A biodegradable non-covered self-expandable stent to treat pancreatic duct strictures in chronic pancreatitis: a proof of principle

Endoscopic interventions in pancreatic strictures and stones-A structured approach

Chronic pancreatitis (CP) is an irreversible disease of varied etiology characterized by destruction of pancreatic tissue and loss of both exocrine and endocrine function. Pain is the dominant and most common presenting symptom. The common cause for pain in CP is ductal hypertension due to obstruction of the flow of pancreatic juice in the main pancreatic duct either due to stones or stricture or a combination of both. With advances in technology and techniques, endoscopic retrograde cholangiography (ERCP) and stenting should be the first line of therapy for strictures of the main pancreatic duct (MPD). Small calculi in the MPD can be extracted by ERCP and balloon trawl. Extracorporeal shockwave lithotripsy (ESWL) remains the standard of care for large pancreatic calculi and aims to fragment the stones 3 mm or less that can easily be extracted by a subsequent ERCP. Single operator pancreatoscopy with intraductal lithotripsy is a technique in evolution and can be tried when ESWL is not available or is unsuccessful in producing stone fragmentation.

Pancreatic duct stents

Pancreatic duct stenting using endoscopy or surgery is widely used for the management of benign and malignant pancreatic diseases. Endoscopic pancreatic stents are mainly used to relieve pain caused by chronic pancreatitis and pancreas divisum, and to treat pancreatic duct disruption and stenotic pancreaticointestinal anastomosis after surgery. They are also used to prevent postendoscopic retrograde cholangiopancreatography pancreatitis and postoperative pancreatic fistula, treat pancreatic cancer, and locate radiolucent stones. Recent advances in endoscopic techniques, such as endoscopic ultrasonography and balloon enteroscopy, and newly designed stents have broadened the indications for pancreatic duct stenting. In this review we outlined the types, insertion procedures, efficacy, and complications of endoscopic pancreatic duct stent placement, and summarized the applications of pancreatic duct stents in surgery.

USE of Biodegradable STENTS in Pancreaticoduodenectomy: Initial Experience

Background. Plastic stents have been used to avoid postoperative pancreatic fistula (POPF) following Whipple's Pancreaticoduodenectomy (WPD), but they may cause some stent-related complications. Biodegradable stents have been recently introduced and might be a safe alternative. Here we present our initial experience with their use. Methods. Between March 1, 2020, and September 30, 2020, ten (10) consecutive patients underwent WPD. They all had conventional two-layer pancreaticojejunostomy with the placement of an internal biodegradable stent. They were assessed for technical feasibility, pancreatic leak, and stent-related complications. Results. The use of biodegradable stents was technically feasible in all patients, despite some difficulties in insertion due to stent stiffness and design. After a median follow-up period of 124 days, none of the patients suffered POPF. One patient had a biochemical pancreatic leak with no clinical significance. The median hospital stay was 7 days, and there were no stent-related complications. Conclusion. Biodegradable stents are technically feasible and safe in WPD with good short-term outcomes. They might provide a better alternative to plastic stents and their potential complications. Larger long-term studies are needed to validate efficacy and safety. Few modifications of the stent's design might be needed to facilitate use in open surgery.

Covered self-expandable metal stents for pancreatic duct stricture: a systematic review and meta-analysis

Background and study aims  Placement of a covered (C)-self-expandable metal stent (SEMS) has been recently investigated as an alternative endoscopic treatment for main pancreatic duct stricture (MPDS) in chronic pancreatitis. Our aim was to carry out a systematic review and meta-analysis of studies quantifying efficacy and safety of C-SEMSs in the management of MPDS. Methods  A multiple database search was performed, including MEDLINE, Embase and Cochrane Library, from January 2000 to September 2020, to identify studies reporting the efficacy and safety of C-SEMSs in patients with MPDS. Stricture and pain resolution were investigated. Other outcomes included technical success, stent migration, stricture recurrence and need for repeated stent placement. Pancreatitis, severe abdominal pain requiring stent removal and de-novo stricture were recorded as complications. Results  Nineteen studies were identified, which included a total of 300 patients. C-SEMSs showed a pooled stricture resolution rate of 91 % [95 % confidence interval (CI), 85 %-96 %] and a pooled pain resolution rate of 92 % (95 % CI, 85 %-98 %). The pooled proportion for stricture recurrence was equal to 6 % (95 % CI, 1 %-14 %), while stent migration occurred in 33 of 300 patients, the pooled proportion being 7 % (95 % CI 1 %-15 %). The pooled mean stent duration was 133 days (95 % CI, 100-166 days). The most common complication was pancreatitis (3 %, 95 % CI 0 %-8 %), while de-novo stricture pooled proportion was 2 % (95 % CI, 0 %-5 %). Conclusions  C-SEMSs are effective and safe in the treatment of MPDS. However, there is a significant need for further high-quality, well-designed studies to produce evidence-based data on short and long-term efficacy, safety, costs of C-SEMSs, and also optimal stent duration.

