The similarity between microbiota of gut and pancreatic necrotic drainage fluid in infected pancreatic necrosis and its potential diagnostic value: a prospective observational cohort study.

Clinical evaluation of probe capture-based targeted next-generation sequencing in suspected infected pancreatic necrosis: a prospective pilot diagnostic study.

BackgroundAcute pancreatitis (AP) is a common abdominal emergency, often associated with severe complications such as infected pancreatic necrosis (IPN) and the need for surgical intervention. Platelet count dynamics during the course of AP may be linked to disease progression and outcomes.PurposeThis study aimed to identify clinically meaningful longitudinal platelet count patterns in AP.MethodsLongitudinal platelet count patterns were derived using group-based trajectory modeling (GBTM). Generalized additive models were used to demonstrate the association between platelet counts and outcomes.Results2225 AP patients are enrolled in the analysis and classified into 5 subclasses using GBTM. Class 1 (n=269) had a low initial platelet count, which increased slowly; Class 2 (n=983) and Class 4 (n=597) had different initial platelet count levels, but fluctuated within the normal range; Class 3 (n=225) and Class 5 (n=151) had different initial platelet count levels, but both increased beyond the normal range. A significantly decreased risk of infected pancreatic necrosis (IPN) is observed in classes 2 (OR 0.3, CI 0.16–0.55) and 4 (OR 0.14, CI 0.06–0.33), but the risk was comparable among classes 1 (ref), 3 (OR 1.25, CI 0.66–2.41), and 5 (OR 0.69, CI 0.28–1.56). The risks of the surgical interventions were similar. However, the 30-day and 90-day mortality rates were significantly lower in classes 2, 3, 4, and 5 than in class 1. Generalized additive models also demonstrated the lowest risk of IPN, surgical intervention, and in-hospital mortality as platelet counts remained within the normal range.ConclusionPatients with platelet counts within the normal range had the lowest risk of IPN, surgical intervention, and mortality. Both thrombocytopenia and thrombocytosis indicate an increased risk of IPN and surgical intervention; however, mortality is significantly increased only in patients with thrombocytopenia.

The clinical and microbiological burden of gastrointestinal fistulas in patients with infected pancreatic necrosis: a retrospective study.

ABSTRACTSevere acute pancreatitis (SAP) involves dynamic shifts from inflammation to immunosuppression, where peptidomic profile evolution may reveal prognostic biomarkers. Here, the plasma peptidome of rats with taurocholate‐induced SAP at 1, 3, 6, 12, and 24 h compared with controls was characterized using nLC‐MS/MS. Ten peptides derived from eight precursor proteins were differentially regulated across time points. The 12‐h period showed eight differentially regulated peptides, while the 6‐ and 24‐h periods had four differentially regulated peptides, and one peptide was regulated between 1 and 3 h. Peptides derived from alpha‐1‐microglobulin (A1M) increased from 3 h onward, while peptides from actin showed major alterations at 12–24 h, coinciding with peak mortality (46%). Bioinformatic enrichment analyses revealed transient activation of mTOR, JAK/STAT, and cell adhesion pathways at 6 h, followed by bacterial invasion and actin cytoskeleton regulation pathways at later stages. These temporal profiles suggest an early antioxidant response and subsequent structural and infection‐related remodeling. These findings suggest that A1M‐derived peptides could represent potential early indicators of disease severity, although further validation in human clinical settings is required. These findings highlight the plasma peptidome as a promising tool for clinical diagnostics, providing a better understanding of SAP progression and identification of phase‐specific biomarkers in pancreatitis.SummaryThis study reveals dynamic changes in the plasma peptidome during the progression of severe acute pancreatitis in rats. Through the identification of differentially regulated peptides, bioinformatic analysis was performed to define the altered pathways and genes, demonstrating the relationship between peptide alterations and disease progression. The 6‐h time point after pancreatitis induction showed the highest number of signaling terms/pathways that characterize the inflammatory phase of the disease. In subsequent moments, the enrichment of pathways related to infection and the regulation of the actin cytoskeleton at 12‐ and 24‐h post‐pancreatitis induction suggests that this period is associated with the process of bacterial translocation and pancreatic necrosis infection. Therefore, the peptide profile and pathways may have implications for defining prognosis and early diagnosis of infection.

