Palliation of malignant bile duct obstruction with metallic biliary endoprostheses: technique, results, and complications.

Expandable metallic stents were placed in 34 patients with pathologically proved malignant bile duct obstruction to determine ease of insertion, benefits of a one-stage insertion, and cost-effectiveness relative to conventional plastic stents. Thirty-eight strictures, ranging in length from 1 to 7 cm (mean, 3.2 cm), were present in the 34 patients. Strictures were located in the lower common bile duct (n = 22), middle of the common bile duct (n = 6), and hilar confluence (n = 10). In 13 patients (38%) metallic stents were placed at the time of initial biliary drainage (one-stage procedure), while the remaining patients underwent stent placement within 1-7 days of biliary drainage (two-stage procedure). Biliary obstruction was relieved in 31 of 34 patients (91%). Three patients died within 14 days of stent insertion of unrelated causes, without any change in biliary status. Mean duration of follow-up for all patients was 5.3 months (range, 0.5-14 months). Four episodes of stent occlusion occurred in three patients (12% occlusion rate); each episode was treated successfully. The average length of hospital stay for patients who underwent a one-stage procedure was 13 days (range, 3-33 days) and was 20 days (range, 9-42 days) for patients who underwent a two-stage procedure. The facility of one-step insertion, low occlusion rate, and the many strategies available for treatment of occluded stents make metallic stents an attractive alternative to conventional plastic stents in palliating patients with malignant biliary obstruction.     

Evaluation of the Effects of Temporary Covered Nitinol Stent Placement in the Prostatic Urethra: Short-Term Study in the Canine Model

Purpose To evaluate the effect of temporary stent placement on the canine prostatic urethra. Methods Retrievable PTFE-covered nitinol stents were placed in the prostatic urethras of 8 beagle dogs under fluoroscopic guidance. Retrograde urethrography was obtained before and after stenting. Retrograde urethrography and endoscopy were performed 1 and 2 months after deployment. The endoscopic degree of hyperplasia was rated on a scale of 0 to 4 (0 = absence, 4 = occlusion). On day 60, stents were removed and urethrography was performed immediately before euthanasia. Pathologic analysis was performed to determine the degree of glandular atrophy, periurethral fibrosis, and urethral dilation. Results Stent deployment was technically successful in 7 animals, and failed in 1 dog due to a narrow urethral lumen. Complete migration was seen in 2 animals at 1 month, and an additional stent was deployed. On day 30, endoscopy showed slight hyperplasia (grade 1) in 3 animals. On day 60, moderate hyperplasia (grade 2) was evidenced in 4 cases. No impairment of urinary flow was seen during follow-up. Retrieval was technically easy to perform, and was successful in all dogs. The major histologic findings were chronic inflammatory cell infiltrates; prostate glandular atrophy, with a mean value of 1.86 (SD 0.90); periurethral fibrosis, with a mean ratio of 29.37 (SD 10.41); and dilatation of the prostatic urethra, with a mean ratio of 6.75 (SD 3.22). Conclusion Temporary prostatic stent placement in dogs is safe and feasible, causing marked enlargement of the prostatic urethral lumen. Retrievable covered stents may therefore be an option for bladder outlet obstruction management in men.     

Flexible tantalum stents: Effects in the stenotic canine urethra

Purpose Evaluate the effects of flexible tantalum stents (Strecker) implanted into stenotic canine urethras.Methods Eight conditioned, adult, German shepherd dogs, weighing 30–40 kg, were used. Strictures were created surgically in the bulbar urethra just proximal to the os penis. Two months postsurgery, strictures were documented radiographically and then balloon dilated. Following dilatation, a single Strecker stent was placed across the stricture. Stents were 7 mm in expanded diameter and either 2 or 4 cm in length. Retrograde urethrography was performed immediately after stent placement and then biweekly for up to 12 months. Two dogs were sacrificed at 2, 4, 6, and 12 months post-stenting, and necropsy was performed. The urethra was excised, fixed, and examined by scanning electron and light microscopy.Results Clinical success was achieved without complications in all animals. Hyperplasia of the urothelium was noted 4–6 weeks after stent placement and was most pronounced at 4–6 months. Mucosal folds were found between the stent struts. Restenosis occurred at the distal end of the stent in one dog. Histological alterations were noted in the deeper layers of the urethral wall.Conclusion Strecker stents were well tolerated in all animals and seem useful for the treatment of urethral strictures.Presented at CIRSE Annual Meeting and Postgraduate Course, Budapest, June 20–24, 1993     

