The clinical outcome from early versus delayed minimally invasive intervention for infected pancreatic necrosis: a systematic review and meta-analysis

Controversies in endoscopic ultrasonography-guided management of walled-off necrosis

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.

Early Endoscopic Interventions for Pancreatic Necrosis: Indications, Technique, and Outcomes

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.

Long-Term Outcome of Immediate Versus Postponed Intervention in Patients With Infected Necrotizing Pancreatitis (POINTER): Multicenter Randomized Trial

OBJECTIVE

To compare the long-term outcomes of immediate drainage versus the postponed-drainage approach in patients with infected necrotizing pancreatitis.

BACKGROUND

In the randomized POINTER trial, patients assigned to the postponed-drainage approach using antibiotic treatment required fewer interventions, as compared with immediate drainage, and over a third were treated without any intervention.

METHODS

Clinical data of those patients alive after the initial 6-month follow-up were re-evaluated. The primary outcome was a composite of death and major complications.

RESULTS

Out of 104 patients, 88 were re-evaluated with a median follow-up of 51 months. After the initial 6-month follow-up, the primary outcome occurred in 7 of 47 patients (15%) in the immediate-drainage group and 7 of 41 patients (17%) in the postponed-drainage group (RR 0.87, 95% CI 0.33-2.28; P =0.78). Additional drainage procedures were performed in 7 patients (15%) versus 3 patients (7%) (RR 2.03; 95% CI 0.56-7.37; P =0.34). The median number of additional interventions was 0 (IQR 0-0) in both groups ( P =0.028). In the total follow-up, the median number of interventions was higher in the immediate-drainage group than in the postponed-drainage group (4 vs. 1, P =0.001). Eventually, 14 of 15 patients (93%) in the postponed-drainage group who were successfully treated in the initial 6-month follow-up with antibiotics and without any intervention remained without intervention. At the end of follow-up, pancreatic function and quality of life were similar.

CONCLUSIONS

Also, during long-term follow-up, a postponed-drainage approach using antibiotics in patients with infected necrotizing pancreatitis results in fewer interventions as compared with immediate drainage and should therefore be the preferred approach.

TRIAL REGISTRATION

ISRCTN33682933.

Prediction of survival in patients with infected pancreatic necrosis: a prospective cohort study

BACKGROUND

Infected pancreatic necrosis (IPN) is a severe complication of acute pancreatitis, with mortality rates ranging from 15 to 35%. However, limited studies exist to predict the survival of IPN patients and nomogram has never been built. This study aimed to identify predictors of mortality, estimate conditional survival (CS), and develop a CS nomogram and logistic regression nomogram for real-time prediction of survival in IPN patients.

METHODS

A prospective cohort study was performed in 335 IPN patients consecutively enrolled at a large Chinese tertiary hospital from January 2011 to December 2022. The random survival forest method was first employed to identify the most significant predictors and capture clinically relevant nonlinear threshold effects. Instantaneous death risk and CS was first utilized to reveal the dynamic changes in the survival of IPN patients. A Cox model-based nomogram incorporating CS and a logistic regression-based nomogram were first developed and internally validated with a bootstrap method.

RESULTS

The random survival forest model identified seven foremost predictors of mortality, including the number of organ failures, duration of organ failure, age, time from onset to first intervention, hemorrhage, bloodstream infection, and severity classification. Duration of organ failure and time from onset to first intervention showed distinct thresholds and nonlinear relationships with mortality. Instantaneous death risk reduced progressively within the first 30 days, and CS analysis indicated gradual improvement in real-time survival since diagnosis, with 90-day survival rates gradually increasing from 0.778 to 0.838, 0.881, 0.974, and 0.992 after surviving 15, 30, 45, 60, and 75 days, respectively. After further variables selection using step regression, five predictors (age, number of organ failures, hemorrhage, time from onset to first intervention, and bloodstream infection) were utilized to construct both the CS nomogram and logistic regression nomogram, both of which demonstrated excellent performance with 1000 bootstrap.

CONCLUSION

Number of organ failures, duration of organ failure, age, time from onset to first intervention, hemorrhage, bloodstream infection, and severity classification were the most crucial predictors of mortality of IPN patients. The CS nomogram and logistic regression nomogram constructed by these predictors could help clinicians to predict real-time survival and optimize clinical decisions.

Early versus delayed EUS-guided drainage for postoperative pancreatic fluid collections: a systematic review and meta-analysis

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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

Time to think prime times for treatment of necrotizing pancreatitis: Pendulum conundrum

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.

Timing of minimally invasive step-up intervention for symptomatic pancreatic necrotic fluid collections: A systematic review and meta-analysis

BACKGROUND AND AIMS

Minimally invasive step-up interventions are now the standard treatment recommended by current guidelines for symptomatic pancreatic necrotic fluid collections (PNFC); however, it is controversial whether delayed treatment after four weeks should always be used in patients who have failed conservative treatment and whose condition has not improved or worsened. The aim of this meta-analysis was to evaluate the impacts of the different timing of interventions on the clinical outcomes and prognosis of patients with symptomatic PNEC requiring intervention.

