Walled-off necrosis (WON) develops as local complications after acute necrotizing pancreatitis. Although less invasive interventions such as endoscopic ultrasonography (EUS)-guided drainage and endoscopic necrosectomy are selected over surgical interventions, delayed and step-up interventions are still preferred to avoid procedure-related adverse events. However, there is a controversy about the appropriate timing of drainage and subsequent necrosectomy. The advent of large-caliber lumen-apposing metal stents has also brought about potential advantages of proactive interventions, which still needs investigation in future trials. When step-up interventions of necrosectomy and additional drainage are necessary, a structured or protocoled approach for WON has been reported to improve safety and effectiveness of endoscopic and/or percutaneous treatment, but has not been standardized yet. Finally, long-term outcomes such as recurrence of WON, pancreatic endocrine, and exocrine function are increasingly investigated in association with disconnected pancreatic duct syndrome. In this review we discuss current evidence and controversy on EUS-guided management of WON.

Postoperative pancreatic fistulas (POPFs) are common adverse events that occur after pancreatic surgery. Endoscopic ultrasonography (EUS)-guided drainage (EUS-D) is a first-line treatment, similar to that for pancreatic fluid collection (PFCs) after acute pancreatitis. However, some POPFs do not develop fluid collections depending on the presence or location of the surgical drain, whereas others develop fluid collections, such as postoperative fluid collections (POPFCs). Although POPFCs are similar to PFCs, the strategy and modality for POPF management need to be modified according to the presence of fluid collections, surgical drains, and surgical type. As discussed for PFCs, the indications, timing, and selection of interventions or stents for EUS-D have not been fully elucidated for POPFs. In this review, we discuss the management of POPFs and POPFCs in comparison with PFCs due to acute pancreatitis and summarize the topics that should be addressed in future studies.

Percutaneous biopsy and drainage of pancreatic lesions, though less frequent due to advancements in endoscopic techniques, remain vital skills for interventional radiologists. This review details the indications, options, approaches, and technical considerations for pancreatic biopsy and (peri)pancreatic fluid drainage by examining a comprehensive range of literature. The importance of a multidisciplinary approach is emphasized to ensure optimal patient care and outcomes, highlighting current best practices and recent advancements.

Disconnected pancreatic duct syndrome (DPDS) is a pathological condition that causes various symptoms due to the continuous secretion of pancreatic enzymes from the pancreas upstream, which has been separated due to disconnection of the pancreatic duct (DPD) for various reasons.Acute necrotizing pancreatitis includes a certain probability of DPDS appearance, which makes it necessary to provide various treatments for DPDS. Furthermore, DPDS can impact long-term results, such as recurrence and impaired pancreatic function. Although the development of various modalities has contributed to diagnosis and treatment, especially less invasive endoscopic therapy, DPDS is often overlooked, and the diagnosis can be delayed due to the lack of consensus on its definition and classification. This review summarizes the current knowledge and challenges of DPDS and discusses the optimal strategy for its diagnosis and treatment, as well as future perspectives.

Given the lack of established definition, diagnosis, and treatment of DPDS, we conducted a thorough review of the existing literature.

It is emphasized that a standardized definition and classification of DPDS is essential for designing and conducting clinical studies to address current unmet needs in managing patients with DPDS.

Acute necrotizing pancreatitis is a severe and life-threatening condition. It poses a considerable challenge for clinicians due to its complex nature and the high risk of complications. Several minimally invasive and open necrosectomy procedures have been developed. Despite advancements in treatment modalities, the optimal timing to perform necrosectomy lacks consensus.

To evaluate the impact of necrosectomy timing on patients with pancreatic necrosis in the United States.

A national retrospective cohort study was conducted using the 2016-2019 Nationwide Readmissions Database. Patients with non-elective admissions for pancreatic necrosis were identified. The participants were divided into two groups based on the necrosectomy timing: The early group received intervention within 48 hours, whereas the delayed group underwent the procedure after 48 hours. The various intervention techniques included endoscopic, percutaneous, or surgical necrosectomy. The major outcomes of interest were 30-day readmission rates, healthcare utilization, and inpatient mortality.

