CT and MRI assessment of symptomatic organized pancreatic fluid collections and pancreatic duct disruption: an interreader variability study using the revised Atlanta classification 2012

The i-EUS consensus on the management of pancreatic fluid collections - Part 1

Pancreatic fluid collections (PFCs), including pancreatic pseudocysts (PPs) and walled-off pancreatic necrosis (WON), are common complications of pancreatitis and pancreatic surgery. Historically, the treatment of these conditions has relied on surgical and radiological approaches; however, it has later shifted toward an endoscopy-based approach. With the development of dedicated lumen-apposing metal stents (LAMS), interventional Endoscopic Ultrasound (EUS)-guided procedures have become the standard approach for PFC drainage. However, there is still limited consensus on several aspects of the multidisciplinary management of PFCs. The interventional endoscopy and ultrasound (i-EUS) group is an Italian network of clinicians and scientists with special interest in biliopancreatic interventional endoscopy, especially interventional EUS. This manuscript describes the first part of the results of a consensus conference organized by i-EUS with the aim of providing evidence-based guidance on aspects such as indications for treating PFCs, the timing of intervention, and different technical strategies for managing patients with PFCs.

Endoscopic management of pancreatic collections. Endoscopic Ultrasound Group, Spanish Society of Digestive Endoscopy (GSEED-USE) Clinical Guidelines

Acute pancreatitis is associated with significant morbidity and mortality. It can develop complications such as fluid collections and necrosis. Infection of necrosis occurs in about 20-40 % of patients with severe acute pancreatitis, and is associated with organ failure and worse prognosis. In the past few years the treatment of pancreatic collections has shifted from open surgery to minimally invasive techniques such as endoscopic ultrasound-guided drainage. These guidelines from a selection of experts among the Endoscopic Ultrasound Group, Spanish Society of Gastrointestinal Endoscopy (GSEED-USE) are intended to provide advice on the management of pancreatic collections based on a thorough review of the available scientific evidence. It also reflects the experience and clinical practice of the authors, who are advanced endoscopists or clinical pancreatologists with extensive experience in managing patients with acute pancreatitis.

Endoscopic Drainage of Pancreatic Fluid Collections

Pancreatic fluid collections (PFCs) are commonly encountered complications of acute and chronic pancreatitis. With the advancement of endoscopic ultrasound (EUS) techniques and devices, EUS-directed transmural drainage of symptomatic or infected PFCs has become the standard of care. Traditionally, plastic stents have been used for drainage, although lumen-apposing metal stents (LAMSs) are now favored by most endoscopists due to ease of use and reduced procedure time. While safety has been repeatedly demonstrated, follow-up care for these patients is critical as delayed adverse events of indwelling drains are known to occur.

Long-term follow-up study of necrotising pancreatitis: interventions, complications and quality of life

OBJECTIVE

To describe the long-term consequences of necrotising pancreatitis, including complications, the need for interventions and the quality of life.

DESIGN

Long-term follow-up of a prospective multicentre cohort of 373 necrotising pancreatitis patients (2005-2008) was performed. Patients were prospectively evaluated and received questionnaires. Readmissions (ie, for recurrent or chronic pancreatitis), interventions, pancreatic insufficiency and quality of life were compared between initial treatment groups: conservative, endoscopic/percutaneous drainage alone and necrosectomy. Associations of patient and disease characteristics during index admission with outcomes during follow-up were assessed.

RESULTS

During a median follow-up of 13.5 years (range 12-15.5 years), 97/373 patients (26%) were readmitted for recurrent pancreatitis. Endoscopic or percutaneous drainage was performed in 47/373 patients (13%), of whom 21/47 patients (45%) were initially treated conservatively. Pancreatic necrosectomy or pancreatic surgery was performed in 31/373 patients (8%), without differences between treatment groups. Endocrine insufficiency (126/373 patients; 34%) and exocrine insufficiency (90/373 patients; 38%), developed less often following conservative treatment (p<0.001 and p=0.016, respectively). Quality of life scores did not differ between groups. Pancreatic gland necrosis >50% during initial admission was associated with percutaneous/endoscopic drainage (OR 4.3 (95% CI 1.5 to 12.2)), pancreatic surgery (OR 3.2 (95% CI 1.1 to 9.5) and development of endocrine insufficiency (OR13.1 (95% CI 5.3 to 32.0) and exocrine insufficiency (OR6.1 (95% CI 2.4 to 15.5) during follow-up.

CONCLUSION

Acute necrotising pancreatitis carries a substantial disease burden during long-term follow-up in terms of recurrent disease, the necessity for interventions and development of pancreatic insufficiency, even when treated conservatively during the index admission. Extensive (>50%) pancreatic parenchymal necrosis seems to be an important predictor of interventions and complications during follow-up.

Endoscopic Ultrasound-Guided Drainage of Pancreatic Fluid Collections: Not All Queries Are Already Solved

Pancreatic fluid collections (PFCs) are well-known complications of acute pancreatitis. The overinfection of these collections leads to a worsening of the prognosis with an increase in the morbidity and mortality rate. The primary strategy for managing infected pancreatic necrosis (IPN) or symptomatic PFCs is a minimally invasive step-up approach, with endosonography-guided (EUS-guided) transmural drainage and debridement as the preferred and less invasive method. Different stents are available to drain PFCs: self-expandable metal stents (SEMSs), double pigtail stents (DPPSs), or lumen-apposing metal stents (LAMSs). In particular, LAMSs are useful when direct endoscopic necrosectomy is needed, as they allow easy access to the necrotic cavity; however, the rate of adverse events is not negligible, and to date, the superiority over DPPSs is still debated. Moreover, the timing for necrosectomy, the drainage technique, and the concurrent medical management are still debated. In this review, we focus attention on indications, timing, techniques, complications, and particularly on aspects that remain under debate concerning the EUS-guided drainage of PFCs.

Magnetic resonance imaging for acute pancreatitis in type 2 diabetes patients

Type 2 diabetes mellitus (T2DM) and its complications have significantly increased the burden of mortality and disability globally, making diabetes one of the most dangerous and prevalent chronic diseases. Acute pancreatitis (AP) is one of the most frequent gastrointestinal causes for hospital admission, which is a common exocrine pancreatic inflammatory disease that can cause severe abdominal pain and multiple organ dysfunction. There is an inseparable relationship between AP and diabetes. Diabetes is a high risk factor of AP, and patients with AP can develop pancreatogenic diabetes. In T2DM patients, the incidence rate of AP is significantly higher than that of the general population, and the clinical symptoms are more severe, with the majority of cases being moderate to severe AP. This review briefly introduces the pathogenesis and clinical features of AP in T2DM patients, focusing on the magnetic resonance imaging (MRI) manifestations of AP in T2DM patients. Our aim is to evaluate the severity of AP in patients with T2DM by MRI, so as to help clinicians assess the patient's condition and prognosis.

