treatment, warrant either a surgical repair or stent placement.Stent placement posses both short and long term risks such as immediate ischemic events, in-stent stenosis and stent breakage, thus the choice of stent type is critical. Advances in stent technology have made cervical stent placement a viable option. We report our experience with the LEO + (Balt Extrusion, Montmorency, France) nitinol flexible self expanding stent for post-traumatic ICA aneurysms. Methods: 5 patients suffering a post-traumatic cervical ICA pseudo-aneurysms refractory to standard treatment were treated with nitinol braided flexible self expanding stent. This stent has a shape memory and superelasticity virtues making it suitable. Diagnosis was made with CT angiography and confirmed by catheter angiography. All procedures were preformed under local anesthesia. Time between trauma and treatment ranged six days to over five years. Follow-up was performed by CT angiography or conventional angiography. Results: Five patients, having eight aneurysms were treated using 12 stents. In all cases, appropriate stent placement was achieved. No immediate or late complications, as well as no neurological sequele reported at 6 months. Radiological follow-up exams demonstrated complete pseudoaneurysm closure. Conclusion: Stent placement can be a safe and definitive treatment option for patients to conventional medical treatment.

ENDOSCOPIC STENT FOR PALLIATING MALIGNANT AND BENIGN BILIARY OBSTRUCTION

To study the techniques of placement of memory alloy plating gold biliary stent and plastic stent for palliation of malignant and benign biliary obstruction, and to assess its clinical effectiveness. Methods: The patients in plastic stent group included paplilla of duodenum inflamational strictures (n=24), common bile duct inflammational inferior segment strictures (n=4), choledocholithiasis (n=5), bile leak (n=11), bile duct surgery injurey (n=7) and pancreatic carcinoma (n=1). The patients in plating gold stent group included common bile duct carcinoma (n=5) and pancreatic carcinoma (n=6). Under fluoroscopic guidance the stent was inserted into biliary obstruction sites from oral cavity in all cases. Complications, liver function and blood serum amylase were investigated during the study period. Results: Successful stent placement was achieved in all cases. After operation of 7 days, in gold biliary stent groups, the rates of decrease of blood serum total bilirubin, glutamic-pyruvic transaminase, r-glutamyl transpeptidase and alkaline phosphatase were 67.16%, 58.37%, 40.63% and 41.54% respectively. In plastic stent group, the rates of decrease of STB, ALT, r-GT and AKP were 53.24%, 55.03%, 37.15%, 34.12% respectively. Early complication included post-ERCP pancreatitis and cholangititis. Occlusion of stent was the major late complication. Conclusion: Memory alloy plating gold biliary stent and plastic stent were safe and efficacious methods for malignant and benign biliary obstruction, and could improve patient抯 living quality. Plastic stent was an efficient complement for therapy of bile leak and bile duct injury.

Percutaneous trans-hepatic bilateral biliary stenting in Bismuth Ⅳ malignant obstruction

