覆膜支架治疗颅内动脉疾病

近年来覆膜支架治疗颅内动脉疾病的报道渐多,由冠脉覆膜支架的临床应用过渡到专用颅内覆膜支架的基础研究和临床试验。应用覆膜支架治疗的颅内动脉疾病主要为巨大、宽颈或微小脑动脉瘤、各种原因所致的颅内动脉假性动脉瘤、椎基底动脉梭形或夹层动脉瘤和海绵窦动静脉瘘等。这类颅内动脉的病变是目前手术和血管内治疗材料和技术难以解决的。覆膜支架使用后可直接、有效封堵动脉瘤颈和瘘口,使梭形动脉瘤及载瘤血管再塑形。但也会产生脑神经功能缺失、穿支或母体血管闭塞。本文对覆膜支架治疗颅内动脉病变的国内、外应用和研究动态,所治疗的疾病部位和类型、治疗效果及存在问题进行回顾性分析。     

覆膜支架在颅颈动脉疾病中的临床应用

颅颈动脉应用覆膜支架主要用于治疗巨大或宽颈动脉瘤、各种原因所致的颅颈动脉假性动脉瘤、椎基底动脉梭形动脉瘤、海绵窦动静脉瘘、椎动脉-颈静脉瘘和溃疡性粥样斑块动脉狭窄等.这类病变是目前手术及血管内治疗材料和技术难以解决的.对颅颈动脉病变应用覆膜支架治疗的状况进行综述.     

覆膜支架在颅颈动脉疾病中的临床应用

颅颈动脉应用覆膜支架主要用于治疗巨大或宽颈动脉瘤、各种原因所致的颅颈动脉假性动脉瘤、椎基底动脉梭形动脉瘤、海绵窦动静脉瘘、椎动脉一颈静脉瘘和溃疡性粥样斑块动脉狭窄等。这类病变是目前手术及血管内治疗材料和技术难以解决的。对颅颈动脉病变应用覆膜支架治疗的状况进行综述。     

生物可降解镁合金覆膜支架治疗兔颈内动脉动脉瘤的可行性分析

目的 研究具有生物降解特性的镁合金覆膜支架对于兔颈内动脉动脉瘤治疗的可行性.方法 利用40只新西兰大白兔建立颈内动脉动脉瘤模型,分别使用Willis覆膜支架和镁合金覆膜支架植入对实验兔进行治疗.定期对植入支架的实验兔进行血管造影检查和钼靶检查,观察植入支架后动脉瘤的情况、颈内动脉的情况和支架的降解程度.结果 所有大白兔造模成功,20只大白兔植入了Willis覆膜支架,20只大白兔植入了镁合金覆膜支架.血管造影检查结果显示,植入支架后40只大白兔的动脉瘤均显示为腔闭塞状态,且动脉瘤所处的颈内动脉通畅;3个月后植入镁合金覆膜支架的20只大白兔的动脉瘤均显示为腔闭塞状态且颈内动脉通畅,而植入Willis覆膜支架的19只正常,1只大白兔颈内动脉呈现出闭塞状态;植入1年后19只大白兔动脉瘤治愈,1只大白兔的颈内动脉闭塞未完全痊愈.钼靶检查结果显示镁合金覆膜支架具有生物降解的特性,随着时间的延长而降解,而Willis覆膜支架并不随着时间延长而降解.结论 具有生物降解特性的镁合金覆膜支架治疗兔颈内动脉动脉瘤较传统治疗方式具有更好的疗效.     

