Prospective Analysis of the Mechanisms Underlying Ineffective Deep Vein Thrombosis Prophylaxis in Necrotizing Pancreatitis

The risk of developing splanchnic vein thrombosis in acute pancreatitis increases 3 days after symptom onset: A systematic review and meta-analysis

BACKGROUND

Splanchnic vein thrombosis is a complication of acute pancreatitis (AP) and is likely often underdiagnosed.

OBJECTIVES

We aimed to understand the time course and risk factors of splanchnic vein thrombosis in the early phase of AP.

METHODS

A systematic search was conducted using the PRISMA guidelines (PROSPERO registration CRD42022367578). Inclusion criteria were appropriate imaging techniques in adult AP patients, studies that reported splanchnic vein thrombosis data from the early phase, and reliable information on the timing of imaging in relation to the onset of pancreatitis symptoms or hospital admission. The proportion of patients with thrombosis with 95% confidence intervals (CI) was calculated using random-effects meta-analyses, and multiple subgroup analyses were performed.

RESULTS

Data from 1951 patients from 14 studies were analyzed. The proportion of patients with splanchnic vein thrombosis within 12 days after symptom onset was 0.13 (CI 0.07-0.23). The occurrence was lowest at 0.06 (CI 0.03-0.1) between 0 and 3 days after symptom onset, and increased fourfold to 0.23 (CI 0.16-0.31) between 3 and 11 days. On hospital admission, the proportion of patients affected was 0.12 (CI 0.02-0.49); it was 0.17 (CI 0.03-0.58) 1-5 days after admission. The prevalence in mild, moderate, and severe AP was 0.15 (CI 0.05-0.36), 0.26 (CI 0.15-0.43), and 0.27 (CI 0.17-0.4), respectively. Alcoholic etiology (0.31, CI 0.13-0.58) and pancreatic necrosis (0.55, CI 0.29-0.78, necrosis above 30%) correlated with increased SVT prevalence.

CONCLUSION

The risk of developing splanchnic vein thrombosis is significant in the early stages of AP and may affect up to a quarter of patients. Alcoholic etiology, pancreatic necrosis, and severity may increase the prevalence of splanchnic vein thrombosis.

Venous Thrombosis in Acute Pancreatitis: What to and Not to Do?

Acute pancreatitis is an acute inflammatory condition of the pancreas that has not only local but systemic effects as well. Venous thrombosis is one such complication which can give rise to thrombosis of the peripheral vasculature in the form of deep vein thrombosis, pulmonary embolism, and splanchnic vein thrombosis. The prevalence of these complications increases with the severity of the disease and adds to the adverse outcomes profile. With better imaging and awareness, more cases are being detected, although many at times it can be an incidental finding. However, it remains understudied and strangely, most of the guidelines on the management of acute pancreatitis are silent on this aspect. This review offers an overview of the incidence, pathophysiology, symptomatology, diagnostic work-up, and management of venous thrombosis that develops in AP.

Determinants and impact of splanchnic vein thrombosis in acute pancreatitis

BACKGROUND

Splanchnic vein thrombosis (SVT) is a well-recognised though little-studied complication in acute pancreatitis (AP). SVT risk factors, its clinical consequences and the role of anticoagulation (AC) therapy is scarce.

AIMS

To evaluate the incidence and natural history of SVT in AP.

METHODS

Post hoc analysis of a prospective multicentre cohort study involving 23 hospitals in Spain. AP complications were identified by computer tomography, and patients with SVT were re-evaluated after two years.

RESULTS

A total of 1655 patients with AP were included. The overall incidence of SVT was 3.6%. SVT was significantly associated with male gender, younger age and alcoholic aetiology. Every local complication increased SVT incidence, and this risk rose gradually with larger extension and infection of necrosis. These patients had a longer hospital stay and underwent a greater number of invasive treatments, regardless of AP severity. Forty-six patients with SVT were followed up. SVT resolution rate was 54.5% in the AC group and 30.8% in the non-AC group with lower thrombotic complications in the SVT resolution group (83.3% vs 22.7%; p<0.001). No AC-related adverse events occurred.

CONCLUSION

This study identifies the risk factors and negative clinical impact of SVT in AP. Our results justify future trials to demonstrate the role of AC in this clinical scenario.

