A new fully covered metal stent with anti-migration features for the treatment of malignant dysphagia

Structural optimization and in vivo evaluation of a colorectal stent with anti-migration and anti-tumor properties

Clinically, colorectal stents can only palliatively relieve obstruction caused by colorectal cancer (CRC), with a high incidence of stent migration and tumor-related re-obstruction. To overcome these shortcomings, we developed a colorectal stent composed of a structure-optimized nitinol braided stent and a tubular film including an inner layer of poly (ethylene-co-vinyl acetate) (EVA) and a segmental outer layer of EVA with paclitaxel (PTX). The braiding pattern, segment number, and end shape of the stent were optimized based on the mechanical properties, ex vivo and in vivo anti-migration performance, and tissue response of the stent. The optimized nitinol stent had a structure of one middle segment in a hook-pattern and two end segments in a cross-pattern with two studs on each end in a staggered arrangement. Structure-optimized colorectal stents were prepared and evaluated in vivo. PTX released from the stent was mostly distributed in the rabbit rectum in contact with it. The biosafety of the colorectal stent was evaluated using blood tests, biochemical analysis, anatomical observation, and pathological analysis. The anti-tumor effect of the stent was also evaluated by endoscopy, anatomical observation, and pathological and immunohistochemical analyses in rabbits with orthotopic CRC. The results demonstrate that the optimized colorectal stents have effective anti-migration ability and anti-tumor effects with good biosafety. STATEMENT OF SIGNIFICANCE: In order to overcome the most common disadvantages of migration and re-obstruction of colorectal stents clinically, a colorectal stent composed of a structure-optimized nitinol stent and a tubular film including an inner layer of EVA and a segmental outer layer of EVA with PTX was put forward in this study. The optimized nitinol stent had a structure of one middle segment in hook-pattern and two end segments in cross-pattern with two studs on each end in staggered arrangement. The resulting colorectal stent has been proved with good anti-migration ability, anti-tumor effects, and biosafety in vivo, which provides a safe and effective potential treatment modality for patients with colorectal cancer.

Performance and Predictors of Migration of Partially and Fully Covered Esophageal Self-Expanding Metal Stents for Malignant Dysphagia

BACKGROUND & AIMS

Self-expanding metal stents (SEMS) are routinely used to palliate malignant dysphagia. However esophageal SEMS can migrate or obstruct due to epithelial hyperplasia. The aim of this study was to evaluate the rates and factors predicting migration and obstruction, and the nutritional outcomes in partially covered (pc) vs. fully covered (fc) SEMS vs. fcSEMS with antimigration fins (AF) placed for malignant dysphagia.

METHODS

A retrospective review of consecutive patients undergoing SEMS placement for malignant dysphagia at three academic medical centers.

RESULTS

Among 357 patients, there were 55 (15.4%) stent migrations, 45 (12.6%) obstructions from epithelial hyperplasia, and 20 (5.6%) food impactions. Median overall survival was 79 days (IQR 41,199). The percent weight change/change in albumin at 30 and 60 days after SEMS placement were -2.24%/-0.544 g/dL and -2.98%/-0.55 g/dL, respectively. Stent migration occurred significantly more often with fcSEMS than pcSEMS (25.3% vs 10.9%; P < .003), but there was no difference when either group was compared to fcSEMS-AF (19.3%). The overall rate of epithelial hyperplasia resulting in stent obstruction was low (12.6%) and not different between stent types. Factors associated with increased risk of SEMS migration on multivariable logistic regression included stricture traversability with a diagnostic endoscope (OR, 2.37; 95% CI, 1.29-4.35) and use of fcSEMS (OR, 2.56; 1.31-5.00) or fcSEMS-AF (OR, 2.30, 1.03-5.14).

CONCLUSIONS

Traversability of a malignant esophageal stenosis predicts SEMS migration. In these patients with a limited overall survival, pcSEMS are associated with lower rates of stent migration and similar rates of obstruction compared to fcSEMS.

Palliation of malignant esophageal obstruction using an anti-migration self-expandable metal stent: Results of a prospective multicenter study

BACKGROUND

Self-expanding metal stents (SEMS) placement is primarily indicated to palliate dysphagia for patients with expected short-term survival. We aimed to assess the migration rate and other stent-related adverse events (AEs) of a fully covered SEMS with an anti-migration system (FCSEMS-AMS) for palliation of malignant dysphagia.