A total of 1309 patients with pancreatic necrosis were included. After propensity score matching, 349 cases treated with early necrosectomy were matched to 375 controls who received delayed intervention. The early cohort had a 30-day readmission rate of 8.6% compared to 4.8% in the delayed cohort (P = 0.040). Early necrosectomy had lower rates of mechanical ventilation (2.9% vs 10.9%, P < 0.001), septic shock (8% vs 19.5%, P < 0.001), and in-hospital mortality (1.1% vs 4.3%, P = 0.01). Patients in the early intervention group incurred lower healthcare costs, with median total charges of $52202 compared to $147418 in the delayed group. Participants in the early cohort also had a relatively shorter median length of stay (6 vs 16 days, P < 0.001). The timing of necrosectomy did not significantly influence the risk of 30-day readmission, with a hazard ratio of 0.56 (95% confidence interval: 0.31-1.02, P = 0.06).

Our findings show that early necrosectomy is associated with better clinical outcomes and lower healthcare costs. Delayed intervention does not significantly alter the risk of 30-day readmission.

Endoscopic ultrasound (EUS)-guided transluminal drainage has become a first-line treatment modality for symptomatic pancreatic pseudocysts. Despite the increasing popularity of lumen-apposing metal stents (LAMSs), plastic stents may resolve non-necrotic fluid collections effectively with lower costs and no LAMS-specific adverse events. To date, there has been a paucity of data on the appropriate stent type in this setting. This trial aims to assess the non-inferiority of plastic stents to a LAMS for the initial EUS-guided drainage of pseudocysts.

The WONDER-02 trial is a multicentre, open-label, non-inferiority, randomised controlled trial, which will enrol pancreatic pseudocyst patients requiring EUS-guided treatment in 26 centres in Japan. This trial plans to enrol 80 patients who will be randomised at a 1:1 ratio to receive either plastic stents or a LAMS (40 patients per arm). In the plastic stent group, EUS-guided drainage will be performed using two 7-Fr double pigtail stents. In the LAMS group, the treatment will be performed in the same way except for LAMS use. The step-up treatment will be performed via endoscopic and/or percutaneous procedures at the trial investigator's discretion. The primary endpoint is clinical success, which is defined as a decrease in a pseudocyst size to ≤ 2 cm and an improvement in inflammatory indicators (i.e. body temperature, white blood cell count, and serum C-reactive protein). Secondary endpoints include technical success, adverse events including mortality, pseudocyst recurrence, and medical costs.

The WONDER-02 trial will investigate the efficacy and safety of plastic stents compared to a LAMS in EUS-guided treatment of symptomatic pancreatic pseudocysts with a particular focus on the non-inferior efficacy of plastic stents. The findings will help establish a new treatment algorithm for this population.

ClinicalTrials.gov NCT06133023 registered on 9 November 2023. UMIN000052647 registered on 30 October 2023. jRCT1032230444 registered on 7 November 2023.

No comprehensive study has examined short- and long-term adverse outcomes of endoscopic ultrasound (EUS)-guided treatment of pancreatic fluid collections (PFCs) including walled-off necrosis (WON) and pseudocysts.

In a multi-institutional cohort of 357 patients receiving EUS-guided treatment of PFCs (228 with WON and 129 with pseudocysts), we examined PFC type-specific risk factors for procedure-related adverse events (AEs), clinical failure, and recurrence. Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were computed using the logistic and Cox regression models, respectively, adjusting for potential confounders.

Adverse events were observed predominantly in WON, and risk factors were WON extension to the pelvis (OR 2.49; 95% CI 1.00-6.19) and endoscopic necrosectomy (OR 5.15; 95% CI 1.61-16.5). Risk factors for clinical failure in WON treatment included higher Charlson Comorbidity Index (OR for ≥3 vs. ≤2, 2.58; 95% CI 1.05-6.35), extension to the pelvis (OR 3.63; 95% CI 1.57-8.43), nonuse of a lumen-apposing metal stent (OR 2.88; 95% CI 1.10-7.54), and percutaneous drainage (OR 3.73; 95% CI 1.27-10.9). Patients with pseudocysts extending to the paracolic gutter and the need for more than two endoscopic/percutaneous procedures had ORs for clinical failure of 5.28 (95% CI 1.10-25.3) and 5.52 (95% CI 1.61-18.9), respectively. Pseudocysts requiring the multigateway approach were associated with a high risk of recurrence (HR 4.00; 95% CI 1.11-11.6).

The adverse outcomes at various phases of EUS-guided PFC treatment may be predictable based on clinical parameters. Further research is warranted to optimize treatment strategies for high-risk patients.

Endoscopic ultrasound (EUS)-guided endoscopic necrosectomy is an effective and minimally invasive treatment for walled-off pancreatic necrosis (WON). This study investigated the factors affecting the time interval of EUS-guided WON necrosectomy.