Acute pancreatitis: A review of diagnosis, severity prediction and prognosis assessment from imaging technology, scoring system and artificial intelligence

Acute pancreatitis (AP) is a potentially life-threatening inflammatory disease of the pancreas, with clinical management determined by the severity of the disease. Diagnosis, severity prediction, and prognosis assessment of AP typically involve the use of imaging technologies, such as computed tomography, magnetic resonance imaging, and ultrasound, and scoring systems, including Ranson, Acute Physiology and Chronic Health Evaluation II, and Bedside Index for Severity in AP scores. Computed tomography is considered the gold standard imaging modality for AP due to its high sensitivity and specificity, while magnetic resonance imaging and ultrasound can provide additional information on biliary obstruction and vascular complications. Scoring systems utilize clinical and laboratory parameters to classify AP patients into mild, moderate, or severe categories, guiding treatment decisions, such as intensive care unit admission, early enteral feeding, and antibiotic use. Despite the central role of imaging technologies and scoring systems in AP management, these methods have limitations in terms of accuracy, reproducibility, practicality and economics. Recent advancements of artificial intelligence (AI) provide new opportunities to enhance their performance by analyzing vast amounts of clinical and imaging data. AI algorithms can analyze large amounts of clinical and imaging data, identify scoring system patterns, and predict the clinical course of disease. AI-based models have shown promising results in predicting the severity and mortality of AP, but further validation and standardization are required before widespread clinical application. In addition, understanding the correlation between these three technologies will aid in developing new methods that can accurately, sensitively, and specifically be used in the diagnosis, severity prediction, and prognosis assessment of AP through complementary advantages.

Modified Appleby procedure for locally advanced pancreatic carcinoma: A primer for the radiologist

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent pancreatic neoplasm accounting for more than 90% of pancreatic malignancies. Surgical resection with adequate lymphadenectomy remains the only available curative strategy for patients with PDAC. Despite improvements in both chemotherapy regimen and surgical care, body/neck PDAC still conveys a poor prognosis because of the vicinity of major vascular structures, including celiac trunk, which favors insidious disease spread at the time of diagnosis. Body/neck PDAC involving the celiac trunk is considered locally advanced PDAC in most guidelines and therefore not eligible for upfront resection. However, a more aggressive surgical approach (i.e., distal pancreatectomy with splenectomy and en-bloc celiac trunk resection [DP-CAR]) was recently proposed to offer hope for cure in selected patients with locally advanced body/neck PDAC responsive to induction therapy at the cost of higher morbidity. The so-called "modified Appleby procedure" is highly demanding and requires optimal preoperative staging as well as appropriate patient preparation for surgery (i.e., preoperative arterial embolization). Herein, we review current evidence regarding DP-CAR indications and outcomes as well as the critical role of diagnostic and interventional radiology in patient preparation before DP-CAR, and early identification and management of DP-CAR complications.

Transpapillary Stenting Improves Treatment Outcomes in Patients Undergoing Endoscopic Transmural Drainage of Ductal Disruption-Associated Pancreatic Fluid Collections

INTRODUCTION

Endoscopic transmural drainage (TMD) has been accepted as the preferred therapy for symptomatic pancreatic fluid collections (PFCs). Recurrence of PFCs presents a unique challenge in patients with disrupted pancreatic duct (PD). We aimed to evaluate whether transpapillary drainage (TPD) provides additional benefits to TMD in patients with PD disruption.

METHODS

This was a multicenter retrospective study. Consecutive patients who underwent TMD, TPD, or combined drainage (CD) of PFCs were included. The primary outcome was to compare PFC recurrence among different groups. The secondary outcomes were the technical success rate, length of hospital stay, and procedure-related complications.

RESULTS

A total of 153 patients, which consists of 57 patients with pancreatic pseudocysts and 96 patients with walled-off necrosis, were included. PFC recurrence was more common in patients with PD disruption than those with an intact main duct (19% vs 1.4%, P < 0.001). PD disruption was identified as a major risk factor of PFC recurrence by univariable and multivariable analyses. The recurrence rate of CD was significantly lower than TMD only or TPD only (6.5% vs 15.4% vs 22.7%, P < 0.01). The length of hospital stay of CD was significantly shorter than TMD only or TPD only (5 [3.0-9.0] vs 7.0 [5.0-12.0] vs 9 [7.0-16.0], P < 0.001). Dual-modality drainage did not increase procedure-related complications compared with TMD only (13.0% vs 12.8%, P > 0.05). Partial PD disruption was bridged in 87.3% cases while complete PD disruption was reconnected in 55.2% cases. Although statistically not significant, the clinical success rate in walled-off necrosis cases with actively bridged ducts was much higher than those with passively bridged ducts (76.9% vs 40%).

DISCUSSION

Transpapillary pancreatic duct stenting seems to improve the efficacy of endoscopic TMD of pancreatic duct disruption-associated PFCs by reducing the recurrence rate and shortening the length of hospital stay.

EUS-guided drainage of large walled-off pancreatic necroses using plastic versus lumen-apposing metal stents: a single-centre randomised controlled trial

OBJECTIVE

In treating pancreatic walled-off necrosis (WON), lumen-apposing metal stents (LAMS) have not proven superior to the traditional double pigtail technique (DPT). Among patients with large WON (>15 cm) and their associated substantial risk of treatment failure, the increased drainage capacity of a novel 20-mm LAMS might improve clinical outcomes. Hence, we conducted a study comparing the DPT and 20-mm LAMS in patients with large WON.

DESIGN

A single-centre, open-label, randomised, controlled superiority trial using an endoscopic step-up approach in patients with WON exceeding 15 cm in size. The primary endpoint was the number of necrosectomies needed to achieve clinical success (clinical and CT resolution), while the secondary endpoints included technical success, adverse events, length of stay and mortality.

RESULTS

Twenty-two patients were included in the DPT group and 20 in the LAMS group, with no significant differences in patient characteristics. The median size of WON was 24.1 cm (P25-P75: 19.6-31.1). The technical success rates were 100% for DPT and 95% for LAMS (p=0.48), while clinical success rates were 95.5% and 94.7%, respectively (p=1.0). The mean number of necrosectomies was 2.2 for DPT and 3.2 for LAMS (p=0.42). Five patients (12%) developed procedure-related serious adverse events (DPT=4, LAMS=1, p=0.35). The median length of stay was 43 (P25-P75: 40-67) and 58 days (P25-P75: 40-86) in the DPT and LAMS groups (p=0.71), respectively, with an overall mortality of 4.8%.

