Self-expandable metallic stents in nonmalignant large airway disease

Airway self-expandable metallic stents (SEMS) were initially studied in malignant airway obstruction; however, their use in benign airway diseases has become progressively more frequent. This may be explained by their ease of insertion compared with silicone stents, which require rigid bronchoscopy for insertion. While initial experience with SEMS in benign disease suggested efficacy and promising short-term safety profile, long-term follow-up revealed significant complication rates. In addition to a high complication rate, the management of these complications is made more difficult by the semipermanent nature of these devices. Reported complications include infection, granulation tissue formation, stent migration, stent fracture, airway perforation and fistula formation, as well as extension of the initial injury, potentially eliminating other therapeutic options such as surgical resection. Therefore, SEMS should only be used in nonmalignant large airway disease as a last resort for patients in whom other endoscopic methods, including silicone stents and dilations, as well as surgical options have failed or are technically not feasible.     

Airway stenting for severe endobronchial papillomatosis

Severe endobronchial papillomatosis is associated with recurrent respiratory infections and airway obstruction. Current management includes treatment with antiviral and cytotoxic agents to slow papilloma growth and endobronchial therapies to excise the lesions. We report 2 cases of severe tracheobronchial papillomatosis which were managed with endobronchial laser and airway stenting. A 32-year-old man and a 55-year-old woman with known history of tracheobronchial papillomatosis were admitted with hemoptysis and dyspnea, respectively. They presented increasing frequencies of respiratory infections in the preceding year despite therapy with interferon alpha-2A, acyclovir, methotrexate and endobronchial treatment. Moreover, the 2nd patient presented 6 months previously to another institution with central airway obstruction which was treated with a covered metallic stent. Both patients underwent rigid bronchoscopy which revealed airway obstruction by papillomatous lesions. In the 2nd case, the metallic stent was broken due to fatigue and was infiltrated by a giant papilloma. Both patients received laser treatment and airway silicone stenting. After stenting, respiratory infection rate was greatly reduced and no further complications related to the papillomas occurred. This paper highlights the serious complications which may arise if endobronchial management of the disease includes insertion of metallic stents. In contrast, airway stenting with a silicone prosthesis may be useful in refractory endobronchial papillomatosis and may offer permanent control of symptoms.     

Efficacy and tolerance of a new silicone stent for the treatment of benign tracheal stenosis: preliminary results

STUDY OBJECTIVE: In inoperable patients with tracheal stenosis who are treated using silicone stents, stent migration occurs in 18.6% of cases. To decrease the migration rate, we have designed a new silicone stent with narrow central and larger distal parts. This study analyzes the stability and tolerance of this new stent. DESIGN: Preliminary prospective study conducted in two French university hospitals. PATIENTS: Thirteen inoperable patients with benign complex tracheal stenosis due to intubation or tracheotomy. INTERVENTIONS: Tracheal stent insertion was performed under general anesthesia with a rigid bronchoscope. The patients were followed up clinically up to stent removal, which was planned at 18 months. RESULTS: Stent insertion or removal was very simple and did not differ from other silicone stents. No migration occurred after a mean follow-up of 22.8 months. Minimal granuloma formation occurred in only one patient (7.7%). Sputum retention remained similar to that with other silicone stents and could be improved by a smoother internal wall. Stents have been removed in seven patients after a mean duration of 19.6 months, with a complete stenosis cure in four cases. CONCLUSION: This new stent combines the excellent stability of the metallic stents and the tolerance and easy removal of straight silicone stents. This allows a prolonged use in order to obtain curative action.     

