Biodegradable stents in gastrointestinal endoscopy

Technical Review on Endoscopic Treatment Devices for Management of Upper Gastrointestinal Postsurgical Leaks

Upper gastrointestinal postsurgical leaks are challenging to manage and often require radiological, endoscopic, or surgical intervention. Nowadays, endoscopy is considered the first-line approach for their management, however, there is no definite consensus on the most appropriate therapeutic approach. There is a wide diversity of endoscopic options, from close-cover-divert approaches to active or passive internal drainage approaches. Theoretically, all these options can be used alone or with a multimodality approach, as each of them has different mechanisms of action. The approach to postsurgical leaks should always be tailored to each patient, taking into account the several variables that may influence the final outcome. In this review, we discuss the important developments in endoscopic devices for the treatment of postsurgical leaks. Our discussion specifically focuses on principles and mechanism of action, advantages and disadvantages of each technique, indications, clinical success, and adverse events. An algorithm for endoscopic approach is proposed.

Biodegradable biliopancreatic stents could help conserve health care resources during the COVID-19 pandemic: An observational multicenter study

BACKGROUND

Considering limited resources for follow-up due to COVID-19, we used biodegradable stents (BPBS) for a range of biliopancreatic diseases.

AIMS

This observational multicenter study aimed to evaluate technical safety and give first insights into clinical utility.

METHODS

Technical success, clinical success, and necessity of follow-up visits for BPBS placed at three Austrian tertiary care hospitals between April 2020 and January 2021 were retrospectively analyzed.

RESULTS

63 stents were deployed in 60 patients. Main indications were prophylaxis of post-ERCP pancreatitis (PEP; n = 30/63; 48%) and bridging of prolonged waiting times to cholecystectomy (n = 21/63; 33%). Median time to surgery was 47 days (range: 136 days). The technical success rate was 94% (n = 59/63; 95% CI [0.84, 0.98]). Technical difficulties primarily arose with dislocations. Clinical success was achieved in 90% (n = 57/63; 95% CI [0.80, 0.96]). Clinical failure despite successful deployment was caused by papillary bleeding (1 patient) and cholestasis (1 patient). Both required reinterventions. No follow-up visits were needed in 97% of cases (n = 57/59; 95% CI [0.88, 1.00]).

CONCLUSION

Biodegradable stents could help conserve health care resources without compromising treatment standards for PEP prophylaxis, which is particularly valuable in times of restricted resources. First insights into feasibility as bridging to cholecystectomy indicate a favorable safety profile.

Feasibility and safety of inserting transient biodegradable stents in the pylorus during pylorus-preserving gastrectomy for gastric cancer: a preliminary study in a porcine for proof of concept

BACKGROUND

To evaluate whether insertion of self-biodegradable stent into the pylorus to prevent delayed-gastric emptying after pylorus-preserving gastrectomy is feasible and safe through porcine experiment.

METHODS

Self-biodegradable dumbbell-shaped pyloric stents were designed from absorbable suture materials: poly(glycolide-co-caprolactone) (PGCL) or poly-p-dioxanone (PPDO). After gastrotomy on ten pigs, each stent was inserted: two shams, four PGCL stents, and four PPDO stents. Body weight (Bwt), body temperature (BT), complete blood cell (CBC) count, and plain X-ray were evaluated. On postoperative day (POD) 13, euthanasia was performed for histologic evaluation.

RESULTS

Operation was successfully performed in all ten pigs. Without tagging suture, both stents migrated before POD 3. The migration was delayed up to POD 13, when the tagging sutures (-t) were applied between stent and stomach wall. Self-degradation of PGCL started from POD 3, and stents were completely excreted from the abdomen by POD 8. Although PPDO were also weakened as self-degradation progressed, its shape was maintained in gastrointestinal tract for 13 days. Unexpected sudden death occurred in the pig with PPDO-t2 on POD 10, which is more likely due to acute volvulus rather than stent-related complication. There was no significant difference between three groups in terms of Bwt, BT, CBC, and histology (sham vs. PGCL vs. PPDO, all p > 0.05).

CONCLUSION

The concept of biodegradable stents made of absorbent suture material seems feasible in porcine experiment. Among them, PGCL which has shown rapid absorption, appears to be a more suitable material for transient pyloric absorbable stent when considering safety aspect.

Recent developments in antibacterial or antibiofilm compound coating for biliary stents

Cholestasis of the indwelling biliary stents usually leads to stone recurrence after endoscopic retrograde cholangio pancreatoraphy (ERCP). Biliary stents, including metallic and none-degradable plastic stents are widely used in clinical settings due to their many excellent properties. However, conventional biliary stents still suffer from poor antibacterial activity and anti-bile-adhesion, which lead to injured, local fibroblasts proliferating. Currently, various coatings for biliary stents have been prepared to meet the clinical demands. In this review, we start by summarizing and discussing classifications of biliary stents and antibacterial/antibiofilm mechanism. Then, the latest advances about developing antibacterial and antibiofilm coatings for improving the properties of biliary stents are reviewed and discussed in detail. Lastly, we list several possible directions for future development of biliary stents coatings and biliary stent, such as anti-bile-adhesion coating, multifunctional coating, drug-eluting biodegradable biliary stents and 3D printed biliary stents.