AIM: To investigate the clinical efficiency of percutaneous trans-hepatic bilateral biliary metallic stenting for the management of Bismuth Ⅳ malignant obstructive disease. METHODS: Our hospital's database was searched for all patients suffering from the inoperable malignant biliary obstruction Bismuth Ⅳ, and treated with percutaneous bilateral trans-hepatic placement of selfexpandable nitinol stents. The indication for percutaneous stenting was an inoperable, malignant, symptomatic, biliary obstruction. An un-correctable coagulation disorder was the only absolute contra-indication for treatment. Bismuth grading was performed using magnetic resonance cholangiopancreatography. Computed tomography evaluation of the lesion and the dilatation status of the biliary tree was always performed prior to the procedure. All procedures were performed under conscious sedation. A single trans-hepatic track technique was preferred (T-configuration stenting) and a second, contra-lateral trans-hepatic track (Y-configuration stenting) was used only in cases of inability to access the contra-lateral lobe using a single track technique. The study's primary endpoints were clinical success, defined as a decrease in bilirubin levels within 10 d and patient survival rates. Secondary endpoints included peri-procedural complications, primary and secondary patency rates. RESULTS: A total of 35 patients (18 female, 51.4%) with a mean age 69 ± 13 years (range 33-88) were included in the study. The procedures were performed between March 2000 and June 2008 and mean time follow-up was 13.5 ± 22.0 mo (range 0-96). The underlying malignant disease was cholangiocarcinoma (n = 10), hepatocellular carcinoma (n = 9), pancreatic carcinoma (n = 5), gastric cancer (n = 2), bile duct tumor (n = 2), colorectal cancer (n = 2), gallbladder carcinoma (n = 2), lung cancer (n = 1), breast cancer (n = 1) or non-Hodgkin lymphoma (n = 1). In all cases, various self-expandable bare metal stents with diameters ranging from 7 to 10 mm were used. Stents were placed in Y-configuration in 24/35 cases (68.6%) using two stents in 12/24 patients and three stents in 12/24 cases (50%). A T-configuration stent placement was performed in 11/35 patients (31.4%), using two stents in 4/11 cases (36.4%) and three stents in 7/11 cases (63.6%). Follow-up was available in all patients (35/35). Patient survival ranged from 0 to 1763 d and the mean survival time was 168 d. Clinical success rate was 77.1% (27/35 cases), and peri-procedural mortality rate was 5.7% (2/35 patients). Biliary reobstruction due to stent occlusion occurred in 25.7% of the cases (9/35 patients), while in 7/11 (63.6%) one additional percutaneous re-intervention due to stent occlusion resulting in clinical relapse of symptomatology was successfully performed. In the remaining 4/11 patients (36.4%) more than 1 additional reintervention was performed. The median decrease of total serum bilirubin was 60.5% and occurred in 81.8% of the cases (27/33 patients). The median primary and secondary patency was 105 (range 0-719) and 181 d (range 5-1763), respectively. According to the KaplanMeyer survival analysis, the estimated survival rate was 73.5%, 47.1% and 26.1% at 1, 6 and 12 mo respectively, while the 8-year survival rate was 4.9%. Major and minor complication rates were 5.7% (2/35 patients) and 17.1% (6/35 patients), respectively. CONCLUSION: Percutaneous bilateral biliary stenting is a safe and clinically effective palliative approach in patients suffering from Bismuth Ⅳ malignant obstruction.

Double-layered covered stent for the treatment of malignant oesophageal obstructions: Systematic review and meta-analysis

AIM To investigate the efficacy of double-layered covered stent in the treatment of malignant oesophageal obstructions.METHODS A systematic review and meta-analysis was performed following the PRISMA process. Pub Med(Medline),EMBASE(Excerpta Medical Database),AMED(Allied and Complementary medicine Database),Scopus and online content,were searched for studies reporting on the Ni Ti-S polyurethane-covered double oesophageal stent for the treatment of malignant dysphagia. Weighted pooled outcomes were synthesized with a random effects model to account for clinical heterogeneity. All studies reporting the outcome of palliative management of dysphagia due to histologically confirmed malignant oesophageal obstruction using double-layered covered nitinol stent were included. The level of statistical significance was set at α = 0.05.RESULTS Six clinical studies comprising 250 patients in total were identified. Pooled technical success of stent insertion was 97.2%(95%CI: 94.8%-98.9%; I2 = 5.8%). Pooled complication rate was 27.6%(95%CI: 20.7%-35.2%; I2 = 41.9%). Weighted improvement of dysphagia on a scale of 0-5 scoring system was-2.00 [95%CI:-2.29%-(-1.72%); I2 = 87%]. Distal stent migration was documented in 10 out of the 250 cases examined.Pooled stent migration rate was 4.7%(95%CI: 2.5%-7.7%; I2 = 0%). Finally,tumour overgrowth was reported in 34 out of the 250 cases with pooled rate of tumour overgrowth of 11.2%(95%CI: 3.7%-22.1%; I2 = 82.2%). No funnel plot asymmetry to suggest publication bias(bias = 0.39,P = 0.78). In the sensitivity analysis all results were largely similar between the fixed and random effects models.CONCLUSION The double-layered nitinol stent provides immediate relief of malignant dysphagia with low rates of stent migration and tumour