Diagnostic performance of digital tomosynthesis to evaluate silicone airway stents and related complications

BackgroundDigital tomosynthesis (DTS) is an imaging technique with benefits in reconstructing sequential cross-sectional images. We evaluated the diagnostic performance of DTS for silicone airway stents and stent-related complications in patients who underwent bronchoscopic intervention.MethodsThis retrospective study included patients who underwent bronchoscopic intervention after chest radiography (CXR) and DTS examinations from September 2013 to August 2020. The interval between CXR, DTS, and bronchoscopic intervention was a maximum of 10 days. CXR and DTS images were evaluated using a bronchoscopic view as a reference. We calculated the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for assessing the diagnostic performance.ResultsThe total CXR, DTS, and bronchoscopic intervention-matching datasets comprised 213 cases from 119 patients and, silicone stents were present in 167 of them. The ability of DTS to detect silicone stents was better than that of CXR (sensitivity, 92.8% vs. 71.3%, P<0.001). Of the 167 cases with silicone stents, 53 experienced stent migration and 121 experienced stent obstructions due to granulation tissue or fibrosis. The sensitivity for detecting stent migration was also higher with DTS than with CXR (45.3% vs. 24.5%, P=0.025). The sensitivity for detecting the stent obstruction was better with DTS than with CXR (64.5% vs. 19.0%, P<0.001).ConclusionsDTS was more sensitive and accurate in revealing silicone airway stents and silicone stent-related complications than CXR. However, there were limitations in confirming stent migration and obstruction with DTS due to granulation tissue growth and fibrosis.     

Performance of a self-expanding silicone stent in palliation of benign airway conditions

INTRODUCTION: The Polyflex stent (Boston Scientific; Boston, MA) is a self-expanding, thin-walled, silicone stent. Its use has been described in the management of patients with malignant airway obstruction, yet reports of its use for treatment of benign airway conditions are rare. Study: We report a retrospective review of our experience with the Polyflex stent in the management of benign airway conditions. RESULTS: A total of 16 stents were deployed in 12 patients. The indications for the stent placement included the following: anastomotic stenosis following lung transplantation (LTR) [four patients]; tracheal stenosis (three patients); tracheobronchomalacia (two patients); tracheobronchopathiaosteochondroplastica (one patient); relapsing polychondritis (one patient); and bronchopleural fistula (one patient). Even though immediate palliation was established in most cases (90%), the incidence of complications was 75%. Stent migration was the most common consequence, with time to the event ranging from < 24 h to 7 months. One stent was expectorated within < 24 h. One patient coughed up a portion of the inner lining of the stent 7 months after its placement. Emergent bronchoscopy was required in four patients for mucous impaction. The complication rate was 100% in patients with LTR-related anastomotic stenosis. CONCLUSION: The use of the Polyflex stent for the treatment of benign airway conditions is associated with a high complication rate. We have abandoned its use under such conditions in our practice.     

Stenting therapy for stenosing airway disease

Stenosing airway disease is classified as intraluminal obstruction, extrinsic compression, and malacia by the anatomical site of the lesion. Stenting therapy is indicated for symptomatic relief of life-threatening dyspnea caused by the last two types. Airway stents are made with metal mesh and/or silicone rubber, and currently more than 20 kinds of stent are available. The metal stent (e.g. Gianturco stent, Wallstent) is easy to insert, may not need general anesthesia, and has wider internal lumen. Because it is very hard to reposition or remove, it is mainly used in malignant airway obstruction. Among many kinds of silicone stent, the Dumon stent is most widely used for benign and malignant airway stenoses, but general anesthesia and rigid bronchoscopy are needed for insertion. It can be removed when the stenosing airway disease subsides completely. In many clinical studies, most patients (85-90%) improved immediately after stenting, and procedure-related mortality is low (< 3%) in experienced centers. Stent displacement, mucus impaction, and granulation tissue formation are potential complications. Stenting is one of many effective therapeutic modalities for stenosing central airway disease. Careful patient selection, experiences, and continuous development of new technology will bring better results.     