Background. Acute pancreatitis (AP) is often complicated by the formation of fluid collections, which require individuali­zed treatment strategies. Recently, minimally invasive procedures (percutaneous, endoscopic, laparoscopic, combined) have proven effective within the step-up approach for necrotizing AP. Diabetes mellitus (DM) represents an important comorbidity affecting AP severity and outcomes. The purpose of the study was to investigate the impact of carbohydrate metabolism disorders on the clinical course, complications, and treatment outcomes in patients with AP. Materials and methods. The study included 354 patients with AP. Fluid collections developed in 154 (43.5 %) of them; 51 (14.4 %) had DM, including 18 (11.7 %) with newly diagnosed DM. Diagnosis included clinical, laboratory, and imaging assessments with mandatory determination of glycated hemoglobin (HbA1c), fasting glucose and oral glucose tolerance testing. Treatment strategies followed the step-up approach: primary conservative treatment for small and asymptoma­tic collections, in case of failure — minimally invasive methods, in complex cases — combined approaches or open drainage from lapa­rotomic access. Results. Percutaneous drainage was performed in 25 (27.7 %), laparoscopic drainage in 38 (42.2 %), and endoscopic transmural drainage in 10 (11.1 %) cases. Retroperitoneal drainage via lumbotomy was used in 17 (18.8 %) patients, open drainage via laparotomy in 15 (14.3 %). In 58 (64.5 %) patients, one of the minimally invasive procedures was used as the definitive treatment method, while in 32 (35.5 %) — step-up approach. Mortality in patients with AP was 11.6 % (41 patients). Infected pancreatic necrosis was more frequent in patients with concomitant DM — in 28 of 51 (54.9 %), while in the group without diabetes — only in 97 of 303 (32 %; p < 0.05). Conclusions. Minimally invasive techniques in fluid collections are effective in 64.5 % of cases and allow avoidance of open surgery in some patients. Diabetes mellitus is associated with more severe disease, a statistically significant increase in complication rates, and longer hospital stay, highlighting the need for systematic screening and glycemic control in this cohort.

ObjectiveTo investigate the impact of stress-induced hyperglycemia (SHG) at admission on clinical outcomes in acute pancreatitis (AP) by collecting and analyzing relevant clinical data.MethodsThis study enrolled AP patients diagnosed at Shanxi Bethune Hospital from January 1, 2017, to December 31, 2022. Clinical data and 24-h laboratory indicators were retrospectively collected. We employed propensity score matching (PSM) to compare the impact of SHG on AP clinical outcomes before and after matching. A temporal split allocated patients into training/validation cohorts for developing and validating a clinical prediction model for infected pancreatic necrosis (IPN).ResultsThis study included 1343 acute pancreatitis patients, with 348 having SHG at admission. Before PSM, SHG patients showed significantly longer hospital stays (13.8 vs 12.28 days, p<0.001), higher ICU admission rates (6% vs 2%, p<0.001), and increased infected pancreatic necrosis (IPN) (15% vs.6%). After using PSM to control for confounding factors, SHG patients maintained longer hospitalizations (13.61 vs 12.28 days, p=0.004), higher ICU admissions (6% vs 2%, p=0.005), and IPN rates (15% vs 6%, p<0.001). These results confirm SHG as an independent poor prognostic factor for AP rather than a reflection of baseline differences. In the training cohort, seven independent IPN predictors were identified: hyperlipidemia, SHG, modified CT severity index (MCTSI), systemic inflammatory response syndrome (SIRS), Prothrombin Time Activity (PT%), LDL-C, and peripancreatic effusion. The clinical prediction model demonstrated good performance in the validation cohort, with an area under the receiver operating characteristic curve (AUC) of 0.891.ConclusionPSM confirmed that SHG adversely impacts clinical outcomes in acute pancreatitis. The prediction model incorporating seven variables—hyperlipidemia, SHG, MCTSI, SIRS, PT%, LDL-C, and peripancreatic effusion—demonstrated favorable predictive performance and clinical utility for infected pancreatic necrosis (IPN) in acute pancreatitis patients. Meanwhile, we developed a web-based calculator to enhance its clinical utility.

Effect of oral rifaximin for prevention of infected pancreatic necrosis and mortality in severe acute pancreatitis: An open-label randomized controlled trial.

