Endoscopic submucosal dissection combined with the placement of biodegradable stents for recurrent esophageal cancer after chemoradiotherapy

Comprehensive review of materials, applications, and future innovations in biodegradable esophageal stents

Esophageal stricture (ES) results from benign and malignant conditions, such as uncontrolled gastroesophageal reflux disease (GERD) and esophageal neoplasms. Upper gastrointestinal endoscopy is the preferred diagnostic approach for ES and its underlying causes. Stent insertion using an endoscope is a prevalent method for alleviating or treating ES. Nevertheless, the widely used self-expandable metal stents (SEMS) and self-expandable plastic stents (SEPS) can result in complications such as migration and restenosis. Furthermore, they necessitate secondary extraction in cases of benign esophageal stricture (BES), rendering them unsatisfactory for clinical requirements. Over the past 3 decades, significant attention has been devoted to biodegradable materials, including synthetic polyester polymers and magnesium-based alloys, owing to their exceptional biocompatibility and biodegradability while addressing the challenges associated with recurring procedures after BES resolves. Novel esophageal stents have been developed and are undergoing experimental and clinical trials. Drug-eluting stents (DES) with drug-loading and drug-releasing capabilities are currently a research focal point, offering more efficient and precise ES treatments. Functional innovations have been investigated to optimize stent performance, including unidirectional drug-release and anti-migration features. Emerging manufacturing technologies such as three-dimensional (3D) printing and new biodegradable materials such as hydrogels have also contributed to the innovation of esophageal stents. The ultimate objective of the research and development of these materials is their clinical application in the treatment of ES and other benign conditions and the palliative treatment of malignant esophageal stricture (MES). This review aimed to offer a comprehensive overview of current biodegradable esophageal stent materials and their applications, highlight current research limitations and innovations, and offer insights into future development priorities and directions.

Endoscopic luminal stenting: Current applications and future perspectives

Endoscopic luminal stenting (ELS) represents a minimally invasive option for the management of malignant obstruction along the gastrointestinal tract. Previous studies have shown that ELS can provide rapid relief of symptoms related to esophageal, gastric, small intestinal, colorectal, biliary, and pancreatic neoplastic strictures without compromising cancer patients’ overall safety. As a result, in both palliative and neoadjuvant settings, ELS has largely surpassed radiotherapy and surgery as a first-line treatment modality. Following the abovementioned success, the indications for ELS have gradually expanded. To date, ELS is widely used in clinical practice by well-trained endoscopists in managing a wide variety of diseases and complications, such as relieving non-neoplastic obstructions, sealing iatrogenic and non-iatrogenic perforations, closing fistulae and treating post-sphincterotomy bleeding. The abovementioned development would not have been achieved without corresponding advances and innovations in stent technology. However, the technological landscape changes rapidly, making clinicians’ adaptation to new technologies a real challenge. In our mini-review article, by systematically reviewing the relevant literature, we discuss current developments in ELS with regard to stent design, accessories, techniques, and applications, expanding the research basis that was set by previous studies and highlighting areas that need to be further investigated.

Recent Advances of Biomedical Materials for Prevention of Post-ESD Esophageal Stricture

Esophageal stricture commonly occurs in patients that have suffered from endoscopic submucosal dissection (ESD), and it makes swallowing difficult for patients, significantly reducing their life qualities. So far, the prevention strategies applied in clinical practice for post-ESD esophageal stricture usually bring various inevitable complications, which drastically counteract their effectiveness. Nowadays, with the widespread investigation and application of biomedical materials, lots of novel approaches have been devised in terms of the prevention of esophageal stricture. Biomedical polymers and biomedical-derived materials are the most used biomedical materials to prevent esophageal stricture after ESD. Both of biomedical polymers and biomedical-derived materials possess great physicochemical properties such as biocompatibility and biodegradability. Moreover, some biomedical polymers can be used as scaffolds to promote cell growth, and biomedical-derived materials have biological functions similar to natural organisms, so they are important in tissue engineering. In this review, we have summarized the current approaches for preventing esophageal stricture and put emphasis on the discussion of the roles biomedical polymers and biomedical-derived materials acted in esophageal stricture prevention. Meanwhile, we proposed several potential methods that may be highly rational and feasible in esophageal stricture prevention based on other researches associated with biomedical materials. This review is expected to offer a significant inspiration from biomedical materials to explore more effective, safer, and more economical strategies to manage post-ESD esophageal stricture.

