Predicting success of direct endoscopic necrosectomy with lumen-apposing metal stents for pancreatic walled-off necrosis

Necrosectomy and its timing in relation to clinical outcomes of EUS-guided treatment of walled-off pancreatic necrosis: a multicenter study

BACKGROUND AND AIMS

EUS-guided transmural drainage with on-demand endoscopic necrosectomy (EN) is increasingly used to manage walled-off necrosis (WON). It has not been fully elucidated how EN and its timing are correlated with treatment outcomes compared with the drainage-based approach.

METHODS

Within a multi-institutional cohort of 423 patients with pancreatic fluid collections, including 227 patients with WON, 153 patients were identified who received the step-up treatment after the initial EUS-guided drainage of symptomatic WON; this included 102 EN patients and 51 non-EN (drainage) patients. Using the competing-risks multivariable proportional hazards regression model with adjustment for potential confounders, we calculated subdistribution hazard ratios (SHRs) for clinical treatment success (WON resolution) according to use of EN and its timing.

RESULTS

Compared with drainage alone, the EN-based treatment was associated with a shorter time to clinical success with a multivariable SHR of 1.66 (95% confidence interval, 1.12-2.46). Despite a higher risk of procedure-related bleeding in the EN group, there were no differences in the rates of severe adverse events (7.8% vs 5.9% in the EN and non-EN groups, respectively) or mortality (6.9% vs 9.8%). In the EN-treated patients, the timing of EN was not statistically significantly associated with the time to clinical success (Ptrend = .34).

CONCLUSIONS

Among patients receiving EUS-guided treatment of symptomatic WON, the use of EN in addition to drainage procedures was associated with earlier disease resolution. Further research is desired to determine the optimal timing of initiating EN considering a risk-benefit balance and cost-effectiveness.

Endoscopic Step-Up Approach in Management of Necrotizing Pancreatitis

The endoscopic step-up approach in the management of necrotizing pancreatitis involves sequential steps of intervention at different time points in the clinical course of the disease. EUS -guided drainage of walled-off necrosis is the first step of the endoscopic step-up approach. Lumen-apposing metal stents are preferred over plastic stents for safe and effective drainage because of their wide caliber. Successive steps in the endoscopic step-up approach include direct endoscopic necrosectomy and/or irrigation using naso-cystic tube in symptomatic patients, primarily based on necrotic debris characteristics. Minimally invasive percutaneous radiological and/or surgical drainage are considered when endoscopic drainage is not feasible or successful.

Outcomes of percutaneous endoscopic versus endoscopic transmural necrosectomy for necrotizing pancreatitis: A propensity score-matched study

BACKGROUND

Few published studies exist that compare the outcomes of different endoscopic necrosectomy methods for necrotizing pancreatitis (NP). We compared the safety and efficacy of percutaneous versus transmural endoscopic necrosectomy for NP patients.

METHODS

In this retrospective cohort study, we analyzed adult NP patients who underwent either percutaneous endoscopic necrosectomy (PEN) or endoscopic transmural necrosectomy (ETN), and compared safety and efficacy between the two groups. Propensity score-matched analysis and multivariable logistic regression analysis were conducted.

RESULTS

A total of 280 patients were enrolled, among which 142 underwent PEN and 138 underwent ETN. There were differences in baseline characteristics between the two groups, including body mass index, C-reactive protein, systemic inflammatory response syndrome score. The incidences of sepsis, respiratory failure, and intensive care unit stay were higher among patients who underwent PEN than those who underwent ETN (all P < 0.01). Ninety-one pairs were matched with comparable baseline characteristics and severity. The incidence of postoperative complications, open surgery, clinical success, radiological success, collection recurrence, and reintervention were not significantly different between the ETN group and PEN group (all P > 0.05). Multivariate analysis also showed that the approaches (PEN vs ETN) was not associated with postoperative complications or mortality.

CONCLUSIONS

In real world setting, sicker patients tend to be more effectively managed through PEN compared to ETN. PEN demonstrates comparable efficacy and safety to ETN in the treatment of NP patients.

Lumen-apposing metal stents: A primer on indications and technical tips

Lumen-apposing metal stents have ushered a new frontier for interventional endoscopic ultrasound. Initial use for the drainage of pancreatic fluid collections has rapidly expanded to the bile duct, gallbladder and small bowel. Intra-luminal applications for short strictures have also emerged. Electrocautery enhancement has made the stent delivery speedy. While the advent of lumen-apposing metal stents (LAMS) has brought a paradigm shift in the practice of interventional endoscopic ultrasound, their use is associated with certain technicalities that any advanced endosonologist should know. Understanding indications for LAMS is critical and their use in appropriate settings. Troubleshooting in tricky situations is always a challenge and the background considerations for their use include knowing the target organ, cautery and puncture technique, managing partially opened LAMS and also managing maldeployment. In this review, we discuss the intricacies and technical tips for the use of lumen-apposing metal stents.

WONDER-02: plastic stent vs. lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic pseudocysts-study protocol for a multicentre randomised non-inferiority trial

BACKGROUND

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.

METHODS

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.

DISCUSSION

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.

