Site and size of extrapancreatic necrosis are associated with clinical outcomes in patients with acute necrotizing pancreatitis.

BACKGROUND: The site and size of extrapancreatic necrosis (EPN) as assessed on computed tomography may influence the severity of acute necrotizing pancreatitis (ANP). The objective of the study was to evaluate the impact of site and size of EPN on the clinical outcomes in patients with acute necrotizing pancreatitis (ANP). METHOD AND MATERIALS: This retrospective study comprised of consecutive patients with ANP who were admitted between January 2017 and March 2019. Patients in whom the initial contrast enhanced CT showed EPN were eligible for inclusion. The site, volume and maximum dimension of EPN were recorded. The severity of AP and modified CT severity index (MCTSI) was calculated. Clinical outcomes were recorded. RESULTS: A total of 119 patients (mean age, 37.56 years, 91 males) were included. There was a significant association between the location of EPN and the outcome parameters. The left posterior pararenal collections were significantly associated with mortality (P = 0.041), left paracolic gutter collections with the length of hospitalisation (LOH) (P = 0.014), and right paracolic gutter and mesenteric collections with the intensive care unit (ICU) stay (P = 0.024, and P = 0.021, respectively). There was a significant correlation between the volume and the maximum dimension of collection with LOH and ICU stay. The area under the receiver operating characteristic curve for volume, maximum dimension and MCTSI for predicting death was 0.724 (95% CI, 0.612-0.837), 0.644 (95% CI, 0.516-0.772) and 0.574 (95% CI, 0.452-0.696), respectively. CONCLUSION: The site and size of EPN provide reliable and objective information for assessing clinical outcomes in patients with ANP.

Significant inter-observer variation in the diagnosis of extrapancreatic necrosis and type of pancreatic collections in acute pancreatitis - An international multicenter evaluation of the revised Atlanta classification.

BACKGROUND: For consistent reporting and better comparison of data in research the revised Atlanta classification (RAC) proposes new computed tomography (CT) criteria to describe the morphology of acute pancreatitis (AP). The aim of this study was to analyse the interobserver agreement among radiologists in evaluating CT morphology by using the new RAC criteria in patients with AP. METHODS: Patients with a first episode of AP who obtained a CT were identified and consecutively enrolled at six European centres backwards from January 2013 to January 2012. A local radiologist at each center and a central expert radiologist scored the CTs separately using the RAC criteria. Center dependent and independent interobserver agreement was determined using Kappa statistics. RESULTS: In total, 285 patients with 388 CTs were included. For most CT criteria, interobserver agreement was moderate to substantial. In four categories, the center independent kappa values were fair: extrapancreatic necrosis (EXPN) (0.326), type of pancreatitis (0.370), characteristics of collections (0.408), and appropriate term of collections (0.356). The fair kappa values relate to discrepancies in the identification of extrapancreatic necrotic material. The local radiologists diagnosed EXPN (33% versus 59%, P < 0.0001) and non-homogeneous collections (35% versus 66%, P < 0.0001) significantly less frequent than the central expert. Cases read by the central expert showed superior correlation with clinical outcome. CONCLUSION: Diagnosis of EXPN and recognition of non-homogeneous collections show only fair agreement potentially resulting in inconsistent reporting of morphologic findings.

Clinical outcomes of combined necrotizing pancreatitis versus extrapancreatic necrosis alone.

INTRODUCTION: Extrapancreatic necrosis (EPN) alone, i.e., in the absence of pancreatic parenchyma necrosis has gradually come to be regarded as a separate entity of acute necrotizing pancreatitis (ANP). However, data regarding the prognostic significance of EPN are quite limited, and the outcomes of interventions for patients with EPN alone are not well elucidated. The aim of this study was to explore the differences in the outcomes of patients with EPN alone and patients with both the pancreatic parenchyma and extrapancreatic necrosis (combined necrosis). METHODS: From January 2009 to December 2013, a total of 334 patients with ANP who had received interventions in the West China Hospital in China were included. Based on the extent of necrosis as assessed with contrast-enhanced CT, the patients were divided into Group 1 (n = 285) in which the necrosis involved both the pancreatic parenchyma and extrapancreatic tissues (combined necrosis) and Group 2 (n = 49) in which the necrosis involved only the extrapancreatic tissues. Additionally, Group 3 included 443 patients with interstitial pancreatitis who were also included in the analyses. The demographic characteristics, support treatment information, organ failure information, infection necrosis, persistent systemic inflammatory response syndrome (SIRS) in the first week of onset, CT severity index, and intervention types, as well as the postoperative stay lengths, ICU utility, and complications were collected and compared. RESULTS: Compared with the patients in Group 1, the patients in Group 2 suffered less persistent SIRS in the first week of onset (12/24.5% vs. 145/50.9%; P < 0.05), less persistent organ failure (6/12.2% vs. 95/33.3%; P < 0.05), less persistent multiple organ failure (3/6.1% vs. 67/23.5%; P < 0.05), and less bacteremia (5/10.2% vs. 107/37.5%; P < 0.001). The intervention types were significantly different between the two groups (P < 0.001); initial open necrosectomy was performed in 174/61.6% and 8/16.3% of the patients in Groups 1 and 2, respectively, and initial percutaneous catheter drainage (PCD) was performed in 73/25.6% and 29/59.2% of the patients in the two respective groups. Second open necrosectomies following PCD were required in 61/83.5% and 9/31.0% of the patients in Groups 1 and 2, respectively (P < 0.001). A greater number of patients in Group 1 were diagnosed with infected necrosis (204/71.6% vs. 10/20.4%; P < 0.001) and had to be sent to the ICU for further postoperative care (221/77.5% vs. 23/46.9%; P < 0.001). The postoperative stay was longer for Group 1 (median: 43.0 vs. 26.5 days; P < 0.001). Residual necrotic tissue or abscess was the most common postoperative complication in both groups. The mortality was higher in Group 1 (52/18.2% vs. 1/2.1%; P < 0.05). Compared with the patients in Group 2, the patients with interstitial pancreatitis exhibited milder courses and better outcomes. Subgroup comparisons with Group 1 indicated that early multiple organ failure was significantly associated with higher mortality. CONCLUSION: The patients with EPN alone exhibited significantly better prognoses than those with combined necrosis, and EPN alone should be regarded as a separate group of acute necrotizing pancreatitis. Open necrosectomy can be avoided in the majority of patients with EPN alone, who receive PCD as the initial first intervention.