Intestinal stents: Structure, functionalization and advanced engineering innovation

Intestinal stents are a palliative treatment option that solves many shortcomings of traditional surgeries for cancer-induced intestinal obstructions. The present review provides an overview of the incidence, clinical manifestations and limitations in the treatment of intestinal cancers. The paper also discusses material property requirements, indications, complications and the future of stent-assisted therapy. The advantages and disadvantages of different materials and processing techniques for intestinal stents are reviewed along with new stent treatment combinations for colorectal cancer. Challenges that require further cooperative studies are also detailed. The future development of intestinal stents will depend on innovation in material designs as well as the utilization of multi-functional strategies and innovative engineering solutions.

Endoscopic Management of Luminal Strictures: Beyond Dilation

Luminal strictures can occur as part of many different gastrointestinal (GI) disorders anywhere along the GI tract and affect all age groups. The end goal of managing any stricture is to re-establish an adequate and durable luminal patency that is sufficient to resolve the presenting clinical symptoms. Treatment options can be generally categorized into medical, endoscopic, and surgical. However, within each of these categories, multiple different options are available. Therefore, choosing the best treatment modality is often challenging and depends on multiple factors including the type, location, and complexity of the stricture, as well as the preference of the treating physician. In this article, we will review the most current literature regarding foregut strictures, particularly esophageal and gastric, beyond dilation.

A Complex In Vitro Degradation Study on Polydioxanone Biliary Stents during a Clinically Relevant Period with the Focus on Raman Spectroscopy Validation

Biodegradable biliary stents are promising treatments for biliary benign stenoses. One of the materials considered for their production is polydioxanone (PPDX), which could exhibit a suitable degradation time for use in biodegradable stents. Proper material degradation characteristics, such as sufficient stiffness and disintegration resistance maintained for a clinically relevant period, are necessary to ensure stent safety and efficacy. The hydrolytic degradation of commercially available polydioxanone biliary stents (ELLA-CS, Hradec Králové, Czech Republic) in phosphate-buffered saline (PBS) was studied. During 9 weeks of degradation, structural, physical, and surface changes were monitored using Raman spectroscopy, differential scanning calorimetry, scanning electron microscopy, and tensile and torsion tests. It was found that the changes in mechanical properties are related to the increase in the ratio of amorphous to crystalline phase, the so-called amorphicity. Monitoring the amorphicity using Raman spectroscopy has proven to be an appropriate method to assess polydioxanone biliary stent degradation. At the 1732 cm⁻¹ Raman peak, the normalized shoulder area is less than 9 cm⁻¹ which indicates stent disintegration. The stent disintegration started after 9 weeks of degradation in PBS, which agrees with previous in vitro studies on polydioxanone materials as well as with in vivo studies on polydioxanone biliary stents.

A review on biodegradable biliary stents: materials and future trends

Biliary stricture is defined as the reduction and narrowing of the bile duct lumen, which can be caused by many factors such as cancer and inflammation. Biliary stent placement can effectively alleviate benign and malignant biliary strictures. However, the commonly used plastic or metallic biliary stents are far from ideal and do not satisfy all clinical requirements，although several types of biodegradable biliary stents have been developed and used clinically. In this review, we summarized current development status of biodegradable stents with the emphasis on the stent materials. We also presented the future development trends based on the published literature.

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Summary of current development status of bioresorbable biliary stents with the emphasis on the stent materials.

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The future development trends based on the published literature.

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The advantages of bioresorbable biliary stents compared with metallic and plastic biliary stents.

Bio-Degradable Stents: Primary Experience in a Tertiary Hepatopancreaticobiliary Center in the United Kingdom

BACKGROUND

Management of benign biliary strictures (BBS) post bilioenteric anastomoses requires a multidisciplinary approach including surgical, radiological, and/or endoscopic input. Patients often need multiple hospital visits for treatment with the long-term possibility of restenosis. Conventionally BBS have been treated with serial percutaneous transhepatic biliary dilatations necessitating repeat procedures for drain exchange or removal. Surgery may become necessary in refractory strictures. In the last decade, there have been increasing reports of the use of biodegradable stents (BDS) in treating biliary strictures mainly to address the need for repeated procedures for drain exchange.

AIM

 This study aimed to report the early outcomes in patients with BBS treated with BDS.

METHODS

Retrospective analysis of prospectively collected data was performed in patients who had a bilioenteric anastomosis presenting with an anastomotic stricture and were intended to be treated with BDS. The primary endpoints reported were technical success (defined as a successful resolution of stricture on repeat cholangiogram) and clinical success (defined as the absence of repeated cholangitis). Clavien-Dindo (CD) grade of complication was reported.

RESULTS

Twelve patients presented with BBS and nine patients had BDS. Three patients were not considered suitable for BDS due to a non-traversable stricture and had surgery. The male-female ratio was 1:2. There was 100% technical and clinical success with one patient having stent migration not needing intervention. The procedure took an average of 45 min. In seven (77.7%) patients, it was safely performed under local anesthesia with sedation. Two patients preferred general anesthesia. There was no restenosis noted at a median follow-up of 11 months.