METHODS

This is a prospective study including patients with inoperable esophageal cancer that received a FCSEMS-AMS (Taewoong, Niti-S Beta™), in five tertiary-care endoscopic centers from January 2014 to February 2016.

RESULTS

Fifty-three consecutive patients were enrolled. Tumor location was proximal, mid and distal esophagus±esophago-gastric junction (EGJ) in 6, 14, and 33 cases, respectively. Overall, non-severe AEs were reported in 18 patients (34.0%), 13 of them required an additional endoscopic procedure. Migration occurred in 7 patients (13.2%): 3 from the upper and 4 from the lower esophagus and EGJ. Stent retrieval was necessary in one patient due to intolerable pain. Food bolus impaction and tumor overgrowth occurred in 2 patients (3.8%) and 4 (7.5%) patients respectively. Four patients complained of gastroesophageal reflux as late AEs. Median follow-up was 19.3 months. Dysphagia significantly improved until 3 and 6 months from stent insertion (median score before FCSEMS-AMS: 3, vs median score: 1). Median dysphagia-free time was 10 months.

CONCLUSIONS

Placement of the Taewoong, Niti-S Beta™ stent appeared to be a safe and effective treatment of malignant dysphagia. The anti-migration system reduced the overall migration rate, although it remained high in strictures located in the upper esophagus and when the stent was placed across the EGJ.

Through-the-scope esophageal stent for the relief of malignant dysphagia: Results of a multicentric study (with video)

BACKGROUND AND AIM

In presence of malignant dysphagia, in patients unfit for surgery, the placement of a self-expandable metal stent (SEMS) represents a safe and effective palliative treatment. Esophageal stents (ES) present an over-the-wire mechanism where the stent is deployed under X-ray control. Recently a through-the-scope (TTS) ES was launched. The aim of our retrospective study is to assess the technical and clinical success of the new TTS-ES.

MATERIALS AND METHODS

Patients with malignant dysphagia caused by esophageal cancer or ab-extrinsic compression, who underwent TTS esophageal stent in six Italian endoscopic referral centers, were retrospectively reviewed.

RESULTS

A total of 40 patients were enrolled. TTS stent placement was successful in 39/40 patients (97.5%). 31 patients had an Ogilvie score of 4, nine an Ogilvie 3. After 2 weeks from stent placement 29 reported Ogilvie score of 0, eight a score of 1. None of the patients developed retrosternal pain requiring drugs. No patient experienced perforation, bleeding or migration. A total of seven patients (18%) developed dysphagia as late adverse event (AE).

CONCLUSION

Through-the-scope ES presented less AEs, in terms of bleeding and perforation, if compared to the previous published data. An anti-migration system could be helpful, especially when the stent is placed for "ab-extrinseco" malignant dysphagia.

Through-the-scope placement of a fully covered metal stent for palliation of malignant dysphagia: a prospective cohort study (with video)

BACKGROUND AND AIMS

To further optimize endoscopic stent placement, an esophageal fully covered self-expandable metal stent with a through-the-scope (TTS) delivery system was designed, providing direct endoscopic control during stent placement. The aim of the study was to assess the feasibility and safety of a TTS stent approach for palliation of malignant dysphagia.

METHODS

This multicenter prospective feasibility study included patients with malignant dysphagia undergoing stent placement. The primary outcome was technical success of TTS stent placement. Secondary outcomes included functional outcome, adverse events, and survival. Patients were prospectively evaluated at days 14 and 28, and monthly thereafter, until death or stent removal.

RESULTS

In total, 33 stents were placed in 32 patients. TTS stent placement was feasible in 30 (91%) procedures. In the other 3 procedures (9%), no large-channel endoscope could be introduced because of patient discomfort. In 10 (33%) TTS procedures, technical success was achieved because no fluoroscopy and/or guidewire was used, whereas in 20 (67%) TTS procedures, placement was supported by a guidewire (n = 9), or fluoroscopy and a guidewire (n = 11). After 2 weeks, dysphagia scores had improved in 24 (86%) patients. Median dysphagia-free time was 32 days (interquartile range [IQR], 17-76 days). In 20 (63%) patients, 29 serious adverse events (SAEs) occurred. Recurrent dysphagia occurred in 13 (41%) patients due to migration (n = 5), tissue overgrowth (n = 4), and stent deformation (n = 4). Other SAEs included significant retrosternal pain (n = 4), hemorrhage (n = 2), and esophageal perforation (n = 1). No patient died from a stent-related cause. Median survival was 42 days (IQR, 28-91 days).