尿道内支架置入术初步实验研究

目的：主要了解尿道粘膜对内支架置入后的反应。材料与方法：雄性犬５条。球囊扩张式钽丝支架（Ｓｔｒｅｃｋｅｒｓｔｅｎｔ），内支架扩张后内径６ｍｍ。先行逆行尿道造影后，支架置入前列腺部位尿道内，术后３天、２周和１个月造影复查，取病理检查。结果：造影复查显示尿道通畅，有１例内支架移位。病理巨检见支架与尿道结合紧密，支架网眼内粘膜增生，镜检示粘膜上皮细胞增生，结缔组织内有炎性细胞浸润及小血管增生，电镜下钽丝表面光滑。结论：粘膜上皮对该内支架无明显炎性反应，适用于前列腺成形术。     

食管支架治疗食管良恶性狭窄：附23例分析

作者总结了采用２７根镍钛合金Ｕｌｔｒａｆｌｅｘ食管支架置入术治疗各种良恶性食管狭窄２３例。其中食管化学烧伤后狭窄１例，食管－胃吻合口狭窄６例，食管和／或贲门癌１６例。将吞咽困难分为０￣３级。２３例中，３级１２例，２级１１例。经治疗后，０级１３例（５６．５２％），１级６级（２６．０８％），２级３例（１３．０４％），３级１例（４．３５％）。其中，２级中的３例治疗前为３级，因此，总有效率为９５．６６％。     

Treatment of refractory benign biliary stenoses in liver transplant patients by placement and retrieval of a temporary stent-graft: work in progress

PURPOSE: To evaluate patency of refractory benign biliary strictures in liver transplant patients treated with retrievable stent-grafts. MATERIALS AND METHODS: Eight male liver transplant patients who ranged in age from 42 to 52 years developed nine symptomatic biliary strictures (intrahepatic left duct, 1; hilar, 2; anastomotic, 6). These strictures had recurred despite multiple previous attempts of treatment (n = 33), including angioplasty (n = 27), surgery (n = 1), atherectomy (n = 1), metallic stent (n = 1), and prolonged catheter drainage (n = 3). As an alternative method of treatment for these refractory biliary strictures, transhepatic placement of expanded polytetrafluoroethylene stent-grafts across the strictures was performed through 10-F sheaths. In total, 14 stent-grafts were placed to treat the nine lesions, and nine of these stent-grafts were subsequently retrieved through 12-16-F sheaths. RESULTS: Stent-grafts were deployed successfully. Delayed migrations in two patients required additional stent-graft placement. One patient died of pneumonia 1 month after stent-graft placement; the remaining seven patients had stent-grafts successfully removed at 3-10 months (mean, 5.6 months). Nine intended stent-graft retrievals were performed successfully, with two requiring use of elongated forceps. Immediately after treatment, all strictures were widely patent. Five to 6 months after stent-graft removal in these seven patients, significant strictures recurred in four of eight lesions (50%). One patient underwent surgical revision. At 6-29 months (mean, 12 months) after stent-graft removal, the remaining six patients were without clinical or laboratory evidence of biliary obstruction, despite three patients with significant recurrent strictures. CONCLUSION: Temporary stent-graft placement for treatment of benign biliary strictures in liver transplant patients is technically feasible. Longer follow-up with larger patient series is necessary to assess effectiveness and possible broader applications.     

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.     

Recurrent traumatic urethral strictures near the external sphincter: treatment with a covered,retrievable, expandable nitinol stent--initial results

PURPOSE: To investigate the clinical effectiveness of a covered, retrievable, expandable nitinol stent in treating traumatic urethral strictures near the external sphincter. MATERIALS AND METHODS: The stent was 10 mm in diameter when fully expanded and 40-50 mm long. To make it removable, two nylon drawstrings were attached to its lower inner margin. Twelve consecutive men (19-67 years; mean age, 47 years) with traumatic urethral strictures near the external sphincter that were refractory to endoscopic urethrotomy were treated. With fluoroscopic guidance, a stent was placed to completely bridge the external sphincter. The stent was electively removed with a retrieval hook wire 2 months after placement. Stent placement and removal were successful in all patients, with no procedural complications. RESULTS: Mean maximum urine flow rate was 5 mL/sec (range, 3-7 mL/sec) before stent placement and 27 mL/sec (range, 16-40 mL/sec) at 1 week after placement. During the mean follow-up of 20 months (range, 2-37 months) after the first stent removal, strictures recurred in eight of 12 patients. For the eight patients with recurrence, a second stent was placed and 4 months later was removed from seven of the eight patients. During the mean follow-up of 18 months (range, 4-32 months) after the second stent removal, strictures recurred in two patients, in whom a third stent was placed and then removed 4 months later, with good results. Four (33%) of 12 patients, five (62%) of eight patients, and two (100%) of two patients were successfully treated with placement of the first stent, the second stent, and the third stent, respectively. In the remaining patient, the second stent remains in place. CONCLUSION: Placement of a covered, retrievable, expandable nitinol stent seems to be effective in treating urethral strictures near the external sphincter and warrants further investigation.     

