Pancreatic Walled-Off Necrosis: Cross-Sectional Imaging Depiction of Debris Predicts the Success of Endoscopic Drainage Using Lumen-Apposing Metal Stents.

INTRODUCTION: The use of endoscopic ultrasound (EUS)-guided transmural stent placement for pancreatic walled-off necrosis (WON) drainage is widespread. This study retrospectively analyzed imaging parameters predicting the outcomes of WON endoscopic drainage using lumen-apposing metal stents (LAMS). METHODS: This study analyzed the data of 115 patients who underwent EUS-guided debridement using LAMS from 2011 to 2015. Pre-intervention CT or MRI was used to analyze the total volume of WON, percentage of debris, multilocularity, and density. Success measures included technical success, the number of endoscopic sessions, the requirement of percutaneous drainage, long-term success, and recurrence. RESULTS: The primary cause of pancreatitis was gallstones (50.4%), followed by alcohol (27.8%), hypertriglyceridemia (11.3%), idiopathic (8.7%), and autoimmune (1.7%). The mean WON size was 674 mL. All patients underwent endoscopic necrosectomy, averaging 3.1 sessions. Stent placement was successful in 96.5% of cases. Procedural complications were observed in 13 patients (11.3%) and 6 patients (5.2%) who needed additional percutaneous drainage. No patients reported recurrent WON posttreatment. Univariate analysis indicated a significant correlation between debris percentage and the need for additional drainage and long-term success (p < 0.001). The number of endoscopic sessions correlated significantly with debris percentage (p < 0.001). CONCLUSION: Pre-procedural imaging, particularly debris percentage within WON, significantly predicts the number of endoscopic sessions, the need for further percutaneous drainage, and overall long-term success.

Endoscopic and surgical drainage for pancreatic fluid collections are better than percutaneous drainage: Meta-analysis.

BACKGROUND: Pancreatic pseudocyst (PP) and walled-off necrosis can be managed endoscopically, percutaneously or surgically, but with diverse efficacy. AIMS & METHODS: A comprehensive literature search was carried out from inception to December 2018, to identify articles which compared at least two of the three kinds of treatment modalities, regarding the mortality, clinical success, recurrence, complications, cost and length of hospitalisation (LOH). RESULTS: The outcomes of endoscopic (ED) and percutaneous drainage (PD) were comparable in six articles. The clinical success of endoscopic intervention was better considering any types of fluid collections (OR = 3.36; 95% confidence interval (CI) 1.48, 7.63; p = 0.004). ED was preferable regarding recurrence of PP (OR = 0.23; 95% CI 0.08, 0.66; p = 0.006). Fifteen articles compared surgical intervention with ED. Significant difference was found in postoperative LOH (WMD (days) = -4.61; 95%CI -7.89, -1.33; p = 0.006) and total LOH (WMD (days) = -3.67; 95%CI -5.00, -2.34; p < 0.001) which favored endoscopy, but ED had lower rate of clinical success (OR = 0.54; 95% CI 0.35, 0.85; p = 0.007) and higher rate of recurrence (OR = 1.80; 95% CI 1.16, 2.79; p = 0.009) in the treatment of PP. Eleven studies compared surgical and percutaneous intervention. PD resulted in higher rate of recurrence (OR = 4.91; 95% CI 1.82, 13.22; p = 0.002) and lower rate of clinical success (OR = 0.13; 95% CI 0.07, 0.22, p < 0.001). CONCLUSION: Both endoscopy and surgery are preferable over percutaneous intervention, furthermore endoscopic treatment is associated with shorter hospitalisation than surgery.

Comparative Effectiveness of Lumen-Apposing Metal Stents and Plastic Stents for the Treatment of Pancreatic Walled-Off Necrosis: A Meta-analysis.

Background: Plastic stents (PS), lumen-apposing metal stents (LAMS) and biflanged metal stents (BFMS) are used for initial drainage of pancreatic walled-off necrosis (WON). There are no strong evidence to support the use of LAMS/BFMS over PS, and prior systematic reviews lack comparative analyses and also lack both trial data and observational studies for WON efficacy outcomes. The aim of this study is to compare the efficacy and adverse events (AEs) in LAMS/BFMS versus PS in patients with pancreatic WON. Methods: A comprehensive search up to December 1, 2020, was performed. The primary outcome was clinical improvement after drainage. Secondary outcomes included AEs and technical failure. Pooled odds ratios (OR) with 95% confidence intervals (CI) were reported using random effects models. Heterogeneity was evaluated with the Cochrane I 2 statistic. Subgroup and sensitivity analyses were performed. The quality of the evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluations (GRADE). Results: Nine studies (one randomized controlled trial and eight observational) were included for the primary outcome including 493 patients treated with LAMS/BFMS and 514 with PS. LAMS/BFMS were associated with higher odds of clinical improvement compared with PS (OR 2.58; 95% CI 1.81, 3.68; I 2 = 1%). This association remained robust in sensitivity analyses. The use of LAMS/BFMS was not associated with higher AEs (OR 1.22; 0.61, 2.46; I 2 = 71%). There was no difference in technical failure (OR 1.06; 0.19, 6.00; I 2 = 12%). Conclusions: LAMS/BFMS seem to result in better clinical outcomes compared with PS in patients with pancreatic WON, with comparable AEs and technical failure. Larger randomized controlled trials for this comparison are warranted.

