Clinical Experience with Covered Wallstents for Biliary Malignancies: 23-Month Follow-Up

Purpose: To evaluate the effectiveness of partially covered metallic Wallstents to prevent tumoral ingrowth in patients with neoplastic obstruction of the biliary tract. Methods: Twenty-one patients with malignant obstructive jaundice have been treated with Wallstents partially covered with a polyurethane polymer. In total, 36 covered stents (8 and 10 mm in diameter, 70 and 90 mm long) were deployed. All the stents were free from covering at both ends. Results: Jaundice was successfully treated in 100% of cases. There were no problems related to the releasing system during stent positioning, no major complications, and no incompatibility reactions to the materials composing the endoprostheses. At 23-month follow-up, 6 patients are still alive and 15 are dead; of these 15 patients, 11 died in the first 6 months and the last 4 died between 6 and 23 months. Seven patients had an obstructed stent; in four of these, cholangioscopy showed the presence of tumoral ingrowth and in one it showed necrotic tissue with biliary pigments and inflammatory cells. No biopsy specimen was obtained in the remaining two patients with stent obstruction. The follow-up, ranging from 7 to 23 months, showed a primary patency of 46.8% and 24.6% and an assisted patency of 66.3% and 59% at 6 months and 23 months, respectively. Conclusions: Covered metallic stents are effective and may produce improved survival in patients with malignant biliary obstruction (27.8% at 23 months). Stent patency, however, is similar to that of uncovered stents. Modifications in the design of the covering membrane may reduce stent obstruction resulting from disruption of the plastic covering. Received: 0/00/00/Accepted: 0/00/00     

In vivo study of polyurethane-coated gianturco-rosch biliary Z-stents

Purpose: Prototypes of Gianturco-Rosch Z-stents coated with polycarbonate urethane (PCU) were placed in the biliary tree of pigs, in order to test their biomechanical behavior, stability, and biocompatibility. Methods: The stents were surgically implanted in the common bile duct of three pairs of pigs, which were killed after 1, 3, and 6 months respectively. Explanted livers from pigs of the same race, age, and size were used to provide comparative data. The bile ducts were radiologically and histopathologically examined; the stents were processed and examined by scanning electron microscopy. Results: No complications occurred and the animals showed a normal weight gain. The main bile duct appeared radiologically and macroscopically dilated, but the stents proved to be in place. Histologically, the bile duct epithelium was destroyed, but neither hyperplastic nor inflammatory fibrotic reactions of the wall were evident. Both the metallic structure and the polymeric coating of the stents were intact. A layer of organic material with a maximum thickness of approximately 3 μm was evident on the inner surface of the stents. Conclusion: The present in vivo study demonstrates the biocompatibility, efficacy, and stability of PCU-coated Gianturco-Rosch stents in the biliary environment.     

Metallic stents in malignant biliary obstruction

Purpose Retrospective analysis of our results with metallic stent placement for malignant biliary strictures. We sought to determine parameters that influence stent patency. Methods A total of 95 Wallstents were implanted in 65 patients (38 men, 27 women; mean age, 65.1 years) with malignant biliary obstruction. Serum bilirubin levels were assessed in 48 patients; the mean value prior to intervention was 15.0 mg/dl. Results In 12 patients (21%) complications occurred as a result of percutaneous transhepatic drainage. Stent implantation was complicated in 13 patients, but was possible in all patients. A significant decrease in bilirubin level was seen in 83.3% of patients following stent implantation. Approximately 30% of patients developed recurrent jaundice after a mean 97.1 days. In 9 patients (15%) the recurrent jaundice was caused by stent occlusion due to tumor growth. The mean follow-up was 141.8 days, the mean survival 118.7 days. Patients with cholangiocarcinomas and gallbladder carcinomas had the best results. Worse results were seen in patients with pancreatic tumors and with lymph node metastases of colon and gastric cancers. Conclusions The main predictive factors for occlusion rate and survival are the type of primary tumor, tumor stage, the decrease in bilirubin level, and the general condition of the patient.     

