Anatomical variations of the pancreas are relatively frequent and often understudied. The ductal system of the pancreas has multiple variations, which are not frequently reported in the literature.

The anatomy of the pancreas was studied through macroscopic anatomical dissection on 50 organ complexes (the pancreas, spleen, and duodenum) donated to the department of human anatomy, from patients, who died of causes not related to pancreatic diseases.

In type I, the main pancreatic duct (Wirsung's duct, MPD) and the accessory pancreatic duct (Santorini's duct, APD) were merged but most of the head was drained by the MPD (10% of cases). In type II, the MPD and APD were merged but most of the head was drained by the APD (4% of cases). In type III, the APD was absent and the head was drained by the MPD (14% of cases). In type IV, there was an inverted pancreas divisum where the ducts did not merge but each drained a part of the head (6% of cases). Classical pancreas divisum where the ducts did not merge but each drained a part of the head was considered as type V (4% of cases). In type VI, the MPD and APD merged and each drained a part of the head (48% of cases). In type VII, the MPD and APD merged but the upper part of the head was drained by the main pancreatic duct (4% of cases). In type VIII, the MPD and APD merged but the lower part of the head was drained by the main pancreatic duct (4% of cases). In the IX type, the MPD and APD merged but the head was drained by the branches of the MPD (6% of cases).

There are several drainage patterns of the pancreas. In some cases, one of the ducts provides more drainage of the gland than the other. This is clinically relevant since blockage of the main source of drainage leads to pancreatic juice stasis. It also explains cases when partial or total blockage of the duct results in the pancreatitis of an isolated zone.

Disconnected duct syndrome (DDS) is an adverse sequela of acute necrotizing pancreatitis in which there is disruption of the pancreatic duct leading to a failure to deliver pancreatic secretions into the duodenum. Its presentation may range from a persistent external pancreatic fistula to a treatment-resistant pancreatic pseudocyst. The diagnosis is often delayed in the acute setting if there is concurrent necrosis as management is often directed to the associated peripancreatic fluid collection. A combination of imaging modalities may be required to evaluate ductal anatomy. No definitive consensus has been achieved regarding the optimal treatment strategy for DDS, and there is a lack of published level I evidence on the topic. Treatment should be tailored to each individual patient, depending on the anatomy of ductal disruption, the presence of sepsis, the degree of physiological derangement, and the patients' performance status. Patients with DDS represent a specific cohort of patients with complex pancreatic disease that requires the input from a diverse multidisciplinary team to ensure that a good clinical outcome can be achieved.

To evaluate the efficacy of endoscopic retrograde stenting of the pancreatic duct for acute severe pancreatitis.

We analyzed 94 patients with acute severe pancreatitis who underwent surgery (n=87, 92.6%) and endoscopic retrograde pancreatic stenting (n=28, 29.8%). The first group included 15 patients (16%) after pancreatic duct stenting in aseptic phase of acute pancreatitis. The second group enrolled 13 patients (13.8%) who underwent pancreatic duct stenting in the phase of sequestration and infection. The third group consisted of 66 patients (70.2%) after open surgery without pancreatic duct stenting.

In the 1^st group, we recanalized the necrosis zone up to distal pancreas via stenting. Infection was detected in 14 out of 15 patients. Surgical treatment was performed in 13 patients (13.8%). In the second group, pancreatic duct stenting was carried out in the phase of infected pancreatitis. We applied stenting to block the area of duct destruction or restore outflow in case of distal defect. No infection was observed in 1 out of 13 patients. Pancreatic duct stenting was not performed in 66 patients of the third group. Surgical treatment was performed in 59 patients (62.8%). In general, 11 of 94 patients (11.7%) were free from infection.

Better postoperative outcomes were observed in patients with damage to pancreatic duct, pancreatic drainage through percutaneous drains installed at the first stage of treatment. Early pancreatic duct stenting did not lead to significant improvement in treatment outcomes.

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.

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).

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

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.

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.

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.

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.

Acute kidney injury (AKI) is a common complication of acute pancreatitis (AP) that is associated with increased mortality. Conventional assessment of AKI is based on changes in serum creatinine concentration and urinary output. However, these examinations have limited accuracy and sensitivity for the diagnosis of early-stage AKI. This review summarizes current evidence on the use of advanced imaging approaches and artificial intelligence (AI) for the early prediction and diagnosis of AKI in patients with AP. CT scores, CT post-processing technology, Doppler ultrasound, and AI technology provide increasingly valuable information for the diagnosis of AP-induced AKI. Magnetic resonance imaging (MRI) also has potential for the evaluation of AP-induced AKI. For the accurate diagnosis of early-stage AP-induced AKI, more studies are needed that use these new techniques and that use AI in combination with advanced imaging technologies.

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.

To study the predictive value of semi-quantitative pleural effusion and pulmonary consolidation for acute pancreatitis (AP) severity.

