Management of Severe Acute Pancreatitis: An Update

Early prediction of severe acute pancreatitis using machine learning

BACKGROUND

Acute pancreatitis (AP) is one of the most common causes of gastrointestinal-related hospitalizations in the United States. Severe AP (SAP) is associated with a mortality rate of nearly 30% and is distinguished from milder forms of AP. Risk stratification to identify SAP cases needing inpatient treatment is an important aspect of AP diagnosis.

METHODS

We developed machine learning algorithms to predict which patients presenting with AP would require treatment for SAP. Three models were developed using logistic regression, neural networks, and XGBoost. Models were assessed in terms of area under the receiver operating characteristic (AUROC) and compared to the Harmless Acute Pancreatitis Score (HAPS) and Bedside Index for Severity in Acute Pancreatitis (BISAP) scores for AP risk stratification.

RESULTS

61,894 patients were used to train and test the machine learning models. With an AUROC value of 0.921, the model developed using XGBoost outperformed the logistic regression and neural network-based models. The XGBoost model also achieved a higher AUROC than both HAPS and BISAP for identifying patients who would be diagnosed with SAP.

CONCLUSIONS

Machine learning may be able to improve the accuracy of AP risk stratification methods and allow for more timely treatment and initiation of interventions.

Impacts of body composition parameters and liver cirrhosis on the severity of alcoholic acute pancreatitis

AIM

Liver cirrhosis and features of muscle or adipose tissues may affect the severity of acute pancreatitis (AP). We aimed to evaluate the impact of body composition parameters and liver cirrhosis on the severity of AP in patients with alcohol-induced AP (AAP).

METHODS

Patients with presumed AAP who underwent CT within one week after admission were retrospectively enrolled. L3 sectional areas of abdominal fat and muscle, and mean muscle attenuations (MMAs) were quantified. The presence of liver cirrhosis was determined using clinical and CT findings. Factors potentially associated with moderately severe or severe AP were included in the multivariable logistic regression analysis.

RESULTS

A total of 242 patients (47.0 ± 12.6 years, 215 males) with presumed AAP were included. The mild and moderately severe/severe (MSS) groups included 137 (56.6%) and 105 patients (43.4%), respectively. Patients in the MSS group had higher rates of liver cirrhosis, organ failure, and local complications. Among body composition parameters, mean MMA (33.4 vs 36.8 HU, P<0.0001) and abdominal muscle mass (126.5 vs 135.1 cm2, P = 0.029) were significantly lower in the MSS group. The presence of liver cirrhosis (OR, 4.192; 95% CI, 1.620-10.848) was found to be a significant risk factor for moderately severe or severe AP by multivariable analysis.

CONCLUSION

The results of this study suggest that liver cirrhosis has a significant impact on the severity of AAP. Of the body composition parameters examined, MMA and abdominal muscle mass showed potential as promising predictors.

Percutaneous catheter drainage of pancreatic associated pathologies: A systematic review and meta-analysis

PURPOSE

The main goal of this systematic review was to assess the technical and clinical success, adverse events (AEs), surgery, and overall mortality proportion after percutaneous catheter drainage (PCD) of two pancreatic lesions.

METHODS

An extant search in online databases including Scopus, PubMed (Medline), Embase (Elsevier), Web of Science, Cochrane library, and Google Scholar, was conducted to recognize all studies that used PCD intervention in the management of pancreatic necrosis (PN) and pancreatic pseudocysts (PP). Random effects meta-analysis was performed, and Cochrane's Q test and I²statistic were utilized to determine heterogeneity. In addition, meta-regression was used to explore the influence of categorical variables on heterogeneity.