Acute pancreatitis induces a transient hypercoagulable state in murine models

BACKGROUND/OBJECTIVES

Although understudied, risk of venous thromboembolism (VTE) appears to be increased during acute pancreatitis (AP). We aimed to further characterize a hypercoagulable state associated with AP utilizing thromboelastography (TEG), a readily available, point of care test.

METHODS

AP was induced in C57/Bl6 mice using l-arginine and caerulein. TEG was performed with citrated native samples. The maximum amplitude (MA) and coagulation index (CI), a composite marker of coagulability, were evaluated. Platelet aggregation was assessed using whole blood collagen-activated platelet impedance aggregometry. Circulating tissue factor (TF), the initiator of extrinsic coagulation, was measured with ELISA. A VTE model using IVC ligation followed by measurement of clot size and weight was evaluated. After IRB approval and consent, blood samples from patients hospitalized with a diagnosis of AP were evaluated by TEG.

RESULTS

Mice with AP displayed a significant increase in MA and CI, consistent with hypercoagulability. Hypercoagulability peaked at 24 h after induction of pancreatitis, then returned to baseline by 72 h. AP resulted in significantly increased platelet aggregation and elevated circulating TF. Increased clot formation with AP was observed in an in vivo model of deep vein thrombosis. In a proof of concept, correlative study, over two thirds of patients with AP demonstrated an elevated MA and CI compared to the normal range, consistent with hypercoagulability.

CONCLUSIONS

Murine acute pancreatitis results in a transient hypercoagulable state that can be assessed by TEG. Correlative evidence for hypercoagulability was also demonstrated in human pancreatitis. Further study to correlate coagulation measures to incidence of VTE in AP is warranted.

Deep Venous Thrombosis in Acute Pancreatitis Is Associated with High Mortality: A Prospective Study

BACKGROUND

Incidence and risk factors for the development of extremity deep vein thrombosis (eDVT) in admitted patients of acute pancreatitis have been rarely explored.

AIMS

To identify the incidence of eDVT and to explore role of clinical scores for predicting eDVT in admitted patients of acute pancreatitis.

METHODS

We prospectively enrolled admitted patients of acute pancreatitis and performed a weekly eDVT screen for the duration of their admission. Well's score and Padua's score were also calculated weekly. The incidence of venous thrombosis (eDVT and splanchnic thrombosis based on contrast-enhanced CT scan abdomen) was noted, and the risk factors were determined using multivariate analysis. The correlation between Well's score, Padua's score, and development of DVT was calculated using Pearson's correlation.

RESULTS

Of the 102 patients of acute pancreatitis enrolled, 73.5% of patients had necrotizing pancreatitis. Total of 46 patients (45.1%) developed thrombosis: 43 patients had splanchnic vein thrombosis; 5 patients had eDVT; and 1 patient had pulmonary embolism. Patients with eDVT had higher BISAP score (2.6 ± 0.9 vs 1.7 ± 0.8; p = 0.039), requirement of mechanical ventilation (60% vs 8.2%; p = 0.008), and mortality (60% vs 12.4%; p = 0.022). Well's score of ≥ 2 had sensitivity and specificity of 80% and 96.9% for prediction of eDVT and it had better correlation with the development of eDVT compared to Pauda's score.

CONCLUSION

Incidence of DVT is 5% in patients with acute pancreatitis requiring admission. It is associated with higher disease severity and mortality. The Well's score is useful to predict the development of eDVT in routine clinical practice.

Contemporary Surgical Management of Pancreatic Necrosis

Importance

For decades, infected or symptomatic pancreatic necrosis was managed by open surgical necrosectomy, an approach that has now been largely supplanted by an array of techniques referred to as the step-up approach.

Observations

This review describes the evidence base behind the step-up approach, when to use the different techniques, and their technical basics. The most common treatment strategies are included: percutaneous drainage, video-assisted retroperitoneal debridement, sinus tract endoscopy, endoscopic transgastric necrosectomy, and surgical transgastric necrosectomy. Also included is the evidence base around management of common complications that can occur during step-up management, such as hemorrhage, intestinal fistula, and thrombosis, in addition to associated issues that can arise during step-up management, such as the need for cholecystectomy and disconnected pancreatic duct syndrome.

Conclusions and Relevance

The treatment strategies highlighted in this review are those most commonly used during step-up management, and this review is designed as a guide to the evidence base underlying these strategies, as surgeons tailor their therapeutic approach to individual patients.