覆膜支架腔内隔绝术治疗外周动脉瘤

目的探讨外周动脉瘤应用覆膜支架腔内隔绝术治疗的疗效和安全性。方法对12例外周动脉瘤(真性动脉瘤5例,假性动脉瘤7例)患者行经股动脉穿刺插管造影,之后于病变部位放置覆膜支架行腔内隔绝术。结果 12例成功进行外周动脉瘤覆膜支架腔内隔绝术,其中11例动脉瘤腔完全封闭隔绝,1例动脉瘤治疗后有内漏,无手术相关并发症,即刻造影示置入覆膜支架远端动脉均血流通畅。随访观察3～36个月,无动脉瘤复发及动脉瘤相关并发症发生,1例3个月后发生覆膜支架腔内闭塞。结论覆膜支架腔内隔绝术治疗外周动脉瘤是一种创伤小、安全易行、疗效确切的治疗方法。     

肢体及肾脏假性动脉瘤的介入治疗

目的评价肢体及肾脏假性动脉瘤应用覆膜支架及栓塞技术治疗的价值,分析相关的并发症及处理方法。方法3例肢体假性动脉瘤应用覆膜支架置入术将其隔绝,2例肾动脉假性动脉瘤应用明胶海绵栓塞。结果5例假性动脉瘤均完全闭合,2例置入覆膜支架者其远端动脉搏动正常。1例股动脉假性动脉瘤患者术中出现支架内血栓形成,溶栓后消失。1例患者由于其他原因,致穿刺部位又出现假性动脉瘤。结论应用覆膜支架及栓塞技术可使肢体及肾脏假性动脉瘤得到有效治疗,且创伤小,恢复快,尤其适用于不能耐受传统手术治疗者,远期疗效尚待进一步观察。     

一种新型的脑动脉瘤血管内治疗技术——脑血管覆膜支架术的问世

虽然传统的动脉瘤腔内栓塞治疗颅内动脉瘤方法在临床应用广泛,但有其自身的缺陷。专为颅内血管设计的Willis覆膜支架技术其治疗行为发生在载瘤动脉,其机制是使动脉瘤与体循环隔绝,直至动脉瘤内自愈性血栓形成。Willis覆膜支架柔顺性好,在选择病例容易进入颈内动脉远端。采用覆膜支架治疗C5段以下假性、外伤性动脉瘤方法简单、效果肯定。在其他部位以及其他类型动脉瘤,如颈内动脉和椎动脉巨大动脉瘤、夹层或夹层动脉瘤、弹簧圈栓塞后复发之动脉瘤,也可选择覆膜支架治疗。载瘤动脉过度迂曲应视为Willis覆膜支架的禁忌证。分支动脉开口,特别是脉络膜前动脉、眼动脉,应尽量避免。Willis覆膜支架的应用,彻底改变了颅内动脉瘤血管内治疗的传统理念,由于其操作简单,效果满意,为颅内动脉瘤的血管内治疗技术的发展提供了新的方向。增加临床病例的积累以完整评价Willis覆膜支架的长期临床效果是需要的。     

可降解镁合金覆膜支架治疗兔颈总动脉侧壁型动脉瘤可行性研究

目的 评价可降解镁合金覆膜支架治疗兔颈总动脉侧壁型动脉瘤的可行性.方法 20只新西兰大白兔饲养1周后采用间断式外翻缝合法将右侧颈总动脉与静脉囊吻合,构建20枚颈总动脉侧壁型动脉瘤.72 h内分别实施可降解镁合金覆膜支架植入术和Willis覆膜支架植入术.术前、术后即刻、术后3、6、12个月作DSA造影检查,对比动脉瘤闭塞、内漏、血管痉挛、血管损伤、血栓事件、血管闭塞和狭窄等情况.结果 可降解镁合金覆膜支架和Willis覆膜支架各植入10枚,技术成功率为100％.支架植入术后即刻造影显示所有动脉瘤腔完全闭塞,载瘤动脉通畅,可降解镁合金覆膜支架组血管痉挛3例,Willis覆膜支架组血管痉挛1例;术后3、6、12个月复查造影显示动脉瘤完全消失,载瘤动脉通畅.结论 可降解镁合金覆膜支架治疗兔颈总动脉侧壁型动脉瘤是可行的.     

