Initial Experience with the Resonance Metallic Stent for Antegrade Ureteric Stenting

Background and purpose We describe our initial experience with a new metallic ureteric stent which has been designed to provide long-term urinary drainage in patients with malignant ureteric strictures. The aim is to achieve longer primary patency rates than conventional polyurethane ureteric stents, where encrustation and compression by malignant masses limit primary patency. The Resonance metallic double-pigtail ureteric stent (Cook, Ireland) is constructed from coiled wire spirals of a corrosion-resistant alloy designed to minimize tissue in-growth and resist encrustation, and the manufacturer recommends interval stent change at 12 months. Methods Seventeen Resonance stents were inserted via an antegrade approach into 15 patients between December 2004 and March 2006. The causes of ureteric obstruction were malignancies of the bladder (n = 4), colon (n = 3), gynecologic (n = 5), and others (n = 3). Results One patient had the stent changed after 12 months, and 3 patients had their stents changed at 6 months. These stents were draining adequately with minimal encrustation. Four patients are still alive with functioning stents in situ for 2–10 months. Seven patients died with functioning stents in place (follow-up periods of 1 week to 8 months). Three stents failed from the outset due to bulky pelvic malignancy resulting in high intravesical pressure, as occurs with conventional plastic stents. Conclusion Our initial experience with the Resonance metallic ureteric stent indicates that it may provide adequate long-term urinary drainage (up to 12 months) in patients with malignant ureteric obstruction but without significantly bulky pelvic disease. This obviates the need for regular stent changes and would offer significant benefit for these patients with limited life expectancy.     

Management of recurrent airway strictures in lung transplant recipients using AERO covered stents

The potential role of AERO tracheobronchial covered stents in the management of recurrent postinfectious strictures of the bronchus intermedius was studied in three lung transplant recipients. Six devices were inserted. Five of the stents migrated immediately on placement. Buildup of thick mucus was observed in all stents remaining in the airway for longer than 1 week. Strictures recurred in all patients 1, 3, and 5 months after stent deployment. Attempts at stent retrieval were successful for three of five devices. The use of AERO stents may not offer a therapeutic advantage versus balloon dilation of bronchus intermedius strictures in lung transplant recipients.     

Metallic stents for the treatment of biliary obstruction: A report of 100 cases

The results of the first 100 patients to receive Gianturco-Rösch “Z” stents is presented along with recommendations for their use. The patient population was comprised of 57 men and 43 women, age range 17–85 years (mean 65 years). Fifty-four of the patients had benign obstruction and 46 had malignant obstruction. Of the benign lesions, 11 had sclerosing cholangitis and the remainder had postoperative strictures. Thirty-one of the malignant obstructions were secondary to cholangiocarcinoma with the majority of the others secondary to metastases from various sources. All but one had multiple systems involved. Patients with benign postoperative strictures were all initially treated with balloon angioplasty; if this failed, stents were inserted. In patients who had stents in place for greater than 1 year, the occlusion rate was 13%. The overall occlusion rate in the 43 patients was 7%. Patients with sclerosing cholangitis did less well. In those with sclerosing cholangitis secondary to intraarterial chemotherapy, the occlusion rate was 77%, and we no longer use the metallic “Z” stent in these patients. The stent was not used for malignant common duct obstruction. All patients had hilar involvement. In the patients with malignant obstruction, 17% reobstructed prior to their death. The patients with cholangiocarcinoma did well with a mean survival time of 14 months and a re-obstruction rate of 16%. All late obstructions were secondary to tumor over-growth either proximal or distal to the stents. We conclude that the “Z” stent is an effective form of treatment in patients with benign postoperative strictures and those with malignant obstruction involving the hilum. We do not recommend it as a replacement for conventional stents, but rather as an additional device that allows treatment of some of the more difficult causes of obstruction.     

Use of the Amplatz introducer sheath to facilitate ureteral stent placement

In eight patients, 7-French double pigtail stents could not be passed through tight ureteric strictures. Coaxial placement using a 10F sheath from an Amplatz nephrolithotomy set allowed the stent to be passed through the sheath.     

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.     

