Esophageal cancer: self-expanding metallic stents

The Role of Self-Expandable Metallic Stents in the Treatment of Malignant Strictures in all Segments of the Gastrointestinal Tract

Objectives

Management of malignant gastrointestinal (GI) obstruction presents a significant challenge. Most patients are in a profoundly decompensated state due to underlying malignancy and are not ideal candidates for invasive surgical procedures. Self-expandable metallic stents (SEMSs) are used to provide permanent or temporary patency in all endoscopically accessible stenosis of the GI tract. In this study, it is aimed to analyse the characteristics and the efficacy of patients with malignant stenosis treated with SEMS, in all segments of the GI tract.

Material and Methods

The sample consisted of 60 patients who underwent SEMS replacement, between 10 March 2014 and 16 December 2020, to treat malignant-related strictures in the GI tract at the Gastroenterology Department of the Health Sciences University Umraniye Training and Research Hospital. The data of the patients, hospital data processing database and electronic endoscopic database records were retrospectively scanned and recorded. The general characteristics of the patients and the treatment-related features were analysed.

Results

The mean age of patients who were placed SEMS was 69.7 ± 13.7 years. Uncovered (15%, n: 9), fully covered (13.3%, n: 8), or partially covered (71.6%, n: 43) SEMS were successfully placed in all patients. Clinical success in patients with SEMS was 85.7% in the esophagus, 100% in the small intestine and 90.9% in the stomach and colon. About 11.4% migration, 14.2% pain, 11.4% overgrowth and 5.7% ingrowth were detected in patients who had SEMS placed in the oesophagus. Pain was detected in 9.1% and ingrowth in 18.2% of patients who had SEMS placed in the stomach. Pain was detected in 18.2% of the patients who had SEMS placed in the colon and migration was found in 9.1%.

Conclusion

SEMS implant is a minimally invasive effective method in the palliative treatment of malignant strictures of the GI tract.

Interventional Endoscopy for Palliation of Luminal Gastrointestinal Obstructions in Management of Cancer: Practical Guide for Oncologists

Self-expanding metal stents placed during endoscopy are increasingly the first-line treatment for luminal obstruction caused by esophageal, gastroduodenal, and colorectal malignancies in patients who are not candidates for definitive surgical resection. In this review, we provide a practical guide for clinicians to optimise patient and procedure selection for endoscopic stenting in malignant gastrointestinal obstructions. The role of endoscopic stenting in each of the major anatomical systems (esophageal, gastroduodenal, and colorectal) is presented with regard to pre-procedural patient evaluation, procedural techniques, clinical outcomes, and potential complications, as well as post-procedure aftercare.

A Review of Self-Expanding Esophageal Stents for the Palliation Therapy of Inoperable Esophageal Malignancies

Esophageal cancer is a very deadly disease, killing more than 15,000 people in the United States annually. Almost 400,000 new cases happen in the worldwide every year. More than 50% esophageal cancer patients are diagnosed at an advanced stage when they need an esophageal stent to open the blocked esophagus for feeding and drinking. Esophageal stents have evolved in stages over the years. Current clinically used stents commonly include stainless steel or nitinol self-expandable metallic stent (SEMS) and self-expandable plastic stent (SEPS). There are many choices of different types of stents and sizes, with fierce competition among manufacturers. However, current stent technology, whether uncovered, partially covered, fully covered SEMS or SEPS, has their own advantages to solve the dysphagia, stricture, and fistula problems, but they also cause some clinical complications. The ideal stent remains elusive. New 3D printing technique may bring new promising potential to manufacturing personalized esophageal stents. Drug-eluting stents could be the new avenue to do more than just pry open a stricture or cover a defect in the esophageal lumen, a possibility of proving local anticancer therapy simultaneously. Additionally, the lack of esophageal cancer animal models also hinders the progress of stent development. This paper reviews these topics for a comprehensive understanding of this field. In a conclusion, the ultimate goal of the future esophageal stent would have multifunction to treat the underlying conditions and restore esophageal function to near normal.

Double-layered covered stent for the treatment of malignant oesophageal obstructions: Systematic review and meta-analysis

AIM

To investigate the efficacy of double-layered covered stent in the treatment of malignant oesophageal obstructions.