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     

Gianturco expandable metallic biliary stents: results of a European clinical trial

Eleven patients with benign strictures (after choledochojejunostomy, n = 10; chronic pancreatitis, n = 1) and 16 with malignant biliary strictures (cancer of the pancreas, n = 7; cholangiocarcinoma, n = 5) were treated with a self-expanding metallic biliary stent. The patients with benign disease had failed treatment with surgical reconstruction and transhepatic balloon dilation. All patients had immediate relief of jaundice and cholangitis. In a follow-up period of 6-21 months, nine of the 11 patients with benign disease had no difficulties with infection, pruritus, or recurrent jaundice. In patients with malignant strictures, the stent produced relief of biliary obstruction unless recurrent tumor invaded the bile ducts. With careful patient selection, this stent appears to be useful in the management of biliary obstruction, particularly in benign disease.     

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.     

Rhenium-188 mercaptoacetyltriglycine-filled balloon dilation in the treatment of recurrent urethral strictures: initial experience with five patients

PURPOSE: To evaluate the efficacy of beta-irradiation therapy with use of a rhenium-188 mercaptoacetyltriglycine ((188)Re-MAG(3))-filled balloon for the prevention of restenosis in urethral strictures refractory to repetitive surgical or interventional procedures. MATERIALS AND METHODS: Five male patients with traumatic (n = 4) or postoperative anastomotic (n = 1) recurrent urethral strictures were included. One to four sessions of 20-30 Gy beta-irradiation at a 1-mm tissue depth with (188)Re-MAG(3)-filled balloon dilation were undertaken in each patient. RESULTS: No procedural complications or toxicities were noted. During the mean follow-up period of 16.2 months, the stricture did not recur in two patients, whereas three patients required additional interventional procedures. In two of these patients, the treatment intervals between the required sessions were significantly prolonged. For the entire group, the mean treatment interval was prolonged from 2.2 months before (188)Re-MAG(3)-filled balloon dilation to 10.7 months after therapy. CONCLUSION: (188)Re-MAG(3)-filled balloon dilation shows promise in preventing or delaying stricture recurrence in patients with recurrent urethral strictures.     

Treatment of tracheobronchial obstruction with a polytetrafluoroethylene-covered retrievable expandable nitinol stent

PURPOSE: To evaluate the clinical effectiveness of polytetrafluoroethylene (PTFE)-covered retrievable expandable nitinol stents in tracheobronchial strictures. MATERIALS AND METHODS: With fluoroscopic guidance, PTFE-covered retrievable expandable nitinol stents were placed in 15 symptomatic patients with benign (n = 6) or malignant (n = 9) tracheobronchial strictures. Complications and improvement in respiratory status were evaluated. Stents were removed electively 6 months after placement in benign strictures or if complications occurred. Membrane degradation or separation from the wire mesh was evaluated in removed stents. RESULTS: A total of 17 stents were successfully placed and were well tolerated in all patients. Sputum retention, stent migration, and tissue hyperplasia occurred in 23.5% (n = 4), 17.6% (n = 3), and 17.6% (n = 3) of stents, respectively. A total of 11 stents were successfully removed electively 6 months after placement (n = 4) or when complications occurred (n = 7). All 11 such stents were removed without difficulty with use of standard techniques, antecedent balloon dilation being necessary in two cases as a result of tissue hyperplasia. No removed stent showed signs of membrane degradation, and two removed stents showed signs of membrane separation from the mesh. CONCLUSIONS: PTFE-covered retrievable expandable nitinol stents were effective in the treatment of tracheobronchial strictures. Stent removal was easy with use of standard techniques, and no removed stent showed evidence of membrane degradation.     