CONCLUSIONS

For treating large WON, LAMS are not superior to DPT. The techniques are associated with comparable needs for necrosectomy and hospital stay, and no gross difference in adverse events.

TRIAL REGISTRATION NUMBER

NCT04057846.

Short- and long-term outcomes of a disruption and disconnection of the pancreatic duct in necrotizing pancreatitis: a multicenter cohort study in 896 patients : Disrupted pancreatic duct in acute pancreatitis

OBJECTIVES

Necrotizing pancreatitis may result in a disrupted or disconnected pancreatic duct (DPD) with the potential for long lasting negative impact on a patient's clinical outcome. There is a lack of detailed data on the full clinical spectrum of DPD which is critical for the development of better diagnostic and treatment strategies.

METHODS

We performed a long-term post-hoc analysis of a prospectively collected nationwide cohort of 896 patients with necrotizing pancreatitis (2005-2015). The median follow-up after hospital admission was 75 months (P25-P75:41-151). Clinical outcomes of patients with and without DPD were compared using regression analyses, adjusted for potential confounders. Predictive features for DPD were explored.

RESULTS

DPD was confirmed in 243 (27%) of the 896 patients and resulted in worse clinical outcomes during both the patient's initial admission and follow-up. During hospital admission, DPD was associated with an increased rate of new-onset intensive care unit admission (adjusted-OR2.52 [95%-CI 1.62-3.93]), new-onset organ failure (adjusted-OR2.26 [95%-CI 1.45-3.55]), infected necrosis (adjusted-OR4.63 [95%-CI 2.87-7.64]) and pancreatic interventions (adjusted-OR7.55 [95%-CI 4.23-13.96]). During long-term follow-up, DPD increased the risk of pancreatic intervention (adjusted-OR9.71 [95%-CI 5.37-18.30], recurrent pancreatitis (adjusted-OR2.08 [95%-CI 1.32-3.29]), chronic pancreatitis (adjusted-OR2.73 [95%-CI 1.47-5.15]) and endocrine pancreatic insufficiency (adjusted-OR1.63 [95%-CI 1.05-2.53]).Central or subtotal pancreatic necrosis on computed tomography (CT), (OR9.49 [95%-CI 6.31-14.29] and a high levels of serum C-reactive protein (CRP) in the first 48 hours after admission (per 10 points increase, OR1.02 [95%-CI 1.00-1.03] were identified as independent predictors for developing DPD.

CONCLUSIONS

At least one of every four patients with necrotizing pancreatitis suffer from DPD which is associated with detrimental, short and long-term interventions and complications. Central and subtotal pancreatic necrosis and high levels of serum CRP in the first 48 hours are independent predictors for DPD.

The endoscopic ultrasound features of pancreatic fluid collections and their impact on therapeutic decisions: an interobserver agreement study

BACKGROUND

A validated classification of endoscopic ultrasound (EUS) morphological characteristics and consequent therapeutic intervention(s) in pancreatic and peripancreatic fluid collections (PFCs) is lacking. We performed an interobserver agreement study among expert endosonographers assessing EUS-related PFC features and the therapeutic approaches used.

METHODS

50 EUS videos of PFCs were independently reviewed by 12 experts and evaluated for PFC type, percentage solid component, presence of infection, recognition of and communication with the main pancreatic duct (MPD), stent choice for drainage, and direct endoscopic necrosectomy (DEN) performance and timing. The Gwet's AC1 coefficient was used to assess interobserver agreement.

RESULTS

A moderate agreement was found for lesion type (AC1, 0.59), presence of infection (AC1, 0.41), and need for DEN (AC1, 0.50), while fair or poor agreements were stated for percentage solid component (AC1, 0.15) and MPD recognition (AC1, 0.31). Substantial agreement was rated for ability to assess PFC-MPD communication (AC1, 0.69), decision between placing a plastic versus lumen-apposing metal stent (AC1, 0.62), and timing of DEN (AC1, 0.75).

CONCLUSIONS

Interobserver agreement between expert endosonographers regarding morphological features of PFCs appeared suboptimal, while decisions on therapeutic approaches seemed more homogeneous. Studies to achieve standardization of the diagnostic endosonographic criteria and therapeutic approaches to PFCs are warranted.

Managing severe acute and necrotizing pancreatitis

ABSTRACT

Acute pancreatitis is associated with significant morbidity and mortality, and is one of the most common gastrointestinal disorders requiring hospitalization. This article describes current concepts in the diagnosis and management of severe acute and necrotizing pancreatitis. Management of this disease requires IV fluids, pain control, and advanced medical and interventional care. Early identification and intervention may help to prevent patient morbidity and mortality.

Radiologic Predictors of Increased Number of Necrosectomies During Endoscopic Management of Walled-off Pancreatic Necrosis

GOALS

No established methods exist to predict who will require a higher number of endoscopic necrosectomy sessions for walled-off necrosis (WON). We aim to identify radiologic predictors for requiring a greater number of necrosectomy sessions. This may help to identify patients who benefit from aggressive endoscopic management.

MATERIALS AND METHODS

This is a multicenter retrospective study of patients with WON at 3 tertiary care centers. WON characteristics on preintervention computed tomography imaging were evaluated to determine if they were predictive of requiring more endoscopic necrosectomy.

RESULTS

A total of 104 patients were included. Seventy patients (67.3%) underwent endoscopic necrosectomy, with median of 2 necrosectomies. WON largest transverse diameters (P=0.02), largest coronal diameters (P=0.01), necrosis pattern [likelihood ratio (LR)=17.85, P<0.001], spread (LR=11.02, P=0.01), hemorrhage (LR=8.64, P=0.003), and presence of disconnected pancreatic duct (LR=6.80, P=0.01) were associated with undergoing ≥2 necrosectomies. Patients with septations/loculations were significantly less likely to undergo ≥2 necrosectomies (LR=4.86, P=0.03).

CONCLUSIONS

Several computed tomography radiologic features were significantly associated with undergoing ≥2 necrosectomies. These could help identify patients who will undergo a higher number of endoscopic necrosectomy sessions.

Endoscopic Management of Complications in Chronic Pancreatitis

PURPOSE OF REVIEW

Management of complications in patients with chronic pancreatitis is often suboptimal. This review discusses detailed endoscopic approaches for managing complications in CP.

LITERATURE FINDINGS

CP is characterized by progressive and irreversible destruction of pancreatic parenchyma and ductal system resulting in fibrosis, scarring, and loss of glandular function. Abdominal pain remains is the most common symptom of the disease and the main aim of medical, endoscopic, and surgical therapy is to help relieve symptoms, prevent disease progression, and manage complications related to CP. In fact, advances in our understanding of CP have improved medical care and quality of life in these patients. With significant sequela, morbidity and a progressive nature, a thorough understanding of the pathophysiology, natural course, diagnostic approaches, and optimal management strategies for this disease is warranted. The existing modalities and new innovations in this field are safe, effective, and likely to have a positive impact on management of complication in CP whenever used in the right context.