CONCLUSION

The use of BDS in the treatment of BBS is a safe and effective procedure. Longer-term follow-up with multi-institutional reporting on a national database is needed to assess its long-term benefits.

Gastrointestinal Luminal Stenting: The Early US Experience with the Duodenal HANAROSTENT

Self-expandable metal stents (SEMSs) are frequently utilized for palliation of malignant gastric and/or duodenal outlet obstruction (GDOO). Re-establishing luminal patency with accurate SEMS positioning while limiting migration and adjacent tissue injury is an important technical consideration and aim. The duodenal HANAROSTENT^® was introduced in the USA in 2019 and developed with these challenges in mind. As the first center in the USA to deploy the duo-denal HANAROSTENT^® in clinical practice, we herein examine our early experience with its use. Specifically, we describe 7 consecutive cases of malignant GDOO in which a duodenal HANAROSTENT^® was placed for on-label use, defined as palliative treatment of malignant gastric and/or duodenal obstruction. All stents were 22 mm in diameter, with 5 being 90 mm and 2 being 120 mm in length. Technical and clinical success with duodenal HANAROSTENT^® placement were achieved in all 7 cases (100%). In no case was stent adjustment required post-deployment. There were no stent-related adverse events, and no subsequent endoscopic procedures were necessary in any of the patients during a mean follow-up of 5 months (range 1-12 months). In summary, the duodenal HANAROSTENT^® appears to perform well and be a promising alternative to other available duodenal SEMSs. As experience in the USA with this newly introduced duodenal SEMS grows, multicenter prospective data should be collected to better establish its relative safety and efficacy.

A Comprehensive Review of Endoscopic Management of Sleeve Gastrectomy Leaks

BACKGROUND

Bariatric surgery leaks result in significant morbidity and mortality. Experts report variable therapeutic approaches, without uniform guidelines or consensus.

OBJECTIVE

To review the pathogenesis, risk factors, prevention, and treatment of gastric sleeve leaks, with a focus on endoscopic approaches. In addition, the efficacy and success rates of different treatment modalities are assessed.

DESIGN

A comprehensive review was conducted using a thorough literature search of 5 online electronic databases (PubMed, PubMed Central, Cochrane, EMBASE, and Web of Science) from the time of their inception through March 2020. Studies evaluating gastric sleeve leaks were included. MeSH terms related to "endoscopic," "leak," "sleeve," "gastrectomy," "anastomotic," and "bariatric" were applied to a highly sensitive search strategy. The main outcomes were epidemiology, pathophysiology, diagnosis, treatment, and outcomes.

RESULTS

Literature search yielded 2418 studies of which 438 were incorporated into the review. Shock and peritonitis necessitate early surgical intervention for leaks. Endoscopic therapies in acute and early leaks involve modalities with a focus on one of: (i) defect closure, (ii) wall diversion, or (iii) wall exclusion. Surgical revision is required if endoscopic therapies fail to control leaks after 6 months. Chronic leaks require one or more endoscopic, radiologic, or surgical approaches for fluid collection drainage to facilitate adequate healing. Success rates depend on provider and center expertise.

CONCLUSION

Endoscopic management of leaks post sleeve gastrectomy is a minimally invasive and effective alternative to surgery. Their effect may vary based on clinical presentation, timing or leak morphology, and should be tailored to the appropriate endoscopic modality of treatment.

Safety and efficacy of biodegradable stents in octogenarian patients with esophageal achalasia

Backgrounds and study aims  Treatment of octogenarian patients with achalasia with conventional treatments is effective but with compromised safety. Biodegradable stents (BS) are promising. We aimed to evaluate their safety, efficacy and clinical outcomes at early, mid and long-term in this population. Patients and methods  Naïve or previously-treated achalasic octogenarian patients underwent to BS placement (BSP) between December, 2010 and November, 2011, and were followed-up for 9-years. A strict follow-up was performed. Results  Thirty-two patients were included, (17 men [53.1 %]; median age 82 years [78-92]). BSP was performed in all patients. At 9y, 18/32 (56.2 %) completed protocol. Mean BSP time was 37.5±12.1 min and 34.4 % presented thoracic pain. At 1 m, six BS were migrated (18.7 %), requiring a second BSP fixed with hemoclips. At 3 m, twenty-three (72.8 %) completed degradation process. At 6 m, eighteen (56.2 %) presented clinical dysphagia, of whom 5/32 (15.6 %) presented stenotic-tissue hyperplasia, responding to balloon dilation in all cases. Pre-BSP Eckardt, Timed barium esophagram and integrated relaxation pressure improved post-BSP 6 m values (9 vs 2, p = 0.001; < 50 % = 93.8 % vs > 80 % = 81.5 %, p = 0.003 and 18.8 ± 3.2 vs 11.1 ± 2.6 mmHg, p = 0.001, respectively), and there were no significant changes up to 9y post-BSP. Esophagitis grade A or B was presented between 4.7 % to 11.2 % and controlled with PPI. After 9 years we had clinical success rates of 94.4 %, 72 %, and 65.4 % for time point evaluation, per protocol and intention to treat analysis, respectively. Conclusions  BSP represents a feasible alternative option in octogenarian patients with achalasia who are high risk with other treatments, presenting acceptable early, mid-, and long-term outcomes.