INTRODUCTION: Destructive forms of acute pancreatitis are accompanied by a pronounced systemic inflammatory response and rapid development of pancreatogenic sepsis. This condition induces the development of hypermetabolism-hypercatabolism syndrome, characterized by increased energy expenditure and profound disturbances in protein metabolism. As a result, a critical nutrient deficiency is formed, aggravating organ dysfunction and increasing mortality. In this regard, optimization of nutritional support taking into account individual metabolic needs is a key aspect of intensive care for this category of patients. OBJECTIVE: To evaluate the effectiveness of targeted nutritional support based on indirect calorimetry in comparison with standard nutritional therapy in patients with pancreatogenic sepsis. MATERIALS AND METHODS: A single-center retrospective-prospective study was conducted involving 140 patients with infected pancreatic necrosis complicated by sepsis, divided into 2 groups: 1st (n = 71) — standard nutritional support, 2nd (n = 69) — targeted nutritional support using indirect calorimetry. Instrumental, anthropometric, laboratory parameters, the dynamics of the severity of nutritional deficiency, as well as patient survival were assessed over 28 days. RESULTS: In the 2nd group, the energy requirement was 22.6–37.8 kcal/kg/day, protein intake was 1.0–1.8 g/kg/day, carbohydrate intake was 1.5–4.9 g/kg/day, and lipid intake was 1.1–1.8 g/kg/day. The total protein level (p &lt; 0.05), absolute lymphocyte count (p &lt; 0.05), and BMI (p &lt; 0.05) were higher in the group receiving targeted nutritional support. The incidence of severe nutritional deficiency and 28-day mortality were significantly lower in the 2nd study group. CONCLUSIONS: Personalized nutritional support based on the use of indirect calorimetry promotes adequate correction of metabolic disorders, improving clinical outcomes, and should be included in recommendations for intensive care of acute pancreatitis.

BackgroundGiven the evidence that poor glycemic control is associated with immunological dysfunction, serum glycosylated hemoglobin A1c (HbA1c), as a useful indicator reflecting blood glucose homeostasis, has potential to predict infectious complications. In this study, we aimed to explore the association between poor glycemic control (HbA1c ≥ 6.5 as an indicator) and infected pancreatic necrosis (IPN) in patients with acute necrotizing pancreatitis (ANP).MethodsThis is a secondary analysis of pooled data from the TRACE trial and a retrospective single-center cohort, involving ANP patients admitted within 72 h after onset of abdominal pain between March 2017 and October 2022. Patients had no HbA1c data at enrollment/admission were excluded. The Multivariable Cox proportional hazards regression (MCPHR) model was used to assess the association between poor glycemic control and 90-day IPN. Mediation analyses were used to define the relationships between the independent variables and 90-day IPN.ResultsA total of 153 patients were enrolled, of whom 20.3% (31/153) patients developed IPN within 90 days. Most patients with IPN had HbA1c ≥ 6.5% at admission (25/31, 80.6%), compared to 38.5% (47/122) in the non-IPN patients. In the MCPHR model, HbA1c ≥ 6.5% [HR (95%CI) = 4.10 (1.42–11.90); p = 0.009], SOFA score on admission [HR (95%CI) = 1.47 (1.26–1.70); p < 0.001] and pancreatic necrosis extent > 50% [HR (95%CI) = 3.15 (1.06–9.35); p = 0.039] were independent risk factors for 90-day IPN. In addition, patients with HbA1c ≥ 6.5% experienced a higher incidence of hyperglycemia during the first week of enrollment [RR (95%CI) = 9.19 (4.23–19.95); p < 0.001]. Mediation analyses showed that the presence of hyperglycemia completely mediated the association between HbA1c ≥ 6.5% and 90-day IPN.ConclusionAmong ANP patients, HbA1c ≥ 6.5% was associated with the development of IPN. The mediation effect of hyperglycemia may explain it.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12876-025-04324-w.

