Role of fully covered metal stents in the management of chronic pancreatitis
Article information
Abstract
Chronic pancreatitis (CP), a progressive inflammatory disease that results in irreversible pancreatic damage, is often complicated by ductal strictures and debilitating pain. Fully covered self-expandable metal stents (FCSEMS) have emerged as significant innovations in the endoscopic management of refractory pancreatic duct strictures. This review synthesizes recent evidence highlighting the benefits and limitations of FCSEMS, such as superior patency, reduced need for reinterventions, and effective symptom relief compared to traditional plastic stents, alongside risks, such as stent migration and de novo strictures. A comparison with plastic stents and an algorithm for pancreatic duct stricture management are provided. Regional variations in clinical guidelines from the United States, Europe, Japan, and Korea reflect diverse approaches to integrating FCSEMS into practice. Emerging innovations in stent technology are promising for improving CP management outcomes.
INTRODUCTION
Chronic pancreatitis (CP) is a progressive fibro-inflammatory condition that causes irreversible structural damage to the pancreas. It is characterized by chronic abdominal pain, pancreatic duct strictures, and endocrine and exocrine insufficiency.1,2 Pain, reported in up to 85% of patients,3 is the most challenging symptom, often resulting from increased ductal pressure due to dominant pancreatic duct strictures2. The management of CP-related pain requires a stepwise approach, starting with minimally invasive endoscopic procedures and escalating to surgical interventions when necessary,1 since treatments can result in complications, such as bleeding, infection, or even death.4,5 The advent of fully covered self-expandable metal stents (FCSEMS) has advanced the endoscopic management of CP-related pancreatic duct strictures owing to their superior patency, larger lumen, and ability to prevent tissue ingrowth compared with plastic stents, although their use is tempered by potential complications. With such concerns, some guidelines, such as the 2024 American Society for Gastrointestinal Endoscopy (ASGE) guidelines6 suggest against the routine use of FCSEMS for refractory pancreatic duct strictures and recommend individualized patient assessment. This review focuses on the role of FCSEMS in the management of CP-related strictures, emphasizing their benefits, limitations, and recent evidence.
COMPARISON OF ENDOSCOPIC INTERVENTION VS. SURGERY FOR PAIN MANAGEMENT
Surgical and endoscopic treatments are both used to manage pain in CP; however, surgery often provides superior long-term outcomes. A meta-analysis by Mendieta et al.,7 including 13 studies and 981 patients, compared surgical and endoscopic interventions for pain relief in patients with CP. The analysis found that surgery offered significantly better long-term pain relief, with a pooled relative risk (RR) of 1.35 (95% confidence interval [CI], 1.12–1.63; p<0.001). Additionally, surgical treatment reduced the need for reinterventions compared to endoscopic approaches (RR, 0.34; 95% CI, 0.16–0.74). Similarly, Ma et al.8 conducted a meta-analysis comparing these interventions and reported that surgery was associated with superior pain relief (RR, 1.42; 95% CI, 1.11–1.81) and a lower rate of endocrine insufficiency (RR, 0.57; 95% CI, 0.42–0.77). Despite these advantages, surgery is often reserved for patients who fail to respond to less invasive therapies. The 2024 ASGE guidelines primarily recommend surgical approaches for CP-related pancreatic duct strictures and emphasize the importance of timely surgical referral, noting that prolonged endotherapy can negatively impact surgical outcomes, especially in patients with ductal strictures at the tail or large stones and dense calcifications, which would cause difficulties in complete endoscopic relief of the obstruction.6,9 However, guidelines from the European Society of Gastrointestinal Endoscopy (ESGE) and the American Gastroenterological Association (AGA) advocate a stepwise approach to pain management and recommend endoscopic therapy as the first-line option because of its minimally invasive nature and lower perioperative risks.2,4 For patients with significant comorbidities or a preference for avoiding major surgery, endoscopic techniques, such as stent placement and extracorporeal shock wave lithotripsy, remain viable alternatives. This stepwise approach balances the efficacy of surgical interventions with the need to minimize patient morbidity, highlighting the importance of tailoring treatment strategies to individual patient profiles. However, a stepwise approach may fail to achieve optimal timing for surgery.