治疗良性前列腺增生的六种新微创手术

良性前列腺增生(BPH)是导致男性下尿路症状最常见的一种病因。当药物治疗无效或传统手术无法满足患者的某些需求时,临床上可以考虑采用新微创手术,如微创前列腺悬扩术、前列腺动脉栓塞、前列腺水蒸气消融、前列腺高能水切割术、临时植入式镍钛装置、前列腺支架等。这些新微创手术对患者的射精功能和勃起功能均有较好的保护作用,且大多能采用局部麻醉在门诊进行,手术时间和恢复时间也更短。临床医生可根据患者的具体情况以及每种术式的特点进行个体化选择。

经内镜胆道支架治疗胆道良恶性梗阻的临床研究

目的探讨胆道良恶性梗阻时塑料和镍钛记忆合金镀金支架内镜置入的操作技术及其临床疗效.方法该组塑料支架组52例,包括十二指肠乳头炎性狭窄24例,胆总管下段炎性狭窄4例,老年胆总管巨大结石5例,胆漏11例,胆管外科损伤狭窄7例,胰腺癌1例;镀金支架组28例,包括中下段胆管癌11例,肝门部胆管癌6例,十二指肠乳头癌5例,胰腺癌6例.所有病人均行ERCP以证实狭窄部位及其程度,选择合适的支架.经十二指肠镜插入导丝至梗阻远端,狭窄明显者沿导丝进行球囊扩张;在X线监视下沿导丝用支架推送器将支架送至狭窄远端2 cm.术后观察病人黄疸改善情况,同时观察肝功能、血清淀粉酶变化,并随访3～6个月.结果该组支架均一次置入成功,成功率100%.镀金支架置入后1周,患者血清总胆红素(STB)下降67.16%,谷丙转氨酶(ALT)下降58.37%,r-谷胺酰转肽酶(r-GT)下降40.63%,碱性磷酸酶(AlP)下降41.54%;塑料支架置入后1周,STB下降53.24%,ALT下降55.03%,r-GT下降37.15%,AlP下降34.12%.早期并发症包括:高淀粉酶血症、ERCP术后胰腺炎、胆管炎,晚期并发症有支架堵塞.镀金支架组随访期间有4例(14.29%)死于肿瘤进展.结论经内镜塑料和镍钛记忆合金镀金支架治疗胆道良恶性梗阻安全、有效、并发症少;塑料支架在胆漏及胆道损伤治疗中的应用为肝胆外科手术并发症的治疗提供了较好的弥补手段.

经支气管镜置入支架及植入放射性粒子治疗肺癌中心气管狭窄

目的探讨经支气管镜置入支架及植入125I放射性粒子治疗晚期肺癌中心气管狭窄的疗效及可行性。方法对15例晚期肺癌中心气管狭窄患者,先采用支气管镜直视下置入国产镍钛记忆合金支架到狭窄部位,然后通过支气管镜把125I放射性粒子植入到气管狭窄部位的管壁、管壁外肿瘤组织。结果15例共置入17枚支架,均一次性成功置入,共植入125I放射性粒子35粒。治疗后狭窄管腔均明显扩大,气急减轻,随访3～13个月,均见支架扩张好、无移位,未见支架内及上下缘肿瘤生长导致气管狭窄。15例均未出现严重并发症。结论通过支气管镜置入支架联合125I放射性粒子植入疗效肯定、操作安全,可用于晚期肺癌中心气管狭窄的姑息治疗。

镍钛合金血管支架的有限元分析及疲劳测试

对镍钛合金血管支架的疲劳寿命要求、有限元分析及疲劳寿命测试等方面分别进行了简要阐述。

纤维支气管镜定位和纤维支气管镜直视下置入镍钛合金支架治疗气管狭窄的比较

目的对纤维支气管镜定位(broncho fibroscope location,BFL)和纤维支气管镜直视下(bronchofi-broscope direct observation,BFDO)置入镍钛(nitinol,NT)合金支架治疗良恶性病变所致气道狭窄治疗方法进行比较。方法对各种原因导致的28例气道狭窄,用BFL和BFDO置入NT支架,比较放置的准确率、放置所需时间、术后感染率、住院时间和住院费用。结果BFL放置支架的准确率显著高于BFDO法,且前者放置支架所需的时间、术后感染率、住院时间和住院费用都显著少于后者(P<0.05)。结论BFL置入NT支架具有准确、安全和快速等优点,适于基层医院,值得推广应用。