MR Imaging for Early Extrapancreatic Necrosis in Acute Pancreatitis.

RATIONALE AND OBJECTIVES: To study the MRI characteristics of early extrapancreatic necrosis and compare them with those of peripancreatic fluid collections in acute pancreatitis (AP). MATERIALS AND METHODS: This retrospective study enrolled 70 AP patients who had extrapancreatic collections visible on MRI within 1 week of onset. Extrapancreatic collections were divided into extrapancreatic necrosis and peripancreatic fluid collections based on follow-up MRI, CT, or pathology. The number and area of extrapancreatic collections, extrapancreatic inflammation on MRI (EPIM) score, MR severity index score and clinical characteristics were evaluated and compared between the two groups. RESULTS: Of the seventy AP patients, 32 (45.7%) had extrapancreatic necrosis, and 38 (54.3%) had peripancreatic fluid collections. The number and area of extrapancreatic collections, MR severity index score, EPIM score, and prevalence of associated hemorrhage were significantly higher in extrapancreatic necrosis patients than in those with peripancreatic fluid collections (p < 0.001). Among the single indicators, the accuracy of the area of extrapancreatic collections (AUC = 0.871) was comparable to that of the EPIM score for predicting extrapancreatic necrosis and was significantly higher than that of the other two indicators. The combination of all indicators showed the highest predictive accuracy (AUC = 0.949), and combinations of two or more indicators demonstrated significantly higher predictive accuracy for extrapancreatic necrosis than any single indicator (p < 0.05) except for the area of extrapancreatic collections (p > 0.05). CONCLUSION: The MRI characteristics have the potential to differentiate early extrapancreatic necrosis from peripancreatic fluid collections and help indicate extrapancreatic necrosis.

Extrapancreatic necrosis volume: A new tool in acute pancreatitis severity assessment?

BACKGROUND: Many scores have been suggested to assess the severity of acute pancreatitis upon onset. The extrapancreatic necrosis volume is a novel, promising score that appears to be superior to other scores investigated so far. AIM: To evaluate the discriminatory power of extrapancreatic necrosis volume to identify severe cases of acute pancreatitis. METHODS: A total of 123 patients diagnosed with acute pancreatitis at Institute of Gastroenterology and Hepatology, St Spiridon Hospital between January 1, 2017 and December 31, 2019 were analyzed retrospectively. Pancreatitis was classified according to the revised Atlanta classification (rAC) as mild, moderate, or severe. Severity was also evaluated by computed tomography and classified according to the computed tomography severity index (CTSI) and the modified CTSI (mCTSI). The results were compared with the extrapancreatic volume necrosis to establish the sensitivity and specificity of each method. RESULTS: The CTSI and mCTSI imaging scores and the extrapancreatic necrosis volume were highly correlated with the severity of pancreatitis estimated by the rAC (r = 0.926, P < 0.001 and r = 0.950, P < 0.001; r = 0.784, P < 0.001, respectively). The correlation of C-reactive protein with severity was positive but not as strong, and was not significant (r = 0.133, P = 0.154). The best predictor for the assessment of severe pancreatitis was the extrapancreatic necrosis volume [area under the curve (AUC) = 0.993; 95% confidence interval (CI): 0.981-1.005], with a 99.5% sensitivity and 99.0% specificity at a cutoff value of 167 mL, followed by the mCTSI 2007 score (AUC = 0.972; 95%CI: 0.946-0.999), with a 98.0% sensitivity and 96.5% specificity, and the CTSI 1990 score (AUC = 0.969; 95%CI: 0.941-0.998), with a 97.0% sensitivity and 95.0% specificity. CONCLUSION: Radiological severity scores correlate strongly and positively with disease activity. Extrapancreatic necrosis volume shows the best diagnostic accuracy for severe cases.