Palliation of postoperative gastrointestinal anastomotic malignant strictures with flexible covered metallic stents: Preliminary results

Purpose: To evaluate the efficacy of the placement of covered metallic stents for palliation of gastrointestinal anastomotic strictures secondary to recurrent gastric cancer. Methods: Under fluoroscopic guidance, placement of one or two self-expandable covered metallic stents was attempted perorally in 11 patents (aged 48–76 years) with anastomotic stenoses due to recurrent gastric malignancies. The strictures involved both the afferent and efferent loops in three patients. All patients had poor peroral food intake with severe nausea and vomiting after ingestion. The technical and clinical success was evaluated. Results: Placement of the covered stent was technically successful in 13 of 15 (87%) attempts in ten patients. After the procedure, 9 of 11 (82%) patients overall were able to ingest at least a liquid diet and had markedly decreased incidence of vomiting. During the follow-up of 2–31 weeks (mean 8.5 weeks) there were no major complications. Conclusion: These preliminary results suggest that flexible, covered stents may provide effective palliation of malignant anastomotic stricture secondary to recurrent gastric cancer.     

Assessment of a Polyester-Covered Nitinol Stent in the Canine Aorta and Iliac Arteries

Purpose: To evaluate the patency and healing characteristics of a woven polyester fabric-covered stent in the canine model. Methods: Twenty-four self-expanding covered stents were placed in the infrarenal aorta and bilateral common iliac arteries of eight dogs and evaluated at 1 (n = 2), 3 (n = 2), and 6 (n = 4) months. Stent assessment was done using angiography prior to euthanasia, and light and scanning electron microscopy. Results: Angiographically, just prior to euthanasia, 8 of 8 aortic and 14 of 16 iliac endovascular covered stents were patent. Histologically, the stented regions showed complete endothelialization 6 months after graft implantation. A neointima had formed inside the stented vessel regions resulting in complete encasement of the fabric-covered stent by 3 months after graft implantation. Medial compression with smooth muscle cell atrophy was present in all stented regions. Explanted stent wires, examined by scanning electron microscopy, showed pitting but no cracks or breakage. Conclusion: The covered stent demonstrated predictable healing and is effective in preventing stenosis in vessels 10.0 mm or greater in diameter but does not completely preclude stenosis in vessels 6.0 mm or less in diameter.     

Transhepatic insertion of a metallic stent for the relief of malignant afferent loop obstruction

A 65-year-old man with a polya gastrectomy presented with biliary obstruction. Percutaneous cholangiography indicated strictures of the distal common bile duct and afferent duodenal loop due to an inoperable carcinoma of the head of the pancreas. The patient was unfit for bypass surgery, and a previous gastrectomy precluded endoscopic intervention. Successful palliation of the biliary obstruction was achieved by placing metallic stents across the duodenal and biliary strictures via the transhepatic route. The use of stents for gastrointestinal stricture is reviewed.     

Treatment of popliteal artery aneurysms with uncovered wallstents

We report two patients with acutely thrombosed popliteal artery aneurysms that were successfully treated with a combination of thrombolytic therapy and placement of noncovered Wallstents. RID=" ID=" <E5>Correspondence to:</E5> M.B. Lobrano, M.D.     

Malignant biliary obstruction treated by wallstents and strecker tantalum stents: A retrospective review

Purpose To evaluate retrospectively the role and the effectiveness of self-expandable Wallstents and balloon-expandable Strecker stents in patients with inoperable malignant obstruction of the biliary tree. Methods Fifty patients with malignant biliary obstruction were treated from August 1991 to August 1992 by percutaneous placement of 55 metallic endoprostheses (39 Wallstents, 16 Strecker stents). All patients were followed by clinical evaluation, laboratory data, and ultrasonographic examination until death. Results Wallstent placement was successful in 36 patients without procedure-related complications. One partial occlusion after 1 year was resolved by percutaneous balloon dilatation. Fourteen patients were treated with 16 Strecker stents. Stenting was unsuccessful in four cases; four occlusions (after 6 h, 48 h, 2 and 6 months) were encountered. Conclusion Wallstent endoprostheses have good results and long-term patency. There were some problems with Strecker stents during the placement and there was a higher occlusion rate.     