METHODS

A systematic review and meta-analysis was performed following the PRISMA process. PubMed (Medline), EMBASE (Excerpta Medical Database), AMED (Allied and Complementary medicine Database), Scopus and online content, were searched for studies reporting on the NiTi-S polyurethane-covered double oesophageal stent for the treatment of malignant dysphagia. Weighted pooled outcomes were synthesized with a random effects model to account for clinical heterogeneity. All studies reporting the outcome of palliative management of dysphagia due to histologically confirmed malignant oesophageal obstruction using double-layered covered nitinol stent were included. The level of statistical significance was set at α = 0.05.

RESULTS

Six clinical studies comprising 250 patients in total were identified. Pooled technical success of stent insertion was 97.2% (95%CI: 94.8%-98.9%; I² = 5.8%). Pooled complication rate was 27.6% (95%CI: 20.7%-35.2%; I² = 41.9%). Weighted improvement of dysphagia on a scale of 0-5 scoring system was -2.00 [95%CI: -2.29%-(-1.72%); I² = 87%]. Distal stent migration was documented in 10 out of the 250 cases examined. Pooled stent migration rate was 4.7% (95%CI: 2.5%-7.7%; I² = 0%). Finally, tumour overgrowth was reported in 34 out of the 250 cases with pooled rate of tumour overgrowth of 11.2% (95%CI: 3.7%-22.1%; I² = 82.2%). No funnel plot asymmetry to suggest publication bias (bias = 0.39, P = 0.78). In the sensitivity analysis all results were largely similar between the fixed and random effects models.

CONCLUSION

The double-layered nitinol stent provides immediate relief of malignant dysphagia with low rates of stent migration and tumour overgrowth

Closure of benign leaks, perforations, and fistulas with temporary placement of fully covered metal stents: a retrospective analysis

INTRODUCTION

Partially covered self-expanding metal stents (SEMS), have been suggested as an alternative to surgery in the treatment of esophageal fistulas of benign etiology. Nevertheless, uncomplicated removal remains difficult. The use of fully covered (FC) SEMSs could solve this problem.

OBJECTIVES

To review our experience with FC-SEMS placement in patients with benign upper gastrointestinal leaks or perforations. We wanted to assess successful closure of the perforations and short-term and long-term complications.

MATERIALS AND METHODS

Multicenter study, including 3 tertiary centers. Retrospective review of patients who underwent FC-SEMS placement for benign perforations.

RESULTS

Eighty-eight stents were placed in 56 patients. We achieved leak closure in 44 patients (78.6%). There were 18 migrations. All of them could be solved endoscopically. A severe septic situation was associated with a higher mortality rate (27.6% vs. 7.4%; P=0.049) and a lower success rate (34.5% vs. 7.4%; P=0.088), compared with those patients who did not present severe sepsis. However, these differences could not be confirmed by multivariable analysis. The results in the subgroup of 11 patients with leaks after sleeve gastrectomy were also good (73% success without surgery and 0% mortality).

CONCLUSIONS

Temporary placement of FC-SEMS for benign perforations, fistulas, and leaks is feasible in sealing the leaks. All migrations could be solved endoscopically. It is very important to insert the stent before sepsis is established. This article also would be an addition to the growing body of literature supporting stenting as a good alternative if not standard approach to controlling these leaks.

Engineering Stent Based Delivery System for Esophageal Cancer Using Docetaxel

Esophageal cancer patients are often diagnosed as "advanced" cases. These patients are subjected to palliative stenting using self-expanding metallic stents (SEMS) to maintain oral alimentation. Unfortunately, SEMS get reoccluded due to tumor growth, in and over the stent struts. To investigate potential solutions to this problem, docetaxel (DTX) delivery films were prepared using PurSil AL 20 (PUS), which can be used as a covering material for the SEMS. Drug-polymer miscibility and interactions were studied. Bilayer films were prepared by adhering the blank film to the DTX loaded film in order to maintain the unidirectional delivery to the esophagus. In vitro release and the local DTX delivery were studied using in vitro permeation experiments. It was found that DTX and PUS were physically and chemically compatible. The bilayer films exhibited sustained release (>30 days) and minimal DTX permeation through esophageal tissues in vitro. The rate-determining step for the DTX delivery was calculated. It was found that >0.9 fraction of rate control lies with the esophageal tissues, suggesting that DTX delivery can be sustained for longer periods compared to the in vitro release observed. Thus, the bilayer films can be developed as a localized sustained delivery system in combination with the stent.