Biodegradable JDBM coating stent has potential to be used in the treatment of benign biliary strictures

In our previous study, to find out the optimal alloy suitable for biliary surgery, magnesium alloy Jiao Da Bio-magnesium (denoted as JDBM) alloy, Zn-3Cu alloys, and their respective coating (MgF₂-PDLLA) products were produced for our research. We found that JDBM seems to be a potential material for clinical biliary stent application due to its uniform degradation and good compatibility. In order to apply the JDBM alloy to treat benign bile duct stricture, our group prepared the bare JDBM and its coating product into finished stents by mesh weaving carving technology and conducted the mechanical property tests, degradation tests and biocompatibility tests. During the mechanical property tests, we found the bare JDBM stent was more suitable than titanium alloy stent when applies to the bile duct, and the coating of the JDBM coating stent has no effect on its mechanical properties. Our in vitro and in vivo experiments revealed that the degradation rate of the JDBM coating stent is lower than that of the JDBM stent, and both stents were biosafe. Thus, there is promise for JDBM coating stents for the treatment of benign biliary strictures.

Absorbable stents for treatment of benign biliary strictures: long-term follow-up in the prospective Spanish registry

OBJECTIVES

Benign strictures of the bile duct may be difficult to treat endoscopically due to altered bowel anatomy. Furthermore, recurrence of stenosis and symptoms remains high. The aim of the Spanish Prospective Registry BiELLA study was to investigate the safety and efficacy of absorbable stents in the treatment of benign biliary strictures and their outcomes on the medium and long-term follow-up.

METHODS

A prospective, multicenter, observational, non-randomized study (the BiELLA study) was conducted from January 2014 to September 2018. One hundred fifty-nine patients with benign biliary strictures, mostly postsurgical, were enrolled for implantation of absorbable biliary stents in the 11 participating Spanish tertiary hospitals. The average patient follow-up was 45.4 ± 15.9 months (range, 12-60 months). The follow-up data included symptoms, biochemical parameters, and ultrasound images at 1, 6, and 12 months and then yearly for up to 60 months.

RESULTS

The immediate technical and clinical success rates were 100%. In all patients, stent placement resulted in improvement of clinical symptoms and biochemical parameters. The primary mean patency for stent was 86.7, 79.6, and 78.9% at 12, 36, and 60 months, respectively (95% CI). Biliary restenosis and occlusion occurred in 40 (26.6%) patients. Of the 40 patients, 18 (12%) patients were treated with a second stent and 22 (14.6%) patients had operative repair of the recurrent strictures. There were no major complications associated with stent implantation.

CONCLUSIONS

Implantation of an absorbable polydioxanone biliary stent is safe and effective for treatment of benign biliary strictures refractory to balloon dilatation or other biliary intervention.

KEY POINTS

• Percutaneous implantation of biodegradable prostheses for the treatment of benign postsurgical biliary strictures is a safe and effective procedure. • More than 75% of the patients presented patency of the stented biliary tree at 5 years follow-up. • Absorbable stents improved clinical symptoms and signs (jaundice, itching, fever), and laboratory parameters in a few days after stent placement.

A Novel Biodegradable Tubular Stent Prevents Pancreaticojejunal Anastomotic Stricture

Stricture of pancreatic-enteric anastomoses is a major late complication of a pancreaticoduodenectomy for the treatment of a periampullary tumor and can lead to exocrine and endocrine insufficiency such as malnutrition and diabetes mellitus. We investigated the safety and efficacy of a biodegradable tubular stent (BTS) for preventing a pancreaticojejunostomy (PJ) anastomotic stricture in both a rat and porcine model. The BTS was manufactured using a terpolymer comprising poly p-dioxanone, trimethylene carbonate, and glycolide. A cohort of 42 rats was randomized into 7 groups of 6 animals each after BTS placement into the duodenum for the biodegradation assay. A total of 12 pigs were randomized equally into a control and BTS placement group. The effectiveness of the BTS was assessed by comparing radiologic images with histologic results. Surgical procedures and/or BTS placements were technically successful in all animals. The median mass losses of the removed BTS samples from the rat duodenum were 2.1, 6.8, 11.2, 19.4, 26.1, and 56.8% at 1, 2, 3, 4, 6, and 8 weeks, respectively. The BTS had completely degraded at 12 weeks in the rats. In the porcine PJ model, the mean luminal diameter and area of the pancreatic duct in the control group was significantly larger than in the BTS group (all p < 0.05). BTS placement thus appears to be safe and effective procedure for the prevention of PJ anastomotic stricture. These devices have the potential to be used as a temporary stent placement to treat pancreatic-enteric anastomoses, but further investigations are required for optimization in human.