COMPARISON OF METALLIC STENT AND PLASTIC STENTS
Notably, the routine use of FCSEMS for refractory main pancreatic duct strictures is not recommended because there is scarce evidence of its efficacy and safety. No randomized prospective studies have compared the use of metal and plastic stents in the management of pancreatic duct strictures associated with CP. However, some single-arm studies have demonstrated several advantages of FCSEMS over plastic stents. A meta-analysis by Tringali et al.10 reported that FCSEMS achieved a 92% rate of pain resolution and a 91% rate of stricture resolution, outperforming multiple plastic stents (MPS), which showed 83% of stricture resolution.11 Supporting this, a systematic review and meta-analysis by Sofi et al.12 compared FCSEMS with MPS in refractory pancreatic duct strictures, revealing no significant difference in the overall stricture resolution rates between the two groups. However, FCSEMS significantly reduced the number of endoscopic interventions required, with fewer procedure-related complications, suggesting improved procedural efficiency and patient convenience. Similarly, Sharaiha et al.3 highlighted the reduced need for repeated endoscopic procedures with FCSEMS compared to plastic stents, enhancing patient convenience and reducing healthcare burdens. The structural design of the FCSEMS, featuring a larger lumen diameter, facilitates more effective drainage of pancreatic secretions and reduces the risk of stent occlusion. This design also prevents tissue ingrowth, which is a common complication observed with plastic stents and ensures safer and easier stent removal. These benefits are reflected in the current clinical guidelines. The ESGE recommends the use of FCSEMS for refractory strictures or when plastic stents fail.4 Similarly, the AGA supports the use of FCSEMS in specific scenarios of CP.2 Additionally, the Japanese Society of Hepato-Biliary-Pancreatic Surgery has provided guidelines that align with these recommendations, endorsing the use of FCSEMS in the management of pancreatic duct strictures.1 However, despite these benefits, adverse events, such as stent migration and de novo strictures remain concerns, and in addition to scarce well-designed prospective comparative trials, prevent the routine use of FCSEMS, as suggested by the ASGE guideline.6 Migration rates vary widely, from 2.8% in studies utilizing anti-migrative designs, such as flared stents to 47.7% in cases with softer stents lacking such features, as reported by Sherman et al.13 De novo strictures have been observed in up to 48.6% of patients, particularly those with prolonged stent placement, as noted by Ko et al.14 Nonetheless, innovations in stent design have significantly mitigated these risks. Considering the high efficacy rates in symptom relief and ductal patency, along with the manageable adverse event profile, there remains a strong argument for the selective use of FCSEMS in managing refractory pancreatic duct strictures, particularly when MPS therapy fails to achieve adequate results (Table 1).
Comparing FCSEMS and plastic stents
RECENT STUDIES ABOUT FCSEMS FOR CP IN 10 YEARS
Over the past decade, FCSEMS have been extensively investigated for their efficacy and safety in the management of CP-related ductal strictures (Table 2).3,13-24 Research from the United States has been pivotal, with studies such as Sharaiha et al.3 demonstrating significant clinical success, reporting an 87.9% resolution of ductal strictures and reduced procedural frequency compared with plastic stents. Similarly, Sherman et al.13 highlighted the technical success of soft FCSEMS, achieving a 97% success rate, although challenges, such as stent migration (47.7%) remain critical considerations. In Europe, Tringali et al.15 reported long-term stricture resolution in 93.3% of cases, while Korpela et al.16 highlighted a resolution rate of 70.6% with a recurrence rate of 30.0% following stent removal.
Studies regarding FCSEMS for CP in recent 10 years
In Japan, innovative designs have contributed to improved outcomes; for example, Ogura et al.17 achieved a 100% stricture resolution rate, and Matsubara et al.18 reported a resolution rate of 80% with improved stent designs, such as the Niti-S Bumpy stent. Yamada et al.19 explored a dumbbell-type stent design and reported 86.3% resolution and no symptom recurrence after removal.
In India, Shah et al.20 provided prospective evidence, reporting a resolution rate of 86.1% with manageable complications. Recent findings by Rai et al.21 underscore the versatility of FCSEMS in complex cases, with a 100% resolution rate and limited complications.
Korean researchers have made significant contributions in advancing the application and understanding of FCSEMS in the treatment of CP. Oh et al.22 investigated the outcomes of a 6-mm diameter FCSEMS for benign refractory pancreatic duct strictures and reported high technical success (100%) and clinical success (83.3%) rates, with long-term pain relief in 86.7% of patients after stent removal during a median follow-up of 47.3 months. Ko et al.14 provided an 11-year follow-up study demonstrating an 85.1% stricture resolution rate with sustained pain relief, although stent-induced de novo strictures were noted in 48.6% of patients. Lee et al.23 compared FCSEMS with plastic stents and found superior outcomes in terms of stricture resolution (87.0% vs. 42.0%) and pain relief (76.9% vs. 53.7%) during a median follow-up of 33.7 months. Innovations in stent design were also explored by Lee et al.24 who introduced a modified non-flared FCSEMS to reduce migration and stent-induced ductal injuries. Their study reported a technical success rate of 100%, with no FCSEMS-related de novo strictures during a median follow-up period of 34 months. These studies collectively highlight FCSEMS as a pivotal advancement in the endoscopic management of pancreatic duct strictures, providing durable outcomes and reduced procedural burden while paving the way for further innovation in stent design and patient selection.