Primary patency of femoropopliteal arteries treated with nitinol versus stainless steel self-expanding stents: propensity score-adjusted analysis

PURPOSE: To evaluate, in a propensity score-adjusted analysis, the intermediate-term primary patency rates associated with nitinol versus stainless steel self-expanding stent placement for treatment of atherosclerotic lesions in femoropopliteal arteries. MATERIALS AND METHODS: The authors analyzed the clinical and imaging data of 175 consecutive patients with peripheral artery disease and either intermittent claudication (n = 150) or critical limb ischemia (n = 25) who underwent femoropopliteal artery implantation of nitinol (n = 104) or stainless steel (n = 123) stents in a nonrandomized setting. The stents were placed owing to either significant residual stenosis (ie, >30% lumen diameter reduction) or flow-limiting dissection after initial balloon angioplasty of the femoropopliteal artery. Patients were followed up for a median period of 9 months (mean, 13 months; range, 6-66 months) for the detection of a first in-stent restenosis, defined as a greater than 50% lumen diameter reduction that was seen at color-coded duplex ultrasonography and confirmed at angiography. RESULTS: Cumulative patency rates at 6, 12, and 24 months were 85%, 75%, and 69%, respectively, after nitinol stent placement versus 78%, 54%, and 34%, respectively, after stainless steel stent placement (P =.008, log-rank test). There were no statistically significant differences in associated patency among the three different nitinol stents used (P =.72, log-rank test). Multivariate Cox proportional hazard analysis, in which the effect of propensity to receive a nitinol stent was considered, revealed a significantly reduced risk of restenosis with the nitinol stents compared with the risk of restenosis with the stainless steel stents (adjusted hazard ratio, 0.44; 95% confidence interval: 0.22, 0.85; P =.014). CONCLUSION: Nitinol stents are associated with significantly improved primary patency rates in femoropopliteal arteries compared with stainless steel stents. Randomized controlled trials are needed to confirm these results.     

Palliative treatment of neoplastic strictures by self-expanding nitinol Strecker stent

The purpose of this study was to evaluate technical and clinical results of self-expanding esophageal stent implanted in patients with malignant esophageal strictures and clinically significant dysphagia. From June 1992 to September 1994, 27 patients with inoperable tumors of the esophagus or gastric cardiac were treated by placement of 37 self-expanding nitinol stents. Water-soluble contrast and endoscopy studies were performed after the procedure and during the follow-up period. Successful stenting of the stricture was achieved in 27 patients. The mean dysphagia grade dropped from 2.3 to 1 (SD ± 0.54) immediately after the procedure. After the insertion of the stent, 16 patients died in a period of time ranging from 0 to 13 months (mean 5.6 months), whereas at the end of the study 11 patients were alive 4–15 months after the procedure (mean 8.3 months). No major complications were observed. The results of this study are encouraging because esophageal stent placement was technically easy and clinically effective. Correspondence to: F. Maspes     

动脉灌注化疗及食管内支架治疗恶性食管狭窄

目的：用动脉管注化疗及食管内支架治疗恶性食管狭窄。方法：对８例食管癌患者分别置放ＷＡＬＬＳＴＥＮＴ,ＳＴＲＥＣＫ－ＥＲＳＴＥＮＴ及ＺＳＴＥＮＴ,共１０个支架,先用导丝探索通过狭窄段,经球囊扩张后置放支架。置放支架１周后行食管动脉管注化疗,１次／４～６周。结果：８例患者造影显示５例患者食管完全梗阻,３例患者严重狭窄。所有患者均一次顺利完成支架置放。３例分别随访１年,２例分别随访８个月及６个月。患者进普食顺利,疗效满意。２例半年后又出现吞咽困难。造影显示原支架上下两端又出现狭窄经第二次置放支架后进食顺利,疗效满意。８例共行供血动脉管注５０次。结论：食管内支架治疗恶性食管狭窄,安全,可靠,疗效好,并发症少。但必须配合动脉灌注化疗     

Early symptomatic strictures after gastric surgery: palliation with balloon dilation and stent placement