Recent Advances in Gastrointestinal Stent Development

Endoscopic stenting is increasingly being used in the management of gastrointestinal luminal obstruction, and has become the current treatment of choice for the palliation of blockage caused by malignant or benign growths. A variety of stents have been developed to enhance the efficacy of the procedure, and improvements are ongoing. In this article, we review the history of, and recent advances in, gastrointestinal stenting. We describe the rationale behind the design as well as the resulting outcome for each stent type.

Recent Advances in Gastrointestinal Stent Development

Endoscopic stenting is increasingly being used in the management of gastrointestinal luminal obstruction, and has become the current treatment of choice for the palliation of blockage caused by malignant or benign growths. A variety of stents have been developed to enhance the efficacy of the procedure, and improvements are ongoing. In this article, we review the history of, and recent advances in, gastrointestinal stenting. We describe the rationale behind the design as well as the resulting outcome for each stent type.

Conventional stents versus stents loaded with (125)iodine seeds for the treatment of unresectable oesophageal cancer: a multicentre, randomised phase 3 trial

BACKGROUND

The combination of stent insertion and single high-dose brachytherapy is a feasible and safe palliative treatment regimen in patients with unresectable oesophageal cancer. We aimed to further assess the efficacy of this treatment strategy compared to a conventional covered stent in patients with dysphagia caused by unresectable oesophageal cancer.

METHODS

In this multicentre, single-blind, randomised, phase 3 trial, we enrolled patients with unresectable oesophageal cancer from 16 hospitals in China. We included adult patients (aged ≥ 20 years) with progressive dysphagia, unresectable tumours due to extensive lesions, metastases, or poor medical condition, and with clear consciousness, cooperation, and an Eastern Cooperative Oncology Group (ECOG) performance status score of 0-3. Eligible patients were randomly assigned (in 1:1 ratio, no stratification) to receive either a stent loaded with (125)iodine radioactive seeds (irradiation group) or a conventional oesophageal stent (control group). The primary endpoint was overall survival. Survival analyses were done in a modified intention-to-treat group. This study is registered with ClinicalTrials.gov, number NCT01054274.

FINDINGS

Between Nov 1, 2009, and Oct 31, 2012, 160 patients were randomly assigned to receive treatment with either an irradiation stent (n=80) or a conventional stent (n=80). During a median follow-up of 138 days (IQR 72-207), 148 stents (73 in the irradiation group and 75 in the control group) were successfully placed into the diseased oesophagus in 148 participants. Median overall survival was 177 days (95% CI 153-201) in the irradiation group versus 147 days (124-170) in the control group (p=0.0046). Major complications and side-effects of the treatment were severe chest pain (17 [23%] of 73 patients in the irradiation group vs 15 [20%] of 75 patents in the control group), fistula formation (six [8%] vs five [7%]), aspiration pneumonia (11 [15%] vs 14 [19%]), haemorrhage (five [7%] vs five [7%]), and recurrent dysphagia (21 [28%] vs 20 [27%]).

INTERPRETATION

In patients with unresectable oesophageal cancer, the insertion of an oesophageal stent loaded with (125)iodine seeds prolonged survival when compared with the insertion of a conventional covered self-expandable metallic stent.

Evidence-based recommendations on upper gastrointestinal tract stenting: a report from the stent study group of the korean society of gastrointestinal endoscopy

Endoscopic stents have evolved dramatically over the past 20 years. With the introduction of uncovered self-expanding metal stents in the early 1990s, they are primarily used to palliate symptoms of malignant obstruction in patients with inoperable gastrointestinal (GI) cancer. At present, stents have emerged as an effective, safe, and less invasive alternative for the treatment of malignant GI obstruction. Clinical decisions about stent placement should be made based on the exact understanding of the patient's condition. These recommendations based on a critical review of the available data and expert consensus are made for the purpose of providing endoscopists with information about stent placement. These can be helpful for management of patients with inoperable cancer or various nonmalignant conditions in the upper GI tract.