Infected pancreatic necrosis (IPN) is a severe complication of acute pancreatitis, requiring prompt diagnosis. Conventional microbial culture, the current gold standard, has limitations in sensitivity and turnaround time. Metagenomic next-generation sequencing (mNGS) offers rapid, comprehensive pathogen detection, but its diagnostic performance for IPN remains unclear. We conducted a systematic review and meta-analysis following PRISMA-DTA guidelines, prospectively registered in PROSPERO (CRD420251008574). PubMed, Embase, and Web of Science databases were searched from inception to March 2025. Seven studies (313 patients) evaluating mNGS for IPN diagnosis were included, with four providing direct comparisons to culture. Pooled sensitivity, specificity, and area under the curve (AUC) were calculated using a random-effects model. Heterogeneity was assessed using I2 statistics. In double-arm analysis, mNGS showed significantly higher sensitivity (0.87, 95% CI: 0.72-0.95) than culture (0.36, 95% CI: 0.23-0.51), with comparable specificity (0.83 for both). The AUC for mNGS (0.92, 95% CI: 0.79-0.94) surpassed that of culture (0.52, 95% CI: 0.27-0.86). Single-arm analysis confirmed mNGS as a reliable standalone test (sensitivity: 0.86; specificity: 0.85; AUC: 0.89). A threshold effect (r = -0.991) indicated variability in diagnostic criteria across studies. mNGS outperforms culture in diagnosing IPN, offering higher sensitivity and faster results. Its ability to detect diverse pathogens, including fastidious and polymicrobial infections, makes it a valuable tool for early intervention. However, challenges like cost, standardization, and interpretation persist. Future studies should focus on prospective validation and cost-effectiveness to integrate mNGS into routine clinical practice.

PurposeThis study aimed to establish a nomogram for early and accurate identification of infected pancreatic necrosis (IPN) among patients with acute necrotizing pancreatitis (ANP) by integrating clinical data and radiomic information from contrast-enhanced computed tomography (CECT).Patients and MethodsThis retrospective single-center study included 203 ANP patients who underwent CECT. Patients were divided into training (n=142) and test set (n=61). Radiomic features were extracted from CECT images using PyRadiomics. Three machine learning classifiers were employed to construct a radiomic signature. Clinical factors were identified through regression analysis. A combined nomogram was developed using multivariate logistic regression. ROC and calibration curves were plotted to assess the efficacy of the model. Decision curve analysis (DCA) was applied to identify the clinical value and utility.ResultsIn the training and test set, 56 (39.43%) and 23 (37.70%) patients developed into IPN, respectively. The optimal Rad score was achieved by the LightGBM classifier. APACHE II and MCTSI scores were independent predictors of IPN. The combined clinical-radiomic nomogram achieved the best predictive efficacy, with an AUC of 0.877 in the training set and 0.829 in the test set. The calibration curve proved good accordance, and the decision curve demonstrated great clinical utility.ConclusionThe clinical-radiomic combined nomogram performed well in predicting IPN in patients with ANP. It could potentially serve as a quantitative, non-invasive tool for early IPN prediction in patients with ANP.

S5257 Percutaneous Endoscopic Necrosectomy for Infected Pancreatic Necrosis: A Minimally Invasive Salvage Approach

Multiple transluminal gateway technique for drainage of an infected walled-off pancreatic necrosis and pancreatic pseudocyst

BackgroundThis study aimed to elucidate the impact of COVID-19 pandemic on multidrug-resistant organism (MDRO) infection in patients with infected pancreatic necrosis (IPN).MethodsThis post-hoc analysis of a prospective cohort included patients with IPN stratified into three phases: pre-pandemic (2016–2019), pandemic period (2020–2022), and post-pandemic period (2023–2024). Logistic regression and interrupted time-series analysis (ITSA) were employed to identify risk factors and longitudinal trends.ResultsMDRO infection decreased significantly during the pandemic period compared to pre-pandemic levels (44.8% vs 81.1%, P<0.001). There was no significant difference in the incidence of MDRO infection between the pandemic and post-pandemic period (44.1% vs 44.8%, P=0.924). During the pandemic, both prophylactic antimicrobial usage (64.8% vs 85.1%, P<0.001) and ICU stays (median: 6.0 vs 15.0 days, P<0.001) were significantly reduced compared to the pre-pandemic period. Logistic regression identified prophylactic antimicrobial usage (OR 17.28, P<0.001), ICU stays (OR 1.07, P<0.001), and the COVID-19 pandemic (OR 0.21, P<0.001) as independent factors associated with MDRO infection. ITSA revealed a significant decrease in the trend of MDRO infection during the pandemic compared to the pre-pandemic period (P=0.006). An immediate level of MDRO infection increased during the post-pandemic period compared to the pandemic (P=0.040). The similar trend variations were observed in the proportion of prophylactic antimicrobial usage.ConclusionThe COVID-19 pandemic has led to a notable reduction in MDRO infection among IPN patients, likely attributable to stringent infection prevention and control measures which led to reduced prophylactic antimicrobial usage and ICU stays during this period.