RESULTS

Thirty-two studies (1398 patients) including PN in 26 (1256 cases, 89.8%) studies and PP in 6 (142 cases, 10.2%) studies were identified. Technical success proportion was 100% (95% confidence interval [CI] 100%-100%, I²: 0.0%), clinical success 63% (95% CI 55%-71%, I²: 92.9%), AEs 26% (95% CI 21%-31%, I²: 78%), surgery after PCD intervention 33% (95% CI 25%-40%, I²: 92.4%), and overall mortality was 13% (95% CI 9%-17%, I²: 82.8%). The most common ADs after PCD intervention were development of fistula (106, 42.6%), hemorrhage (44, 17.7%), sepsis (40, 16.1%).

CONCLUSION

A significant clinical success proportion with low AEs, surgery, and overall mortality proportion after PCD intervention was found, although the results should be interpreted with caution due to the high heterogeneity.

Safety and Efficacy of Early (<4 Weeks of Illness) Endoscopic Transmural Drainage of Post-acute Pancreatic Necrosis Predominantly Located in the Body of the Pancreas

BACKGROUND

Endoscopic transmural drainage is usually not performed for pancreatic necrotic collection (PNC) < 4 weeks after onset of acute necrotizing pancreatitis (ANP) because of lack of encapsulating wall and increased risk of complications.

OBJECTIVE

Study safety and efficacy of early (<4 weeks) endoscopic transluminal drainage in patients with symptomatic PNC.

METHODS

Retrospective analysis of data base of patients with PNC treated with endoscopic transmural drainage within 4 weeks of onset of ANP (early drainage) was done. The outcomes and complications were compared with patients with PNC who underwent delayed endoscopic drainage (≥4 weeks of onset of ANP).

RESULTS

Thirty-four patients (26 males; mean age: 35.9 ± 8.6 years) underwent early and 136 patients (115 males; mean age: 37.9 ± 9.4 years) underwent delayed endoscopic drainage. The PNC was significantly larger (12.3 ± 2.1 cm vs 10.5 ± 2.7 cm, p <0.001) with increased solid component (47.7 ± 8.9% vs 28.3 ± 11.7%, p <0.001) in the early group. Clinical success was achieved in 94% patients in the early group and all patients in the delayed group. Direct endoscopic necrosectomy was performed more frequently in the early group (50% vs 7.4%; p<0.001). There was increased mortality (5.7% vs 0%), need for rescue surgical necrosectomy (5.7% vs 0%), and clinically significant bleeding (20% vs 1.5%, p<0.001) in the early group as compared to the delayed group.

CONCLUSION

Early endoscopic drainage of PNC is feasible and seems to be safe as well as effective but is associated with increased risk of complications as compared to delayed drainage.

Abdominal paracentesis drainage attenuates intestinal mucosal barrier damage through macrophage polarization in severe acute pancreatitis

Abdominal paracentesis drainage (APD), as an effective treatment of severe acute pancreatitis (SAP) in clinical settings, can ameliorate intestinal barrier damage and the overall severity of SAP. However, the mechanism underlying therapeutic effects of APD on damaged intestinal mucosal barrier during SAP is still unclear. Here, SAP was induced by injecting 5% Na-taurocholate retrograde into the biliopancreatic duct of rats to confirm the benefits of APD on enteral injury of SAP and further explore the possible mechanism. Abdominal catheter was placed after SAP was induced in APD group. As control group, the sham group received no operation except abdominal opening and closure. By comparing changes among control group, sham group, and APD group, APD treatment obviously lowered the intestinal damage and reduced the permeation of intestinal mucosal barrier, which was evidenced by intestinal H&E staining, enteral expression of tight junction proteins, intestinal apoptosis measurement and detection of serum diamine oxidase, intestinal fatty acid binding protein and D-lactic acid. Furthermore, we found that APD polarized intestinal macrophages toward M2 phenotype by the determination of immunofluorescence and western blotting, and this accounts for the benefits of APD for intestinal injury in SAP. Importantly, the protective effect against intestinal injury by APD treatment was mediated through the inhibited ASK1/JNK pathway. In summary, APD improved the intestinal mucosal barrier damage in rats with SAP through an increasing portion of M2 phenotype macrophages in intestine via inhibiting ASK1/JNK pathway.