A new biodegradable stent in bilio-pancreatic diseases: A prospective multi-center feasibility study

Introduction Biodegradable stents of various designs are reportedly used in pancreato-biliary conditions with promising results. Their major advantage is the avoidance of a repeat endoscopic procedure for stent removal thereby reducing overall cost along with ERCP associated adverse events. To evaluate the feasibility and safety of a new biodegradable stent in patients with pancreato-biliary diseases. Methods Prospective multicenter pilot study. All consecutive patients 18 years-old who underwent biliary or pancreatic stenting using the new biodegradable Archimedes stent were included. There were three biodegradation profiles. Technical and clinical success, feasibility and safety were assessed during a pre-established follow-up schedule. Results Fifty-three patients (mean age: 48.54±19.29, 66% male) having biliary (n=29, 54.7%%) or pancreatic (n=24, 45.3%) indications were included. The distribution of stents used according to degradation properties were as follows: fast (n=11, 20.8%), medium (n=16, 30.2%) and slow (n=26, 49.1%). The technical and clinical success were 100% and 77.8%. Thirty-five patients were followed for a median of 26 weeks (range: 4-56, 66%). There were 9 procedure-related adverse events (17%), all mild, including one uneventful stent-related event (external migration). Conclusion The biodegradable Archimedes stent placement is feasible and safe in pancreato-biliary diseases.

Mechanical properties and degradation process of biliary self-expandable biodegradable stents

OBJECTIVES

The clinical outcomes and prevalence of adverse events associated with biliary biodegradable stents (BS) can differ according to degradation process and time. The aim of this study was to observe the degradation process and time of different BS prototypes, and to evaluate sequential changes in their mechanical properties.

METHODS

Using an in vitro bile flow phantom model, we compared degradation time, radial force changes, and morphologic changes among four different BS prototypes: polydioxanone (PDO) BS, polyglycolide (PGA) BS, polydioxanone/poly-l-lactic acid (PDO/PLLA) sheath-core BS, and polydioxaone/magnesium (PDO/Mg) sheath-core BS. Using an in vivo swine bile duct dilation model, we performed a direct peroral cholangioscopy (DPOC) examination to observe the biodegradation process and related adverse events at regular intervals.

RESULTS

In the bile flow phantom model, the PGA BS and PDO/Mg BS prototypes showed rapid radial force reduction and morphological changes and complete degradation within six weeks. PDO/PLLA BS maintained high radial force and kept their original shape for longer than the PDO BS, up to 16 weeks. A total of 24 BS were inserted into the dilated bile ducts of 12 swine. In this animal model, DPOC examination revealed that PDO BS and PDO/PLLA BS maintained their original shapes for approximately 12 weeks, but PDO BS showed a greater degree of fragmentation and induced biliary stones and bile duct obstruction.

CONCLUSION

Our results showed that PDO/PLLA BS maintained their original shape and radial force for a relatively long time and minimized adverse events.