Role of extrapancreatic necrosis volume in determining early prognosis in patients with acute pancreatitis.

PURPOSE: This study aims to evaluate the capacity of the clinical and radiological findings and the extrapancreatic necrotic tissue volume in early (2-6 days) computerized tomography (CT) images of patients diagnosed with AP to predict reliably the temporary or permanent organ failure and other local or systemic complications due to pancreatitis. MATERIALS AND METHODS: Adult patients who were diagnosed with AP based on Revised Atlanta classification and underwent abdomen CT scans between May 2015 and May 2018 were examined retrospectively. Extrapancreatic necrosis volume was compared to various clinical parameters that indicate the prognosis of AP such as C-reactive protein (CRP) at 48-72th h, organ failure, infection, requirement for percutaneous or surgical intervention, length of hospital stay, and mortality, and to various imaging-based scoring systems such as the computerized tomography severity index (CTSI) and the modified CTSI (mCTSI). The receiver operating characteristic (ROC) curve was used to estimate the optimal threshold for predicting clinical prognosis. RESULTS: Extrapancreatic necrosis volume had moderate positive correlation with length of hospital stay (p = 0.0001) and CRP (at 48-72th h) (p = 0.0001) and strong positive correlation with CTSI (p = 0.0001), mCTSI (p = 0.0001), and white blood cell count (p = 0.0001). CONCLUSION: Extrapancreatic necrosis volume was found to be particularly better in predicting organ failure and infection compared to the imaging-based scoring systems (Balthazar, CTSI, and mCTSI) and the laboratory-based scoring systems (CRP at 48-72th h).

Variability of contrast enhancement of pancreas on computed tomography in patients with acute pancreatitis and isolated extrapancreatic necrosis.

BACKGROUND AND STUDY AIM: To evaluate the variability in the enhancement of pancreas on computed tomography (CT) in patients with acute pancreatitis (AP) and isolated extrapancreatic necrosis (EPN) and to investigate whether it affects the extrapancreatic findings and patient outcomes. PATIENTS AND METHODS: This retrospective study comprised of consecutive patients with isolated EPN evaluated between April 2017 and April 2019. A radiologist measured the pancreatic attenuation values (PAV) of head, body, and tail on a contrast enhanced CT. Using a cut-off PAV of 100HU, patients were divided into two groups. The extrapancreatic CT findings and outcome parameters were compared between the two groups. RESULTS: Thirty patients (mean age, 42.13 years, 17 males) with isolated EPN were evaluated. The mean PAV in the head, body, and tail was 83.13 HU (range, 59-161), 84.17 HU (range, 60-160), and 82.23 HU (range, 53-137). The overall mean PAV was 83.12 HU (range, 58-152). There were six patients with overall mean PAV≥100 HU. The group with PAV≥100 HU had a higher number of patients with infected necrosis (66.6% vs. 14.2%, P=0.018). PAV had a significant association with length of hospitalization (P=0.045). CONCLUSION: There is significant variability in the pancreatic enhancement on CT among patients with AP and isolated EPN. Patients with PAV≥100 HU had a significantly longer hospital stay. This, however, may be related to a greater number of patients with infected necrosis in this group.

Impact of the site of necrosis on outcome of acute pancreatitis.

OBJECIVES: To compare the clinical outcome of patients with extrapancreatic necrosis (EXPN) alone with that of acute interstitial pancreatitis (AIP), pancreatic parenchymal necrosis (PPN) alone, and combined PPN and EXPN. BACKGROUND: There are only a few studies in the literature in which EXPN has been recently recognized as a subtype of acute necrotizing pancreatitis (ANP), with a better prognosis. METHODS: We analyzed clinical data and outcome variables of 411 consecutive acute pancreatitis (AP) patients between January 2012 and December 2014. Contrast-enhanced computed tomography (CECT) images of each patient were reviewed and characterized as AIP or ANP. Patients with ANP were divided into EXPN alone, PPN alone, and combined PPN and EXPN. Outcome variables were then compared between these groups. RESULTS: Of the 411 patients, 74 (18%) had AIP, and 337 (82%) had ANP. Patients with EXPN alone (n = 40; 11.8%) had similar outcomes as patients with PPN alone (n = 12; 3.5%); however, their outcome was worse than that of patients with AIP, with a higher frequency of persistent organ failure (POF), need for percutaneous catheter drainage (PCD), and longer length of hospitalization (LOH). Patients with combined PPN and EXPN (n = 285; 84.7%) had the worst clinical course, with higher frequency of POF, infected necrosis, intervention requirement, and longer LOH. CONCLUSION: Patients with combined PPN and EXPN have a severe disease course with the worst clinical outcomes; patients with AIP patients have the most benign course, while patients with EXPN alone stand between the two extremes of disease course with an intermediate grade of severity.