Obesity Worsens Local and Systemic Complications of Necrotizing Pancreatitis and Prolongs Disease Course

BACKGROUND

Obesity is epidemic in the USA. Limited data exist examining obesity's influence on necrotizing pancreatitis (NP) disease course.

METHODS

Retrospective review of prospectively maintained database of 571 adult necrotizing pancreatitis patients treated between 2007 and 2018. Patients were grouped according to body mass index (BMI) at disease onset. Patient characteristics, necrotizing pancreatitis course, and outcomes were compared between non-obese (BMI < 30) and obese (BMI > 30) patients.

RESULTS

Among 536 patients with BMI data available, 304 (57%) were obese (BMI > 30), and 232 (43%) were non-obese (BMI < 30). NP etiology in the obese group was more commonly biliary (55% versus 46%, p = 0.04) or secondary to hypertriglyceridemia (10% versus 2%, p < 0.001) and less commonly alcohol (17% versus 26%, p = 0.01). Obese patients had a higher incidence of baseline comorbid disease. The CT severity index was similar between groups though obese patients had a higher rate of > 50% pancreatic gland necrosis (27% versus 19%, p = 0.02). The rates of infected necrosis and organ failure were higher among obese patients. Percutaneous drainage was more common in obese patients. Time to first necrosis intervention was earlier with increasing BMI. NP disease duration was longer in obese patients. The overall mortality rate of non-obese and obese patients did not differ. However, mortality rate increased with increasing BMI.

CONCLUSION

Necrotizing pancreatitis in obese patients is characterized by a prolonged disease course, a higher risk of organ failure, infected necrosis, and the need for early necrosis-related intervention. Mortality increases with increasing BMI.

Management of Necrotizing Pancreatitis

Necrotizing pancreatitis affects 10% to 15% of all patients with acute pancreatitis. Despite improved understanding of this complex disease, it is still attended by up to 15% mortality. Necrotizing pancreatitis provides the clinical challenges of working in a multi-disciplinary group, determining proper timing for intervention, and identifying appropriate intervention approaches. The step-up approach consists of supportive care initially. When there is documented infected necrosis, treatment begins with antibiotics, progressing to minimally invasive mechanical necrosis intervention, and reserving surgery as the final treatment modality. However, treatment must be tailored to the individual patient. This article provides an overview of necrotizing pancreatitis.

Vascular complications of pancreatitis

More than 200000 hospital admissions happen per year for acute pancreatitis and more than 50000 for chronic pancreatitis in the United States of America. Necrotizing pancreatitis accounts for 20%-30% of the cases. One-quarter of the patients with pancreatitis develop vascular complications, which carries a high mortality. This mini-review will address these complications that can help primary care physicians and hospitalists in managing their patients effectively.

Guidelines for the management of patients with severe acute pancreatitis, 2021

OBJECTIVE

To provide guidelines for the management of the intensive care patient with severe acute pancreatitis.

DESIGN

A consensus committee of 22 experts was convened. A formal conflict-of-interest (COI) policy was developed at the beginning of the process and enforced throughout. The entire guideline construction process was conducted independently of any industrial funding (i.e. pharmaceutical, medical devices). The authors were required to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised.

METHODS

The most recent SFAR and SNFGE guidelines on the management of the patient with severe pancreatitis were published in 2001. The literature now is sufficient for an update. The committee studied 14 questions within 3 fields. Each question was formulated in a PICO (Patients Intervention Comparison Outcome) format and the relevant evidence profiles were produced. The literature review and recommendations were made according to the GRADE® methodology.

RESULTS

The experts' synthesis work and their application of the GRADE® method resulted in 24 recommendations. Among the formalised recommendations, 8 have high levels of evidence (GRADE 1+/-) and 12 have moderate levels of evidence (GRADE 2+/-). For 4 recommendations, the GRADE method could not be applied, resulting in expert opinions. Four questions did not find any response in the literature. After one round of scoring, strong agreement was reached for all the recommendations.

CONCLUSIONS

There was strong agreement among experts for 24 recommendations to improve practices for the management of intensive care patients with severe acute pancreatitis.

Chemoprophylaxis to Prevent Deep Venous Thrombosis in Patients Hospitalized for Pancreatitis: Beneficial or Harmful?