Lesion size and circumferential range identified as independent risk factors for esophageal stricture after endoscopic submucosal dissection

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is used to treat early esophageal cancer and precancerous lesions. Patients undergoing ESD are prone to esophageal stenosis, which impairs therapeutic efficacy and quality of life. This retrospective study aimed to investigate the potential association between patient demographics and esophageal lesion characteristics with the risk of esophageal stenosis following ESD.

METHODS

For this retrospective study 190 consecutive patients who underwent ESD between January 2013 and January 2015 were recruited. Data on patient demographics, esophageal lesion-related factors, operation details, esophageal stenosis occurrence and measures taken to prevent or treat stricture were collected, and the normality of distribution of each indicator was assessed with a Kolmogorov-Smirnov test. Stenosis risk factors were then identified using univariate and multivariate logistic regression.

RESULTS

Post-ESD esophageal stenosis occurred in 51 cases. Multivariate logistic regression analysis was performed to identify independent risk factors. A history of EMR/ESD (OR = 4.185, 95% CI: 1.511-11.589), resection circumferential diameter (OR = 1.721, 95% CI: 1.135-2.610), non-en bloc resection (OR = 7.413, 95% CI: 2.398-22.921), submucosal infiltration (OR = 3.449, 95% CI: 1.014-11.734) and circumferential resection range (OR = 57.493, 95% CI: 17.236-191.782) were identified as independent risk factors for post-ESD esophageal stenosis. Spraying porcine fibrin adhesive on the resection bed reduced neither the incidence of postoperative stenosis nor the extent of postoperative dilation.

CONCLUSION

Post-ESD esophageal stenosis is significantly related to size and circumferential range of lesion resection. EMR/ESD history, non-en bloc resection and submucosal infiltration may be additional risk factors.

3D-printed flexible polymer stents for potential applications in inoperable esophageal malignancies

Palliation therapy for dysphagia using esophageal stents is the current treatment of choice for those patients with inoperable esophageal malignancies. However, the metallic and plastic stents currently used in the clinical setting may cause complications, such as tumor ingrowth and stent migration into the stomach. To effectively reduce/overcome these complications, we designed a tubular, flexible polymer stent with spirals. The parameters of the spirals were computationally optimized by using a finite element analysis. The designed polymer stents with optimized spirals were then printed by a 3D printing technique. 3D-printed tubular polymer stents without spirals served as controls. The self-expansion and anti-migration properties of the printed stent were characterized in an ex vivo normal porcine esophagus. The biodegradability test of the stent was performed in a neutral buffer and acidic gastric buffer. The cytotoxicity of the new stent was examined through the viability test of human esophagus epithelial cells. Results showed the self-expansion force of the 3D-printed polymer stent with spirals was higher than the stent without spirals. The anti-migration force of the 3D-printed stent with spirals was significantly higher than that of the stent without spirals. Furthermore, the stent with spirals significantly decreased the migration distance compared to the non-spiral 3D-printed polymer stent. Degradation study showed that the polymer materials started to degrade after six weeks and the compressive strength of the stent was not significantly decreased with time. In vitro cell viability results further indicated that the polymer stent does not have any cytotoxicity. Together, these results showed that the 3D-printed stent with spirals has potential applications in the treatment of inoperable esophageal malignancies. STATEMENT OF SIGNIFICANCE: In this study, we developed a new 3D-printed flexible tubular polymeric stent with spirals. The mechanical properties of the 3D-printed polymer stent are modulated by changing the ratios of PLA to TPU. The stent is flexible enough to be compressed in a clinically available stent delivery system, and can self-expand after it is released. The self-expansion force of the stent with spirals is higher than that of non-spiral stents. The spirals on the outside of the stent significantly increased the anti-migration force compared to non-spiral stents in an ex vivo normal pig esophagus. Together, the 3D-printed stent with spirals will bring promising potential in the treatment of inoperable esophagus malignancies or benign strictures.

Polymeric Biodegradable Stent Insertion in the Esophagus

Esophageal stent insertion has been used as a well-accepted and effective alternative to manage and improve the quality of life for patients diagnosed with esophageal diseases and disorders. Current stents are either permanent or temporary and are fabricated from either metal or plastic. The partially covered self-expanding metal stent (SEMS) has a firm anchoring effect and prevent stent migration, however, the hyperplastic tissue reaction cause stent restenosis and make it difficult to remove. A fully covered SEMS and self-expanding plastic stent (SEPS) reduced reactive hyperplasia but has a high migration rate. The main advantage that polymeric biodegradable stents (BDSs) have over metal or plastic stents is that removal is not require and reduce the need for repeated stent insertion. But the slightly lower radial force of BDS may be its main shortcoming and a post-implant problem. Thus, strengthening support of BDS is a content of the research in the future. BDSs are often temporarily effective in esophageal stricture to relieve dysphagia. In the future, it can be expect that biodegradable drug-eluting stents (DES) will be available to treat benign esophageal stricture, perforations or leaks with additional use as palliative modalities for treating malignant esophageal stricture, as the bridge to surgery or to maintain luminal patency during neoadjuvant chemoradiation.