覆膜支架和密网支架在复杂内脏动脉瘤的治疗应用(附12例病例分析)

目的评价覆膜支架和密网支架在复杂内脏动脉瘤治疗中的安全性和疗效。方法回顾分析12例内脏动脉瘤患者(脾动脉瘤6例,腹腔干动脉瘤3例,肠系膜上动脉动脉瘤2例,肠系膜下动脉瘤1例)临床及影像学资料,其中6例脾动脉动脉瘤患者行覆膜支架置入治疗,余6例行密网支架重叠置入,所有患者术后均给予抗凝治疗。术后1个月、6个月、1年、2年行CTA检查观察动脉瘤闭塞情况及支架和载瘤动脉通畅情况。结果 12例患者支架均成功置入,6例脾动脉瘤患者覆膜支架置入后造影显示支架管腔通畅,动脉瘤未再显影;其余6例内脏动脉瘤患者密网支架重叠置入后造影显示动脉瘤显影浅淡或基本不显影,穿支动脉未累及。术后近期随访(1个月),1例出现轻度腹痛,给予对症处理后症状消失,所有患者均未见动脉瘤破裂,支架内急性血栓形成等严重并发症。远期随访6例覆膜支架置入患者动脉瘤均未再显影,无内漏及支架内狭窄;6例密网支架置入者动脉瘤较前均缩小或消失,其中1例CTA显示支架轻度狭窄,狭窄<25%同时合并部分穿支动脉闭塞,但无明显临床症状,余患者支架、穿支动脉均通畅。结论覆膜支架和密网支架置入是治疗复杂内脏动脉瘤的安全、有效方法。     

重视覆膜支架在外周血管病中的应用

自1991年Parieli率先应用覆膜支架治疗腹主动脉瘤以来,覆膜支架在主动脉病变中得到较广泛的应用,覆膜支架治疗巨大动脉瘤、假性动脉瘤、血管破裂/穿孔、动静脉瘘等病变取得了可喜的结果,在TIPS通道中覆膜支架的1年初次通畅率比裸支架高。目前覆膜支架应用于血管狭窄及闭塞性病变的研究尚少。覆膜支架植入后血管的长期畅通有待进一步观察。对于高度扭曲的血管植入覆膜支架存在困难和挑战。改进支架材料、覆膜结构和推送装置,开发具有自主知识产权的新支架,拓展覆膜支架的新用途,科学合理地应用支架是介入医师面临的重大课题。     

Interventional Management of Malignant Colorectal Obstruction: Use of Covered and Uncovered Stents

Objective

We wanted to evaluate usefulness of uncovered stent in comparison with covered stent for the palliative treatment of malignant colorectal obstruction.

Materials and Methods

Covered (n = 52, type 1 and type 2) and uncovered (n = 22, type 3) stents were placed in 74 patients with malignant colorectal obstruction. Stent insertion was performed for palliative treatment in 37 patients (covered stent: n = 23 and uncovered stent: n = 14). In the palliative group, the data on the success of the procedure, the stent patency and the complications between the two groups (covered versus uncovered stents) were compared.

Results

The technical success rate was 89% (33/37). Symptomatic improvement was achieved in 86% (18/21) of the covered stent group and in 92% (11/12) of the uncovered stent group patients. The period of follow-up ranged from three to 319 days (mean period: 116±85 days). The mean period of stent patency was 157±33 days in the covered stent group and 165±25 days in the uncovered stent group. In the covered stent group, stent migration (n = 11), stent fracture (n = 2) and poor expansion of the stent (n = 2) were noted. In the uncovered stent group, tumor ingrowth into the stents (n = 3) was noted.

Conclusion

Self-expanding metallic stents are effective for relieving malignant colorectal obstruction. The rate of complications is lower in the uncovered stent group than in the covered stent group.     