Endoscopic management of chronic pancreatitis

Chronic pancreatitis (CP) is an inflammatory process characterized by irreversible morphological changes in the pancreas. Pain is the predominant symptom observed during the course of CP. The etiopathogenesis of pain in CP is multifactorial and includes ductal hypertension due to obstruction of the pancreatic duct (PD), neuropathic causes, and extrapancreatic complications of CP like pseudocyst and distal biliary obstruction. A sizeable proportion of patients with CP are amenable to endoscopic treatment. The mainstay of endotherapy includes decompression of PD with one or more plastic stents in those with stricture, and fragmentation of PD calculi using extracorporeal shock wave lithotripsy. Nearly two-thirds of the patients achieve pain relief in the long term with endotherapy. Upfront assessment for the suitability of endotherapy is paramount to achieve the best outcomes. The predictors of poor response to endotherapy include multifocal disease, like those with multifocal strictures or multiple calculi throughout the pancreas, or a combination of both PD strictures and stones. With the emerging use of covered metal stents, the outcomes are likely to improve in cases with refractory PD strictures as well as CP-related distal biliary obstruction. The optimum stent design and indwell time of metal stents in cases with refractory PD strictures need further evaluation. Endoscopic ultrasonography has emerged as a complementary endoscopic modality in the management of CP as well as associated complications like pseudocysts, refractory pain, and vascular complications.

Endoscopic retrograde cholangiopancreatography: Current practice and future research

Endoscopic retrograde cholangiopancreatography (ERCP) has evolved from a primarily diagnostic to therapeutic procedure in hepatobiliary and pancreatic disease. Most commonly, ERCPs are performed for choledocholithiasis with or without cholangitis, but improvements in technology and technique have allowed for management of pancreatic duct stones, benign and malignant strictures, and bile and pancreatic leaks. As an example of necessity driving innovation, the new disposable duodenoscopes have been introduced into practice. With the advantage of eliminating transmissible infections, they represent a paradigm shift in quality improvement within ERCP. With procedures becoming more complicated, the necessity for anesthesia involvement and safety of propofol use and general anesthesia has become better defined. The improvements in endoscopic ultrasound (EUS) have allowed for direct bile duct access and EUS facilitated bile duct access for ERCP. In patients with surgically altered anatomy, selective cannulation can be performed with overtube-assisted enteroscopy, laparoscopic surgery assistance, or the EUS-directed transgastric ERCP. Cholangioscopy and pancreatoscopy use has become ubiquitous with defined indications for large bile duct stones, indeterminate strictures, and hepatobiliary and pancreatic neoplasia. This review summarizes the recent advances in infection prevention, quality improvement, pancreaticobiliary access, and management of hepatobiliary and pancreatic diseases. Where appropriate, future research directions are included in each section.

Current advances in the management of chronic pancreatitis

Chronic pancreatitis is characterized by irreversible destruction of pancreatic parenchyma and its ductal system resulting from longstanding inflammation, leading to fibrosis and scarring due to genetic, environmental, and other risk factors. The diagnosis of chronic pancreatitis is made based on a combination of clinical features and characteristic findings on computed tomography or magnetic resonance imaging. Abdominal pain is the most common symptom of chronic pancreatitis. The main aim of treatment is to relieve symptoms, prevent disease progression, and manage complications related to chronic pancreatitis. Patients who do not respond to medical treatment or not a candidate for surgical treatment are usually managed with endoscopic therapies. Endoscopic therapies help with symptoms such as abdominal pain and jaundice by decompression of pancreatic and biliary ducts. This review summarizes the risk factors, pathophysiology, diagnostic evaluation, endoscopic treatment of chronic pancreatitis, and complications. We have also reviewed recent advances in endoscopic retrograde cholangiopancreatography and endoscopic ultrasound-guided therapies for pancreatic duct obstruction due to stones, strictures, pancreatic divisum, and biliary strictures.

Endoscopic management of local complications of chronic pancreatitis

Endoscopic treatment of local complications in patients with chronic pancreatitis has gained ground over the surgical alternative in the last few years. The lower aggressiveness of endoscopic treatment, as well as the possibility to use it repeatedly in high-risk patients, has favored this development. In addition, the incorporation of new, highly accurate endoscopic therapeutic options such as pancreatoscopy-guided lithotripsy and endoscopic ultrasound-guided treatments make endoscopic treatment the first choice in many cases, despite discordant data in the literature. This article reviews the endoscopic treatment of the most common local complications of chronic pancreatitis, such as pancreatolithiasis, pseudocysts, and pancreatic, biliary, and duodenal ductal stenosis.