TRIAL REGISTRATION

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

Selection strategy for endoscopic necrosectomy approaches of infected walled-off pancreatic necrosis: Analysis of 101 patients from a single center with long-term follow-up

OBJECTIVES

Endoscopic necrosectomy (EN) is a promising minimally invasive approach for treating infected walled-off pancreatic necrosis (WOPN). Multiple EN approaches are currently available, though criteria for selecting the optimal approaches are lacking. We aimed to propose a rational selection strategy of EN and to retrospectively evaluate its safety and effectiveness.

METHODS

Altogether 101 patients who underwent EN for infected WOPN at a tertiary hospital between June 2009 and February 2023 were retrospectively included for analysis. Demographic characteristics, details of the EN procedures, procedure-related adverse events, and clinical outcomes were investigated.

RESULTS

Among these 101 patients with WOPN, 56 (55.4%) underwent transluminal EN, 38 (37.6%) underwent percutaneous EN, and seven (6.9%) underwent combined approach, respectively. Clinical success was achieved in 94 (93.1%) patients. Seven (6.9%) experienced procedure-related adverse events, and seven (6.9%) died during the treatment period. During a median follow-up of 50 months, 5 (5.3%) of the 94 patients had disease recurrence, 17.0% (16/94) had new-onset diabetes mellitus, and 6.4% (6/94) needed oral pancreatic enzyme supplementation. The clinical success rate, procedure-related adverse event rate, and long-term follow-up outcomes were not significantly different among the three groups. High APACHE-II scores (≥15) and organ failure were identified as factors related to treatment failure.

CONCLUSIONS

A selection strategy for EN approaches, based on the extent of necrosis and its distance from the gastrointestinal lumen (using a threshold of 15 mm), is safe and effective for treating infected WOPN in both short-term and long-term outcomes.

Risk factors for adverse outcomes at various phases of endoscopic ultrasound-guided treatment of pancreatic fluid collections: Data from a multi-institutional consortium

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Indications, Techniques and Future Perspectives of Walled-off Necrosis Management

Necrotizing pancreatitis is a complex clinical condition burdened with significant morbidity and mortality. In recent years, the huge progress of interventional endoscopic ultrasound (EUS) has allowed a shift in the management of pancreatic necrotic collections from surgical/percutaneous approaches to mini-invasive endoscopic internal drainage and debridement procedures. The development of lumen-apposing metal stents (LAMSs), devices specifically dedicated to transmural EUS interventions, further prompted the diffusion of such techniques. Several studies have reported excellent outcomes of endoscopic interventions, in terms of technical success, clinical efficacy and safety compared to surgical interventions, and thus endoscopic drainage of walled-off necrosis (WON) has become a fundamental tool for the management of such conditions. Despite these advancements, some critical unresolved issues remain. Endoscopic therapeutic approaches to WON are still heterogeneous among different centers and experts. A standardized protocol on indication, timing and technique of endoscopic necrosectomy is still lacking, and experts often adopt a strategy based on personal experience more than robust data from well-conducted studies. In this review, we will summarize the available evidence on endoscopic management of WON and will discuss some unanswered questions in this rapidly evolving field.

[Transgastric necrectomy for acute pancreatitis]

The review is devoted to transgastric necrectomy in the treatment of infected forms of acute pancreatitis. The authors discuss the indications for transgastric necrectomy and technical features of these interventions (direct endoscopic necrectomy, laparoscopic and open transgastric necrectomy). Numerous studies devoted to results of transgastric necrectomy indicate advisability of this procedure in carefully selected patients and interdisciplinary interaction of various specialists before and after surgery. Regional specialized centers for the treatment of severe acute pancreatitis are necessary for wider introduction of minimally invasive surgical technologies and their personalization.

Endoscopic Necrosectomy

The management of walled-off necrosis has evolved substantially over the past 23 years since its first description. In this article, we review its history and the evidence supporting modern treatment, which is still subject to heterogeneity across centers and among endoscopists. This allows for creativity and customization of what can be an endoscopic marathon. Our typical practice is discussed with image and video guides aimed at improving procedure success.

Endoscopic treatment of pancreatic necrosis: Still searching for perfection!

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.

Endoscopic ultrasound drainage of pancreatic fluid collections: do we know enough about the best approach?

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.

Direct Endoscopic Necrosectomy of a Recurrent Walled-Off Pancreatic Necrosis at High Risk for Severe Bleeding: A Hybrid Technique Using a Dedicated Device

Direct endoscopic necrosectomy (DEN) is a challenging procedure for the debridement of walled-off pancreatic necrosis (WOPN), which may be complicated by several adverse events, primarily bleeding which may require radiological embolization or even surgery. The lack of dedicated devices for this purpose largely affects the possibility of safely performing DEN which increases the risk of complications. We present the case of a 63 years-old man who underwent an endoscopic ultrasound (EUS)-guided drainage of a WOPN, and who was readmitted one month after stent removal with clinical, endoscopic, and radiological signs of infected necrosis involving the splenic artery. A second EUS-guided drainage was performed, with clear visualization of the arterial vessel in the midst of a large amount of solid necrosis. Due to the high risk of major bleeding during DEN, a hybrid procedure in the angiographic room was performed, in order to identify and avoid, under fluoroscopic control, the splenic artery during the entire procedure guide, which was successfully performed using the EndoRotor system. We hereby review the current literature regarding DEN using the EndoRotor system. The case reported, with a literature overview, may help the management of these patients affected by benign but life-threatening conditions which involve a multidisciplinary setting.