Treatment of malignant biliary obstruction with a PTFE-covered self-expandable nitinol stent.

OBJECTIVE: We wanted to determine the technical and clinical efficacy of using a PTFE-covered self-expandable nitinol stent for the palliative treatment of malignant biliary obstruction. MATERIALS AND METHODS: Thirty-seven patients with common bile duct strictures caused by malignant disease were treated by placing a total of 37 nitinol PTFE stents. These stents were covered with PTFE with the exception of the last 5 mm at each end; the stent had an unconstrained diameter of 10 mm and a total length of 50-80 mm. The patient survival rate and stent patency rate were calculated by performing Kaplan-Meier survival analysis. The bilirubin, serum amylase and lipase levels before and after stent placement were measured and then compared using a Wilcoxon signed-rank test. The average follow-up duration was 27.9 weeks (range: 2-81 weeks). RESULTS: Placement was successful in all cases. Seventy-six percent of the patients (28/37) experienced adequate palliative drainage for the remainder of their lives. There were no immediate complications. Three patients demonstrated stent sludge occlusion that required PTBD (percutaneous transhepatic biliary drainage) irrigation. Two patients experienced delayed stent migration with stone formation at 7 and 27 weeks of follow-up, respectively. Stent insertion resulted in acute elevations of the amylase and lipase levels one day after stent insertion in 11 patients in spite of performing endoscopic sphincterotomy (4/6). The bilirubin levels were significantly reduced one week after stent insertion (p < 0.01). The 30-day mortality rate was 8% (3/37), and the survival rates were 49% and 27% at 20 and 50 weeks, respectively. The primary stent patency rates were 85%, and 78% at 20 and 50 weeks, respectively. CONCLUSION: The PTFE-covered self-expandable nitinol stent is safe to use with acceptable complication rates. This study is similar to the previous studies with regard to comparing the patency rates and survival rates.     

经皮胆道引流术治疗恶性梗阻性黄疸

目的　回顾性分析恶性梗阻性黄疸的介入性经皮胆道引流治疗方法及其疗效。方法　对4 7例患者采用经皮肝穿刺胆道引流术治疗恶性梗阻性黄疸。先行PTC后探查通过阻塞段 ,如不能越过阻塞段 ,则直接进行外引流 ;如能越过阻塞段 ,则置入内外引流管作内外引流或置入金属支架或塑料内涵管作内引流。结果　内引流组 18例 ,15例置入金属支架 ,共 18枚 ,3例置入塑料内涵管 ,共 4根 ;内外引流组 15例 ,置入 18根内外引流管 ;外引流组 14例 ,置入 17根外引流管。术后 1周总胆红素从术前的 (5 14 .1± 2 0 4 .3) μmol/L降至 (2 38.4± 14 2 .8) μmol/L(P <0 .0 0 1) ,碱性磷酸酶与丙氨酸转氨酶均下降明显 (P均 <0 .0 0 1)。 4例于术后 1个月内死亡。跟踪随访 37例 ,平均随访 5 .3个月 ,8例仍存活。随访期内 18例 (48.6 % )总胆红素降至正常范围。结论　经皮肝穿刺胆道引流术是对恶性梗阻性黄疸的一种安全、有效的姑息性治疗方法 ,可明显缓解黄疸、减轻痛苦、提高生存质量 ,并可改善肝脏功能 ,有限地延长生存时间。     

Fracture of memotherm metallic stents in the biliary tract

In a series of 66 patients who had palliation of malignant obstructive jaundice by percutaneous placement of Memotherm expanding metal stents, we report four cases of stent fracture. This has not been reported previously.     