Patients who received EUS-guided necrosectomy in the Endoscopy Center of the First Affiliated Hospital of Chongqing Medical University in the past 5 years were retrospectively analyzed. Data including general information, etiology, blood biochemical indexes, physical signs, CT severity grade, location, size, solid necrotic ratio, type and number of stents, and immediate necrosectomy were collected to explore the relationships between these factors and the interval of endoscopic necrosectomy.

A total of 51 WON patients were included. No significant correlation has been noted between the endoscopic debridement interval and the following indexes, including the patients' general information, the etiology of pancreatitis, blood biochemical indexes (leukocyte count, neutrophil percentage, C-reactive protein), preoperative fever, and WON's location and size, type and number of stents, and whether immediate necrosectomy. However, there were significant differences between the debridement interval and the modified CT Severity Index (MCTSI) (p < 0.001), the solid necrotic ratio of WON (p < 0.001) before the intervention, postoperative fever (p = 0.038), C-reactive protein increasing (p = 0.012) and fever before reintervention (p = 0.024).

The EUS-measured solid necrotic ratio, the MCTSI, postoperative fever, C-reactive protein increase, and fever before reintervention in patients affect the time interval of EUS-guided endoscopic necrosectomy in WON patients. These five indicators may be promisingly effective in predicting and managing endoscopic necrosectomy intervals.

Endoscopic transmural drainage is usually performed for symptomatic well-encapsulated walled-off necrosis (WON) that usually develops in the delayed phase (> 4 weeks after disease onset) of acute necrotising pancreatitis (ANP). Endoscopic drainage is usually not advocated in the early (< 4 weeks after disease onset) stage of illness because of the risk of complications due to an incompletely formed encapsulating wall and poor demarcation of viable from necrotic tissue. However, emerging data from expert tertiary care centres over the last few years shows that the early endoscopic transluminal drainage approach is effective and safe. The development of lumen-apposing metal stents and better accessories for endoscopic necrosectomy has fuelled the expansion of indications of endoscopic drainage of pancreatic necrosis. However, early endoscopic drainage is associated with higher rates of adverse events; therefore, careful patient selection is paramount. This article will review the current indications, techniques and outcomes of early endoscopic transluminal drainage in pancreatic necrotic collections.

Infected acute necrotic collection (ANC) is a fatal complication of acute pancreatitis with substantial morbidity and mortality. Drainage plays an exceedingly important role as the first step in invasive intervention for infected necrosis; however, there is great controversy about the optimal drainage time, and better treatment should be explored.

We report the case of a 43-year-old man who was admitted to the hospital with severe intake reduction due to early satiety 2 wk after treatment for acute pancreatitis; conservative treatment was ineffective, and a pancreatic pseudocyst was suspected on contrast-enhanced computed tomography (CT). Endoscopic ultrasonography (EUS) suggested hyperechoic necrotic tissue within the cyst cavity. The wall was not completely mature, and the culture of the puncture fluid was positive for A-haemolytic Streptococcus. Thus, the final diagnosis of ANC infection was made. The necrotic collection was not walled off and contained many solid components; therefore, the patient underwent EUS-guided aspiration and lavage. Two weeks after the collection was completely encapsulated, pancreatic duct stent drainage via endoscopic retrograde cholangiopancreatography (ERCP) was performed, and the patient was subsequently successfully discharged. On repeat CT, the pancreatic cysts had almost disappeared during the 6-month follow-up period after surgery.

Early EUS-guided aspiration and lavage combined with late ERCP catheter drainage may be effective methods for intervention in infected ANCs.

Pancreatic fluid collections (PFCs) are well-known complications of acute pancreatitis. The overinfection of these collections leads to a worsening of the prognosis with an increase in the morbidity and mortality rate. The primary strategy for managing infected pancreatic necrosis (IPN) or symptomatic PFCs is a minimally invasive step-up approach, with endosonography-guided (EUS-guided) transmural drainage and debridement as the preferred and less invasive method. Different stents are available to drain PFCs: self-expandable metal stents (SEMSs), double pigtail stents (DPPSs), or lumen-apposing metal stents (LAMSs). In particular, LAMSs are useful when direct endoscopic necrosectomy is needed, as they allow easy access to the necrotic cavity; however, the rate of adverse events is not negligible, and to date, the superiority over DPPSs is still debated. Moreover, the timing for necrosectomy, the drainage technique, and the concurrent medical management are still debated. In this review, we focus attention on indications, timing, techniques, complications, and particularly on aspects that remain under debate concerning the EUS-guided drainage of PFCs.

