Esophageal Stents: Placement, Complications, Tips, and Tricks

Wireless Peristaltic Pump for Transporting Viscous Fluids and Solid Cargos in Confined Spaces

The transport of fluids and solids is a vital process inside the human body, facilitated by the wave-like motion in the lumen called peristalsis. However, peristalsis may be compromised due to tumor growth, resulting in difficulties in lumen motility. The dysmotility of the human lumen can result in blockages and pose numerous challenges, including aspiration in the lungs and reproductive issues in the female oviduct. Restoring peristalsis in medical devices, such as medical stents, can prevent device blockage and promote effective transport. Here, a wirelessly actuated soft robotic undulating pump designed to efficiently transport both viscous fluidic and solid cargos is proposed. The kinematics of the single sheet and the coordination between pairs are systematically designed to generate undulation and peristalsis, enabling the pumping of both liquids and solids. The integration of the undulating pump is demonstrated onto an esophageal stent. The same undulating motion-based pumping mechanism can be adapted for usage in other organs, such as the female oviduct, thereby offering potential applications for treating lumen dysmotility in various diseases. The proposed wirelessly actuated robotic pumping mechanism holds promise in facilitating diverse implantable medical devices aimed at treating diseases characterized by impaired peristalsis and dysmotility.

A Comprehensive Analysis of Reported Adverse Events and Device Failures Associated with Esophageal Self-Expandable Metal Stents: An FDA MAUDE Database Study

INTRODUCTION

Esophageal Stents are used to maintain esophageal lumen patency in esophageal strictures caused by intrinsic and/or extrinsic malignancies and the occlusion of concomitant esophageal fistulas. While data on the efficacy and safety of esophageal stents exist, comprehensive evaluation of adverse events is limited. The aim of this study is to investigate the reported adverse events and device failures associated with esophageal self-expandable metal stents (SEMS) using the FDA's Manufacturer and User Facility Device Experience (MAUDE) database.

METHODS

Post-marketing surveillance data for the esophageal SEMSs were analyzed using the FDA's MAUDE database from January 2014 to December 10, 2023. The outcomes of interest were patient-related adverse events and device failures. Statistical analysis was performed using Microsoft Excel 2010 and SPSS. Pooled numbers and percentages were calculated for each adverse event. Continuous variables underwent analysis using a two-tailed student t test, and significance was set to p ≤ 0.05.

RESULTS

During the study period, 548 MAUDE reports revealed 873 device failures and 186 patient-related adverse events. The most common device issues were stent activation, positioning, or separation problems (4 n = 403; 46.2%), followed by device detachment or migration (n = 109, 12.5%), and material problems (n = 93, 10.7%). Patient complications included dysphagia/odynophagia (10%), perforation, pain, and bleeding (each 7.6%). The most common device failures in over-the-wire (OTW) stents and through-the-scope (TTS) stents were activation, positioning, or separation problems (TTS: n = 183, 52.6% vs OTW: n = 220, 41.9%). Compared to OTW stents, TTS stents had higher migration and breakage (13.5% vs. 11.8%, p = 0.24), and (9.2% vs. 6.7%, p = 0.08) respectively, while OTW stents had more challenges with stent advancement or removal (5.1% vs. 0.3%, p < 0.001 and 4.6% vs 3.4%, p = 0.19, respectively) and material problems (14.7% vs. 4.6%, p < 0.001). Activation, positioning, and separation problems were the most frequent device failures in fully covered (FC) and partially covered (PC) stents (FC: n = 62, 32.8%, PC: n = 168, 43.5%). FC stents had higher migration rates (20.6% vs 9.8%, p < 0.001), while PC stents exhibited more material problems (17.4% vs. 5.8%, p < 0.001) and difficulties with advancing the stents (6.7% vs. 0%, p < 0.001).