Radiological criteria for disconnected pancreatic duct syndrome: a targeted literature review

INTRODUCTION

In patients with acute necrotizing pancreatitis (ANP), parenchymal necrosis may involve the pancreatic duct, isolating a segment of the pancreas that remains functional but drains its secretions into the peripancreatic fluid collections, leading to disconnected pancreatic duct syndrome (DPDS). DPDS is an important complication of ANP associated with long-term morbidity and mortality. Unfortunately, this critical entity is under-recognized by radiologists. Endoscopic retrograde cholangiopancreatography (ERCP) is considered the gold standard for diagnosing and treating such patients. However, considering the invasiveness of the ERCP, a noninvasive diagnosis based on radiological tests is desirable. Radiological literature concerning the diagnosis of DPDS is scarce, and there is substantial ambiguity regarding the radiological definitions of DPDS.

AREAS COVERED

Considering the scarcity of published literature regarding the reliable radiologic diagnosis of DPDS, we performed a thorough review of the existing literature to identify definitions and features of this entity on computed tomography (CT) and magnetic resonance imaging (MRI).

EXPERT OPINION

Existing literature regarding radiologic diagnosis of DPDS was reviewed and analyzed and a comprehensive imaging definition of DPDS was proposed.

Endoscopic Retroperitoneal Necrosectomy for Infected Pancreatic Necrosis Using a Self-Expandable Metal Stent

Infected walled-off pancreatic necrosis (WOPN) is a severe complication of acute pancreatitis. Surgery in these critically ill patients can be associated with increased morbidity and mortality. Hence, minimally invasive therapies have emerged as an alternative to surgery. Herein, we report a case of severe acute pancreatitis with WOPN which was treated percutaneously with a flexible endoscope through an esophageal self-expanding metal stent using a total retroperitoneal approach. Percutaneous direct endoscopic necrosectomy (p-DEN) using the retroperitoneal route improved the patient's parameters dramatically with resolution of sepsis without the need for surgery. p-DEN using a flexible endoscope passed through a large bore metal stent shows promise in selected patients with WOPN and can be used in patients who are not ideal candidates for transmural or surgical drainage.

[Chronic pancreatitis: update diagnostic and therapeutic concepts]

INTRODUCTION

Chronic pancreatitis (CP) is a frequent cause for hospitalization and is associated with impaired quality of life and reduced overall survival. The German Society for Gastroenterology (DGVS) has recently completed the S3-Guideline "Pancreatitis" that summarizes key findings on epidemiology, diagnostic and therapeutic concepts for acute and chronic pancreatitis. Here, we recapitulate the most relevant findings for clinicians regarding CP.

RESULTS

The most common cause of CP is chronic alcohol abuse, other causes are hereditary pancreatitis, autoimmune pancreatitis, hyperparathyroidism and idiopathic forms. Apart from the classical hereditary pancreatitis (PRSS1 mutation), a number of genetic associations have been discovered over the last years that are associated with an increased risk to develop idiopathic CP. The conservative management of CP is focused on the appropriate management of exocrine and endocrine insufficiency, and the prevention and treatment of secondary complications such as osteoporosis, vitamin deficiencies and malnutrition. Local complications (bile duct stenosis, duodenal stenosis, pseudocysts and chronic pain) should be managed in multidisciplinary teams in specialized pancreas centres with expert surgeons, radiologists and gastroenterologists. Infected or symptomatic pseudocysts should be primarily addressed by endoscopic drainage. In contrast, patients with chronic pain, dilated pancreas duct and opioid use should be considered for early surgical intervention.

CONCLUSION

Chronic pancreatitis is associated with increased morbidity and mortality and often leads to hospital admissions. The clinical management of complex patients with local complications requires an interdisciplinary approach to tailor available therapeutic modalities depending on the stage of the disease and pre-existing comorbidities.

Multidisciplinary Management of Complicated Pancreatitis: What Every Interventional Radiologist Should Know

Management of acute pancreatitis is challenging in the presence of local complications that include pancreatic and peripancreatic collections and vascular complications. This review, targeted for interventional radiologists, describes minimally invasive endoscopic, image-guided percutaneous, and surgical procedures for management of complicated pancreatitis and provides insight into the procedures' algorithmic application. Local complications are optimally managed in a multidisciplinary team setting that includes advanced endoscopists; pancreatic surgeons; diagnostic and interventional radiologists; and specialists in infectious disease, nutrition, and critical care medicine. Large symptomatic or complicated sterile collections and secondary infected collections warrant drainage or débridement. The drainage is usually delayed for 4-6 weeks unless clinical deterioration warrants early intervention. If collections are accessible by endoscopy, endoscopic procedures are preferred to avoid pancreaticocutaneous fistulas. Image-guided percutaneous drainage is indicated for symptomatic collections that are not accessible for endoscopic drainage or that present in the acute setting before developing a mature wall. Peripancreatic arterial pseudoaneurysms should be embolized before necrosectomy procedures to prevent potentially life-threatening hemorrhage. Surgical procedures are reserved for symptomatic collections that persist despite endoscopic or interventional drainage attempts. Understanding these procedures facilitates their integration by interventional radiologists into the complex longitudinal care of patients with complicated pancreatitis.

Imaging of inflammatory disease of the pancreas

Increasingly acute and chronic pancreatitis (AP and CP) are considered a continuum of a single entity. Nonetheless, if, after flare-up, the pancreas shows no residual inflammation, it is classified as AP. CP is characterised by a long cycle of worsening and waning glandular inflammation without the pancreas ever returning to its baseline structure or function. According to the International Consensus Guidelines on Early Chronic Pancreatitis, pancreatic inflammation must last at least 6 months before it can be labelled CP. The distinction is important because, unlike AP, CP can destroy endocrine and exocrine pancreatic function, emphasising the importance of early diagnosis. As typical AP can be diagnosed by clinical symptoms plus laboratory tests, imaging is usually reserved for those with recurrent, complicated or CP. Imaging typically starts with ultrasound and more frequently with contrast-enhanced computed tomography (CECT). MRI and/or MR cholangiopancreatography can be used as a problem-solving tool to confirm indirect signs of pancreatic mass, differentiate between solid and cystic lesions, and to exclude pancreatic duct anomalies, as may occur with recurrent AP, or to visualise early signs of CP. MR cholangiopancreatography has replaced diagnostic endoscopic retrograde cholangiopancreatography (ERCP). However, ERCP, and/or endoscopic ultrasound (EUS) remain necessary for transpapillary biliary or pancreatic duct stenting and transgastric cystic fluid drainage or pancreatic tissue sampling, respectively. Finally, positron emission tomography-MRI or positron emission tomography-CT are usually reserved for complicated cases and/or to search for extra pancreatic systemic manifestations. In this article, we discuss a broad spectrum of inflammatory pancreatic disorders and the utility of various modalities in diagnosing acute and chronic pancreatitis.