镍钛形状记忆合金血管内支架组织相容性实验研究

将锥形记忆合金支架分别植入６只猪右侧髂动脉，用以研究镍钛形状记忆合金血管内支架生物相容性。支架植入前及植入后８个月，观测动物血常规、肝肾功能以及毛发中镍钛元素含量，均无明显变化（Ｐ＞０．０５）。支架植入后８个月处死动物，全身重要脏器（肝、脾、肾、肺、心、脑等）病理学检查结构正常，无淋巴细胞和单核细胞浸润。支架植入部位上游血管壁内膜光滑，内皮细胞结构正常，内弹力板完整。支架植入段为完整肉芽组织阻塞，光镜检查提示肉芽组织来自机化血栓，无炎症细胞浸润和异物巨细胞反应。提示镍钛形状记忆合金血管内支架组织相容性良好，无明显毒副作用。

自展式网管状镍钛合金支架治疗晚期直肠癌并梗阻

目的 探讨自展式网管状镍钛合金支架治疗晚期直肠癌并梗阻的疗效。方法 对12例直肠癌伴急慢性梗阻患者施行支架置入术者的临床资料进行回顾性分析。结果 10例患者成功置入 ,有效地恢复了排便 ,其中 2例支架脱落后再次置入。现已死亡 5例 ,生存期 5 6～ 72 0d。另 5例已存活 6～ 15个月 ,未再发肠梗阻。另 2例支架置入失败。结论 网管状支架能有效地对晚期直肠癌以及具有高危手术因素的患者进行永久性姑息性治疗 ,可避免结肠造口。配合化疗和免疫治疗 。

经鼻置入气道支架治疗气管支气管狭窄

目的 探讨记忆镍钛合金支架治疗气管支气管狭窄的疗效。方法 在X线监视下 ,经纤维支气管镜放置合金支架治疗气管支气管狭窄患者 42例 ,并观察放置合金支架前、后患者血氧饱和度的变化。结果 本组 42例患者经放置合金支架后 ,显效 3 2例 ,患者狭窄管腔直径显著增加 ,通气功能明显改善 ,血氧饱和度较术前显著提高 (P <0 .0 0 1) ,生活质量明显改善。结论 记忆镍钛合金支架是治疗气管支气管狭窄的一种有效、安全和可靠的方法。

内镜下置放记忆合金支架治疗食管贲门恶性狭窄66例报告

目的探索治疗晚期食管贲门恶性狭窄的介入治疗方法。方法对66例失去手术机会或拒绝手术的晚期食管贲门狭窄病人,均进行电子胃镜引导下放置镍钛合金支架;对狭窄程度重,胃镜不能通过者,先行Savary探条扩张,再放置支架。结果66例均成功置入支架,解除狭窄有效率为100%,4例食管-气管瘘者置入带膜支架后进食,呛咳即刻消失。结论该治疗方法简单,安全,可改善病人的生存质量,延长生存时间。

纤维支气管镜定位和X线引导置入镍钛合金支架治疗气道狭窄的比较

目的比较纤维支气管镜定位(bronchofibroscope location,BFL)和X线引导下置入镍钛(NT)合金支架治疗良恶性病变所致气道狭窄的优缺点。方法对各种原因导致的30例气道狭窄,随机选择16例用BFL置入NT支架,另14例采用X线引导的方法置入NT支架,并比较两者放置的准确率、放置所需时间、术后感染率、住院时间和住院费用。结果BFL放置支架的准确率与X线引导下放置NT支架的相同,但前者放置支架的时间、术后感染率、住院时间和住院费用都显著少于后者(P<0.01)。结论BFL无须气管切开,创伤、痛苦少,且可单人操作,适于基层医院开展,值得推广应用。