Self-expandable metallic stents for palliation of patients with malignant gastric outlet obstruction caused by stomach cancer

AIM: To ascertain clinical outcome and complications of self-expandable metal stents for endoscopic palliation of patients with malignant obstruction of the gastrointestinal (GI) tract. METHODS: A retrospective review was performed throughout August 2000 to June 2005 of 53 patients with gastric outlet obstruction caused by stomach cancer. All patients had symptomatic obstruction including nausea, vomiting, and decreased oral intake. All received self-expandable metallic stents. RESULTS: Stent implantation was successful in all 53 (100%) patients. Relief of obstructive symptoms was achieved in 43 (81.1%) patients. No immediate stent-related complications were noted. Seventeen patients had recurrent obstruction (tumor ingrowth in 14 patients, tumor overgrowth in 1 patient, and partial distal stent migration in 2 patients). The mean survival was 145 d. Median stent patency time was 187 d. CONCLUSION: Endoscopic placement of self-expandable metallic stents is a safe and effective treatment for the palliation of patients with inoperable malignant gastric outlet obstruction caused by stomach cancer.     

Pulmonary function improves after expandable metal stent placement for benign airway obstruction

STUDY OBJECTIVE: To determine whether expandable metal stent placement for benign airway lesions improves pulmonary function. DESIGN: Case series. SETTING: University medical center. PATIENTS: Nine patients who underwent balloon-mediated expandable metal stent deployment for airway obstruction due to benign etiologies. RESULTS: All nine patients had expandable stents deployed for benign airway lesions using fiberoptic bronchoscopy and fluoroscopic guidance. Pulmonary function improved after stent placement. The mean FVC increased by 388 mL (95% confidence interval [CI], 30 to 740 mL), the mean peak expiratory flow (PEF) increased by 1,288 mL (95% CI, 730 to 1,840 mL), the mean FEV1 increased by 550 mL (95% CI, 240 to 860 mL), and the mean forced expiratory flow between 25% and 50% of vital capacity (FEF25-75%) increased by 600 mL (95% CI, 110 to 1,090 mL). Corresponding relative measurements included increases in FVC (12%), PEF (95%), FEV1 (38%), and FEF25-75% (87%). The complete characterization of a benign airway obstruction generally required a multimodal approach. CONCLUSIONS: Expandable metal stent placement appears to be an effective therapy for benign airway obstruction.     

Treatment of benign biliary strictures in chronic pancreatitis by self-expandable metal stents

AIM: To determine the efficacy the value of self-expandable metal stents in patients with benign biliary strictures caused by chronic pancreatitis. METHOD: 61 patients with symptomatic common bile duct strictures caused by alcoholic chronic pancreatitis were treated by interventional endoscopy. RESULTS: Initial endoscopic drainage was successful in all cases, with complete resolution of obstructive jaundice. Of 45 patients who needed definitive therapy after a 12-months interval of interventional endoscopy, 12 patients were treated with repeated plastic stent insertion (19.7%) or by surgery (n = 30; 49.2%). In 3 patients a self-expandable metal stent was inserted into the common bile duct (4.9%). In patients treated with metal stents, no symptoms of biliary obstruction occurred during a mean follow-up period of 37 (range 18-53) months. The long-term success rate of treatment with metal stents was 100%. CONCLUSIONS: Endoscopic drainage of biliary obstruction by self-expandable metal stents provides excellent long-term results. To identify patients who benefit most from self-expandable metal stent insertion, further, prospective randomized studies are necessary.     