Impact of disconnected pancreatic duct syndrome on endoscopic ultrasound-guided drainage of pancreatic fluid collections

BACKGROUND

Endoscopic intervention for pancreatic fluid collections (PFCs) with disconnected pancreatic duct syndrome (DPDS) has been associated with failures and increased need for additional endoscopic and non-endoscopic interventions. The primary aim of this study was to determine the outcomes of endoscopic ultrasound (EUS)-guided transmural drainage of PFCs in patients with DPDS.

METHODS

In patients undergoing EUS-guided drainage of PFCs from January 2013 to January 2018, demographic profiles, procedural indications and details, adverse events, outcomes, and subsequent interventions were retrospectively collected. Overall treatment success was determined by PFC resolution on follow-up imaging or stent removal without recurrence.

RESULTS

EUS-guided drainage of PFCs was performed in 141 patients. DPDS was present in 57 of them (40 %) and walled-off necrosis was the most frequent type of PFC (55 %). DPDS was not associated with lower clinical success, increased number of repeat interventions, or increased time to PFC resolution. Patients with DPDS were more likely to be treated with permanent transmural plastic double-pigtail stents (odds ratio [OR] 6.4; 95 % confidence interval [CI] 2.5 - 16.5; P < 0.001). However, when stents were removed, DPDS was associated with increased PFC recurrence after stent removal (OR 8.0; 95 %CI 1.2 - 381.8; P = 0.04).

CONCLUSIONS

DPDS frequently occurs in patients with PFCs but does not negatively impact successful resolution. DPDS is associated with increased PFC recurrence after stent removal.

Role of endoscopic ultrasonography in the management of peripancreatic collections. Diagnostic and therapeutic approach

Pancreatic fluid collections are surrounded by a wall of granulation tissue and may contain necrotic debris. They occur following a severe acute pancreatitis and most of the cases resolve spontaneously after several weeks. However, their management may lead to a very hardto-treat condition, requiring a multidisciplinary approach. During the last decades we assisted to a change of paradigm involving Endoscopic Ultrasonography, from a pure diagnostic technique to an interventional-therapeutic one, allowing an effective, safe and less invasive approach than other existing treatment standards, historically consisting of surgical and percutaneous drainage. Treatment of pancreatic fluid collections is indicated if they become infected or symptomatic. Over the past years, exponential developments were done in interventional endoscopic approach, making it the first line suggested modality. The use of endoscopic ultrasound allows assessment of the collection, even when it is not directly bulging on gastrointestinal wall, creation of an internal fistulous tract, checking for surrounding vessels with the use of Doppler, and deployment of a stent avoiding the discomfort of external tubes. Several types of stent have been used for endoscopic drainage: plastic double pigtail stents, fully covered self-expanding metal stents and, more recently, lumen apposing metal stents, which are considered revolutionary because of their two-side flanges and wide and short internal channel, a new design that made easier direct endoscopic necrosectomy. This review aims to go through currently available literature on the diagnostic and therapeutic role of Endoscopic Ultrasonography to handle pancreatic fluid collections.

Various Modalities Accurate in Diagnosing a Disrupted or Disconnected Pancreatic Duct in Acute Pancreatitis: A Systematic Review

BACKGROUND

Severe pancreatitis may result in a disrupted pancreatic duct, which is associated with a complicated clinical course. Diagnosis of a disrupted pancreatic duct is not standardized in clinical practice or international guidelines. We performed a systematic review of the literature on imaging modalities for diagnosing a disrupted pancreatic duct in patients with acute pancreatitis.

METHODS

A systematic search was performed in PubMed, Embase and Cochrane library databases to identify all studies evaluating diagnostic modalities for the diagnosis of a disrupted pancreatic duct in acute pancreatitis. All data regarding diagnostic accuracy were extracted.

RESULTS

We included 8 studies, evaluating five different diagnostic modalities in 142 patients with severe acute pancreatitis. Study quality was assessed, with proportionally divided high and low risk of bias and low applicability concerns in 75% of the studies. A sensitivity of 100% was reported for endoscopic ultrasound and endoscopic retrograde cholangiopancreatography. The sensitivity of magnetic resonance cholangiopancreatography with or without secretin was 83%. A sensitivity of 92% was demonstrated for a combined cohort of secretin-magnetic resonance cholangiopancreatography and magnetic resonance cholangiopancreatography. A sensitivity of 100% and specificity of 50% was found for amylase measurements in drain fluid compared with ERCP.

CONCLUSIONS

This review suggests that various diagnostic modalities are accurate in diagnosing a disrupted pancreatic duct in patients with acute pancreatitis. Amylase measurement in drain fluid should be standardized. Given the invasive nature of other modalities, secretin-magnetic resonance cholangiopancreatography or magnetic resonance cholangiopancreatography would be recommended as first diagnostic modality. Further prospective studies, however, are needed.

North American Society for Pediatric Gastroenterology, Hepatology and Nutrition and the Society for Pediatric Radiology Joint Position Paper on Noninvasive Imaging of Pediatric Pancreatitis: Literature Summary and Recommendations

ABSTRACT

The reported incidence of pediatric pancreatitis is increasing. Noninvasive imaging, including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), play important roles in the diagnosis, staging, follow-up, and management of pancreatitis in children. In this position paper, generated by members of the Pancreas Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) and the Abdominal Imaging Committee of The Society for Pediatric Radiology (SPR), we review the roles of noninvasive imaging in pediatric acute, acute recurrent, and chronic pancreatitis. We discuss available evidence related to noninvasive imaging, highlighting evidence specific to pediatric populations, and we make joint recommendations for use of noninvasive imaging. Further, we highlight the need for research to define the performance and role of noninvasive imaging in pediatric pancreatitis.