CONCLUSION

Our examination showed a prevalence of reported device complications associated with stent activation, positioning, and separation problems. Dysphagia or odynophagia emerged as the most frequently reported patient complication. Furthermore, our analysis, provides insights into TTS vs. OTW and FC vs. PC esophageal SEMSs, enabling endoscopists and manufacturers to better understand adverse events and potentially optimize device design for future iterations.

A novel technique to remove migrated esophageal stent under fluoroscopy

PURPOSE

To evaluate the efficacy and safety of a novel technique for removal of migrated esophageal stent (MES) under fluoroscopy.

METHODS

From January 2009 to April 2023, 793 patients with a dysphagia score of 3-4 underwent esophageal stenting at our center, and 25 patients (mean age: 70.06 years old; male/female: 15/10) underwent stent removal using "loop method" under fluoroscopy. The primary outcomes were technical success and complications. The secondary outcomes were procedure time, radiation exposure, biochemical indicators [white blood cell (WBC), hemoglobin (Hb), platelet (PLT), albumin (ALB), alanine transaminase (ALT), total bilirubin (TB), urea nitrogen (UN) and C-reactive protein] of pre- and post-treatment at 2 weeks.

RESULTS

Technical success was 100% without major complications. The mean procedure time was (39.44 ± 9.28) minutes, which showed no statistical significance between benign (n = 5) and malignant (n = 20) group [(42.40 ± 8.85) vs (38.71 ± 9.46) mins, p > 0.05]. The mean radiation exposure was (332.88 ± 261.47) mGy, which showed no statistical significance between benign and malignant group [(360.74 ± 231.43) vs (325.92 ± 273.54) mGy, p > 0.05]. Pre- and post-procedure Hb [(114.46 ± 11.96) vs. (117.57 ± 13.12) g/L] and ALB [(42.26 ± 3.39) vs. (44.12 ± 3.77) g/L] showed significant difference (p < 0.05), while WBC, PLT, CRP, and ALT showed no significance (p > 0.05).

CONCLUSION

Fluoroscopy-guided "Loop method" for MES removal is an effective and safe alternative technique.

Predictors of adverse events and early mortality after esophageal stent placement in a low resource setting: a series of 3823 patients in Kenya

Background and study aims  Dysphagia from esophageal cancer may be palliated with self-expanding metallic stents (SEMS). Controversy exists about the use of dilation before SEMS deployment. Patients and methods  We performed a retrospective cohort study of patients who had SEMS placement without fluoroscopy for palliation at Tenwek Hospital in Bomet, Kenya between January 1999 and April 2019. The primary outcome was any serious adverse event (AE) (chest pain, stent migration, perforation, bleeding, or all-cause mortality) within 30 days of the procedure. Various demographic and clinical characteristics, and procedural details, were examined as risk factors. Technical success, defined as correct SEMS placement, and clinical success, defined as dysphagia score improvement without 30-day mortality, were examined. Results  A total of 3823 patients underwent SEMS placement, with 2844 (74.4 %) placed in the second decade of the study. Technical and clinical success were achieved in 97.2 % and 95.5 %, respectively, with mean dysphagia scores improving from 3.4 (SD 0.6) to 0.9 (SD 1.3) post-stent placement. AEs occurred in 169 patients (4.4 %). AEs, specifically perforations, were associated with dilation to greater than 36F in the first decade. Perforation rates decreased from the first (4.1 %) to the second decade (0.2 %). Only 30% had complete 30-day follow-up data. Conclusions  SEMS placement is a safe, effective method of palliating malignant dysphagia, with low rates of AEs and 30-day mortality and high rates of clinical and technical success. Dilation can facilitate placement of SEMS without fluoroscopy but should not be performed above 36F due to the risk of perforation.

Outcome of dogs and cats with benign oesophageal strictures after balloon dilatation or stenting: 27 cases (2002-2019)

OBJECTIVES

Acquired oesophageal strictures remain challenging to manage in canine and feline patients. The aims of this study were to describe the treatment, complications, short-term outcome and long-term follow-up of benign oesophageal strictures treated by balloon dilatation or stenting in dogs and cats and to describe adjunctive techniques to minimise the complication rate of stent placement.