Background and study aims Recent advances in endoscopic transmural treatment have improved the clinical outcomes of patients with pancreatic fluid collections (PFCs). However, there is still a debate about the preventive effect of long-term placement of a transmural plastic stent (PS) on recurrence after successful endoscopic ultrasound (EUS)-guided treatment of PFCs. We conducted a systematic review and meta-analysis to evaluate PFC recurrence rates with and without a transmural PS after EUS-guided treatment. Patients and methods A systematic literature search of PubMed, Embase, and the Cochrane database was conducted to identify clinical studies comparing outcomes with and without transmural PS published until September 2022. Data on PFC recurrence and adverse events (AEs) were pooled using a random-effects model. Results Nine studies including 380 patients with long-term transmural PS and 289 patients without PS were identified. The rate of PFC recurrence was significantly lower in patients with transmural PS (pooled odds ratio [OR] = 0.23, 95% confidence interval [CI] [0.08-0.65], P = 0.005). In a subgroup analysis limited to studies focusing on patients with disconnected pancreatic duct syndrome, which has been reported to be a risk factor for PFC recurrence, the OR was numerically lower than that for the entire cohort (OR = 0.14, 95% CI [0.04-0.46]). The rate of AEs was significantly higher with long-term transmural PS (OR = 14.77, 95% CI [4.21-51.83]). Conclusions In this meta-analysis, long-term PS placement reduced the risk of PFC recurrence. Given the potential AEs of indwelling PS, further research is required to evaluate the overall benefits of long-term PS placement.

A 54-year-old man was admitted for fever and dyspnea. He presented with severe COVID-19 pneumonia and elevated amylase and lipase levels. He received treatment for COVID-19 and possible acute pancreatitis (AP). Although pneumonia and amylase levels improved, a high-grade fever persisted. On day 39, abdominal CT revealed heterogenous liquid and non-liquid components with a well-defined wall around the pancreas, and he was diagnosed with infected walled-off necrosis (WON) after AP. It was concluded to be associated with COVID-19 because there were no identifiable causes, such as alcohol consumption, gallstones, or other viral infections. The necrotic collection and fever improved after endoscopic transgastric drainage and necrosectomy. SARS-CoV-2 is becoming recognized as a new etiological infectious factor for AP, and COVID-19-associated AP shows higher severity and mortality. Clinicians should evaluate COVID-19 patients for concomitant AP, and if it is present, they should carefully monitor the development of local complications, including WON.

Postoperative pancreatic fluid collections (POPFCs) are common adverse events (AEs) after pancreatic surgery and may need interventions. Endoscopic ultrasound (EUS)-guided drainage for POPFCs is increasingly reported, but its appropriate timing has not been fully elucidated. The aim of this meta-analysis was to evaluate treatment outcomes of POPFCs according to the timing of EUS-guided drainage.

Using PubMed, Embase, Web of Science, and the Cochrane database, we identified clinical studies published until December 2022 with data comparing outcomes of early and delayed EUS-guided drainage for POPFCs. We pooled data on AEs, mortality, and technical and clinical success rates, using the random-effects model.

From 1415 papers identified in the initial literature search, we identified 6 retrospective studies, including 128 and 107 patients undergoing early and delayed EUS-guided drainage for POPFCs. The threshold of early and delayed drainage ranged from 14 to 30 days. Distal pancreatectomy was the major cause of POPFCs, ranging from 44 to 100%. The pooled odds ratio (OR) for AEs was 0.81 (95% confidence interval [CI] 0.40-1.64, P = 0.55) comparing early to delayed drainage. There was no procedure-related mortality. Technical success was achieved in all cases and a pooled OR of clinical success was 0.60 (95% CI 0.20-1.83, P = 0.37).

POPFCs can be managed by early EUS-guided drainage without an increase in AEs.