A narrative review of acute pancreatitis and its diagnosis, pathogenetic mechanism, and management

Acute pancreatitis (AP) is an inflammatory disease that can progress to severe acute pancreatitis (SAP), which increases the risk of death. AP is characterized by inappropriate activation of trypsinogen, infiltration of inflammatory cells, and destruction of secretory cells. Other contributing factors may include calcium (Ca²⁺) overload, mitochondrial dysfunction, impaired autophagy, and endoplasmic reticulum (ER) stress. In addition, exosomes are also associated with pathophysiological processes of many human diseases and may play a biological role in AP. However, the pathogenic mechanism has not been fully elucidated and needs to be further explored to inform treatment. Recently, the treatment guidelines have changed; minimally invasive therapy is advocated more as the core multidisciplinary participation and "step-up" approach. The surgical procedures have gradually changed from open surgery to minimally invasive surgery that primarily includes percutaneous catheter drainage (PCD), endoscopy, small incision surgery, and video-assisted surgery. The current guidelines for the management of AP have been updated and revised in many aspects. The type of fluid to be used, the timing, volume, and speed of administration for fluid resuscitation has been controversial. In addition, the timing and role of nutritional support and prophylactic antibiotic therapy, as well as the timing of the surgical or endoscopic intervention, and the management of complications still have many uncertainties that could negatively impact the prognosis and patients' quality of life. Consequently, to inform clinicians about optimal treatment, we aimed to review recent advances in the understanding of the pathogenesis of AP and its diagnosis and management.

Role of pancreatography in the endoscopic management of encapsulated pancreatic collections – review and new proposed classification

Pancreatic fluids collections are local complications related to acute or chronic pancreatitis and may require intervention when symptomatic and/or complicated. Within the last decade, endoscopic management of these collections via endoscopic ultrasound-guided transmural drainage has become the gold standard treatment for encapsulated pancreatic collections with high clinical success and lower morbidity compared to traditional surgery and percutaneous drainage. Proper understanding of anatomic landmarks, including assessment of the main pancreatic duct and any associated lesions – such as disruptions and strictures – are key to achieving clinical success, reducing the need for reintervention or recurrence, especially in cases with suspected disconnected pancreatic duct syndrome. Additionally, proper review of imaging and anatomic landmarks, including collection location, are pivotal to determine type and size of pancreatic stenting as well as approach using long-term transmural indwelling plastic stents. Pancreatography to adequately assess the main pancreatic duct may be performed by two methods: Either non-invasively using magnetic resonance cholangiopancreatography or endoscopically via retrograde cholangiopan-creatography. Despite the critical need to understand anatomy via pancrea-tography and assess the main pancreatic duct, a standardized approach or uniform assessment strategy has not been described in the literature. Therefore, the aim of this review was to clarify the role of pancreatography in the endoscopic management of encapsulated pancreatic collections and to propose a new classification system to aid in proper assessment and endoscopic treatment.

Management of pancreatic collections: an update

Pancreatic fluid collections frequently occur in the context of moderate and severe acute pancreatitis, and may also appear as a complication of chronic pancreatitis, pancreatic surgery or trauma. It is essential to adhere to the Atlanta classification nomenclature that subclassifies them into four categories (acute peripancreatic fluid collections, acute necrotic collections, pseudocysts, and walled-off necrosis) since it has an impact on prognosis and management. Pseudocysts and walled-off pancreatic necrosis are encapsulated pancreatic fluid collections characterized by a surrounding inflammatory wall, which typically develops three to four weeks after the onset of acute pancreatitis. Most pancreatic fluid collections resolve spontaneously and do not require intervention. However, when they become symptomatic or complicated drainage is indicated, and endoscopic ultrasound-guided drainage has become first-line treatment of encapsulated collections. Drainage of pseudocysts is relatively straightforward due to their liquid content. However, in walled-off necrosis the presence of solid necrotic debris can make treatment more challenging and therefore multidisciplinary management in experienced centers is recommended, being a step-up approach the current standard of care. In this review, we aim to address the management of pancreatic fluid collections with an especial focus on endoscopic drainage.

Endoscopic and surgical treatment options for chronic pancreatitis: an imaging perspective

Chronic pancreatitis is a chronic fibro-inflammatory syndrome characterized by chronic pancreatic inflammation leading to fibrosis and scarring. Patients with this multifactorial debilitating illness often require endoscopic or surgical intervention for treatment. Radiologists play a crucial role in pre-therapeutic workup as well as post-treatment imaging of chronic pancreatitis. This review summarizes the most common surgical and endoscopic treatment options that are currently available for chronic pancreatitis, including the implications on imaging.

Reporting of acute pancreatitis by radiologists-time for a systematic change with structured reporting template

Acute pancreatitis has a wide array of imaging presentations. Various classifications have been used in the past to standardize the terminology and reduce confusing and redundant terms. We aim to review the historical and current classifications of acute pancreatitis and propose a new reporting template which can improve communication between various medical teams by use of appropriate terminology and structured radiology template. The standardized reporting template not only conveys the most important imaging findings in a simplified yet comprehensive way but also allows structured data collection for future research and teaching purposes.

Value of multidisciplinary collaboration in acute and chronic pancreatitis

Multidisciplinary collaboration (MDC) has been widely adopted in healthcare to optimize patient care. MDC brings several specialized healthcare providers to the table using several methods, including multidisciplinary meetings (MDMs), multidisciplinary clinics, teleconferences, and online multidisciplinary expert panels, to reach the goal of achieving the best diagnosis and treatment plan for complex diseases. Diagnosis and management of acute/chronic pancreatitis is complex which necessitates the development and utilization of MDC. The key members of pancreatitis MDM include gastroenterologists, radiologists, pathologists, hepatobiliary surgeons, chairperson, and a coordinator. After selection of admitted or referred patients, the availability of required information is reviewed, and then each case is discussed. The final diagnosis and treatment plan is confirmed by consensus, especially for complex cases that require endoscopic intervention or pancreatectomy and patients with the possibility of pancreatic adenocarcinoma. It has been shown that MDMs have improved the clinical outcome of patients with acute/chronic pancreatitis. In addition to MDM, the feasibility of multidisciplinary clinics, teleconferences, and online multidisciplinary expert panels for the management of pancreatic disorders has been investigated. Understanding structure, potential advantages, and limitations of MDC will help clinicians and healthcare systems in developing an optimized MDC to improve the management of acute/chronic pancreatitis. This narrative review summarized prior recommendations and explored the impact of MDC on clinical outcomes of patients with pancreatitis. Our recommendations offer a generalizable method that can be utilized by healthcare systems.

Acute pancreatitis: an update on the revised Atlanta classification

Acute pancreatitis (AP) is the most common gastrointestinal disease resulting in hospitalization in the United States with reports of over 270,000 hospitalizations and costs up to 2.6 billion dollars per year. AP is highly variable in disease course and outcome. Established in 1992, the original Atlanta classification system aimed to categorize the wide spectrum of AP by creating consensus-based terminology for AP types, severity, and complications. Though the original system standardized terminology, certain terms and definitions (i.e. pancreatic abscess) were unclear and often misused. The 2012 revised Atlanta classification (RAC) system updated terms, clarified definitions, and incorporated the medical community's improved understanding of the physiology of AP. The resulting RAC effectively defined the morphologic types of pancreatitis, provided a more standardized system for disease severity grading, further classified the local retroperitoneal complications, and established objective measures to describe this highly variable but common disease. This review provides an update on the recent literature evaluating the RAC, discusses both the strengths and shortcomings of the RAC system (including problematic interobserver agreement), and considers improvements for future classification systems.