国产镍钛合金气管支架治疗恶性气道狭窄的临床应用

目的评价应用国产镍钛合金气管支架治疗恶性气道狭窄的临床效果。方法11例恶性气道狭窄患者(其中肺癌6例、食管癌晚期伴气管旁淋巴结转移合并气道狭窄5例),其中男性7例,女性4例,年龄46～62岁。术前常规行高千伏胸部X线摄片和CT检查,明确气道狭窄的部位、形态及范围。在X线透视下将多功能导管沿导丝经声门进入气管并越过狭窄段,更换超硬导丝并将导丝留置于狭窄段远端,撤除导管,沿导丝通过置入器置入气管支架。结果11例患者成功置入气管支架。随即所有患者呼吸困难症状明显改善。全部病例均无严重并发症。结论气管支架置入术是治疗恶性气道狭窄的有效方法。

电解抛光提高镍钛合金心血管支架表面性能

植入高性能的心血管支架是治疗心血管疾病的主要手段,而支架的制造工艺决定了其表面性能。采用乙二醇-氯化钠无毒电解液电解抛光工艺来提高镍钛合金心血管支架的表面完整性和生物相容性。试验结果表明,该工艺制造镍钛合金心血管支架的表面完整性和生物相容性明显改善:镍钛合金心血管支架表面光亮平整,没有熔渣和热影响区,表面粗糙度达到Ra 85.5 nm;镍钛合金心血管支架表面化学成分发生改变,表面形成二氧化钛保护膜,阻止了Ni离子析出,且电化学腐蚀性能明显提高,有效改善了支架生物相容性;该工艺采用醇-盐无毒电解液进行抛光,提高了工艺对环境的友好性。此外,该工艺解决了镍钛合金心血管支架制造领域的关键技术难题,制造出了性能优良的镍钛合金心血管支架,为高质量心血管支架制造提供了科学依据。

国产钛镍合金血管支架的生物相容性研究

采用国产钛镍形状记忆合金制成４ ｍ ｍ 内径的血管支架，通过导管置入８ 只正常犬的双侧髂动脉。观察１～６ 个月，发现支架表面为一层新生内膜覆盖，光镜及电镜观察新生内膜表层为血管内皮样细胞。国产钛镍合金血管支架有很好的生物相容性。

NiTi心血管支架的疲劳断裂性能分析

目的对NiTi合金心血管支架进行疲劳寿命的预测研究。方法采用疲劳断裂的有限元分析方法,建立了三维空间NiTi心血管支架结构的模型,并分析了在生理脉动循环载荷作用下的心血管支架结构。结果有限元分析发现支架结构结点附近区域的正应力大、疲劳寿命低、损伤大;同时,支架结构的疲劳寿命预测发现,用结构表面进行氮化、喷丸硬化等方法处理的支架疲劳寿命较高。相关的实验结果显示疲劳裂纹或断裂总是发生在支架结点附近区域。结论生理载荷下的模拟结果与相关的实验结果相吻合,最终为心血管支架结构的安全性指导和设计提供了理论依据。

放射性NiTi合金血管内支架可行性及安全性的实验观察

目的 观察 2 .3μCi的放射性NiTi合金血管内支架植入正常兔腹主动脉后的安全性及可行性。 方法 将16只兔随机分为放射性支架组 (n =8)及非放射性支架组 (n =8) ,分别于腹主动脉内植入放射性NiTi合金血管内支架和不具有放射性的NiTi合金血管内支架。于 3个月后处死两组动物 ,肉眼观察支架局部有无血栓形成 ,光镜及透射电镜观察支架局部血管的结构改变 ;生化法测定肝功、肾功 ;骨穿涂片观察骨髓象。结果 放射性支架组新生血管内膜厚度明显低于非放射性支架组 ,新生血管内膜平滑肌细胞 (SMCs)明显减少 ,中膜的厚度和SMCs与非放射组无显著性差异 ,两组新生血管内膜均完全内皮化 ,无血栓形成 ;两组的谷丙转氨酶、谷草转氨酶和尿素氮、肌酐均无显著性差异 ;两组动物的骨髓增生均正常。结论 2 .3μCi的放射性NiTi合金血管内支架可减少血管新生内膜增生 ,对血管中膜、邻近重要脏器及骨髓造血无影响 ,可安全应用。