Endoscopic Management of Benign Colonic Obstruction and Pseudo-Obstruction

There are a variety of causes of intestinal obstruction, with the most common cause being malignant diseases; however, volvulus, inflammatory bowel disease or diverticulitis, radiation injury, ischemia, and pseudo-obstruction can also cause colonic obstruction. These are benign conditions; however, delayed diagnosis of acute intestinal obstruction owing to these causes can cause critical complications, such as perforation. Therefore, high levels of clinical suspicion and appropriate treatment are crucial. There are variable treatment options for colonic obstruction, and endoscopic treatment is known to be a less invasive and an effective option for such. In this article, the authors review the causes of benign colonic obstruction and pseudo-obstruction and the role of endoscopy in treating them.

Endoscopic stenting of malignant, benign and iatrogenic colorectal disorders: a primer for radiologists

In recent years, endoscopic placement of intraluminal stents is increasingly used to manage a widening range of colorectal disorders. Self-expanding metal stents represent an established alternative to surgery for the palliation of unresectable carcinomas and currently allow a "bridge-to-surgery" strategy to relieve large bowel obstruction and optimise the patients' clinical conditions before elective oncologic resection. Additionally, intraluminal stents represent an appealing option to manage obstructing extracolonic tumours and selected patients with benign conditions such as refractory anastomotic strictures and post-surgical leaks.This educational paper reviews the technical features and current indications of colorectal stenting and presents the expected and abnormal radiographic, CT and MRI appearances observed during the endoscopic management of malignant, benign and iatrogenic colonic disorders with stents. The aim is to provide radiologists with a thorough familiarity with stent-related issues, which is crucial for appropriate reconstruction of focused CT images, correct interpretation of early post-procedural studies and elucidation of stent-related complications such as misplacement, haemorrhage, perforation, migration and re-obstruction.

A novel braided biodegradable stent for use in congenital heart disease: Short-term results in porcine iliac artery

To evaluate the properties and efficacy of a novel braided biodegradable stent (BBS) consisting of poly (p-dioxanone) (PPDO) and polycaprolactone (PCL) for usage in children with congenital cardiovascular diseases. PCL/PPDO composite filaments were fabricated by coating PCL layers onto PPDO filaments, which were fused with PPDO monofilaments to form the BBS. Physical properties of BBSs including elastic recovery rate, deformation rate, and mechanical characteristics with adjunctive post-dilation were evaluated by radial force-tests. Ten BBS stents and 10 metallic wall stents (WS) as controls were implanted into the common carotid arteries of 10 pigs and angiography as well as histological examinations were performed 4 and 8 weeks after implantation. An 8 mm BBS with adjunctive post-dilation had the best morphological retention and dimension stability being similar to an 8 mm WS. Luminal gain percentages of BBS and WS immediately, 4 weeks and 8 weeks after implantation were 20.44 ± 2.82% and 27.08 ± 0.88%, 12.34 ± 0.18% and 17.32 ± 8.24%, as well as -1.76 ± 2.45% and - 0.98 ± 3.23%. Luminal areas, internal elastic laminas, neointimal areas, neointimal thicknesses, and area stenosis were not significantly different at 4 weeks and 8 weeks after implantation. Injury and inflammation were similar in both groups and no malposition, thrombosis or dissection occurred. BBS with adjunctive post-dilation showed good physical properties and mechanical stability noninferior to WS. In vivo evaluations showed that a BBS with post-ballooning had similar short-term outcomes as a WS. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1667-1677, 2019.

Targeting anti-fibrotic pathways in Crohn's disease - The final frontier?

Intestinal fibrosis with stricture formation affects up to half of patients with Crohn's disease (CD), resulting in impaired quality of life, increased risk of surgical intervention, and associated patient morbidity. The underlying pathophysiologic mechansisms responsible for initiating and perpetuating intestinal fibrosis are complex, dynamic, and implicate both inflammation-dependent and independent pathways. Previously thought to be an irreversible complication of long-standing inflammation unresponsive to medical therapy, fibrostenotic CD has been traditionally managed with endoscopic or surgical approaches. However, recent advances in our understanding of the humoral, cellular, and environmental pathways driving intestinal fibrosis has the potential to fundamentally change these management paradigms for CD-related strictures. Furthermore, the promise of fibrosis treatments in other organ systems has encouraged hope that anti-fibrotic treatment approaches for CD may be within reach. Here, we summarize the key breakthroughs in our molecular understanding of intestinal fibrosis, review current medical, endoscopic, and surgical treatment approaches to CD-related strictures, propose future directions for anti-fibrotic therapy in CD, and identify crucial research questions in this field that require additional investigation.

A systematic review of biodegradable biliary stents: promising biocompatibility without stent removal

Biodegradable self-expanding stents are an emerging alternative to standard biliary stents as the development of endoscopic insertion devices advances. The aim was to systematically review the existing literature on biodegradable biliary stents. In-vivo studies on the use of biodegradable stents in the biliary duct were systematically reviewed from 1990 to 2017. Despite extensive research on the biocompatibility of stents, the experience so far on their clinical use is limited. A few favorable reports have recently been presented on endoscopically and percutaneously inserted self-expanding biodegradable polydioxanone stents in benign biliary strictures. Another potential indication appears to be postcholecystectomy leak of the cystic duct. The main benefit of biodegradable stents is that stent removal can be avoided. The biocompatibility of the current biodegradable stent materials, most prominently polydioxanone, is well documented. In the few studies currently available, biodegradable stents are reported to be feasible and safe, also in humans. The initial results of the endoscopic use of these stents in benign biliary stricture management and for treating postcholecystectomy bile leaks are promising. Further controlled studies on long-term clinical results and cost-effectiveness are needed.