Chronic pancreatitis

Chronic pancreatitis is a multifactorial, fibroinflammatory syndrome in which repetitive episodes of pancreatic inflammation lead to extensive fibrotic tissue replacement, resulting in chronic pain, exocrine and endocrine pancreatic insufficiency, reduced quality of life, and a shorter life expectancy. The incidence and prevalence of chronic pancreatitis is rising and no curative treatment is available. Using novel diagnostic algorithms, definitive chronic pancreatitis can be diagnosed by imaging criteria alone, whereas probable chronic pancreatitis requires clinical features and imaging criteria. Criteria for the diagnosis of early chronic pancreatitis are still under discussion and need prospective validation in clinical trials. Cross-sectional imaging should be used first; endoscopic ultrasound is needed only when CT or MRI are inconclusive or to plan therapeutic interventions. Management of chronic pancreatitis requires an interdisciplinary approach including primary care practitioners, gastroenterologists, surgeons, radiologists, pain specialists, and nutritional therapists. Patients with chronic pancreatitis should be seen at least once a year and re-evaluated for causal risk factors, symptom control, and complications such as malnutrition, pancreatic exocrine insufficiency, and diabetes; refer to a specialised centre if symptoms are poorly controlled or there is risk of deterioration. Scoring systems to monitor disease progression have been developed and validated internationally. Interventional treatments for pain or cholestasis should be done by specialists only, and early discussion of treatment approaches should include all medical disciplines involved in care. Throughout this Seminar, we address research needs such as staging of pancreatitis, aspects of malnutrition and pain, and cancer surveillance, to help improve the care of patients.

Chronic pancreatitis: an overview of diagnosis and management

INTRODUCTION

Chronic pancreatitis entails a heavy burden on the healthcare system because of its often protracted evolution, requiring complex diagnostic and therapeutic procedures.

AREAS COVERED

This review focuses on novel imaging and endoscopic diagnostic and therapeutic interventions that have changed the management of patients with chronic pancreatitis. We have conducted an extensive search of original papers and guidelines, in order to provide a comprehensive and up to date review of available evidence in these areas of interest.

EXPERT OPINION

The traditional challenges in managing chronic pancreatitis patients stemmed from the limitations of diagnostic modalities, which could not correctly identify patients in an early stage of the disease, as well as from the scarcity of therapeutic options available. Advances in imaging of CT-scan, MRI, and EUS have opened the way for early diagnosis and staging. This has allowed more aggressive and tailored therapeutic modalities, particularly in endoscopic therapy and minimally invasive surgical interventions. Although high-quality data from large RCTs is still scarce, evidence-based algorithms for diagnosis and therapy are now changing the way we address this chronic disease. In the near future, we can expect a tailored approach based on patient and disease-related predictive factors, relying on a vast armamentarium of endoscopic and surgical solutions.

The Role of Endoscopic and Surgical Treatment in Chronic Pancreatitis

Chronic pancreatitis is a long-term illness leading to hospital admissions and readmission. This disease is often caused by heavy alcohol consumption and smoking. Patients with chronic pancreatitis suffer from acute or chronic pain episodes, recurrent pancreatitis, and complications, such as pseudocysts, biliary duct strictures, and pancreatic duct fistulas. Pancreatic duct strictures and stones may increase intraductal pressure and cause pain. Endoscopic therapy is aiming at decompressing the pressure and relieving the pain, most commonly with pancreatic duct stents and pancreatic duct stone retrieval. Early surgery is another option to treat the pain. In addition, endotherapy has been successful in treating complications related to chronic pancreatitis. The therapy should be individually chosen in a multidisciplinary meeting. Endoscopic therapy and surgery as treatment options for chronic pancreatitis are discussed in this review.

Recent innovations in therapeutic endoscopy for pancreatobiliary diseases

The development of endoscopic treatment for pancreatobiliary diseases in recent years is remarkable. In addition to conventional transpapillary treatments under endoscopic retrograde cholangiopancreatography (ERCP), new endoscopic ultrasound-guided therapy is being developed and implemented. On the other hand, due to the development/improvement of various devices such as new metal stents, a new therapeutic strategy under ERCP is also advocated. The present review focuses on recent advances in the endoscopic treatment of pancreatic pseudocysts, walled-off necrosis, malignant biliary strictures, and benign biliary/pancreatic duct strictures.