Pancreatic fluid collections (PFCs) typically develop as local complications of acute pancreatitis and complicate the clinical course of patients with acute pancreatitis and potentially fatal clinical outcomes. Interventions are required in cases of symptomatic walled-off necrosis (WON) (matured PFCs with necrosis) and pancreatic pseudocysts (matured PFCs without necrosis). In the management of necrotizing pancreatitis and WON, endoscopic ultrasound-guided transluminal drainage combined with on-demand endoscopic necrosectomy (i.e. the step-up approach) is increasingly used as a less invasive treatment modality compared with a surgical or percutaneous approach. Through the substantial research efforts and development of specific devices and stents (e.g. lumen-apposing metal stents), endoscopic techniques of PFC management have been standardized to some extent. However, there has been no consensus about timing of carrying out each treatment step; for instance, it is uncertain when direct endoscopic necrosectomy should be initiated and finished and when a plastic or metal stent should be removed following clinical treatment success. Despite emerging evidence for the effectiveness of noninterventional supportive treatment (e.g. antibiotics, nutritional support, irrigation of the cavity), there has been only limited data on the timing of starting and stopping the treatment. Large studies are required to optimize the timing of those treatment options and improve clinical outcomes of patients with PFCs. In this review, we summarize the current available evidence on the indications and timing of interventional and supportive treatment modalities for this patient population and discussed clinical unmet needs that should be addressed in future research.

Over last few years, there has been a paradigm shift in the management of infected pancreatic necrosis with endoscopic and minimally invasive "step-up" management approach replacing open surgical necrosectomy. Because of being associated with reduced occurrence of new onset multi-organ failure, external pancreatic fistulae, shorter hospital stay, lower costs, and better quality of life compared with minimally invasive surgical approach, endoscopic "step-up" management approach is the preferred intervention for endoscopically accessible pancreatic necrotic collections at expert centers with endoscopic expertise. Development of lumen apposing metal stents and improvised accessories for interventional endoscopic ultrasound has revolutionized the endoscopic management of pancreatic necrosis making it more effective and safer. Despite these promising developments, endoscopic transluminal necrosectomy (ETN) remains the Achilles heel. Lack of dedicated endoscopic accessories, poor endoscopic visualization within the necrotic cavity, limited diameter of the instrument channel of the endoscope that is a significant impediment to remove large amount of necrotic material, and uncertain ability to avoid vessels and vital structures in the necrotic cavity are important limitations during endoscopic necrosectomy. Recent devices and solutions including use of cap assisted necrosectomy, over the scope grasper and powered endoscopic debridement device are welcome steps in our pursuit for an ideal, safer, and efficacious ETN device. This review will discuss recent advances as well as challenges in the endoscopic management of pancreatic necrosis.

Pancreatic fluid collection often occurs as a local complication of acute pancreatitis, and drainage is indicated in symptomatic patients. The drainage may be surgical, percutaneous, or endoscopic ultrasound (EUS) guided. In symptomatic collections older than 4 weeks and localized in the upper abdomen, EUS-guided drainage is the first choice of treatment. Lumen-apposing metal stents are useful in cases of walled-off necrosis, facilitating access to the cavity; however, they do not reduce the number of necrosectomy sessions required. In most pancreatic pseudocysts requiring drainage, plastic stents remain the first choice of treatment. This review aimed to summarize the principles and techniques of step-up therapy of pancreatic fluid collections, including preprocedural and postprocedural assessment and practical approaches of drainage and necrosectomy, making available evidence more accessible to endoscopists aiming to train for this procedure. Successful and safe EUS drainage connotes early recognition and treatment of complications and the presence of a multidisciplinary team for optimal patient management. However, the best time for necrosectomy, modality of drainage method (lumen-apposing metal stents or plastic stents), and duration of antibiotherapy are still under evaluation.

With the increasing popularity of endoscopic ultrasound (EUS)-guided transmural interventions, walled-off necrosis (WON) of the pancreas is increasingly managed via non-surgical endoscopic interventions. However, there has been an ongoing debate over the appropriate treatment strategy following the initial EUS-guided drainage. Direct endoscopic necrosectomy (DEN) removes intracavity necrotic tissue, potentially facilitating early resolution of the WON, but may associate with a high rate of adverse events. Given the increasing safety of DEN, we hypothesised that immediate DEN following EUS-guided drainage of WON might shorten the time to WON resolution compared to the drainage-oriented step-up approach.

The WONDER-01 trial is a multicentre, open-label, superiority, randomised controlled trial, which will enrol WON patients aged ≥ 18 years requiring EUS-guided treatment in 23 centres in Japan. This trial plans to enrol 70 patients who will be randomised at a 1:1 ratio to receive either the immediate DEN or drainage-oriented step-up approach (35 patients per arm). In the immediate DEN group, DEN will be initiated during (or within 72 h of) the EUS-guided drainage session. In the step-up approach group, drainage-based step-up treatment with on-demand DEN will be considered after 72-96 h observation. The primary endpoint is time to clinical success, which is defined as a decrease in a WON size to ≤ 3 cm and an improvement of inflammatory markers (i.e. body temperature, white blood cell count, and C-reactive protein). Secondary endpoints include technical success, adverse events including mortality, and recurrence of the WON.