Remove airway ultraflex stents by flexible bronchoscope

IntroductionDespite removal of airway metallic stents by rigid bronchoscope was presented, there are few reports describing such removal by flexible bronchoscope.Methods36 patients who had airway Ultraflex stents removed by flexible bronchoscope from 2002 to 2009 were reviewed. Factors contributing to removal method and complications during and after removal were analyzed by multinomial logistic regression.ResultsAmong 36 patients with stent extraction; 17 stents (47.2%) were removed by a single procedure and 19 (52.8%) by multiple procedures. There was no mortality or severe morbidity during or after stent removal. There were 21 complications after stent removal, including retained stent pieces (n = 9), mucosal tear with bleeding (n = 5), and re-obstruction requiring silicone stent placement (n = 7). Stent indwelling time > 10 months (adjusted odds ratio: 9.5; 95% confidence interval: 7.9–11.1, P=0.01), obstructive granulation tissue formation before stent removal (adjusted odds ratio: 5.2; 95% confidence interval: 2.2–8.6, P=0.01), and stent fracture before removal (adjusted odds ratio: 3.5; 95% confidence interval: 1.8–15.4, P=0.04) were independent predictors of the need for multiple procedures for stent removal. Stent indwelling time > 10 months (adjusted odds ratio: 4.2; 95% confidence interval: 2.1–8.9, P=0.01), obstructive granulation tissue formation before stent removal (adjusted odds ratio: 16.5; 95% confidence interval, 1.8–49.6, P=0.01), and multiple procedures required for removal (adjusted odds ratio: 6.9; 95% confidence interval, 1.1–43.5, P=0.04) were independent predictors of removal complications.ConclusionsA flexible bronchoscope can be used to remove stents in patients with central airway obstruction and stent-related complications. This procedure should be performed in centers with experienced multidisciplinary teams.     

An audit of metal stent palliation for malignant biliary obstruction

BACKGROUND AND AIMS: Endoscopic stent insertion is the optimum method of palliation for malignant biliary obstruction. Metal stents have several advantages over the polyethylene alternatives, but are significantly more expensive. It has been reported that patients need to survive beyond 6 months to make metal stents more cost-effective. The aim of this study was to audit the performance of expanding metal biliary stents in our endoscopy unit, and to identify factors that might help with patient selection. METHODS: The records of all patients who were selected for endoscopic metal stent insertion at the Royal Perth Hospital for malignant biliary obstruction between September 1994 and November 1998 were reviewed. RESULTS: Thirty-two patients (16 males, mean age 71 years (range 34-88 years) were identified and followed up for a mean 201 days (range 3-810 days). Fifteen (47%) had cholangiocarcinoma, 13 (41%) had pancreatic cancer, and four had metastatic disease as the cause of obstruction. Mortality rates after metal stent insertion were 16, 41 and 55% at 30, 90 and 180 days, respectively. In total, 24 (75%) patients died during the follow-up period. Eleven (34%) stents became obstructed during follow up with a median time to occlusion of 125 days (range 44-729 days). Patients with cholangiocarcinoma had significantly longer survival than pancreatic cancer cases (median 286 vs 58 days, P = 0.04). No other factors were found to correlate with the survival or stent complications. CONCLUSIONS: Less than half of this mixed cohort survived beyond 6 months. Metal stent palliation of malignant biliary obstruction should probably be targeted at those with cholangiocarcinoma, as these patients tend to survive longer.     

Long-term follow-up after biliary stent placement for postoperative bile duct stenosis

BACKGROUND: The outcome of temporary biliary stent placement for postoperative bile duct stenosis was retrospectively evaluated with the main aim of assessing long-term complications after stent removal. METHODS: ERCP was performed between 1981 and 1991 in 74 patients with postoperative bile duct stenoses. Two 10F stents were inserted for a maximum of 12 months with stent exchange every 3 months to avoid cholangitis caused by clogging. RESULTS: Stent insertion failed in 11 patients with complete and 4 patients with incomplete biliary obstruction. Early complications occurred in 14 patients (19%) including 2 deaths. Therefore 57 patients were included in the stent phase of the study. In 10 patients the referring physician did not adhere to the treatment protocol, and nonelective stent exchange for jaundice and/or cholangitis was necessary in 7 (70%). Of the 47 patients treated according to protocol, complications developed in 40% during the period with stents in situ. Stents were eventually removed in 44 patients who were subsequently followed for a median of 9.1 years. Late complications developed in 15 patients (34%) including recurrent stenosis in 9 (20%). All cases of recurrent stenosis occurred within 2 years of stent removal. CONCLUSIONS: Endoscopic treatment is feasible in 80% of patients who undergo an ERCP for postoperative bile duct stenosis. After stent insertion and during the time with stents in situ, complications occur at a significant rate but are usually mild or reflect the patient's underlying condition. After stent removal, recurrent stenosis develops in 20% of patients within 2 years of stent removal. Endoscopic treatment should be the initial management of choice for postoperative bile duct stenosis.     