International, multicenter retrospective trial comparing the efficacy and safety of bi-flanged versus lumen-apposing metal stents for endoscopic drainage of walled-off pancreatic necrosis.

BACKGROUND: To compare fully covered bi-flanged metal stents (BFMS) and lumen-apposing metal stents (LAMS) for endoscopic ultrasound (EUS)-guided drainage/debridement of pancreatic walled-off necrosis (WON). METHODS: Patients with WON managed by EUS-guided therapy were divided into those who underwent: 1) drainage using BFMS; and 2) drainage using LAMS and scheduled direct endoscopic necrosectomy (DEN). Clinical success (resolution of the WON), technical success (successful stent placement), and adverse events (AEs) were evaluated. RESULTS: 387 patients underwent WON endoscopic drainage, 205 using BFMS and 182 using LAMS. The clinical success in the BFMS or LAMS groups were similar (197 [96.1%] vs. 174 [95.6%]; P=0.81). Median number of procedures required for WON resolution was significantly lower in BFMS compared to LAMS (2 vs. 3, P<0.001). Technical success for stent placement was similar in BFMS and LAMS groups (203 [99%] vs. 180 [99%], P=0.90). Procedure-related AEs were similar in the BFMS and LAMS groups (19 [9.3%] vs. 20 [10.9%], P=0.61). Stent dysfunction with occluding debris was higher in the BFMS group compared to LAMS group (21 [10.2 %] vs. 11 [5.9%], P=0.04). The migration rate was higher in the BFMS group than in the LAMS group (15 [7.3%] vs. 3 [1.6%]; P<0.001). DEN was required in 23 [11.2%] patients in the BFMS group after lack of WON resolution by conservative means. CONCLUSION: BFMS with a "step-up approach" and LAMS with scheduled DEN are both safe and effective for EUS-guided drainage/debridement of WON.

Direct endoscopic necrosectomy at the time of transmural stent placement results in earlier resolution of complex walled-off pancreatic necrosis: Results from a large multicenter United States trial.

BACKGROUND AND OBJECTIVES: EUS-guided drainage, and direct endoscopic necrosectomy (DEN) of walled-off necrosis (WON) using a lumen-apposing metal stent (LAMS) is safe and effective. Early debridement of WON may improve overall clinical outcomes. The aim of this study is to perform a multicenter retrospective study to compare the clinical outcomes and predictors of success for endoscopic drainage of WON with LAMS followed by immediate or delayed DEN performed at standard intervals. METHODS: Patients with WON managed by EUS-guided drainage with LAMS were divided into 2 groups: (1) those that underwent immediate DEN at the time of stent placement and (2) those that underwent delayed DEN 1 week after stent placement. DEN was subsequently performed every 1-2 week (s). Technical success (successful placement of LAMS), adverse events (AEs), and clinical success (complete resolution of the WON) were evaluated. RESULTS: Totally, 271 patients underwent WON drainage with LAMS: 69 who underwent immediate DEN and 202 who underwent delayed DEN. The technical success for LAMS placement was 100% in both groups. There was no significant difference in the overall procedural AEs between the immediate and delayed DEN groups (P = 7.2% vs. 9.4%; P = 0.81). Stent dislodgement during index endoscopy occurred in three patients in the immediate DEN group compared to zero in the delayed DEN group (P = 0.016); all three dislodgements occurred during necrosectomy. Clinical success for WON resolution in the immediate DEN group was 91.3% compared to 86.1% in the delayed DEN group (P = 0.3). The mean number of necrosectomy sessions for WON resolution was significantly lower in the immediate DEN group compared to the delayed DEN group (3.1 vs. 3.9, P < 0.001). Performing DEN at the time of stent placement was an independent predictor for resolution of WON with lesser number of DEN sessions (odds ratio 2.3; P = 0.004). CONCLUSIONS: DEN at the time of initial stent placement reduces the number of necrosectomy sessions required for successful clinical resolution of WON.

Management of Inflammatory Fluid Collections and Walled-Off Pancreatic Necrosis.

OPINION STATEMENT: Pancreatic fluid collections are a frequent complication of acute pancreatitis. The revised Atlanta criterion classifies chronic fluid collections into pseudocysts and walled-off pancreatic necrosis (WON). Symptomatic PFCs require drainage options that include surgical, percutaneous, or endoscopic approaches. With the advent of newer and more advanced endoscopic tools and expertise, minimally invasive endoscopic drainage has now become the preferred approach. An endoscopic ultrasonography (EUS)-guided approach for pancreatic fluid collection drainage is now the preferred endoscopic approach. Both plastic stents and metal stents are efficacious and safe; however, metal stents may offer an advantage, especially in infected pseudocysts and in WON. Direct endoscopic necrosectomy is often required in WON. Lumen apposing metal stents allow for direct endoscopic necrosectomy and debridement through the stent lumen and are now preferred in these patients. Endoscopic retrograde cholangiopancreatography with pancreatic duct exploration should be performed concurrent to PFC drainage in patients with suspected PD disruption. PD disruption is associated with an increased severity of pancreatitis, an increased risk of recurrent attacks of pancreatitis and long-term complications, and a decreased rate of PFC resolution after drainage. Ideally, pancreatic ductal disruption should be bridged with endoscopic stenting.