The WONDER-01 trial will investigate the efficacy and safety of immediate DEN compared to the step-up approach for WON patients receiving EUS-guided treatment. The findings will help us to establish new treatment standards for patients with symptomatic WON.

ClinicalTrials.gov NCT05451901, registered on 11 July 2022. UMIN000048310, registered on 7 July 2022. jRCT1032220055, registered on 1 May 2022.

Postponed open necrosectomy or minimally invasive intervention has become the treatment option for necrotizing pancreatitis. Nevertheless, several studies point to the safety and efficacy of early intervention for necrotizing pancreatitis. Therefore, we conducted a systematic review and meta-analysis to compare clinical outcomes of acute necrotizing pancreatitis between early and late intervention.

Literature search was performed in multiple databases for articles that compared the safety and clinical outcomes of early (<4 weeks from the onset of pancreatitis) versus late intervention (≥4 weeks from the onset of pancreatitis) for necrotizing pancreatitis published up to August 31, 2022. The meta-analysis was performed to determine pooled odds ratio (OR) of mortality rate and procedure-related complications.

Fourteen studies were included in the final analysis. For open necrosectomy intervention, the overall pooled OR of mortality rate with the late intervention compared with early intervention was 7.09 (95% confidence interval [CI] 2.33-21.60; I2  = 54%; P = 0.0006). For minimally invasive intervention, the overall pooled OR of mortality rate with the late intervention compared with early intervention was 1.56 (95% CI 1.11-2.20; I2  = 0%; P = 0.01). The overall pooled OR of pancreatic fistula with the late minimally invasive intervention compared with early intervention was 2.49 (95% CI 1.75-3.52; I2  = 0%; P < 0.00001).

These results showed the benefit of late interventions in patients with necrotizing pancreatitis in both minimally invasive procedures and open necrosectomy. Late intervention is preferred in the management of necrotizing pancreatitis.

Pancreatic walled-off necrosis (WON) is a complication of severe pancreatitis. Endoscopic transmural drainage has been recognized as the first-line treatment for pancreatic fluid collections. Endoscopy offers a minimally invasive approach when compared to surgical drainage. Today, endoscopists may choose to use self-expanding metal stents, pigtail stents, or lumen-apposing metal stents to facilitate drainage of fluid collections. Current data suggest that all 3 approaches yield similar outcomes. It was previously thought that drainage should be performed 4 weeks from the initial event of pancreatitis, theoretically allowing the capsule to mature. However, current data show that both early (<4 weeks) and standard (≥4 weeks) endoscopic drainage are comparable. Herein, we provide an up-to-date state-of-the-art review of the indications, techniques, innovations, outcomes, and future perspectives following drainage of pancreatic WON.

A series of randomized controlled trials have investigated the efficacy and safety of different timings of interventions and methods of intervention. However, the optimal treatment strategy is not yet clear.

We searched PubMed, EMBASE, ClinicalTrials.gov and the Cochrane Library until November 30, 2022. A systematic review and Bayesian network meta-analysis were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Trials comparing different treatment strategies for necrotizing pancreatitis were included. This study was registered in the Prospective Register of Systematic Reviews (CRD42022364409) to ensure transparency.

We analyzed a total of 10 studies involving 570 patients and 8 treatment strategies. Although no statistically significant differences were identified comparing odds ratios, trends were confirmed by the surface under the cumulative ranking (SUCRA) scores. The interventions with a low rate of mortality were delayed surgery (DS), delayed surgical step-up approach (DSU) and delayed endoscopic step-up approach (DEU), while the interventions with a low rate of major complications were DSU, DEU and DS. According to the clustered ranking plot, DSU performed the best overall in reducing mortality and major complications, while DD performed the worst. Analysis of the secondary endpoints confirmed the superiority of DEU and DSU in terms of individual components of major complications (organ failure, pancreatic fistula, bleeding, and visceral organ or enterocutaneous fistula), exocrine insufficiency, endocrine insufficiency and length of stay. Overall, DSU was superior to other interventions.

DSU was the optimal treatment strategy for necrotizing pancreatitis. Drainage alone should be avoided in clinical practice. Any interventions should be postponed for at least 4 weeks if possible. The step-up approach was preferred.