Use of self-expanding metal stents for palliation of rectosigmoid cancer

BACKGROUND: Patients with large bowel obstruction can be palliated by colostomy or by endoscopic modalities that restore luminal patency. The clinical results of a series of patients with rectosigmoid cancer in whom self-expanding metal stents were inserted at endoscopy are presented. METHODS: Thirty-seven patients with symptoms related to obstructive rectosigmoid adenocarcinoma were treated by endoscopic insertion of self-expanding metal stents. RESULTS: Metal stents were correctly placed in 36 of 37 patients (97%) with no immediate complications. Early dislodgment of the stent (within 1 week) was observed in 3 cases. The remaining 33 patients (92%) were followed for a median of 7 months (3 weeks-33 months). In 28 patients (78%) there was long-term restoration of luminal patency and disappearance of obstructive symptoms without further treatments. They experienced no pain, tenesmus, or incontinence during the follow-up period. The incidence of complications (early and late) and the mortality rate related to the procedure were 22% and 3%, respectively. CONCLUSIONS: Endoscopic metal stents can be considered a simple and effective solution for long-term palliation of rectosigmoid cancer.     

Stent placement for benign colonic stenosis: case report,review of the literature,and animal pilot data

BACKGROUND: Permanent metal stent placement for malignant intestinal obstruction has been proven to be efficient. Temporary stents for benign conditions of the colon and rectum are less studied. This is a case study, review of the literature, and observation from an animal model on placement of stents in the colorectum for benign disease. MATERIALS AND METHODS: A 55-year-old man presented with recurrent obstructions from a benign stricture of the distal sigmoid colon. After failed balloon dilations, a polyester coated stent was placed. The purpose of the stent was to improve symptoms and avoid surgery. The stent was expelled after 5 days. We conducted a literature review of stents placed for benign colorectal strictures and an animal study to evaluate stent migration. RESULTS: In the literature, there were 53 reports of uncovered metal stents, four covered metal stents, and six polyester stents. Patency rates were 71%, and migration rate was 43%. Migration occurred earlier with polyester stents (mean = 8 days) versus covered (32 days) or uncovered metal stents (112 days). Severe complications were seen in 23% of patients. Four 45-kg pigs underwent rectosigmoid transection with a 21-mm anastomosis and endoscopic placement of a Polyflex stent. Two stents were secured with suture. Stents without fixation were expelled within 24 h of surgery. Stents with fixation were expelled between postoperative days 2 and 14. CONCLUSION: Stents for the treatment of benign colorectal strictures are safe, with comparable patency rates between stent types. Metal stents can cause severe complications. In a pig model, covered polyester stents tend to migrate early even with fixation. Further investigation needs to focus on new stent designs and/or better fixation.     

Endoscopic insertion of biliary stents in 18 patients with metallic duodenal stents who developed secondary malignant obstructive jaundice

AIM: The aim of this work was to evaluate the feasibility of endoscopic insertion of biliary stents in patients with duodenal stents who develop secondary malignant obstructive jaundice. PATIENTS AND METHODS: The study population included 133 patients with unresectable malignant duodenal obstruction. In 106 patients a biliary stent was inserted before or at the same time as the duodenal stent. Malignant biliary obstruction appeared secondarily in 18 patients; fifteen of these patients already had a biliary stent. We present our experience of biliary stent insertion in these 18 patients with metallic duodenal stents. RESULTS: Biliary obstruction was successfully alleviated in 17 out of 18 patients (94%) without complication. Insertion of a new biliary stent failed in one patient because the mesh of the duodenal stent passed over the metallic biliary stent already in place. Mean duration of endoscopic insertion was 95 minutes (range: 60 - 180). All patients remained free of biliary complications to death (57 days, range: 30 - 120). CONCLUSION: Our report shows that endoscopic insertion of a biliary stent is feasible in patients who have metallic duodenal stents. Technical difficulties exist especially if the mesh of the duodenal stent passes over the papilla.     