Endoscopic Submucosal Dissection for Recurrent or Residual Superficial Esophageal Cancer after Chemoradiotherapy: Two Cases

We report two cases of endoscopic submucosal dissection (ESD) for recurrent or residual esophageal squamous cell carcinoma (ESCC) lesions after chemoradiotherapy for advanced esophageal cancer. Case 1 involved a 64-year-old man who had previously undergone chemoradiotherapy for advanced ESCC and achieved a complete response (CR) for 22 months, until metachronous recurrent superficial ESCC was detected on follow-up esophagogastroduodenoscopy (EGD). We performed ESD and found no evidence of recurrence for 24 months. Case 2 involved a 59-year-old man who had previously undergone chemoradiotherapy for advanced ESCC. He responded favorably to treatment, and most of the tumor had disappeared on follow-up EGD 4 months later. However, there were two residual superficial esophageal lugol-voiding lesions. We performed ESD, and he had a CR for 32 months thereafter. ESD can be considered a viable treatment option for recurrent or residual superficial ESCC after chemoradiotherapy for advanced esophageal cancer.

Systematic review: the prevention of oesophageal stricture after endoscopic resection

BACKGROUND

Extensive endoscopic resections for the treatment of early oesophageal neoplasia can result in fibro-inflammatory strictures that require repeated interventions, which significantly alter the patients' quality of life.

AIMS

To review current evidence about the prevention of oesophageal strictures following endoscopic resections.

METHODS

Systematic search of PubMed and Embase from inception to March 2015 using appropriate keywords. All original publications in English were included, and articles on the treatment of oesophageal stricture were excluded.

RESULTS

Of the 461 hits, 62 studies were included in the analysis. Among the wound-protective strategies, polyglycolic acid sheets showed the most convincing evidence with a 37.5% stricture rate and excellent safety. Regenerative medicine, using cell sheets of autologous keratinocytes, resulted in a 25% stricture rate, although with cost and availability concerns. Among anti-proliferative treatment modalities, steroid treatment, either endoscopically injected triamcinolone in the resection wound or orally administered prednisolone, proved effective with an overall stricture rate of 13.5%, with safety concerns regarding late oesophageal perforations and infectious morbidity. Among mechanical treatment options, poorly effective and high-risk preventive balloon dilation tend to be replaced by prophylactic covered stent, with 18-28% stricture rates.

CONCLUSIONS

Although oral or locally injected steroids are promising options, no currently available technique is sufficiently efficient and devoid of significant safety concerns to recommend its routine use for the prevention of strictures after extensive endoscopic resection. Improving our knowledge in the mechanisms of oesophageal wound healing will guide the development of novel methods for stricture prevention.

Endoscopic submucosal dissection for upper gastrointestinal lesions: Our experience with 50 cases

AIM: To discuss the clinical value of endoscopic submucosal dissection (ESD) for treating upper gastrointestinal lesions.

METHODS: A total of 52 patients who underwent ESD between May 2012 and May 2013 were retrospectively analyzed to assess the feasibility, safety and efficacy of ESD for treating upper gastrointestinal lesions.

RESULTS: Among 52 patients, 4 had esophageal lesions, 48 had gastric lesions. Postoperative pathology revealed that 40 were mucosal lesions, including esophageal papilloma (n = 2), cardiac hyperplastic polyps (n = 9), cardiac adenoma (n = 3), early gastric cancer (n = 2), high grade intraepithelial neoplasia (n = 3), low grade intraepithelial neoplasia (n = 5), gastric antral adenomatous polyps (n = 9), hyperplastic polyps (n = 5), and intestinal metaplasia (n = 2); and 12 were submucosal lesions, including esophageal leiomyoma (n = 1), esophageal gastrointestinal stromal tumor (n = 1), gastric heterotopic pancreas (n = 7), gastric body gastrointestinal stromal tumor (n = 2), and lipoma (n = 1). All the lesions were completely resected and were confirmed by pathologic examination. No severe bleeding occurred. Perforation occurred in two cases but was safely managed by conservative treatment.

CONCLUSION: ESD is a safe, effective and recommendable treatment for upper gastrointestinal lesions. It can not only resect the lesions completely, but also provide accurate pathologic information.