MATERIALS AND METHODS

Retrospective analysis of medical records of dogs and cats with benign oesophageal stricture diagnosed under endoscopy between 2002 and 2019.

RESULTS

Eighteen dogs and nine cats were included, representing 39 strictures. Balloon dilatation was used as first-line therapy, with a good outcome in 59% of cases. Stents were placed in eight cases due to stricture recurrence; 88% had a long-term satisfactory outcome. Short-term complications occurred in six of eight cases; migration and aberrant mucosal reaction were uncommon. In three cases, progressive mesh cutting during follow-up reduced discomfort and trichobezoars formation and improved long-term stent tolerance. Overall median survival time was 730 days.

CLINICAL SIGNIFICANCE

Long-term prognosis of balloon dilatation as a first-line therapy for esophageal strictures and of stenting as a rescue therapy was considered satisfactory. Although discomfort associated with stenting was frequent, tolerability might be improved by per-endoscopic adjunctive techniques.

Perforated Gastric Body Secondary to Migrated Esophageal Stent

A 44-year-old male presented to the ER with severe abdominal pain and a reported syncope episode. Focused abdominal sonography in trauma and abdominal exam demonstrated free fluid and peritonitis. CT scan demonstrated a metallic object in the stomach with free air and fluid throughout the abdomen. The following report is a rare case presentation of a perforated stomach secondary to a migrated esophageal stent used for the treatment of a benign esophageal stricture refractory to other treatment modalities.

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.).

In Vitro Evaluation of Mechanical Properties of Segmented Esophageal Self-Expandable Metal Stents: Innovative Test Methods Are Needed

Background: Self-expanding metal stents (SEMSs) in different geometric shapes are well established treatment options in diseases of the esophagus. Mechanical properties and stent design may have an impact on patient comfort, migration rate, and removability. In this in vitro study, we evaluated mechanical properties of three segmented SEMSs (segSEMSs) for the esophagus with regard to distinct stent sections. Materials and Methods: Radial forces were measured using a testing method distinguishing between circumferential radial and local radial force. The center parts of the segSEMSs were measured for circumferential radial forces without being affected by the flared ends. Axial forces were measured at 20° bending. Results: Circumferential radial force measurements over the full stent length showed substantial differences against measurements of the center parts of the stents as the flared ends falsify test results by up to 53%. Although circumferential radial forces of the center parts were about the same (<10% variances) for all segSEMSs, local radial forces showed considerable differences of up to 26%. One segSEMS showed high axial forces, whereas the other two only needed half of the force (up to 53%) to be bent to 20°. Conclusion: Flared ends of segSEMSs have a substantial impact on radial force measurements and therefore alter test results, confirmed by our separated center part test of segSEMSs. Our innovative setup whereby we compressed the stent in an asymmetric manner (local radial force) and evaluated sections of stents separately, indeed revealed differences to circumferential measurements, leading to a more in-depth knowledge of stent characteristics.

Stretch-Induced Drug Delivery from Superhydrophobic Polymer Composites: Use of Crack Propagation Failure Modes for Controlling Release Rates

The concept of using crack propagation in polymeric materials to control drug release and its first demonstration are reported. The composite drug delivery system consists of highly-textured superhydrophobic electrosprayed microparticle coatings, composed of biodegradable and biocompatible polymers poly(caprolactone) and poly(glycerol monostearate carbonate-co-caprolactone), and a cellulose/polyester core. The release of entrapped agents is controlled by the magnitude of applied strain, resulting in a graded response from water infiltration through the propagating patterned cracks in the coating. Strain-dependent delivery of the anticancer agents cisplatin and 7-ethyl-10-hydroxycamptothecin to esophageal cancer cells (OE33) in vitro is observed. Finally the device is integrated with an esophageal stent to demonstrate delivery of fluorescein diacetate, using applied tension, to an ex vivo esophagus.