Intraureteral metallic endoprosthesis in the treatment of ureteral strictures

OBJECTIVE: We report our experience on intraureteral metallic stents placement for the treatment of malignant and benign ureteral strictures. METHODS: Eight patients (six men and two women) with inoperable malignant or benign ureteral strictures, underwent insertion of metallic stents through percutaneous tracts. Six lesions (three malignant, three benign) involved ureterointestinal anastomoses after cystectomy for bladder cancer and ureteroileal urinary diversion or bladder substitution, and two malignant lesions involved the midureter. Self-expandable stents were used in seven cases and a balloon-expandable stent in the remaining one case. One stent was sufficient in seven ureters, and in one ureter, two overlapping stents were placed. RESULTS: Metallic stents were inserted without technical difficulties in all obstructed ureters and patency was achieved in all patients. Ultrasonography revealed resolution of pre-existing hydronephrosis. The duration of follow-up was 6-17 months (mean, 9 months). One ureter was occluded 8 months after stent placement because of ingrowth of tumor and granulation tissue. The other ureters showed no signs of obstruction during follow-up. No major complications directly attributable to the metallic stent occurred. CONCLUSIONS: Our results suggest that insertion of a metallic stent in the ureter is feasible and safe for the treatment of benign or malignant ureteral strictures. However, more work needs to be done to establish the use of these stents for the treatment of ureteral obstruction.     

胃肠道狭窄或梗阻内支架置入术后常见并发症及其处理

目的：探讨肝肠道或梗阻内支架置入术后常见并发症及处理办法。对象与方法：６０例胃肠道狭窄或阻病人，其中食管狭窄或梗阻３９例，胃十二指肠梗阻或狭窄２１例。在Ｘ光线监视下共放置支架６６只，其中带模２７只，不带３９只。结果：６０例病人中，所有支架安放１－３次成功。疼痛１２例，轻微胀痛１０例，中度胀痛１例，重度疼痛，地轻中度胀痛给予止痛片等对症处理：重度疼产能，药物控制无效者，给予硬膜外麻醉止痛。胃财狭窄９     

Metallic stents in benign biliary strictures: Three-year follow-up

Eighteen patients with recurrent benign biliary strictures (BBS) were selected for metallic stents placement because they failed to respond to percutaneous balloon dilatation. None were candidates for surgical corrections. We used “Z” single or double stents in 17 cases and a Wallstent in 1 case. After more than 3 years of follow-up (average period 37 months, range 30–41 months), 10 patients (55.5%) were asymptomatic without signs of bile statis; 5 patients (27.7%) had recurrence of symptoms and were eventually retreated; and 3 patients (16.6%) died, 2 of obstructive jaundice and liver failure and 1 of metastatic gastric cancer. Recurrence was due to stent occlusion by tissue ingrowth in 3 cases, stent migration in 1 case, and an inflammatory lesion of the papilla of Vater in another case, with patency of the metallic stent. The overall patency rate, at 3-year follow-up was 68.7%. In our series, the main factor determining long-term patency of metallic stents has been reactive tissue ingrowth. Nevertheless, long-term results obtained with metallic stents in recurrent benign biliary strictures should be considered satisfactory. In selected patients, metallic stents may represent the only long-term treatment available for maintaining bile flow.     

Esophagogastric neoplasms: palliation with a modified gianturco stent.

Self-expanding metallic stents of a modified Gianturco design were used for palliative treatment of malignant esophagogastric strictures. Over a 10-month period, 10 stents were placed in nine patients. All patients with severe dysphagia due to malignant strictures in whom all other treatment options had failed were candidates for these stents. Neither extensive length of esophageal involvement nor complete esophageal obstruction was a contraindication. All stents were placed with fluoroscopic guidance without any technical failures or procedural morbidity or mortality. Mild reflux occurred in three patients in whom the stent tubes straddled the distal esophageal sphincter. Five patients were still alive after 1-8 months. The remaining four patients died 6-28 weeks after stent placement; all stents were patent at the time of death. These stents are easy to insert, safe, and reasonably effective for short-term palliative treatment of esophagogastric neoplasms.     

Patency and complications of percutaneously inserted metallic stents in malignant biliary obstruction

PURPOSE: The aim of this study was to analyze the patency of percutaneously inserted metallic stents in malignant biliary obstruction and to evaluate all the complications associated with the stents and the reinterventions needed. MATERIALS AND METHODS: Thirty-nine patients with 42 malignant strictures were treated percutaneously with 55 metallic self-expandable stents. Forty-eight were Wallstents and seven were Memotherm stents. Twenty-five strictures were hilar, 16 were in the common bile duct, and one was in the hepaticojejunal anastomosis. The patients were followed until death and the mean follow-up was 6.4 months. RESULTS: Stent insertion was successful in 97% of the patients. Thirty percent had early complications (<30 days), and as many as 66% had late complications, including stent occlusions, which were seen in 10 patients. The patency rates of patients with cholangio-carcinoma were significantly lower than those of the patients with other diagnoses. There was also a tendency toward obstruction with less dilation of the stents, Y, T or tandem-style stent placement, an increasing number of stents, longer strictures, and hilar strictures. Thirty-one percent of the patients alive after the first 30 days had late reinterventions. CONCLUSIONS: Although metallic stents offer an alternative in the palliation of malignant bile duct obstruction, there seem to be numerous early and late complications.     