Airway stabilization with silicone stents for treating adult tracheobronchomalacia: a prospective observational study

Rationale: It is postulated that in patients with severe tracheobronchomalacia (TBM), airway stabilization with stents may relieve symptoms. OBJECTIVES: To evaluate the effect of silicone stents (tracheal, mainstem bronchus, or both) on symptoms, quality of life, lung function, and exercise capacity in these patients. METHODS: A prospective observational study in which baseline measurements were compared to those obtained 10 to 14 days after stent placement. Measurements and main results: Of 75 referred patients, 58 had severe disease and underwent therapeutic rigid bronchoscopy with stent placement. Mean age was 69 years (range, 39 to 91 years), 34 were men, 33 had COPD, and 13 had asthma. Almost all patients (n = 57) had dyspnea as a sole symptom or in combination with cough and recurrent infections; four patients required mechanical ventilation for respiratory failure. In 45 of 58 patients, there was reported symptomatic improvement; quality of life scores improved in 19 of 27 patients (p = 0.002); dyspnea scores improved in 22 of 24 patients (p = 0.001); functional status scores improved in 18 of 26 patients (p = 0.002); and mean exercise capacity improved from baseline, although not significantly. The 49 complications included mainly 21 partial stent obstructions, 14 infections, and 10 stent migrations. Most patients with concomitant COPD also improved on most measures. CONCLUSIONS: In the short term, airway stabilization with silicone stents in patients with severe TBM can improve respiratory symptoms, quality of life, and functional status. Coexisting COPD is not an absolute contraindication to a stenting trial in this population. Stenting is associated with a high number of short-term and long-term but generally reversible complications.     

Comparison of Wallstent and Ultraflex stents for palliation of malignant left-sided colon obstruction: a retrospective, case-matched analysis

BACKGROUND: Self-expandable metal stents (SEMSs) are accepted palliation for malignant colon obstruction. Outcomes of different stent types is unknown. OBJECTIVE: Our purpose was to compare outcomes after palliative placement of the Enteral Wallstent (EW) and the Precision Colonic Ultraflex (PCU) stent. DESIGN: Retrospective study of all SEMS placement during a 7-year period. SETTING: Tertiary care academic medical center. PATIENTS: Malignant left-sided colon obstruction in which through-the-scope (TTS) or non-TTS stent placement was possible. MAIN OUTCOME MEASUREMENTS: Technical and clinical success rates, stent-related complications, reintervention. RESULTS: Demographics, degree, site, and cause of obstruction were comparable. Technical difficulties were more frequent with EW than PCU (16% vs 9%, P not significant), insufficient stent expansion and stent misplacement being most common. Relief of obstruction occurred in all patients when placement was technically successful. Mean follow-up was 93 days (range 7-691 days). Early (<7 days) stent occlusion (6% vs 0%, P not significant) and migration (4% vs 0%, P not significant) occurred more frequently in the EW group. Self-limited hematochezia was more common with PCU (20% vs 2%, P = .002). Delayed complications (perforation, stent occlusion, migration, and erosion) occurred significantly more often in the EW group (38% vs 20%). Reintervention was needed more frequently for EW, endoscopic (40% vs 17%, P = .01) and operative (46% vs 26%, P = .03). CONCLUSIONS: Enteral Wallstents and Precision Ultraflex Colonic stents adequately relieve colonic obstruction. Stent dysfunction, stent-related complications, and need for reintervention are higher after EW placement. Precision Colonic Ultraflex stents appear better suited for palliation of left-sided malignant colon obstruction.     