PURPOSE: To evaluate the clinical efficacy and safety of balloon dilation and stent placement in the treatment of early benign anastomotic strictures after gastric surgery. MATERIALS AND METHODS: From 1997 to 2006, 63 patients with early (< or =3 months) benign anastomotic strictures after gastric surgery underwent fluoroscopic balloon dilation or stent placement due to obstructive symptoms. In all patients, balloon dilation was initially performed. Stent placement was indicated in patients who showed poor response to repeat balloon dilation. RESULTS: Balloon dilations were successfully performed in all 63 patients, with only three intramural tears. Thirty-one of the 63 patients (49%) showed good response to initial balloon dilation and required no further treatment until the end of follow-up or death. Conversely, 32 patients (51%) had poor or no response or recurrence after initial balloon dilation and required multiple balloon dilations (n = 20), stent placement (n = 7), percutaneous gastrojejunostomy (n = 2), and/or surgical revision (n = 3). At multivariate analysis, the anastomotic site was the only independent factor predictive of the response to balloon therapy (P < .001). During a mean follow-up of 12 months, overall clinical success was achieved in 56 of the 63 patients (89%) after a single balloon dilation (n = 31), multiple balloon dilations (n = 20), and stent placement (n = 5). CONCLUSIONS: Balloon dilation is safe and effective for the treatment of patients with early benign anastomotic strictures after gastric surgery. Stent placement can be effective in selected patients with early benign anastomotic strictures refractory to balloon dilation.     

Endovascular treatment of atherosclerotic arterial stenoses and occlusions of the supraaortic arteries: mid-term results from a single center analysis

OBJECTIVE: To determine mid-term patency rates after endovascular treatment of supraaortic atherosclerotic arterial stenoses and occlusions using percutaneous transluminal angioplasty (PTA) and stent placement. PATIENTS AND METHODS: During a period of 83 months, 48 patients (18 female, 30 male; mean age 61 years, range 31-82 years) were included into this prospective single-center study. Fifty-five lesions of the brachial and cephalic arteries (subclavian/axillary artery n = 42, innominate artery n = 7, origin common carotid artery n = 6) were treated using PTA (n = 38), PTA plus stent (n = 11) or primary stent placement (n = 6). For anticoagulation, patients received a bolus of heparin (5000 IU) intraarterially during the intervention followed by intravenous application for 24h. At discharge, life-time application of ASA (100mg/day) was initiated. Follow-up protocol included clinical examination, colour-coded duplex ultrasound and intraarterial angiography in case of re-stenosis. RESULTS: PTA and stent placement were technically successful in all patients (100%). No major complications occurred. Of seven patients presenting with total occlusions, six were treated with stent placement. Stent implantation was also performed in all lesions located at the origin of the supraaortic arteries (n = 6). In 38 lesions, the result of PTA was satisfactory. Mean follow-up time is 22 months (range 1-83 months). During follow-up examinations, re-stenoses occurred in 10 cases (at 1 month n = 2, at 6 months n = 2, at 12 months n = 3, at 24 months n = 3). In 9 lesions, re-interventions were performed (PTA n = 7; PTA plus stent n = 2). According to Kaplan-Meier life-table analysis, cumulative primary and primary assisted patency rates are 69.5% (patients at risk n = 15; standard error 9%) and 90.6% (patients at risk n = 16; standard error 6.3%) at 20 months, respectively. CONCLUSIONS: Endovascular treatment of atherosclerotic obstructive disease in brachial and cephalic arteries is a safe procedure showing promising mid-term patency rates.     

Management of ureteral strictures in renal transplants by antegrade balloon dilatation and temporary internal stenting

Purpose: To evaluate the efficacy of percutaneous balloon dilatation and temporary internal stenting in the treatment of transplant ureteral strictures. Methods: Nine patients presenting with obstructed renal transplants were treated by antegrade nephrostomy insertion, ureteroplasty, and temporary internal stenting. Following stent removal, patients were divided into two groups for analysis according to whether the obstruction occurred less than (group A) or more than (group B) 3 months following transplantation. Results: All procedures were technically successful. In group A (n= 6), all patients were successfully treated by one or two dilatations with stenting. In group B (n= 3), two patients were successfully treated by one dilatation with stenting. Overall, eight patients (89%) have had their primary or secondary stent removed successfully at a mean interval of 97.5 days after insertion, and remain well at a mean follow-up interval of 22 months. Conclusion: Balloon dilatation and temporary internal stenting is a useful method for treating transplant ureteral strictures.     

食管内支架置入术并发症分析

目的：分析内支架置入术治疗食管良恶性狭窄的并发症并提出防治方法。方法：本组５８例,其中食管化学烧伤后狭窄２例,食管－胃吻合口狭窄１１例,食管癌３７例,胃贲门癌８例,支架置入在Ｘ线电视监视下进行。术后给予抗生素、止血药及镇静止痛药,２３例食管癌患者术后行放疗、化疗。结果：１例内支架异位留置,遂加置一根支架,其余５７例支架的一次置入成功,术后 后疼痛２１例,大出血１例,随访１～６个月,食物嵌顿１例,支