The radiological management of biliary complications following liver transplantation

Purpose: Biliary complications contribute significantly to morbidity and mortality in the liver transplant recipient. Surgery has been the mainstay of therapy, but interventional radiological techniques have made significant progress. Methods: Diagnostic percutaneous transhepatic cholangiography (PTC) was performed in 12 patients; percutaneous transhepatic drainage (PTD) was performed in 10 patients. Additional interventional procedures included laser lithotripsy, biopsy, dilatation, and stent implantation. Results: In 6 patients PTC revealed anastomotic, and in 6 patients nonanastomotic biliary strictures. Four patients had intrahepatic stones. Biliary strictures were treated by implantation of Palmaz stents in 5 of 6 patients with anastomotic strictures, and in 3 of 6 patients with nonanastomotic strictures. The intrahepatic stones were fragmented with dye laser lithotripsy under cholangioscopic control in 3 of 4 patients. One spontaneous stent migration after 24 months and one stent occlusion were observed; the remaining stents are still patent. Patients with anastomotic strictures had a more favorable outcome: 5 of 6 of these patients are still alive and symptom-free after an average of 27.4 months, but only 3 of 6 patients with nonanastomotic strictures are alive after an average of 9.8 months. Conclusion: The different outcomes in patients with anastomotic versus nonanastomotic strictures may be explained by the different causes of these types of stricture.     

Self-expandable stainless steel braided endoprosthesis for biliary strictures

A new type of biliary stent was inserted in 45 patients with symptomatic biliary strictures, 40 malignant and five benign. The stent is made of stainless steel woven into a tubular mesh. It is introduced in compressed form on a 7- or 9-F delivery catheter and released at the site of the stricture. Fully open, the stent has an internal diameter of 1 cm. The 30-day mortality was 7%. The early (less than 72 hours) complication rate was 16%. Recurrent jaundice occurred in 42%; late complications of sepsis without jaundice occurred in an additional 11%. None of the stents migrated. This new design allows a large-diameter stent to be inserted percutaneously without increased risk of complications. The frequency of recurrent jaundice, however, was not less than that observed with plastic stents, but this may have reflected the spectrum of patients treated, many with hilar strictures and previous interventions.     

输尿管狭窄支架置入术的临床应用

目的探讨塑料支架和金属内支架在输尿管狭窄中的应用价值,寻求支架的合理选用。方法对28例输尿管良恶性狭窄患者,采用经皮肾穿刺顺行法或经尿道逆行法插管,行球囊扩张后支架置入。10例置入金属内支架,18例置入塑料支架。结果手术成功率100%,随访2~48个月,患者尿路梗阻解除,临床症状减轻或消失,感染得到控制,肾功能好转。12例恶性狭窄患者,能耐受常规剂量动脉插管化疗。结论输尿管狭窄支架置入术,具有创伤小,操作简单,疗效显著,值得推广。金属内支架通畅性好,在良性输尿管狭窄中,疗效确切,两种支架可酌情选用。     

被膜支架在食管癌术后的吻合口瘘及继发瘘中的临床应用

目的:探讨被膜支架治疗食管癌术后吻合口瘘及继发瘘的临床价值。方法:在X线监视下对18例吻合口瘘及继发瘘成功实施被膜食管支架治疗。结果:16例吻合口瘘及2例食管癌继发食管气管瘘患者手术成功,共置入19枚支架,仅1例为重新置入特制支架,瘘口闭塞,纵隔及肺部感染均得到有效控制,生活质量得到改善,手术成功率为100%。结论:被膜食管支架治疗食管癌术后的吻合瘘及继发瘘是一种安全、简便、有效的方法。     

Self-expandable metal stents in the management of cervical oesophageal and/or hypopharyngeal strictures

AIM: To assess the usefulness of self-expandable metal stents in the recanalization of cervical and/or hypopharyngeal strictures. MATERIALS AND METHODS: We report our experience in 10 patients with inoperable cervical and/or hypopharyngeal strictures treated by implantation of 11 uncovered self-expandable metal stents inserted perorally under fluoroscopic guidance. The stent was placed in the hypopharynx and cervical oesophagus in 3 patients and cervical oesophagus alone in 7. There were 8 men and 2 women, mean age 70.2 years, range 45-85 years. All patients but two had malignant stricture caused by squamous cell carcinoma, in one case there was a benign postoperative stenosis secondary to laryngectomy, and in the last patient a local recurrence from thyroid cancer. RESULTS: Eleven stents were placed in 10 patients: technical success was achieved in 9 cases while clinical improvement was obtained in 8 cases. Seven of ten patients had a rapid improvement of dysphagia. One patient had a distal misplacement of the prosthesis, while in the other two cases stent position was very proximal and interfered with swallowing. A mean 9-month follow-up was obtained (range 3-24 months). Four patients with malignant stricture developed proliferation of neoplastic tissue after 2-5 months. The only patient treated for a benign stricture developed inside proliferation of granulation tissue after 4 months. CONCLUSION: Despite several technical difficulties and a high rate of late complications, recanalization of cervical oesophageal strictures by self-expandable metal stents allowed good palliation of symptoms. Stents proved to be effective and well tolerated palliative treatment also for hypopharyngeal stenoses.     