METHODS

We searched Embase, Cochrane Library, PubMed and Web of Science databases to identify comparative studies assessing the safety and efficacy of early and postponed interventions in treating symptomatic PNFC.

PRIMARY OUTCOME

Mortality. Secondary outcomes included some major complications, need for further minimally invasive necrosectomy and length of hospital stay.

RESULTS

This meta-analysis included ten studies (2 RCTs and 8 observational studies) with a total of 1178 symptomatic PNFC patients who required intervention. Pooled results showed that there was no significant difference between early minimally invasive intervention and postponed intervention in mortality(OR 1.41, 95%CI 0.93-2.12;p = 0.10) and the incidence of early and late complications, but the early intervention group had a significantly increased need for further minimally invasive necrosectomy compared with postponed intervention (OR 2.04,95%CI 1.04-4.03; p = 0.04). There was no increase in length of stay for patients who received early intervention compared to postponed drainage (MD 3.53, 95% CI -4.20, 11.27; p = 0.37).

CONCLUSION

Intervention before four weeks should be considered for patients with PNFC complicated by persistent organ failure or infections, who have been treated conservatively to the maximum extent possible.

The optimal timing and intervention to reduce mortality for necrotizing pancreatitis: a systematic review and network meta-analysis

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Early versus delayed interventions for necrotizing pancreatitis: A systematic review and meta-analysis

Objectives

Interventions for necrotizing pancreatitis are generally postponed until 4 weeks after the onset of acute pancreatitis, but there remains controversy about whether we should always wait >4 weeks or can intervene early when necessary. This meta‐analysis was conducted to evaluate treatment outcomes of necrotizing pancreatitis according to the cut‐off defined in the revised Atlanta classification (≤4 vs. >4 weeks).

Methods

Using PubMed, Web of Science, and the Cochrane database, we identified clinical studies published until March 2022 with data comparing outcomes of early and delayed interventions of necrotizing pancreatitis. We pooled data on adverse events, mortality, technical and clinical success rates, and needs for necrosectomy and open surgery, using the random‐effects model.

Results

We identified 11 retrospective studies, including 775 patients with early interventions and 725 patients with delayed interventions. Patients with early interventions tended to be complicated by organ failure. The rate of adverse events was comparable (OR 1.41, 95% CI 0.66–3.01; p = 0.38) but the rate of mortality was significantly higher (OR 1.70, 95% CI 1.21–2.40; p < 0.01) in early interventions. Technical success rates were similarly high but clinical success rates tended to be low (OR 0.39, 95% CI 0.15–1.00; p = 0.05) in early interventions, though not statistically significant. Pooled ORs for necrosectomy and open surgery were 2.14 and 1.23, respectively.

Conclusions

Early interventions for necrotizing pancreatitis were associated with higher mortality rates and did not reduce adverse events or improve clinical success. However, our results should be confirmed in prospective studies.

Immediate Catheter Drainage Versus Delayed Drainage in the Management of Infected Necrotizing Pancreatitis

Background: Immediate or delayed catheter drainage of infected pancreatic necrosis remains a subject of debate. The present study aimed to evaluate the optimum timing for drainage in patients with infected necrotizing pancreatitis. 

Methods: A prospective, observational study was undertaken at the Department of Surgery, Liaquat University of Medical & Health Sciences (LUMHS), between 1st March 2018 and 6th July 2020. All patients 18 years or older presenting with acute pancreatitis (AP) in whom necrotizing pancreatitis was confirmed or suspected were enrolled in the study. The exclusion criteria included prior intervention for necrotizing pancreatitis. Those who were diagnosed with infected necrotizing pancreatitis were labeled as Group A and Group B. Group A patients underwent immediate catheter drainage (within 24 h of admission) while Group B patients underwent delayed drainage (after 24 h). Clinical outcome variables including complication rate, mortality, length of hospital, and intensive care unit (ICU) stay were collected in a predefined pro forma.

Results: One hundred and thirty patients were enrolled in the study. There were 65 patients in each group. The present study revealed no significant differences in patient outcomes in the immediate drainage group vs. the postponed drainage group. Overall, the mortality rate was 15.38% in Group A while the mortality rate was a little lower in Group B, i.e. 10.77% (p=0.44). The acute onset multiple organ failure was lower in Group A as compared to Group B, however, the difference was statistically insignificant (p=0.08). The rate of wound infection rate was 10.77% and 15.38% in Group A and Group B, respectively (p=0.61).

Conclusion: In the present study, we failed to find any significant difference between the immediate and postponed drainage group in terms of patient outcome. As per current findings, the timing of drainage did not impact the prognosis of patients with necrotizing pancreatitis.