Clinical outcomes and risk factors of invasive candidiasis in patients with infected pancreatic necrosis.

BackgroundThis study investigated the effects of different early resuscitation fluid replenishment rates (FRRs) on inflammation (serum interleukin-6 (IL-6) and C-reactive protein (CRP), PCT and complications in patients with severe acute pancreatitis (SAP).MethodsSixty-six patients with SAP were studied. According to the ratio of total fluid replenishment 24 h after admission to 72 h (FRR), the patients were rolled into a low FRR group (Low group), a moderate FRR group (Moderate group), and a high FRR group (High group), with 22 cases in each. Serum-related indexes, APACHE II score, HCT, systemic inflammatory response syndrome (SIRS) duration, length of hospital stay (LOS), and complication rate (CR) were determined and compared.ResultsThe results suggested that ALT, AST, SCr, BUN, TBil, APACHE II, scores and HCT in the Moderate group were the lowest (P< 0.05), while those in the High group were the highest (P<0.05). After the patients were treated for 72 h, the IL-6, CRP and PCT in the Low and High groups were higher than those in the Moderate groups, exhibiting differences with P<0.05 and P<0.01, respectively. The SIRS duration and LOS in the Low and High groups were longer. They presented differences with P<0.05 and P<0.01 to the Moderate group, respectively. The rates of MODS, mechanical ventilation, pancreatic necrosis infection, and death in the Moderate group were the lowest (P<0.05).Conclusionsthe moderate FRR could effectively alleviate the inflammatory response of patients with SAP shorten the treatment time, and reduce the CR.

To evaluate the efficacy and safety of early pancreatic stenting in patients with acute biliary pancreatitis. We retrospectively analyzed the effect of early (within 48 hours after admission) pancreatic stenting on severity of disease, incidence of complications, mortality and hospital-stay in patients with severe acute biliary pancreatitis. Moreover, there were patients with acute biliary pancreatitis who underwent delayed endoscopic retrograde intervention and only conservative therapy. Early pancreatic stenting reduced the risk of local (p=0.047) and systemic complications (p=0.027) compared to delayed intervention and conservative treatment. Early pancreatic stenting contributed to shorter hospital-stay when compared with delayed intervention (p=0.038). There was no between-group difference in mortality or severity of disease. Pancreatic stenting after 48 hours had no advantages over early stenting or conservative treatment, but significantly increased the risk of infected pancreatic necrosis (p=0.023). Early pancreatic stenting seems to be safe and effective procedure in reducing the number of complications in patients with acute biliary pancreatitis. Neither early nor late pancreatic stenting has a significant effect on disease severity, mortality and hospital-stay.

BackgroundTo study the value of ensemble machine learning (EL) model in the prediction of infected pancreatic necrosis (IPN) among patients with acute necrotizing pancreatitis (ANP).MethodsThis study comprehensively analyzed 1073 acute necrotizing pancreatitis (ANP) patients admitted to Xiangya hospital from January 2011 to December 2023. The patients were divided into IPN group and sterile pancreatic necrosis (SPN) group based on IPN occurrence. All ANP patients were randomly divided into training dataset and validation dataset with a ratio of 7:3. The EL model was built by integrating multiple machine learning models (LASSO, random forest, and SVM). To verify the stability of the EL model, 78 ANP patients from the Third Xiangya hospital were included for external validation, and a Fagan nomogram was constructed to assess the posterior probability.ResultsThe EL model was constructed with 31 risk factors identified through LASSO regression. The prediction accuracy of the EL model in the training dataset was 92.6%. In the validation dataset, the prediction accuracy was 91.5%. Compared with the LR model, the EL model demonstrated higher AUC values (training dataset: 0.916 vs. 0.744; validation dataset: 0.919 vs. 0.742) and net benefit rate. The AUC of the EL model for predicting IPN within 7 days, 7–14 days, and after 14 days were 0.888, 0.906, and 0.901, respectively. In addition, the external validation results further indicated the accuracy of the EL model (AUC: 0.883). An EL model-based Fagan nomogram could be used to estimate the accuracy of IPN predictions.ConclusionThe EL model demonstrates superior predictive efficiency for IPN compared to the LR model, offering greater predictive value and potential clinical benefits. Furthermore, the EL model shows stable performance across different stages of IPN onset, enabling clinicians to make timely adjustments to treatment strategies and ultimately improve patient outcomes.Trial registrationThe study is registered at www.researchregistry.com (Unique Identifying number: researchregistry10652).Supplementary InformationThe online version contains supplementary material available at 10.1186/s13017-025-00642-2.