实验犬留置不同类型气管支架的基础研究

目的 探讨不同类型气管覆膜支架植入在实验动物中的应用价值.方法 健康成年杂种犬18只,随机平均分为3组,气管内留置不同类型支架,A组留置全覆膜支架(全长6 cm覆膜),B组留置中段覆膜支架(全长6 cm,上下两端各1 cm不覆膜,覆膜长度4 cm),C组留置裸支架(全长6 cm).术后观察动物进食、排痰、呼吸情况,饲养20周后分别处死.观察气管标本大体和HE镜下改变,并行增殖细胞核抗原(PCNA)染色,定量分析增生细胞的阳性表达.结果 各组实验犬均未发生支架留置后的急性呼吸困难,有轻至中度呛咳,经观察,排痰量并无明显差异.均可正常饮水、进食,发声无异常.部份犬活动减少.支架不覆膜处,气管内壁组织增生较明显,气管腔狭窄程度大于支架覆膜处.各组HE染色镜下均表现为炎性反应,低柱状上皮细胞鳞状化生、肉芽增生和纤维增生性改变.3组覆膜处与不覆膜处的黏膜增殖细胞阳性表达有显著的统计学差异(P＜0.05).不覆膜处的黏膜增殖细胞比率较高.结论 ①气管支架有无覆膜在留置的短期内对于进食、呼吸状况及痰液的排出无明显影响;②气管支架留置后,覆膜段气管内膜组织增生水平要小于不覆膜段;③气管支架留置后,覆膜段的黏膜增值细胞阳性表达小于不覆膜段.覆膜支架的生物相容性好.     

Placement of covered stents for carotid blowout in patients with head and neck cancer: follow-up results after rescue treatments

BACKGROUND AND PURPOSE: Placement of a covered stent to control carotid blowout (CB) in malignant tumors of the head and neck has been reported to be an effective treatment. However, it is not uncommon to encounter recurrent hemorrhage. The purpose of this study was to evaluate the follow-up results of patients treated with covered stents. MATERIALS AND METHODS: We retrospectively reviewed the results of 7 consecutive patients who underwent placement of a covered stent to control CB. Most of them had poor wound healing because of previous irradiation, surgery, or both. The initial procedures were successful in all patients. Their clinical course was reviewed for rebleeding, additional endovascular treatments in recurrent cases, and outcomes. RESULTS: Recurrence developed in 6 of 7 patients. The interval between the first procedure and the hemorrhagic event was from 3 to 44 days. In 6 patients who had a recurrent CB, 4 had rebleeding from the previous site of the stent, whereas 2 other patients experienced recurrent bleeding in a different area from the site of the stent. Additional endovascular treatments were carried out in all affected patients by another insertion of a covered stent (n = 3), coil embolization (n = 2), or insertion of a covered stent followed by permanent arterial occlusion (n = 1). CONCLUSION: Placement of a covered stent in patients with head and neck cancer who sustain CB showed frequent rebleeding despite favorable initial rescue results. Recurrent CB at the previous stent site developed frequently in patients with uncontrolled wound infection. Concomitant or short-interval arterial trapping should be considered selectively in those conditions.     

颈内动脉的功能解剖及覆膜支架应用的可行性探讨

覆膜支架用于颅段颈内动脉的病变,是医学界一直关注的问题.将冠脉支架加载膜性材料（覆膜支架）后用于颅内段颈动脉血管病变的治疗,近年来,国外已有个案报道.颈内动脉的颅段走行在骨性结构中,迂曲而且发出许多分支动脉,因此,有必要在深入了解颈内动脉功能解剖的基础上,再对覆膜支架在颈内动脉中使用的可行性进行探讨.     