ADVERSE EVENTS
Adverse events associated with FCSEMS in CP have been extensively analyzed, with stent migration, de novo strictures, and other complications being the most frequently reported (Table 3).3,13-24 To control FCSEMS-specific adverse events, such as de novo strictures and stent migration, multiple dedicated stents have been developed and used (Table 4).14,18,19,24 Stent migration rates vary widely, from 2.8% in studies using flared designs, such as Oh et al.22 to 47.7% in Sherman et al.,13 which used softer stents without anti-migrative features. Ko et al.14 reported a migration rate of 17.1% over an 11-year follow-up period using flared stents, highlighting the role of anti-migration designs in mitigating this complication. However, while these features reduce migration risks, they may contribute to de novo strictures, as noted by Ko et al.,14 in where 48.6% of the patients developed strictures following prolonged stent placement. Conversely, shorter stent indwelling durations, as reported by Oh et al.,22 are associated with fewer de novo strictures, suggesting that the timing of stent removal is a critical factor in minimizing complications.
Adverse events reported in studies regarding FCSEMS for chronic pancreatitis in recent 10 years
Dedicated FCSEMS for adverse events
Other adverse events included cholangitis, severe abdominal pain, and acute pancreatitis. Severe abdominal pain was reported in 8.3% of cases by Shah et al.,20 while post-ERCP pancreatitis was observed in 2.8% of patients by Oh et al.22 The cholangitis rates range from 2% to 20%, with higher rates often associated with prolonged stent placement or inadequate drainage. These findings underline the importance of optimizing the stent design, determining the appropriate indwelling duration, and carefully selecting patients to minimize the risk of adverse events. Recent innovations aim to balance the benefits of anti-migratory stents with their potential to induce ductal injury, paving the way for safer and more effective stent technologies.
MANAGEMENT ALGORITHM FOR PAIN IN CP
The management of pain in CP should follow a stepwise algorithm, integrating both endoscopic and surgical options, while considering individualized patient factors. The initial treatment typically involves endoscopic management with a single plastic stent, which is maintained for up to 1 year.4 If the pain worsens during this period or persists beyond 1 year, additional plastic stents can be introduced. For patients with refractory pain despite MPS, the placement of FCSEMS is considered. However, the 2024 ASGE guidelines emphasize that FCSEMS should not be used routinely and advocate for individualized decision-making based on patient-specific factors, including the presence of comorbidities, prior stent failures, and tolerance to invasive procedures.6 Patients with significant surgical risks owing to comorbidities may benefit from prolonged endoscopic therapy, whereas those with recurrent stent occlusions or intolerance to repeated endoscopic interventions may be better suited for early surgical consultations. If FCSEMS placement fails to achieve pain relief, surgical intervention should be considered as the definitive approach because surgery offers superior long-term pain control in numerous cases.7 This algorithm ensures that treatment decisions are tailored to the patient’s clinical context, thereby optimizing both efficacy and safety (Fig. 1).
Management algorithm for pain in chronic pancreatitis. FCSEMS, fully covered metal stent.
CONCLUSIONS
For the optimal treatment of CP-related strictures, patient-specific factors (comorbidities, previous stent failures, and tolerance to invasive procedures), institutional experience, and cost should be considered. The FCSEMS represents a transformative advancement in the endoscopic management of CP-related pain. Although surgery offers superior long-term outcomes, FCSEMS provide a minimally invasive and effective alternative, particularly in patients for whom surgical intervention is unsuitable. Further research should focus on optimizing stent designs to reduce complications, such as migration, and refining patient selection criteria to maximize therapeutic success.
Notes
Conflicts of Interest
The authors have no potential conflicts of interest.
Funding
None.
Acknowledgments
The authors would like to thank the staff of Ulsan University Hospital for their support in providing access to research materials.
Author Contributions
Conceptualization: YJ, HS; Data curation: YJ; Supervision: HS, SJB; Writing–original draft: YJ, HS; Writing–review & editing: all authors.