Endoscopic biodegradable stents as a rescue treatment in the management of post bariatric surgery leaks: a case series

BACKGROUND AND AIMS

 Postoperative leak is one of the most feared complications after bariatric surgery. Endoscopic stenting is used to manage leaks by decreasing the gastrointestinal intraluminal pressure. The main advantage of endoscopic management is providing healing while still allowing for oral nutrition. However, limited literature exists on whether biodegradable stents can be used to control leaks when conventional metallic stents fail.

METHODS

 Our series consists of four patients who were found to have a leak as a complication of bariatric surgery. Two patients were initially managed by abdominal/chest drainage, and one required total parenteral nutrition. Conventional endoscopic exclusion techniques with short and long fully covered metallic stents were tried and failed in three of the four patients included in this series. Thus, biodegradable stents were used as a rescue option.

RESULTS

 Biodegradable stents provided immediate improvement for all of the patients, and Gastrografin studies were leak-free 2 days after the procedure. All patients were started on oral feeding and discharged home within 5 - 6 days later. Minimum outpatient follow-up of 8 weeks was achieved with no issues. Follow-up endoscopy was performed 2 - 3 months later in three patients and showed completely resorbed stents. The only drawback was the mucosal reaction to the stent causing dysphagia in two patients, who eventually needed esophageal dilatation.

CONCLUSION

 Biodegradable stents have the potential to provide a reasonable rescue option to manage post bariatric surgery leaks in patients who fail conventional endoscopic exclusion methods. However, data from larger studies are needed to collect information on which theoretical advantages/disadvantages of degradable biomaterials apply to real practice.

A pilot study of endoscopically inserted biodegradable biliary stents in the treatment of benign biliary strictures and cystic duct leaks

BACKGROUND AND AIMS

Self-expanding biodegradable biliary stents (BDBSs) have recently become available for use in endoscopic retrograde cholangiography (ERC). The aim was to evaluate the effectiveness and safety of novel BDBSs in iatrogenic cystic duct leaks and benign biliary strictures (BBSs).

METHODS

Patients providing informed consent were recruited for the prospective study. Braided self-expanding poly-dioxanone BDBSs were inserted using ERC during from 2014 to 2016. Repeated liver function tests and magnetic resonance imaging were performed during follow-up. The main outcomes were treatment success and adverse events.

RESULTS

Thirteen patients, 5 women, median age 67 years (range, 43-79) underwent BDBS insertion for iatrogenic cystic duct leak (n = 7) or BBS (n = 6). Stent insertion using ERC was successful in all cases. All bile leaks were treated uneventfully with BDBSs. In BBSs, the clinical success rate of BDBS therapy was 83% in a median of 21 months of follow-up (range, 14-25). Early ERC-related adverse events included 1 cholangitis (8%) and 1 pancreatitis (8%), both in the stricture group. During the first 90 days, 23% of patients were readmitted for mild cholangitis.

CONCLUSIONS

The short- and long-term safety of endoscopically inserted poly-dioxanone BDBSs was satisfactory. The management of cystic duct leaks and benign distal common bile duct strictures was highly successful. Episodes of mild cholangitis during stent indwelling seemed to be typical of BDBSs. The advantage of BDBSs is the avoidance of repeated endoscopy for stent removal. (Clinical trial registration number: NCT02353286.).

Self-Expanding Biodegradable Stents for Postoperative Upper Gastrointestinal Issues

BACKGROUND AND OBJECTIVES

Endoscopic stenting is a minimally invasive treatment modality for patients with various gastrointestinal conditions. We evaluated the safety and efficacy of uncovered biodegradable stents for postoperative leaks and strictures in the upper gastrointestinal tract.

METHODS

This was a retrospective study of patients treated endoscopically with biodegradable stents from January 2010 through November 2017.

RESULTS

Thirteen patients were enrolled, 7 of whom were men. Their mean age was 46 (range, 21-82) years. The indications for stent placement were postoperative leakage and stricture in 9 and 4 patients, respectively. The primary diagnoses were obesity in 7 patients, gastric cancer in 5, and peptic ulcer in 1. The average time to stent placement after surgery was 35 (range, 17-125) and 166 (range, 153-185) days for patients with postoperative leakage and stricture, respectively. Stent insertion was successful at the first attempt in all patients. Complete resolution of the leak and stricture was achieved after stent application in 11 patients, for a clinical success rate of 85%. The mean follow-up duration was 50 (range, 24-76) months. There were no major complications.

CONCLUSIONS

Compared to self-expanding metal and plastic stents, the main advantages of uncovered biodegradable stents are that they do not have to be removed and have a low migration rate. Our results suggest that these stents have promise for management of postoperative gastrointestinal complications. Further randomized trials with larger sample sizes are necessary to determine the role of biodegradable stents in the treatment algorithm.