Nitinol Esophageal Stents: New Designs and Clinical Indications

Purpose To evaluate the clinical use of covered and noncovered, knitted nitinol stents in patients presenting new stent indications. Methods Self-expandable, knitted nitinol stents were implanted in four patients for treatment of dysphagia. In two patients who had malignant strictures and had esophago-respiratory fistulae and in one patient with an esophagocutaneous fistula, polytetrafluoroethylene (PTFE)-covered stents were implanted. One patient received a noncovered stent, but a retrograde approach through a percutaneous endoscopic gastrostomy (PEG) fistula had to be chosen for recanalization of an esophageal occulusion. Two patients received stents for treatment of benign strictures. Results Recanalization of the stricture and stent implantation were performed under fluoroscopic control without any procedure-related morbidity or mortality. Dysphagia improved in all patients and the esophageal fistulae could be sealed off by covered stents. During a maximum follow-up of 18 months, there was no stent migration or esophageal perforation. Complications observed were stent stenosis due to food impaction (1/4) and benign stent stenosis (2/2). Most complications could be treated by the interventional radiologist. Conclusion Self-expandable, covered Nitinol stents provide an option for the treatment of dysphagia combined with esophageal fistulae. In combination with interventional radiology techniques, even complex strictures are accessible. For benign strictures, the value of stent treatment has not yet been proven.     

Malignant gastric outlet obstructions: treatment by means of coaxial placement of uncovered and covered expandable nitinol stents

PURPOSE: To assess whether coaxial placement of uncovered and covered expandable nitinol stents overcomes the disadvantages of the increased migration rate seen with covered stents and the tumor ingrowth seen in uncovered stents in the treatment of malignant gastric outlet obstructions. MATERIALS AND METHODS: Two types of expandable nitinol stent were designed: an uncovered stent and a covered stent. Under fluoroscopic guidance, the uncovered and covered stents were placed coaxially with complete overlap in 39 consecutive patients with malignant gastric outlet obstruction caused by stomach cancer. Food intake capacity was graded on a scale of 0-4. Stent patency rate was estimated by the Kaplan-Meier method. RESULTS: Technical success rate was 97% (38 of 39 patients). After stent placement, food intake capacity improved at least one grade in 36 patients. Stent migration occurred in three patients (8%), that is, partial (n = 2) or complete (n = 1) upward migration of the inner covered stent into the stomach. Two of these patients were treated by placement of an additional covered stent. During the mean follow-up period of 134 days (range, 15-569 d), 10 patients developed recurrent symptoms of obstruction with tumor overgrowth being the most common cause. Nine underwent placement of an additional covered stent with good results. The median period of primary stent patency was 157 days (mean, 278 d). The 30-, 60-, and 180-day patency rates were 97%, 91%, and 39%, respectively. Four patients (10%) died within 1 month after the procedure. CONCLUSION: Coaxial stent placement technique seems to contribute to decreasing the migration rate of the stent and decrease the rate of recurrent obstruction by preventing or delaying tumor ingrowth.     

Initial experience with Song's covered duodenal stent in the treatment of malignant gastroduodenal obstruction.

PURPOSE: Initial experience with use of Song's covered duodenal stent in the treatment of malignant gastroduodenal obstruction is reported. MATERIALS AND METHODS: Sixteen consecutive patients with malignant gastroduodenal obstruction were treated with peroral placement of Song's covered duodenal stent. The mean age was 58 years (range, 28-90 y). Gastroduodenal obstruction was caused by gastric (n = 8), metastatic (n = 2), gallbladder (n = 3), pancreatic (n = 2), or ampullary (n = 1) cancer. The disease was considered inoperable in all patients. With use of a flexible 20-F introducing system, seven fully covered, three uncovered, and 10 partially covered duodenal stents were placed under fluoroscopic guidance. RESULTS: The technical success rate was 94% (15 of 16) with no major complications. Symptoms of gastroduodenal obstruction improved in 14 patients. Stent migration was observed in three of seven fully covered stents. Patients with migrated stents required endoscopic stent removal and placement of uncovered duodenal stents. Tumor ingrowth was observed in two thirds of uncovered stents. In the 10 procedures with partially covered duodenal stents, no migration or tumor ingrowth was observed. All patients died 1-48 weeks (mean, 12 weeks) after stent placement. CONCLUSION: Peroral placement of Song's covered duodenal stent is a feasible and effective method of palliation in the majority of patients with malignant gastroduodenal obstruction. Migration of fully covered stents and tumor ingrowth of uncovered stents are important limitations that can be overcome with the use of a partially covered duodenal stent.     