Streptokinase irrigation through a percutaneous catheter helps decrease the need for necrosectomy and reduces mortality in necrotizing pancreatitis as part of a step-up approach

BACKGROUND

Percutaneous catheter drainage in pancreatic necrosis with a predominant solid component has a reduced success rate. To improve the efficacy of percutaneous catheter drainage, we used streptokinase in the irrigation fluid in the present study.

METHODS

In this retrospective analysis of 4 prospective randomized studies performed at our center from 2014 to 2019, 108 patients were evaluated. We assessed the safety, feasibility, and efficacy of streptokinase irrigation compared to saline irrigation. Data were also analyzed between 50,000 IU and 150,000 IU streptokinase.

RESULTS

There were 53 patients in the streptokinase irrigation group and 55 in the saline irrigation group, and both groups were comparable in terms of age, sex, etiology, APACHE II score, and percutaneous catheter drainage characteristics. The modified computerised tomography severity index and modified Marshall score at the onset of pain were significantly higher in the streptokinase group. Sepsis reversal was significantly higher in the streptokinase group (75% vs 36%), and the need for necrosectomy (34% vs 54%) was also lower in the streptokinase group. Mortality was lower in the streptokinase group than in the saline group (32% vs 40%). The incidence of bleeding in the streptokinase group was lower than that in the saline group (7% vs 18%). A higher dose of streptokinase (150,000 IU) resulted in lower rates of necrosectomy, bleeding, and mortality compared to those with 50,000 IU streptokinase.

CONCLUSION

Significant reductions in the need for surgery and sepsis reversal were noted in the streptokinase group. The results using 150,000 IU streptokinase were superior to those using 50,000 IU streptokinase.

Head-to-head comparison between endoscopic ultrasound guided lumen apposing metal stent and plastic stents for the treatment of pancreatic fluid collections: A systematic review and meta-analysis

BACKGROUND/AIMS

Peripancreatic fluid collections (PFCs) result from acute or chronic pancreatic inflammation that suffers a rupture of its ducts. Currently, there exists three options for drainage or debridement of pancreatic pseudocysts and walled-off necrosis (WON). The traditional procedure is drainage by placing double pigtail plastic stents (DPPS); lumen-apposing metal stent (LAMS) has a biflanged design with a wide lumen that avoids occlusion with necrotic tissue, which is more common with DPPS and reduces the possibility of migration. We performed a systematic review and meta-analyses head-to-head, including only studies that compare the two main techniques to drainage of PFCs: LAMS vs DPPS.

METHODS

We conducted a systematic review in different databases, such as PubMed, OVID, Medline, and Cochrane Databases. This meta-analysis considers studies published from 2014 to 2020, including only studies that compare the two main techniques to drainage of PFCs: LAMS vs DPPS.

RESULTS

Thirteen studies were included in the meta-analyses. Only one of all studies was a randomized controlled trial. These studies comprise 1584 patients; 68.2% were male, and 31.8% were female. Six hundred sixty-three patients (41.9%) were treated with LAMS, and 921 (58.1%) were treated with DPPS. Six studies included only WON in their analysis, two included only pancreatic pseudocysts, and five studies included both pancreatic pseudocysts and WON. The technical success was similar in patients treated with LAMS and DPPS (97.6% vs 97.5%, respectively, P = .986, RR = 1.00 [95% CI 0.93-1.08]). The clinical success was similar in both groups (LAMS: 90.1% vs DPPS: 84.2%, P = .139, RR = 1.063 [95% CI 0.98-1.15]). Patients treated with LAMS had a lower complication rate than the DPPS groups, with a significant statistical difference (LAMS: 16.0% vs DPPS: 20.2%, P = .009, RR = 0.746 [95% CI 0.60-0.93]). Bleeding was the most common complication in the LAMS group (33 patients, [5.0%]), whereas infection was the most common complication in the DPPS group (56 patients, [6.1%]). The LAMS migration rate was lower than in the DPPS (0.9% vs 2.2%, respectively, P = .05). The mortality rate was similar in both groups, 0.6% in the LAMS group (four patients) and 0.4% in the DPPS group (four patients; P = .640).