Objective: To explore the clinical characteristics of biliary system diseases complicated by severe acute pancreatitis(SAP) and the risk factors. Methods: This is a retrospective cohort study. A retrospective analysis was conducted on the clinical data of 159 SAP patients admitted to the Department of Pancreatic and Biliary Surgery,the First Affiliated Hospital of Harbin Medical University from January 2019 to October 2024. There were 105 male cases, 54 female cases;aged (42.3±10.8)years (range:20 to 71 years). Grouping was performed according to the presence or absence of concurrent acute acalculous cholecystitis (AAC) and biliary stricture. There were 58 cases in the AAC group,including 40 males and 18 females;aged (43.8±10.6) years (range:28 to 71 years);101 cases in the non-AAC group,including 64 males and 37 females;aged (41.5±10.8) years (range:20 to 64 years);there were statistically significant differences between the two groups in terms of admission total bilirubin,Balthazar-CTSI score,fasting time,and the proportions of concurrent shock and sepsis (all P<0.05);the time from onset of SAP to diagnosis of AAC(M (IQR)) was 10.5 (13.3) days (range: 3 to 34 days). There were 15 cases in the biliary stricture group,including 13 males and 2 females;age (46.5±10.0) years (range:33 to 63 years);141 cases in the non-biliary stricture group,including 89 males and 52 females;age (41.9±10.8) years (range: 20 to 71 years); there were statistically significant differences between the two groups in the proportions of infected pancreatic necrosis,pancreatic head necrosis,and lower extremity venous thrombosis (all P<0.05);the time from the onset of SAP to the diagnosis of biliary stenosis in patients with biliary stenosis was 2.0 (3.0) months (range: 1 to 19 months). Univariate analysis was performed using independent sample t-test, Mann-Whitney U test,χ2 test,or Fisher's exact probability method,and variables with P<0.05 in univariate analysis were included in multivariate logistic regression analysis. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic and predictive value of the multivariate logistic regression model for AAC and biliary stricture. Results: There were statistically significant differences in fasting time,Balthazar-CTSI score,admission total bilirubin,and the proportions of concurrent shock and sepsis between the AAC group and non-AAC group (P<0.05). Multivariate logistic analysis showed that admission total bilirubin (OR=1.033,95%CI: 1.010 to 1.058,P=0.004),Balthazar-CTSI score (OR=1.276,95%CI: 1.036 to 1.572,P=0.022),fasting time (OR=1.127,95%CI: 1.044 to 1.216,P=0.002), and sepsis (OR=4.033, 95%CI: 1.419 to 11.462, P=0.009) were independent risk factors for AAC complicated by SAP. The area under the curve (AUC) of the ROC curve was 0.820 (95%CI: 0.752 to 0.888). There were statistically significant differences in the proportions of infected pancreatic necrosis,pancreatic head necrosis,and lower extremity venous thrombosis between the biliary stricture group and non-biliary stricture group (P<0.05). Multivariate logistic analysis showed that infected pancreatic necrosis (OR=7.376,95%CI:1.566 to 37.750,P=0.012) and pancreatic head necrosis (OR=3.898,95%CI:1.180 to 12.877, P=0.026) were independent risk factors for biliary stricture complicated by SAP. The AUC of the ROC curve was 0.806 (95%CI:0.715 to 0.898). Conclusions: AAC typically occurs in the early stage of SAP,and biliary stricture usually occurs in the late stage of SAP. Admission total bilirubin,Balthazar-CTSI score,fasting duration,and concurrent sepsis are independent risk factors for AAC complicating SAP. Infected pancreatic necrosis and pancreatic head necrosis are independent risk factors for biliary stricture complicating SAP.