Radiological image-guided placement of covered Niti-S stent for palliation of dysphagia in patients with cervical esophageal cancer

The aim of this study was to evaluate the clinical effectiveness of covered Niti-S stent placement under multidetector CT and fluoroscopy guidance for the palliation of dysphagia in patients with cervical esophageal cancer. Under radiological imaging guidance using axial and sagittal CT scans, and fluoroscopy, Niti-S esophageal stents were placed in ten consecutive patients with complete obstruction caused by cervical esophageal cancer (9 men and 1 woman; age range = 54–79 years; mean age = 68.1 years) between February 2010 and December 2011. The procedure time and technical success rate were evaluated. Swallowing improvement was assessed by the following items: ability to eat and/or swallow (graded as follows: 3 = ability to eat normal diet, 2 = ability to eat semisolids, 1 = ability to swallow liquids, 0 = complete obstruction). Procedural and post-procedural complications were also evaluated. Survival (mean ± SD) was examined. The mean (±SD) procedure time was 40 ± 19 min (range = 21–69 min). Stent placement was technically successful in all patients; inadequate stent deployment did not occur in any case. Ability to eat and/or swallow was improved and scored 2.4 (score 3 in 5 cases, score 2 in 4 cases, score 1 in 1 case, and score 0 in no case) after stent placement. No major or post-procedural complications were encountered. The mean survival time was 131 ± 77 days (range = 31–259 days). Niti-S stents appeared to be a safe and effective device for the palliation of dysphagia caused by advanced cervical esophageal cancer. Multidetector CT and fluoroscopy image guidance helped the operators accurately place the stents in the cervical esophagus.

Self-expandable metal stents for the treatment of benign upper GI leaks and perforations

BACKGROUND

Self-expandable metal stents (SEMSs) have been suggested for the treatment of benign upper GI leaks and perforations. Nevertheless, uncomplicated removal remains difficult. Placement of a self-expandable plastic stent (SEPS) into an SEMS can facilitate retrieval.

OBJECTIVES

This study reviews our experience with sequential SEMS/SEPS placement in patients with benign upper GI leaks or perforations.

DESIGN

A retrospective review of the chart of each patient who underwent SEMS placement for benign upper GI leaks or perforations, including (1) fistula after bariatric surgery, (2) other postoperative fistulae, (3) Boerhaave syndrome, (4) iatrogenic perforations, and (5) other perforations.

SETTING

Single, tertiary center.

PATIENTS

Eighty-eight patients (37 male, average age 51.6 years, range 18-89 years).

INTERVENTIONS

SEMS placement and removal, with or without SEPS placement.

MAIN OUTCOME MEASUREMENTS

Feasibility of SEMS removal and successful treatment of lesions and short-term and long-term complications.

RESULTS

A total of 153 SEMSs were placed in 88 patients; all placements were successful. Six patients died (not SEMS-related deaths) and 6 patients were lost to follow-up with SEMSs still in place. Seventy-three of the remaining 76 patients had successful SEMS removal (96.1%). The rate of successful SEMS removal per stent was 97.8% (132/135). Resolution of leaks and perforations was achieved in 59 patients (77.6%) with standard endoscopic treatment, and in 64 patients (84.2%) after prolonged, repeated endoscopic treatment. Spontaneous migration occurred in 11.1% of stents, and there were minor complications (dysphagia, hyperplasia, rupture of coating) in 20.9% and major complications (bleeding, perforation, tracheal compression) in 5.9%.

LIMITATIONS

Retrospective design and highly selected patient population.

CONCLUSIONS

Use of SEMSs for the treatment of benign upper GI leaks and perforations is feasible, relatively safe, and effective, and SEMSs can be easily removed 1 to 3 weeks after SEPS insertion. Leaks and perforations were closed in 77.6% of cases.

Stenting of the upper gastrointestinal tract: current status

Minimally invasive image-guided insertion of self-expanding metal stents in the upper gastrointestinal tract is the current treatment of choice for palliation of malignant esophageal or gastroduodenal outlet obstructions. A concise review is presented of contemporary stenting practice of the upper gastrointestinal tract, and the procedures in terms of appropriate patient evaluation, indications, and contraindications for treatment are analyzed, along with available stent designs, procedural steps, clinical outcomes, inadvertent complications, and future technology. Latest developments include biodegradable polymeric stents for benign disease and radioactive or drug-eluting stents for malignant obstructions.