Endoluminal solutions to bariatric surgery complications: A review with a focus on technical aspects and results

Obesity is a growing problem in developed countries, and surgery is the most effective treatment in terms of weight loss and improving medical comorbidity in a high proportion of obese patients. Despite the advances in surgical techniques, some patients still develop acute and late postoperative complications, and an endoscopic evaluation is often required for diagnosis. Moreover, the high morbidity related to surgical reintervention, the important enhancement of endoscopic procedures and technological innovations introduced in endoscopic equipment have made the endoscopic approach a minimally-invasive alternative to surgery, and, in many cases, a suitable first-line treatment of bariatric surgery complications. There is now evidence in the literature supporting endoscopic management for some of these complications, such as gastrointestinal bleeding, stomal and marginal ulcers, stomal stenosis, leaks and fistulas or pancreatobiliary disorders. However, endoscopic treatment in this setting is not standardized, and there is no consensus on its optimal timing. In this article, we aim to analyze the secondary complications of the most expanded techniques of bariatric surgery with special emphasis on those where more solid evidence exists in favor of the endoscopic treatment. Based on a thorough review of the literature, we evaluated the performance and safety of different endoscopic options for every type of complication, highlighting the most recent innovations and including comparative data with surgical alternatives whenever feasible.

Mechanisms, Management, and Treatment of Fibrosis in Patients With Inflammatory Bowel Diseases

In the last 10 years, we have learned much about the pathogenesis, diagnosis, and management of intestinal fibrosis in patients with inflammatory bowel diseases. Just a decade ago, intestinal strictures were considered to be an inevitable consequence of long-term inflammation in patients who did not respond to anti-inflammatory therapies. Inflammatory bowel diseases-associated fibrosis was seen as an irreversible process that frequently led to intestinal obstructions requiring surgical intervention. This paradigm has changed rapidly, due to the antifibrotic approaches that may become available. We review the mechanisms and diagnosis of this serious complication of inflammatory bowel diseases, as well as factors that predict its progression and management strategies.

Endoscopic biodegradable biliary stents in the treatment of benign biliary strictures: First report of clinical use in patients

The first clinical experience of endoscopically inserted polydioxanone biodegradable biliary stents (BDBS) in the treatment of benign biliary strictures is reported. Two patients with a benign common bile duct stricture were endoscopically treated with 8-mm-bore BDBS during endoscopic retrograde cholangiography. Both BDBS insertions were technically successful and without adverse events. At 6 months, the stricture resolution was excellent and BDBS degradation was predicted in repeated magnetic resonance imaging. The first experience with endoscopic BDBS seems promising in the treatment of benign biliary strictures. During 6 months of follow up, BDBS seemed sufficient for remodeling and resolution of strictures. Further studies are needed to confirm the effectiveness of biodegradable biliary stents in endoscopic management of benign biliary strictures.

Biodegradable biliary stents have a different effect than covered metal stents on the expression of proteins associated with tissue healing in benign biliary strictures

BACKGROUND

Benign biliary strictures (BBS) are primarily treated endoscopically with covered self-expandable metal stents (CSEMS). Biodegradable biliary stents (BDBS) may be the future of endoscopic therapy of BBS. The aim was to assess the expression of proteins related to tissue healing in BBS compared with the intact bile duct (BD), and to study the protein expression after therapy with CSEMS or BDBS.

METHODS

Pigs with ischemic BBS were endoscopically treated either with BDBS or CSEMS. Samples were harvested from pigs with intact BD (n = 5), untreated BBS (n = 5), and after six months of therapy with BDBS (n = 4) or CSEMS (n = 5) with subsequent histologic analysis. Two-dimensional electrophoresis with protein identification was performed to evaluate protein expression patterns.

RESULTS

In BBS, the expression of galectin-2 and annexin-A4 decreased, compared to intact BD. Treatment with biodegradable stents normalized galectin-2 level; with CSEMS therapy it remained low. Transgelin expression of intact BD and BBS remained low after BDBS treatment but increased after CSEMS therapy. Histologic analysis did not show unwanted foreign body reaction or hyperplasia in the BD in either group.

CONCLUSIONS

The expression of proteins related to tissue healing in BBS is different after treatment with biodegradable stents and CSEMS. Treatment with biodegradable stents may bring protein expression towards what is seen in intact BD. BDBS seem to have a good biocompatibility.

The role of stents in the treatment of Crohn's disease strictures

BACKGROUND AND AIMS

Stenosis is one of the most frequent local complications in Crohn's disease (CD). Surgery is not the ideal treatment because of the high rate of postoperative recurrence. Endoscopic balloon dilation (EBD) currently is the current treatment of choice for short strictures amenable to the procedure. However, it is not applicable or effective in all the cases, and it is not without related complications. Our goal was to summarize the published information regarding the use and the role of the stents in the treatment of CD stricture. A Medline search was performed on the terms "stricture," "stenosis," "stent" and "Crohn's disease."