CONCLUSION

Placement of an esophageal TTS stent was feasible in most of the patients with malignant dysphagia. However, stent placement was associated with a relatively high adverse event rate, and in more than one-third of patients, stent placement still required fluoroscopy, which limited optimal benefit of the TTS approach. (Clinical trial registration number: NCT03269903.).

Self-expandable metal stents are a valid option in long-term survivors of advanced esophageal cancer

BACKGROUND

self-expandable metal stents are often used for the palliative treatment of dysphagia in patients with advanced esophageal cancer and an anticipated limited survival. Due to previous reports of a high rate of adverse event when used long-term, concerns have been raised with regard to the use of self-expandable metal stents in patients with a longer survival.

AIM

assess the role of esophageal self-expandable metal stents in patients with advanced esophageal cancer that have survived longer than six months.

METHODS

retrospective study of patients with advanced esophageal cancer with a self-expandable metal stent and a stent placement time greater than six months.

RESULTS

forty-two patients were followed up for 298 days. There was a clinical improvement in all patients. However, 59% of patients experienced an adverse event. The median stent patency was 236 days. Endoscopic management was attempted in all self-expandable metal related adverse events, with a clinical success rate of 100%. However, the previously treated adverse event recurred in seven patients. Multivariate analysis showed that strictures that were traversable with an ultrathin gastroscope were associated with a higher risk of adverse events (p = 0.035).

CONCLUSIONS

long-term esophageal stenting in patients with advanced esophageal cancer is associated with a high prevalence of adverse events without an impact on mortality; most cases can be managed endoscopically.

Palliation of dysphagia

Palliation of dysphagia is the cornerstone of palliative treatment in patients with incurable oesophageal cancer. Available palliative options for dysphagia are oesophageal stent placement and radiotherapy. In general, oesophageal stent placement is the preferred therapeutic option in patients with a relatively poor prognosis because of its rapid relief of dysphagia. Regardless of ongoing technical developments, recurrence of dysphagia and stent-related complications are still occurring. For patients with a relatively good prognosis, intra-luminal brachytherapy is advised because of its sustained palliation of dysphagia. Due to limited availability of intra-luminal brachytherapy in clinical practice, fractionated external beam radiation therapy is commonly applied as an alternative. Selection of the optimal palliative approach for patients remains however challenging as conclusive high-quality evidence is limited. Moreover, with the introduction of new palliative treatment options (e.g. palliative chemotherapeutic and radiotherapeutic options) and the concurrent change of patient characteristics, supporting evidence from large randomised studies is warranted.

Esophageal Stenting in Clinical Practice: an Overview

OPINION STATEMENT

PURPOSE OF REVIEW: Esophageal stents are used in clinical practice for endoscopic treatment of a wide variety of esophageal diseases and conditions. This review provides key principles and a literature update on the utility and limitations of esophageal stenting in clinical practice.

RECENT FINDINGS

Indications for esophageal stenting can be subdivided into two groups. The first group consists of patients with malignant or benign dysphagia, in which an esophageal stent restores luminal patency. In the past years, temporary stent placement has increasingly been used in the therapeutic management of refractory benign esophageal strictures. When endoscopic repeated bougie dilation and other endoscopic treatment modalities have failed, an esophageal stent could be considered. Based on the literature, a fully covered self-expandable metal stent may be the preferred choice for the treatment of both malignant and benign dysphagia. The second group consists of patients with leakage from the esophageal lumen into the surrounding tissue. Esophageal leakage can be subdivided into three forms, benign esophageal perforations (iatrogenic and spontaneous), anastomotic leakage after reconstructive esophageal surgery, and fistula. In a carefully selected group of patients, a covered esophageal stent may be used for sealing off the leakage, thereby preventing further contamination of the tissue surrounding the defect. The past few years, several validated prediction tools have been developed that may assist clinicians in the selection of patients eligible for esophageal stent placement. Based on retrospective studies and expert opinion, a partially or fully covered self-expandable metal stent may have a role in treatment of esophageal leakage. Research do date supports the utilization of esophageal stents for the treatment of malignant or benign dysphagia and esophageal leakage.