Application progress of stent placement in esophageal malignant and benign stenosis

Stent placement is widely used for palliation of dysphagia caused by advanced esophageal carcinoma. As the development of technology, many new stents are being used for clinical therapy. Some stents are added with anti-reflux valve or retrievable device, some are loaded with ¹²⁵I; the biodegradable stent are even invented. Improvement of sents can decrease many complications while elevate survival rates. Several nonsurgical palliative modalities including endoluminal laser therapy, photodynamic therapy, electrocoagulation and brachytherapy are available to recanalize malignant stenosis, but the fastest palliative method is stent placement. Reports about treating benign esophageal stricture with stents are increasing, and temporary and biodegradable stents have a better effect.

Clinical outcomes and patency of self-expanding metal stents in patients with malignant upper gastrointestinal obstruction

This study was performed to evaluate clinical outcomes and factors associated with patency of self-expanding metal stents (SEMS) in patients with malignant upper gastrointestinal (UGI) obstruction. In 83 patients with malignant UGI obstruction, 118 SEMS placements were performed. Obstruction sites were esophagus/gastro-esophageal junction (GEJ) and gastric outlet (GO) in 41 and 42 patients, respectively. Technical success was achieved in 99.2% and clinical success in 90.5%, with no procedure-related complications. Re-obstruction and migration occurred in 38.1% during a mean follow-up of 137 days; both occurred significantly more often with GO than esophageal/GEJ obstruction (49.2% vs 23.9%). Patency rates of esophageal/GEJ obstruction were 93.5, 78.1 and 67.0% at 30, 90 and 180 days, respectively, and were significantly higher than those of GO obstruction-71.7, 51.8 and 32.5%. Palliative chemotherapy or radiation therapy was not associated with stent patency. Endoscopic SEMS placement is a safe and effective palliative treatment for malignant UGI obstruction, and complications or stent patency differed according to obstruction site.

Stent collapse as a delayed complication of placement of a covered gastroduodenal stent

OBJECTIVE

The purpose of this study was retrospective evaluation of the incidence, predictive factors, and interventional management of stent collapse after placement of a covered metallic stent in patients with obstruction of the gastric outlet or duodenum due to malignant disease.

MATERIALS AND METHODS

Among 259 patients with symptomatic malignant gastroduodenal obstruction successfully treated with stent placement, stent collapse occurred in 12 (4.6%) of the patients 34-270 days (mean, 101.8 days) after stent placement. Multivariate analysis was performed to evaluate factors predictive of stent collapse. Interventional management of stent collapse also was evaluated.

RESULTS

Multivariate analysis showed that presence of the stent in the peripyloric region (odds ratio, 27.745; p = 0.036), longer survival time (odds ratio, 1.016; p < 0.001), and absence of chemotherapy after stent placement (odds ratio, 31.661; p = 0.048) were independent predictors of stent collapse. Eleven patients with stent collapse were successfully treated with placement of a second bare stent. The twelfth patient refused further treatment.

CONCLUSION

Stent collapse is an uncommon delayed complication of placement of covered metallic stents in patients with malignant gastroduodenal obstruction. Collapse occurs most commonly in the peripyloric region, in patients with longer survival times, and in patients who do not undergo chemotherapy after stent placement. Stent collapse can be managed by coaxial placement of a second bare stent into the collapsed stent.

Estimation of 5-fluorouracil-loaded ethylene-vinyl acetate stent coating based on percolation thresholds

The drug percolation thresholds of 5-fluorouracil-loaded ethylene-vinyl acetate stent coatings were estimated to characterize their drug release behavior and mechanical properties. The stent coatings were prepared using 5-fluorouracil (5-FU) as antitumor drug and ethylene-vinyl acetate (EVA) as matrix forming material in different ratios. In vitro release assays were carried out exposing only one side of coating to pH 6.5 PBS. Based on the release profiles, the drug percolation thresholds were estimated as 0.21 of total porosity (corresponding to ca. 32%, w/w of the drug), which is in approximately agreement with the atomic force microscopy (AFM) result. Based on the coating tensible break strength and tear break strength data, the mechanical percolation thresholds of drug were obtained as 39.7+/-0.3 and 37.5+/-1.4% (w/w) of drug content, respectively.