RESULTS

a total of 19 publications met our search criteria for an overall number of 65 patients. Placing a self-expanding metal stent (SEMS) may be a safe and effective alternative to EBD and/or surgical intervention in the treatment of short stenosis in patients with CD. Indications are the same as those for EBD. In addition, SEMS may be useful in stenosis refractory to EBD and may be suitable in the treatment of longer or more complex strictures that cannot be treated by EBD. With the current information, it seems that the best treatment option is the placement of a fully covered stent for a mean time of 4 weeks. Regarding the use of biodegradable stents, the information is limited and showing poor results.

CONCLUSIONS

the use of stents in the treatment of strictures in CD should be taken into account either as a first endoscopic therapy or in case of EBD failure.

Stents for colorectal obstruction: Past, present, and future

Since the development of uncovered self-expanding metal stents (SEMS) in the 1990s, endoscopic stents have evolved dramatically. Application of new materials and new designs has expanded the indications for enteral SEMS. At present, enteral stents are considered the first-line modality for palliative care, and numerous types of enteral stents are under development for extended clinical usage, beyond a merely palliative purpose. Herein, we will discuss the current status and the future development of lower enteral stents.

Biodegradable Airway Stents - Bench to Bedside: A Comprehensive Review

Airway stents are indicated to treat symptomatic narrowing or to close fistulas of the central airways. They are generally divided into two types: the silicone stents and the metallic stents. Unlike in malignancies, removability is a major objective of temporary stenting in benign conditions, which poses the challenge of a new rigid bronchoscopic procedure under general anesthesia and stent removal with all its attendant risks and costs. The concept of a biodegradable (BD) stent that could maintain the patency of an airway for a predetermined duration of time is very appealing. These BD stents would gradually degrade and eventually vanish from the airway once they are no longer needed. Such stents are currently an area of intense research. Another very promising concept of drug delivery with such stents is also a very exciting area of current research. The aim of this comprehensive review is to discuss all pertinent available literature on the use of BD materials in various clinical applications and to extensively review all animal and humans trials involving BD airway stents.

Biodegradable biliary stent in the endoscopic treatment of cystic duct leak after cholecystectomy: the first case report and review of literature

BACKGROUND

The preferred therapy for simple postcholecystectomy biliary leak consists of percutaneous drainage and biliary stent insertion under endoscopic retrograde cholangiopancreatography (ERCP). With a novel endoscopic insertion device, a biodegradable biliary stent (BDBS) may be used in the treatment of a cystic duct leak without repeated endoscopy for stent removal. The objective of this article was to report the first case of endoscopic insertion of BDBS for postoperative bile leak and assess its feasibility and safety.

PATIENT AND METHODS

A 64-year-old man with a postoperative leak from the cystic duct stump was treated with ERCP, biliary sphincterotomy, and insertion of a self-expandable 40- × 8-mm polydixanone BDBS (Ella CS, Hradec Králové, Czech Republic) after insertion of a percutaneous drain.

RESULTS

Endoscopic insertion of BDBS was successful and uncomplicated. On Day 7 after ERCP, the patient was in good condition, no signs of bile leak or inflammation were observed, and the percutaneous drain was removed. At 3 months, magnetic resonance imaging showed that the BDBS was patent and in the right location. At 6 months, the stent had expectedly degraded.

CONCLUSIONS

A novel endoscopic insertion device with a polydixanone BDBS appears feasible in treating disorders of the human biliary duct. BDBS now offers an encouraging option for endoscopic therapy of bile leaks.

Biodegradable stent or balloon dilatation for benign oesophageal stricture: Pilot randomised controlled trial

AIM: To undertake a randomised pilot study comparing biodegradable stents and endoscopic dilatation in patients with strictures.

METHODS: This British multi-site study recruited seventeen symptomatic adult patients with refractory strictures. Patients were randomised using a multicentre, blinded assessor design, comparing a biodegradable stent (BS) with endoscopic dilatation (ED). The primary endpoint was the average dysphagia score during the first 6 mo. Secondary endpoints included repeat endoscopic procedures, quality of life, and adverse events. Secondary analysis included follow-up to 12 mo. Sensitivity analyses explored alternative estimation methods for dysphagia and multiple imputation of missing values. Nonparametric tests were used.

RESULTS: Although both groups improved, the average dysphagia scores for patients receiving stents were higher after 6 mo: BS-ED 1.17 (95%CI: 0.63-1.78) P = 0.029. The finding was robust under different estimation methods. Use of additional endoscopic procedures and quality of life (QALY) estimates were similar for BS and ED patients at 6 and 12 mo. Concomitant use of gastrointestinal prescribed medication was greater in the stent group (BS 5.1, ED 2.0 prescriptions; P < 0.001), as were related adverse events (BS 1.4, ED 0.0 events; P = 0.024). Groups were comparable at baseline and findings were statistically significant but numbers were small due to under-recruitment. The oesophageal tract has somatic sensitivity and the process of the stent dissolving, possibly unevenly, might promote discomfort or reflux.

CONCLUSION: Stenting was associated with greater dysphagia, co-medication and adverse events. Rigorously conducted and adequately powered trials are needed before widespread adoption of this technology.