Recurrent TIPS failure associated with biliary fistulae: Treatment with PTFE-covered stents

Purpose: To evaluate the efficacy of covered stents for the treatment of transjugular intrahepatic portosystemic shunt (TIPS) obstruction in human subjects with identified or suspected biliary fistulae. Methods: Five patients were treated for early failure of TIPS revisions. All had mid-shunt thrombus, and four of these had demonstrable biliary fistulae. Three patients also propagated thrombus into the native portal venous system and required thrombolysis. TIPS were revised in four patients using a custom-made polytetrafluoroethylene (PTFE)-covered Wallstent, and in one patient using a custom-made PTFE-covered Gianturco Z-stent. Results: All identified biliary fistulae were successfully sealed. All five patients maintained patency and function of the TIPS during follow-up ranging from 2 days to 21 months (mean 8.4 months). No patient has required additional revision. Thrombosis of the native portal venous system was treated with partial success by mechanical thrombolysis. Conclusion: Early and recurrent failure of TIPS with mid-shunt thrombosis, which may be associated with biliary fistulae, can be successfully treated using covered stents. Stent-graft revision appears to be safe, effective, and potentially durable.     

金属与塑料支架姑息性治疗恶性胆道梗阻疗效对比研究

目的 :比较经皮肝穿金属支架与塑料支架置入术姑息性治疗恶性梗阻性黄疸的临床疗效及开通时间 ,探讨两种支架治疗的适应证。方法 :对 45例金属支架与 3 4例塑料支架介入治疗恶性梗阻性黄疸的临床资料进行回顾性分析。结果 :两组术后对降低胆红素和改善临床症状均有明显疗效 ,选择病例以肝门部梗阻占多数。术后早期并发症较少 ,晚期并发症主要为支架阻塞。金属支架中位开通时间为 2 76d ,明显长于塑料支架的 112d(P <0 .0 1)。结论 :两种支架均能有效解除胆道梗阻 ,且对高位梗阻具有优势 ,适用于不宜手术者。金属支架开通期明显长于塑料支架 ,但价格较贵 ;估计生存期 >3个月者 ,宜选择金属支架 ;生存期 <3个月和 /或经济条件不许可者 ,可选用塑料支架     

A simplified percutaneous hepatogastric drainage technique for malignant biliary obstruction

We describe a technique to bypass a malignant biliary obstruction by creating a direct connection between the left biliary tree and the stomach. First, adherence between the left liver parenchyma and the stomach is achieved by a Cope anchor system. Then, the left biliary tree and stomach are connected by Colapinto needle puncture of the stomach from a left biliary duct with the needle inserted through a 9 Fr transhepatic sheath. Over a stiff guidewire, a Ring drainage catheter is placed. Later, the Ring catheter is replaced by a metallic stent. Four patients with malignant biliary obstruction underwent this procedure. The mean survival time was 77 days with maximum follow-up of 171 days. Neither obstruction nor dislocation of the metallic stents occurred.Presented at the 18th CIRSE Meeting, Budapest 1993     

Duplex ultrasonography in assessing restenosis of renal artery stents

Purpose: To determine the accuracy and optimal threshold values of duplex ultrasonography (US) in assessing restenosis of renal artery stents. Methods: Twenty-four consecutive patients with 33 renal arteries that had previously been treated with placement of a Palmaz stent underwent duplex US prior to intraarterial digital subtraction angiography (DSA), which was the reference standard. Diagnostic accuracy of in-stent peak systolic velocity (PSV) and reno-aortic ratio (RAR = PSV renal stent/PSV aorta) in detecting > 50% in-stent restenosis were evaluated by the receiver operating characteristic curve. Sensitivity and specificity were determined using the optimal threshold values, and using published threshold values: RAR > 3.5 and in-stent PSV > 180 cm/sec. Results: Six examinations were technically inadequate. Nine stents had residual or restenosis > 50% at DSA. The two duplex parameters were equally accurate since areas under the curves were similar (0.943). With optimal threshold values of 226 cm/sec for PSV and 2.7 for RAR, sensitivities and specificities were 100% and 90%, and 100% and 84%, respectively. Using the published duplex criteria resulted in sensitivities and specificities of 100% and 74% for PSV, and 50% and 89% for RAR. Conclusion: Duplex US is a sensitive modality for detecting in-stent restenosis if laboratory-specific threshold values are used.     