Extracorporeal shock wave lithotripsy and stents: Fluoroscopic observations and a hypothesis on the mechanisms of stent function

Fluoroscopic observations made during voiding cystography on 5 patients suggest that a possible reason that double-J ureteric stents are effective in the management of steinstrasse after extracorporeal shock wave lithotripsy (ESWL) is because they allow free fluid reflux from the bladder to the kidney. This reflux in turn triggers active peristalsis down the ureter. These observations may help us in understanding the function of ureteric stents, and suggest that stents should only have side holes at their proximal and distal ends; no side holes should be present along the shaft of the stent. Stone fragments are propelled down the ureter around the stent, hence narrow stents are preferred.     

国产支架对食管恶性狭窄的疗效分析

目的 评价并比较国产食管内支架对食管恶性狭窄的治疗效果。方法 26例食管狭窄患，其中食管和贲门癌18例，食管—胃吻合口狭窄6例，食管狭窄伴纵隔和气管瘘各1例，均实施介入治疗。结果 26例食管狭窄或伴食管瘘患全部使用国产支架X线监视下经口腔一次置入成功。其中12例应用带膜支架。结论 国产食管支架在缓解食管狭窄、提高患生活质量上安全有效，值得推广。     

食管内支架置入后的随访研究

目的食管狭窄置入金属支架后长期随访，观察其疗效和并发症。方法４３例食管狭窄放置了金属支架患者有较完整的随访资料。良性狭窄１４例，恶性狭窄２９例。置入Ｕｌｔｒｅｆｌｅｘ支架３２例，ＧｉａｎｔｕｒｃｏＺ型带膜支架４例，国产网状支架６例，Ｗａｌｓｔｅｎｔ支架１例。门诊随访行食管造影和内窥镜检查２７例，电话或信访１６例。结果１～３２个月随访观察，无支架移位。２４例死亡，术后生存时间１７天至２８个月，平均６．８个月。死亡原因：肿瘤广泛转移１９例，肺部感染２例，其他原因引起死亡３例。发生再狭窄１６例，为支架内或两端发生狭窄。肿瘤组织生长造成的狭窄４例，１２例为食管腔内组织过度增生，这类狭窄全部发生在置入支架后４～５个月。支架内狭窄５例，支架两端狭窄１１例，其中１０例为支架上端狭窄。１２例行再次球囊扩张或支架置入。结论肿瘤的生长，特别是粘膜和纤维组织增生是引起再狭窄的主要原因，支架上端狭窄更容易发生吞咽困难。由于再狭窄的发生率较高，对于良性食管狭窄的支架成型术应严格选择病例。     

Use of metallic stents and balloons in the esophagus and gastrointestinal tract

The majority of malignant and benign strictures in the esophagus and GI tract can be treated with use of minimally invasive alternatives to surgery such as balloon dilation or metallic stents. Virtually any obstructing lesion in the esophagus, stomach, duodenum, colon, and rectum can be treated with these methods with use of interventional radiologic or endoscopic techniques. In general, metallic stents are reserved for malignant strictures and balloon dilation is indicated for benign lesions. Patients with malignant esophageal fistulas and perforations can be palliated effectively and promptly by sealing the fistula or leak by deployment of a covered stent. Patients with malignant disease may benefit from a treatment regime that includes metallic stent placement, chemotherapy, radiation therapy and/or brachytherapy, although the efficacy of such combined therapies has yet to be defined. Further refinements to stent design are required. The ideal stent would be resistant to tumor ingrowth and migration. Placing a coating material on uncovered stents to prevent tumor ingrowth may achieve these aims. Finally, a biodegradable stent that dissolves before the development of intimal hyperplasia might enable stents to be used to treat benign strictures.     

Results of temporary placement of covered retrievable expandable nitinol stents for tuberculous bronchial strictures

Covered retrievable expandable nitinol stents were successfully placed in nine patients with tuberculous bronchial strictures refractory to balloon dilation. Complications included stent migration (n = 1) and tissue hyperplasia at the proximal portion of the stent (n = 2). During the follow-up period (5-52 months), stricture recurred in three of five patients (60%) after temporary stent placement for 2 months, whereas stricture did not recur in the other four patients after temporary stent placement for 6 months. Temporary placement of covered retrievable stents appears to be an effective method for the treatment of patients with tuberculous bronchial strictures refractory to balloon dilation.