Self-Expandable Metallic Stent Placement for the Palliation of Esophageal Cancer

Esophageal stents have been used to palliate patients with dysphagia caused by esophageal cancer. Early rigid plastic prostheses have been associated with a high risk of complications. However, with the development of self-expanding stents, it has developed into a widely accepted method for treating malignant esophageal strictures and esophagorespiratory fistulas (ERFs). The present review covers various aspects of self-expanding metallic stent placement for palliating esophageal cancer, including its types, placement procedures, indications, contraindications, complications, and some of innovations that will become available in the future.

Postsurgical Perforation of the Esophagus Can Be Treated Using a Fully Covered Stent in Children

OBJECTIVES

Surgery and conservative treatment of esophageal or gastric perforations are both often associated with poor results and carry a high morbidity and mortality rate. The aim of the present study was to evaluate the effectiveness and safety of using fully covered self-expending metallic stents (SEMS) in children with upper digestive leaks.

METHODS

This retrospective study reviewed all children with esophageal or gastric perforation who were treated with placement of an SEMS from January 2011 to January 2015. Closure of the perforation was the primary outcome measured. Secondary outcomes were the duration of antibiotic therapy and parenteral nutrition, adverse events, and length of hospitalization.

RESULTS

A total of 19 SEMS were placed in 10 patients (median age: 5.5 years; 5 girls) treated for postanastomotic leaks of esophageal atresia (n = 3), esophagogastroplasty (n = 4), resection of esophageal duplication (n = 1) or perforation during Toupet surgical dismantling (n = 1), and gastric rupture after Nissen surgery (n = 1). The perforation closed in 9 out of 10 patients in a mean of 36 days after stenting (range: 13-158 days). All patients received antibiotic therapy for an average of 17.5 days (3-109 days) and parenteral nutrition for 49 days (17-266 days). During a median follow-up of 8.9 months, 4 out of 9 sealed perforations developed stenosis, which was efficiently treated by endoscopic dilations in 2 patients and surgical redo in 2 patients with dilation-resistant stenosis.

CONCLUSIONS

Covered stents appear to be beneficial in closing esophageal perforations in children and can avoid the high morbidity of a surgical repair. Stenosis, however, occurred frequently after larger leakages.

Antireflux versus conventional self-expanding metallic Stents (SEMS) for distal esophageal cancer: results of a multicenter randomized trial

INTRODUCTION

Self-expanding metal stents (SEMS) are commonly used in the palliation of dysphagia in patients with inoperable esophageal carcinoma. However, they predispose to gastroesophageal reflux when deployed across the gastroesophageal junction. The aims of this study were to: 1) assess the influence of the antireflux valve on trans-prosthetic reflux (primary outcome); and 2) compare the results of SEMS with and without antireflux valve in terms of reflux symptoms, quality of life (QOL), improvement of dysphagia and adverse events (secondary outcomes).

PATIENTS AND METHODS

Thirty-eight patients were enrolled in nine centers. Carcinomas were locally advanced (47 %) or metastatic. After randomization, patients received either a covered SEMS with antireflux valve (n = 20) or a similar type of SEMS with no antireflux device but assigned to standard proton pump inhibitor therapy and postural advice (n = 18). Trans-prosthetic reflux was assessed at day 2 using a radiological score based on barium esophagography performed after Trendelenburg maneuver and graded from 0 (no reflux) to 12 (maximum). Monthly telephone interviews were conducted for Organisation Mondiale de la Santé (OMS) scoring from 0 (excellent) to 5 (poor), QOL assessment (based on the Reflux-Qual Simplifié scoring system) from 0 (poor) to 100 (excellent), dysphagia scoring from 0 (no dysphagia) to 5 (complete dysphagia) and regurgitation scoring from 0 (no regurgitation) to 16 (maximum).

RESULTS

No difference was noted in terms of age, sex, size of lesion, prosthesis length or need for dilation prior to SEMS placement. No difficulty in placing SEMS nor complications were noted. Radiological scores of reflux were found to be significantly lower in patients with an antireflux stent compared to the conventional stent and associated measures. The regurgitation scores were significantly decreased in patients with antireflux stents during the first 2 months after stent placement and thereafter, they were similar in the two groups. QOL and dysphagia were improved in both groups. Survival rates were comparable in the two groups.

CONCLUSIONS

No difference was observed between the two types of SEMS regarding the palliation of dysphagia and improvement of QOL. However, SEMS with an antireflux valve were more effective in preventing trans-prosthetic gastroesophageal reflux but at the cost of an increased likehood of minor adverse events (migrations and/or obstruction of the SEMS).