国产胆道金属支架的临床应用

目的探讨国产胆道金属支架应用的安全性及临床疗效。方法对72例(70例恶性,2例良性)阻塞性黄疸患者施行经皮经肝穿刺植入国产胆道金属支架75枚。结果66例胆道金属支架植入成功,技术成功率92．7％(66／72)。支架植入术后1个月内黄疸缓解率97．0％(64／66),30d内死亡2例,早期并发症发生率7．6％(5／66)。44例随访2～24个月,随访率66．7％。42例恶性患者,随访5～16个月(平均11．6个月),9例存活,33例死亡;生存时间2～23个月,中位生存期5．3个月。随访3、6、12个月的支架通畅率分别为92．8％、89．9％、79．4％。支架再阻塞率14．3％(6／42),中位阻塞期3个月。2例良性梗阻患者,1例支架术后24个月仍通畅,1例术后3个月因其他原因死亡。结论国产胆道金属支架使用方便,临床应用安全可靠,具有临床推广价值。     

恶性梗阻性黄疸介入治疗常见问题的处理

介入治疗作为恶性梗阻性黄疸的重要的治疗手段已经广泛应用,但仍有许多问题值得我们重视和研究。我们总结12年来800余例恶性梗阻性黄疸介入治疗病例的经验;详细分析恶性梗阻性黄疸介入治疗的适应证、禁忌证;研究介入治疗多种并发症的发生原因和处理方法;详细讨论胆管引流方法和胆管支架植入的时机和适应证;提出手术麻醉方法的选择、抗生素和止血药物的应用等见解;总结止痛剂的术前术后临床应用;对术后胰腺炎的发生和处理方法以及围手术期病死率进行了深入的探讨。希望我们的经验和教训能够对介入工作者有所帮助。     

Treatment of a malignant esophageal fistula with a Gore-Tex-covered flexible nitinol stent

In order to treat fistulated esophageal cancer using a flexible stent, a covered flexible stent was constructed by wrapping a nitinol stent with a thin sheet of Gore-Tex, preserving the stents original advantages of flexibility and a low-profile introducer system. This stent was used to perform standard radiotherapy in a case of fistulated esophageal cancer.     

Efficacy and complications of the gianturco-Z tracheobronchial stent for malignant airway stenosis

Purpose: To describe our experience using the Gianturco Z-stent (G-Z stent) for the management of malignant tracheobronchial stenosis, with special reference to complications. Methods: Thirty-six stents were used in 22 patients with 28 lesions. Thirteen patients were grade 5 according to the Hugh-Jones classification. The technical success rates, follow-up results, and complications were reviewed on the basis of the patients' charts and radiographs. Results: All stents were successfully placed in the ideal position without procedure-related complications. After the procedure, respiratory status improved in 95% (21/22) of patients, and performance status improved in 77% (17/22). Mean survival after stent placement was 15 weeks. Four patients suffered from increased thick secretions requiring multiple suctioning and aspiration by bronchoscopy. One of these patients died from asphyxiation 2 weeks after placement. Stent disruption and/or migration was observed in six patients. Of these six, four experienced life-threatening hemoptysis; all four had received aggressive anticancer treatment. Conclusion: G-Z stents are useful for palliation of malignant tracheobronchial obstruction. However, complications of stent strut fracture and migration give cause for concern.