Use of self-expandable metallic stents in benign GI diseases

BACKGROUND: The self-expandable metallic stent is of proven benefit in patients with malignant disease; however, its use in patients with benign disease is not well established. There are few data available regarding long-term complications and outcomes with use of self-expandable metallic stents in benign disease and virtually none regarding attempted removal once the acute problem is resolved. METHODS: Thirteen patients who had a self-expandable metallic stent placed for benign GI disorders were included in a retrospective analysis. Data collected included patient demographics, indication for procedure, type of stent used, complications, and patient outcomes. RESULTS: Thirteen patients (7 women, 6 men; mean age 67 years, range 34-84 years) had one or more self-expandable metallic stents placed for benign disease and were followed for a mean of 3.4 years (3 weeks to 10 years). Of the 13 patients, 8 had esophageal stents, 4 biliary stents, and 1 had dual stents placed in the pancreaticobiliary tree. Complications developed in 8 (62%) patients; 4 (31%) ultimately died, either from the primary disease process (3) or from stent-related complications (1). CONCLUSIONS: Self-expandable metallic stent placement is effective treatment for benign esophageal leaks, providing the stent can be removed. It also may be used in either the esophagus or biliary tree in patients who are poor candidates for surgery and short expected survival. However, a self-expandable metallic stent should not be placed in a patient with a benign GI disorder who has a significant life expectancy and is a good candidate for surgery.     

Clinical outcomes of secondary stent-in-stent self-expanding metal stent placement for primary stent malfunction in malignant gastric outlet obstruction

Background

Although a substantial number of patients require secondary stents insertion due to primary stent malfunction in malignant gastric outlet obstruction, data on the outcomes of secondary self-expanding metal stents are sparse.

Aim

To investigate clinical outcomes and factors related with secondary stent malfunction in patients with malignant gastric outlet obstruction given secondary stent-in-stent self-expanding metal stent insertion.

Methods

For this retrospective study, a total 77 patients who underwent secondary stent-in-stent self-expanding metal stent placement for primary stent malfunction in malignant gastric outlet obstruction were enrolled. We compared the effectiveness and complications of secondary covered and uncovered stents and explored the predictive factors for stent malfunction.

Results

Stent-in-stent self-expanding metal stent placements were technically successful in all patients. Both groups also had comparable clinical success rates (covered stent, 87.2% and uncovered stent, 90.0%, P = 1.000). Stent malfunction rates (31.9% and 36.7% respectively, P = 0.805) and median patency time of stent (165 [95% confidence interval: 112–218] and 165 [95% confidence interval: 126–204] days, respectively, P = 0.358) were similar between secondary covered and uncovered stents. Longer patients’ survival time (≥100 days) was associated with increased risk of stent malfunction (odds ratio: 4.598; 95% confidence interval: 1.473–14.355; P = 0.009).

Conclusions

Secondary stent-in-stent self-expanding metal stent placement is feasible and effective treatment for primary stent malfunctions in malignant gastric outlet obstruction. Covered and uncovered stent are equally acceptable in terms of stent-related complications and stent patency, regardless of primary stent type.     

Endoscopic stenting-Where are we now and where can we go？

Self expanding metal stents （SEMS） play an important role in the management of malignant obstructing lesions in the gastrointestinal tract. Traditionally, they have been used for palliation in malignant gastric outlet and colonic obstruction and esophageal malignancy. The development of the polyflex stent, which is a removable self expanding plastic stent, allows temporary stent insertion for benign esophageal disease and possibly for patients undergoing neoadjuvant chemotherapy prior to esophagectomy. Potential complications of SEMS insertion include perforation, tumour overgrowth or ingrowth, and stent migration. Newer stents are being developed with the aim of increasing technical and clinical success rates, while reducing complication rates. Other areas of development include biodegradable stents for benign disease and radioactive or drug-eluting stents for malignant disease. It is hoped that, in the future, newer stents will improve our management of these difficult conditions and, possibly, provide prognostic as well as symptomatic benefit in the setting of malignant obstruction.