Treatment of disrupted and disconnected pancreatic duct in necrotizing pancreatitis: A systematic review and meta-analysis

BACKGROUND

Necrotizing pancreatitis may lead to loss of integrity of the pancreatic duct, resulting in leakage of pancreatic fluid. Pancreatic duct disruption or disconnection is associated with a prolonged disease course and particular complications. Since a standard treatment for this condition is currently lacking, we performed a systematic review of the literature to compare outcomes of various treatment strategies.

METHODS

A systematic review was performed according to the PRISMA guidelines in the PubMed, EMBASE and Cochrane databases. Included were articles considering the treatment of patients with disrupted or disconnected pancreatic duct resulting from acute necrotizing pancreatitis.

RESULTS

Overall, 21 observational cohort studies were included comprising a total of 583 relevant patients. The most frequently used treatment strategies included endoscopic transpapillary drainage, endoscopic transluminal drainage, surgical drainage or resection, or combined procedures. Pooled analysis showed success rates of 81% (95%-CI: 60-92%) for transpapillary and 92% (95%-CI: 77-98%) for transluminal drainage, 80% (95%-CI: 67-89%) for distal pancreatectomy and 84% (95%-CI: 73-91%) for cyst-jejunostomy. Success rates did not differ between surgical procedures (cyst-jejunostomy and distal pancreatectomy (risk ratio = 1.06, p = .26)) but distal pancreatectomy was associated with a higher incidence of endocrine pancreatic insufficiency (risk ratio = 3.06, p = .01). The success rate of conservative treatment is unknown.

DISCUSSION

Different treatment strategies for pancreatic duct disruption and duct disconnection after necrotizing pancreatitis show high success rates but various sources of bias in the available studies are likely. High-quality prospective, studies, including unselected patients, are needed to establish the most effective treatment in specific subgroups of patients, including timing of treatment and long-term follow-up.

Endoscopic Management of Giant Walled-Off Pancreatic Necrosis With a High Risk of Bleeding

Walled-off pancreatic necrosis (WOPN) is one of the late complications of acute pancreatitis. We present a 37-year-old man who developed a large WOPN 6 weeks after treatment of severe complicated pancreatitis. Imaging studies revealed a necrotic retroperitoneal fluid collection measuring 27 × 12 × 27 cm with large crossing blood vessels. Cystogastrostomy was performed using a lumen-apposing metal stent. He underwent multiple necrosectomies with significant improvement in the cyst size. Bleeding is a major complication of direct endoscopic necrosectomy; hence, specific imaging and a careful approach should be taken into consideration, especially in WOPN with a high risk of bleeding.

Complications of endoscopic retrograde cholangiopancreatography: an imaging review

Endoscopic retrograde cholangiopancreatography (ERCP) has currently become an inseparable tool in the gastroenterologist's armamentarium for treatment of pancreaticobiliary disorders. Given the increase in number of therapeutic ERCP procedures today, the need for prompt and correct diagnosis of its complications is pivotal. This review discusses the mechanisms, risk factors, imaging findings and general management aspects of common and rare complications of ERCP. Furthermore, the review elaborates on imaging indications, recommended protocol and normal imaging findings post ERCP.

MR imaging for acute pancreatitis: the current status of clinical applications

Acute pancreatitis is a common clinical acute abdomen. Imaging examinations play an important role in the management of acute pancreatitis. MR imaging is a noninvasive examination with high tissue contrast and a variety of acquisition sequences that can help determine the diagnosis, complications and severity of acute pancreatitis. The acute pancreatitis classification working group modified the Atlanta classification in 2012 to improve clinical evaluations and standardize the radiologic nomenclature for acute pancreatitis. In particular, the redefinition of necrotizing pancreatitis offers a new understanding of this disease. In clinical practice, there is still a lack of unifying standards between radiologists and physicians, such as for the imaging features of pseudocysts, walled-off necrosis, peripancreatic necrosis and especially for the MR imaging features of acute pancreatitis. In this article, we review the 2012 revised Atlanta classification of acute pancreatitis and recent advances in the clinical applications of MR imaging (MRI) in acute pancreatitis by showing how MRI can provide more optimized information for clinical diagnosis and treatment plan.

Current Concepts in Severe Acute and Necrotizing Pancreatitis: An Evidence-Based Approach

The incidence of acute pancreatitis continues to rise, inducing substantial medical and social burden, with annual costs exceeding $2 billion in the United States alone. Although most patients develop mild pancreatitis, 20% develop severe and/or necrotizing pancreatitis, requiring advanced medical and interventional care. Morbidity resulting from local and systemic complications as well as invasive interventions result in mortality rates historically as high as 30%. There has been substantial evolution of strategies for interventions in recent years, from open surgery to minimally invasive surgical and endoscopic step-up approaches. In contrast to the advances in invasive procedures for complications, early management still lacks curative options and consists of adequate fluid resuscitation, analgesics, and monitoring. Many challenges remain, including comprehensive management of the entire spectrum of the disease, which requires close involvement of multiple disciplines at specialized centers.

Jejunal response to secretin is independent of the pancreatic response in secretin-enhanced magnetic resonance cholangiopancreatography

PURPOSE

To investigate whether jejunal secretions are independent of the pancreatic response to secretin in secretin-enhanced Magnetic Resonance Cholangiopancreatography (s-MRCP) examination of subjects with and without chronic pancreatitis (CP).

METHODS

Patients were identified through a search of s-MRCP examinations performed between 2014-2016 (n = 513) as well as the multidisciplinary pancreatitis clinic registry (n = 586). Fifty cases with CP (based on M-ANNHEIM criteria) and 50 matched controls were selected. Signal intensity changes after secretin administration (˜1-5 min' post-secretin response) in three locations were assessed: second portion of the duodenum (D2), third/fourth portions of the duodenum (D3-4), and the jejunum. The post-secretin response was compared between (cases vs. controls) and within the study groups.

RESULTS

There was a significantly lower 1-5 min' post-secretin response among CP patients in D2 (all p-values <0.01). However, no significant difference in 1-5 min' post-secretin response was detected in the jejunum. Minute-by-minute analysis of the post-secretin response showed a significant increase up to the 5th minute only in D2 of the control group. The post-secretin response in the jejunum was significant after 1 min but was similar among patients with CP and controls. CP was a significant determinant of post-secretin response in D2 but not in the jejunum.

CONCLUSIONS

Early post-secretin response at jejunum is independent of the pancreatic response that can be detected at D2, and should not be misinterpreted as a rapid pancreatic response. Therefore, pancreatic function on s-MRCP should be assessed by the presence of fluid in D2 and not jejunum.