Introduction: Vascular complications in pancreatitis generally occur in the form of hemorrhage or thrombosis. Pancreatitis resulting in splanchnic thrombosis has been well studied, but the cause of this correlation has not been studied in the current era of increasing anticoagulant use for deep venous thrombosis (DVT) prophylaxis. Hemorrhagic pancreatitis and peri-pancreatic bleeding are also known phenomena encountered in relation to pancreatitis, but these risks are not well established in the setting of chemical prophylaxis for DVT.

Objectives: Our objective was to identify whether chemical DVT prophylaxis in pancreatitis harms the patient by increasing the risk of hemorrhagic conversion of pancreatitis or peri-pancreatic hemorrhage or if it is beneficial by preventing splanchnic venous thrombosis in the abdominal vasculature that surrounds the pancreas.

Methods: We undertook a retrospective chart review with approval from the Institutional Review Board on patients who were hospitalized for or developed pancreatitis during their hospital stay from April 2014 to July 2015. We reviewed the charts for imaging suggestive of venous thrombosis or the development of intra-abdominal hemorrhage at admission during hospitalization and within 30 days after hospitalization. We also reviewed the methods of DVT prophylaxis to identify any correlation with the risk of hemorrhage or thrombosis. A bedside index of severity in acute pancreatitis score was used within 24 hours of admission to calculate the severity of the patients’ pancreatitis. The data collected were analyzed for descriptive statistics, correlation using Pearson’s coefficient, and multivariate regression analysis using Microsoft Excel and SPSS Inc. Released 2009. PASW Statistics for Windows, Version 18.0. Chicago: SPSS Inc.

Results: This study included 389 patients who met the inclusion criteria. Of these, 74.6% of patients received chemical prophylaxis, mostly low molecular weight heparin, and 18.5% of patients were not on chemical or mechanical means of DVT prophylaxis. Only 12 patients (3%) had complications related to thrombosis and hemorrhage. Seven patients had splanchnic venous thrombosis, one had a hemorrhagic conversion of pancreatitis, three had a peri-pancreatic hemorrhage, and one had both the hemorrhagic conversion of pancreatitis and peri-pancreatic hemorrhage. Ten patients out of 12 patients had complications before admission, and nine of the 12 patients were on chemical prophylaxis. Pearson’s coefficient showed no statistically significant correlation between the incidence of complications and the use of chemical DVT prophylaxis. Multivariate analysis showed no specific variable that increased the risk of complications.

Conclusions: Our study showed that chemoprophylaxis for DVT in patients hospitalized for acute pancreatitis is neither harmful by causing hemorrhagic conversion of pancreatitis, peri-pancreatic hemorrhage nor beneficial by preventing splanchnic venous thrombosis.

Development and validation of a prediction model for deep vein thrombosis in older non-mild acute pancreatitis patients

BACKGROUND

Deep vein thrombosis (DVT) may cause pulmonary embolus, leading to late deaths. The systemic inflammatory and hypercoagulable state of moderate and severe acute pancreatitis (non-mild acute pancreatitis, NMAP) patients may contribute to the development of venous thromboembolism. Accurate prediction of DVT is conducive to clinical decisions.

AIM

To develop and validate a potential new prediction nomogram model for the occurrence of DVT in NMAP.

METHODS

NMAP patient admission between 2013.1.1 and 2018.12.31 at the West China Hospital of Sichuan University was collected. A total of 220 patients formed the training set for nomogram development, and a validation set was constructed using bootstrapping with 100 resamplings. Univariate and multivariate logistic regression analyses were used to estimate independent risk factors associated with DVT. The independent risk factors were included in the nomogram. The accuracy and utility of the nomogram were evaluated by calibration curve and decision curve analysis, respectively.

RESULTS

A total of 220 NMAP patients over 60 years old were enrolled for this analysis. DVT was detected in 80 (36.4%) patients. The final nomogram included age, sex, surgery times, D-dimer, neutrophils, any organ failure, blood culture, and classification. This model achieved good concordance indexes of 0.827 (95%CI: 0.769-0.885) and 0.803 (95%CI: 0.743-0.860) in the training and validation sets, respectively.

CONCLUSION

We developed and validated a prediction nomogram model for DVT in older patients with NMAP. This may help guide doctors in making sound decisions regarding the administration of DVT prophylaxis.