Biodegradable biliary stents preferable to plastic stent therapy in post-cholecystectomy bile leak and avoid second endoscopy

BACKGROUND

The treatment of post-cholecystectomy bile leak is endoscopic retrograde cholangiography (ERC) with plastic stent (PS) insertion combined with external drainage. Self-expanding biodegradable biliary stents (BDBS) have only recently become available.

AIM

The aim was to compare success rate, adverse events and costs of BDBS with PS in the treatment of post-cholecystectomy cystic duct leak Materials and methods: Patients recruited prospectively for treatment with BDBS during the period 2014-2017 were compared to a control group treated with PS in a non-randomized setting.

RESULTS

Altogether 32 patients (median age 68, range 33-88, 59% male) were treated for Strasberg A bile leak over a period of 3.5 years, accounting for 1.8% of all ERCs. Eight patients were treated with BDBS and 24 with PS. Treatment with BDBS was safe; rate of readmissions and 30-day adverse events were 13% in both groups. There was no statistical difference in the clinical success rate. All cases with laparoscopic lavation or re-ERC with stent exchange occurred in the PS group. Total drain output was lower in BDBS patients (330ml vs 83ml, p=.002). All PS patients required another endoscopy for stent removal, whereas all BDBS patients were spared repeated endoscopy.

CONCLUSION

Treatment of cystic duct leak with BDBS is highly successful and as safe as traditional treatment with PS. The most obvious benefit of BDBS is that it avoids stent removal. The lower drain output after ERC with a trend for fewer unplanned interventions may indicate more efficient leak resolution with the large bore BDBS.

Recent advances in the diagnosis and management of chronic pancreatitis

Chronic pancreatitis is a chronic condition characterized by pancreatic inflammation that causes fibrosis and the destruction of exocrine and endocrine tissues. Chronic pancreatitis is a progressive disease, and no physiological treatment is available to reverse its course. However, with advances in medical technology, the existing diagnostic and treatment methods for chronic pancreatitis are evolving. Managing patients with chronic pancreatitis is challenging and necessitates a multidisciplinary approach. In this review, we discuss the recent advances in the diagnosis and management of chronic pancreatitis and introduce future alternative modalities.

Endoscopic treatment of pain in chronic pancreatitis

PURPOSE OF REVIEW

Pain is the most common symptom of chronic pancreatitis, having a profound effect on patients and a broad socioeconomic impact. Endoscopy is guideline recommended as first-line management for chronic pancreatitis pain in certain clinical scenarios. Herein, we provide an evidence-based review of the endoscopic treatment of pain due to chronic pancreatitis while highlighting some important confounders in the measurement of this outcome in clinical practice and research.

RECENT FINDINGS

Multiple recent studies have reported on the efficacy of current endoscopic therapies for chronic pancreatitis pain. Despite the high technical success rates of these procedures, pain outcomes remain disappointing. Complex mechanisms beyond ductal hypertension, such as central sensitization, visceral hypersensitivity and inflammatory neuritis account for some of the discordance observed between the rates of technical and clinical success. In addition, the sham effect is increasingly recognized as a confounder when interpreting the procedural benefit. Nevertheless, there are multiple promising innovations in the field of pancreatic endoscopy that are aimed to improve technical and clinical outcomes, but rigorous investigation is necessary to establish their role in clinical practice.

SUMMARY

Endoscopic therapy for chronic pancreatitis pain appears to be safe and effective in certain contexts and recent innovations in the field will hopefully further improve outcomes. In addition to evaluating the technical success of endotherapy in chronic pancreatitis, methodologically rigorous research focusing on patient-centered outcomes and accounting for the sham effect is necessary to advance this field.

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.

Pancreatic stents in ERCP. Where are we?

Post-ERCP pancreatitis (PEP) is a common complication most feared by endoscopists. Incidence ranges widelly from 2.1% to 24.4%, which results from patient heterogeneity and differences in endoscopist expertise, method, PEP definition, and severity. Pathophysiology is multifactorial, and involves a combination of chemical, thermal, mechanical, hydrostatic, enzymatic, allergic, and microbiological factors resulting from papillary instrumentation and/or contrast administration within the pancreatic duct (volume and osmolarity). Even genetic abnormalities may represent a risk factor, as is the case with homozygous alpha-1-antitrypsin deficiency, which leads to an increase in hemorrhagic PEP rates.