Endotherapy for pancreatic necrosis: An update

Approximately 20% of patients with acute pancreatitis develop pancreatic necrosis. The presence of necrosis in a pancreatic collection significantly worsens the prognosis. Pancreatic necrosis is associated with high mortality and morbidity. In the last few decades, there has been a significant revolution in the treatment of infected pancreatic necrosis. A step‐up approach has been proposed, from less invasive procedures to the operative intervention. Minimally invasive treatment modalities such as endoscopic drainage and necrosectomy, percutaneous drainage, and minimally invasive surgery have recently replaced open surgical necrosectomy as the first‐line treatment option. Endoscopic intervention for pancreatic necrosis is being increasingly performed with good success and a lower complication rate. However, techniques of endotherapy are still not uniform and vary as per local expertise, and there are still many unresolved questions with regard to the interventions in patients with pancreatic necrosis. The objective of this paper is to critically review the literature and update the concepts of endoscopic interventional therapy of pancreatic necrosis.

Radiological assessment of local resectability status in patients with pancreatic cancer: Interreader agreement and reader performance in two different classification systems

OBJECTIVES

To assess the interreader agreement and reader performance in the evaluation of patients with pancreatic cancer (PC) in two classification systems of local resectability status prior to initiation of therapy, namely the National Comprehensive Cancer Network (NCCN) and Karolinska classification system (KCS).

METHODS

In this ethics review board-approved retrospective study, six radiologists independently evaluated pancreatic CT-examinations of 30 patients randomly selected from a tertiary referral centre's multidisciplinary tumour board database. Based on well-defined criteria of tumour-vessel relationship, each patient was assigned to one of three NCCN and six KCS categories. We assessed the intraclass correlation coefficient (ICC) and compared the percentages of correct tumour classification of the six readers in both systems (Chi-square test; a P-value <0.05 was considered significant). The standard of reference was a consensus evaluation of CT-examinations by three readers not involved in the image analysis.

RESULTS

The ICC for NCCN and KCS was 0.82 and 0.84, respectively (very strong agreement). The percentages of correct tumour classification at NCCN and KCS were 53-83% and 30-57%, respectively, with no statistically significant differences in the overall reader comparison per classification system. In pair-wise comparison between readers for NCCN/KCS, there were statistically significant differences between reader 5 vs. readers 4 (P = 0.012) and 3 (P = 0.045)/ reader 5 vs. reader 4 (P = 0.037).

CONCLUSION

Interreader agreement in both PC classification systems is very strong. NCCN may be advantageous in terms of reader performance compared to KCS.

Review of management options for pancreatic pseudocysts

Pancreatic pseudocysts (PPs) present a challenging problem for physicians dealing with pancreatic disorders. Their management demands the co-operation of surgeons, radiologists and gastroenterologists. Historically, they have been treated either conservatively or surgically, with acceptable rates of complications and recurrence. However, recent advances in radiology and endoscopy, have leaded physicians to implement percutaneous and endoscopic drainage (ED) into their treatment algorithms. Moreover, laparoscopic surgery, with its advantages, has become an attractive alternative choice when surgical drainage (SD) is required. The aim of this review is to summarize the main diagnostic and therapeutic tools in the management of pseudocysts and to present the main studies that compare the three different types of pseudocyst drainage.

Imaging of post-operative pancreas and complications after pancreatic adenocarcinoma resection

Pancreatic ductal adenocarcinoma is one of the leading causes of cancer-related deaths. With surgical resection being the only definitive treatment, improvements in technique has led to an increase in number of candidates undergoing resection by inclusion of borderline resectable disease patients to the clearly resectable group. Post-operative complications associated with pancreaticoduodenectomy and distal pancreatectomy include delayed gastric emptying, anastomotic failures, fistula formation, strictures, abscess, infarction, etc. The utility of dual-phase CT with multiplanar reconstruction and 3D rendering is increasingly recognized as a tool for the assessment of complications associated with vascular resection and reconstruction such as hemorrhage, pseudoaneurysm, vascular thrombosis, and ischemia. Prompt recognition of the complications and distinction from benign post-operative findings such as hepatic steatosis and mesenteric fat necrosis on imaging plays a key role in helping decrease the morbidity and mortality associated with surgery. We discuss, with case examples, some of such common and uncommon findings on imaging to familiarize the abdominal radiologists evaluating post-operative imaging in both acute and chronic post-operative settings.

Revised Atlanta Classification for Acute Pancreatitis: A Pictorial Essay

The 2012 revised Atlanta classification is an update of the original 1992 Atlanta classification, a standardized clinical and radiologic nomenclature for acute pancreatitis and associated complications based on research advances made over the past 2 decades. Acute pancreatitis is now divided into two distinct subtypes, necrotizing pancreatitis and interstitial edematous pancreatitis (IEP), based on the presence or absence of necrosis, respectively. The revised classification system also updates confusing and sometimes inaccurate terminology that was previously used to describe pancreatic and peripancreatic collections. As such, use of the terms acute pseudocyst and pancreatic abscess is now discouraged. Instead, four distinct collection subtypes are identified on the basis of the presence of pancreatic necrosis and time elapsed since the onset of pancreatitis. Acute peripancreatic fluid collections (APFCs) and pseudocysts occur in IEP and contain fluid only. Acute necrotic collections (ANCs) and walled-off necrosis (WON) occur only in patients with necrotizing pancreatitis and contain variable amounts of fluid and necrotic debris. APFCs and ANCs occur within 4 weeks of disease onset. After this time, APFCs or ANCs may either resolve or persist, developing a mature wall to become a pseudocyst or a WON, respectively. Any collection subtype may become infected and manifest as internal gas, though this occurs most commonly in necrotic collections. In this review, the authors present a practical image-rich guide to the revised Atlanta classification system, with the goal of fostering implementation of the revised system into radiology practice, thereby facilitating accurate communication among clinicians and reinforcing the radiologist's role as a key member of a multidisciplinary team in treating patients with acute pancreatitis. (©)RSNA, 2016.

Endoscopic Management of Pancreatic Fluid Collections

Pancreatic fluid collections (PFCs) may develop due to inflammation secondary to acute and/or chronic pancreatitis, trauma, surgery, or obstruction from solid or cystic neoplasms. PFCs can be drained percutaneously, surgically, or endoscopically with endoscopic ultrasound-guided cyst gastrostomy and/or transpapillary drainage through endoscopic retrograde cholangiopancreatography. There has been a paradigm shift in the endoscopic management of PFCs in the past few years with newer techniques including utilization of self-expanding metal stents and multiport devices. This review is a comprehensive update on the classification of PFC, indications for drainage, optimal approach, and techniques.