CONCLUSION

The PFCs drainage is an indication when persistent symptoms or PFCs-related complications exist. EUS guided drainage with LAMS has similar technical and clinical success to DPPS drainage for the management of PFCs. The technical and clinical success rates are high in both groups. However, LAMS drainage has a lower adverse events rate than DPPS drainage. More randomized controlled trials are needed to confirm the real advantage of LAMS drainage over DPPS drainage.

Small Incision Combined with Nephroscope Operation in the Treatment of Infectious Pancreatic Necrosis: A Single-Center Experience of 37 Patients

Objective

To explore the safety and efficacy of small incision combined with nephroscope surgery in the treatment of infectious pancreatic necrosis.

Methods

A retrospective analysis of the clinical data of 37 patients with infectious pancreatic necrosis who underwent small incision combined with nephroscopy in the Department of Hepatobiliary Surgery of Hunan Provincial People's Hospital from January 2018 to December 2019.

Results

All 37 patients successfully completed small incision combined nephroscope surgery. The median time from the onset to the operation of all patients was 38 days (range: 29-80 days), and the hospital stay was 19 days (range: 3-95 days). The median number of drainage tubes placed during the operation was 4 (range: 2-8). According to the different surgical approaches, 13 cases were through the retroperitoneal approach, 11 cases were through the omental sac approach, 2 cases were through the intercostal approach, and 11 cases were combined approach. The operation time was 85.3 ± 31.6 min, and intraoperative bleeding was 63.1 ± 40.0 ml. The incidence of complications (Clavien-Dindo grade 3 and above) was 5.4%. Among them, 2 patients were admitted to the intensive care unit due to postoperative bleeding, 1 case was cured by conservative treatment, and 1 case was cured by interventional treatment. During the follow-up period, 2 patients developed colonic fistula at 2 weeks after operation, and 2 patients developed gastric fistula at 1 week and 3 weeks after operation; all were cured by conservative treatment.

Conclusion

Small incision combined with nephroscope surgery is an effective treatment for patients with infectious pancreatic necrosis by removing necrotic tissue, unobstructed drainage, and reducing complications.

Targeting neutrophil extracellular traps in severe acute pancreatitis treatment

Severe acute pancreatitis (SAP) is a critical abdominal disease associated with high death rates. A systemic inflammatory response promotes disease progression, resulting in multiple organ dysfunction. The functions of neutrophils in the pathology of SAP have been presumed traditionally to be activation of chemokine and cytokine cascades accompanying the inflammatory process. Recently, since their discovery, a new type of antimicrobial mechanism, neutrophil extracellular traps (NETs), and their role in SAP, has attracted widespread attention from the scientific community. Significantly different from phagocytosis and degranulation, NETs kill extracellular microorganisms by releasing DNA fibers decorated with granular proteins. In addition to their strong antimicrobial functions, NETs participate in the pathophysiological process of many noninfectious diseases. In SAP, NETs injure normal tissues under inflammatory stress, which is associated with the activation of inflammatory cells, to cause an inflammatory cascade, and SAP products also trigger NET formation. Thus, due to the interaction between NET generation and SAP, a treatment targeting NETs might become a key point in SAP therapy. In this review, we summarize the mechanism of NETs in protecting the host from pathogen invasion, the stimulus that triggers NET formation, organ injury associated with SAP involving NETs, methods to interrupt the harmful effects of NETs, and different therapeutic strategies to preserve the organ function of patients with SAP by targeting NETs.