Venous covered stent: successful occlusion of a symptomatic internal iliac arteriovenous fistula

We report the placement of a covered stent within the internal iliac vein (IIV) to occlude a symptomatic iatrogenic internal iliac arteriovenous fistula following an abdominal aortic graft. Angiography revealed a direct communication between an internal iliac graft to artery anastomosis and the right IIV with rapid shunting into the inferior vena cava and a small associated pseudoaneurysm. Femoral, brachial or axillary arterial access was precluded. The fistula was successfully occluded by a stent-graft placed in the IIV. Arteriovenous fistula can be treated in a number of ways including covered stent placement on the arterial side. To the best of our knowledge this is the first time placement in a vein has been described. Where access is difficult or the procedure carries a high risk of complication, a venous covered stent may offer an alternative.     

Metallic stent placement in patients with recurrent cancer after gastrojejunostomy

PURPOSE: To assess the technical feasibility and clinical effectiveness of placement of expandable metallic stents in patients with recurrent cancer after a gastrojejunostomy. MATERIALS AND METHODS: Data from 39 consecutive patients who had undergone metallic stent placement for recurrent malignant obstruction after a gastrojejunostomy were retrospectively analyzed. Thirty patients underwent a distal gastrectomy with a gastrojejunostomy with (n=10) or without (n=20) jejunojejunostomy, two patients underwent distal gastrectomy with a Roux-en-Y gastrojejunostomy, and seven patients underwent a palliative gastrojejunostomy with (n=5) or without (n=2) jejunojejunostomy. A total of 57 metallic stents were used in this study: four bare stents, 29 partially covered stents, and 24 fully covered stents. Types of obstruction were classified into 12 patterns and types of stent placement were classified into 16 patterns. RESULTS: Stent placement was technically successful in all patients. After stent placement, 35 of the 39 patients (90%) experienced improvement of their symptoms, two showed no change, and the remaining two showed aggravation of symptoms as a result of faulty stent placement. Two patients treated with stent placement only in the afferent loop died of aspiration pneumonia. In one of two patients who underwent stent placement according to pattern 6, afferent loop syndrome occurred 10 days after stent placement and was treated by percutaneous pigtail catheter drainage. Stent migration occurred in four of 24 fully covered stents, but in none of the bare or partially covered stents. Tumor ingrowth occurred in one of four bare stents, tumor overgrowth in one of 29 partially covered stents, and mucosal prolapse in one of 24 fully covered stents; all were treated with a second stent placement. CONCLUSIONS: Placement of expandable metallic stents in patients with recurrent cancer after a gastrojejunostomy seems to be feasible and effective, but accurate knowledge of the type of surgical procedure performed and determination of the pattern of tumor recurrence are important for successful stent placement.     

Covered stent placement in patients with recurrent cancer after a Billroth I reconstruction

PURPOSE: To assess the technical feasibility and clinical effectiveness of covered stent placement in patients with recurrent malignant obstructions after Billroth I reconstruction. MATERIALS AND METHODS: From June 1997 to November 2005, 16 patients underwent covered stent placement for recurrent gastric cancer after Billroth I reconstruction. A total of 19 covered stents were used, including 14 dual stents and five fully covered stents, as available. RESULTS: Stent placement was technically successful in all patients, with 13 of 16 patients (81%) showing improvement of symptoms. Stent migration occurred in one patient, tumor ingrowth in one, and stent collapse and/or bowel perforation in one. Nine patients (56%) had concomitant (n=7) or subsequent (n=2) biliary obstruction. One patient was lost to follow-up. The remaining 15 patients died 5-628 days (median, 52 days; mean, 120 days) after stent placement due to progression of disease or pneumonia. CONCLUSIONS: Placement of covered metallic stents is feasible and effective in patients with recurrent malignant obstruction after Billroth I reconstruction.