Thorax-abdominal computed tomography (CT) examinations were performed on 309 consecutive AP patients in a single center. Among them, 196 were male, and 113 were female, and the average age was 50±16 years. The etiology of AP was biliary in 43.7% (n=135), hyperlipidemia in 22.0% (n=68), alcoholic in 7.4% (n=23), trauma in 0.6% (n=2), and postoperative status in 1.6% (n=5) cases; 24.6% (n=76) of patients did not have specified etiologies. The prevalence of pleural effusion and pulmonary consolidation was noted. The pleural effusion volume was quantitatively derived from a CT volume evaluation software tool. The pulmonary consolidation score was based on the number of lobes involved in AP. Each patient's CT severity index (CTSI), acute physiology and chronic health evaluation II (APACHE II) scoring system, and bedside index for severity in acute pancreatitis (BISAP) scores were obtained. The semi-quantitative pleural effusion and pulmonary consolidation were compared to these scores and clinical outcomes by receiver operator characteristic (ROC) curve and area under the curve (AUC) analysis.

In the 309 patients, 39.8% had pleural effusion, and 47.9% had pulmonary consolidation. The mean pleural effusion volume was 41.7±38.0 mL. The mean pulmonary consolidation score was 1.0±1.2 points. The mean CTSI was 3.7±1.8 points, the mean APACHE II score was 5.8±5.1 points, and the mean BISAP score was 1.3±1.0 points; 5.5% of patients developed severe AP, and 13.9% of patients developed organ failure. Pleural effusion volume and pulmonary consolidation scores correlated to the scores for the severity of AP. In predicting severe AP, the accuracy (AUC 0.839) of pleural effusion volume was similar to that of the CTSI score (P=0.961), APACHE II score (P=0.757), and BISAP score (P=0.906). The accuracy (AUC 0.805) of the pulmonary consolidation score was also similar to that of the CTSI score (P=0.503), APACHE II score (P=0.343), and BISAP score (P=0.669). In predicting organ failure, the accuracy (AUC 0.783) of pleural effusion volume was similar to that of the CTSI score (P=0.473), APACHE II score (P=0.119), and BISAP score (P=0.980), and the accuracy (AUC 0.808) of the pulmonary consolidation score was also similar to that of the CTSI score (P=0.236), APACHE II score (P=0.293), and BISAP score (P=0.612).

Pleural effusion and pulmonary consolidation are common in AP and correlated to the severity of AP. Furthermore, the pleural effusion volume and pulmonary consolidation lobes can provide early prediction of severe AP and organ failure.

Acute pancreatitis is classically characterized by acute chemical inflammation of the pancreatic gland itself, peripancreatic tissues, and even remote organs. The newly revised Atlanta Classification 2012 redefined the patterns of pancreatic necrosis and local complications in acute pancreatitis. The Atlanta Classification's novelty was in emphasizing that extrapancreatic fat necrosis, which leads to walled-off necrosis, is associated with poor prognosis. Conversely, the free fluid liquid was considered to be less related to complications. The Atlanta's classification's main weakness is that it is mainly computed tomography (CT) based, as contrast-enhanced CT is the predominant imaging technique used for evaluating a wide range of pathological processes of acute pancreatitis. However, some local complications are difficult to distinguish accurately on CT. Recent advances, including significantly better soft-tissue contrast, favor multiparametric magnetic resonance imaging (mpMRI) for a more comprehensive assessment of acute pancreatitis pathology, particularly for small necrotic/fat debris within a collection. In addition, the MRI severity index (MRSI), which combines Balthazar's grade points and points of the extent of pancreatic necrosis, has been proven to be crucial for the initial evaluation, staging, and prognosis of acute pancreatitis. Other innovations, such as the recognition of important MRI features in acute pancreatitis and the utilization of newer, more effective terminology for imaging reporting assistance in the differentiation of the common local complications following this disease, have improved the treatment for acute pancreatitis. In this paper, with reference to the 2012 revised Atlanta classification, we review the strengths and limitations of MRI for identifying acute pancreatitis, the MRI findings of a spectrum of pathological entities, and the important local complications secondary to acute pancreatitis.

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.

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.

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.

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 transmural drainage is performed for symptomatic peripancreatic fluid collections (PPFCs). Long-term transmural double-pigtail stent (DPS) placement is useful in preventing recurrences. There are few reports on the long-term safety of DPS placement. Thus, this study aimed to examine the complications of long-term indwelling DPS for PPFCs.

Among 53 patients who underwent endoscopic ultrasound-guided transmural drainage for symptomatic PPFCs between April 2006 and March 2017, those followed up for over one year were included. Complications of long-term indwelling DPS were examined retrospectively.

This study enrolled 36 patients [30 men, median age 54 years (range 22-82)]. Walled-off necrosis was present in 22 cases (including 9 disconnected pancreatic duct syndrome cases) and pancreatic pseudocysts, in 14 cases. The median stenting period was 20.9 (range 0.8-142.3) months, and median observation period was 56.2 (range 12.4-147.1) months. Colon perforation due to DPS occurred in 3 cases (8.3%), at 5.8, 17.1, and 33.7 months after indwelling DPS placement; 2 cases developed perforation from the serosal side. In 1 case, the patient was treated surgically, and in 2 cases, the patients underwent endoscopic removal of the stent and showed improvement with conservative treatment.

Long-term indwelling transmural DPS for symptomatic PPFCs poses a risk of intestinal perforation. Thus, if possible, it may be better to avoid long-term placement.

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.

To study the MRI findings of the normal transverse mesocolon and the involvement of the mesocolon in acute pancreatitis (AP) as well as the relationship between the involvement of the mesocolon and the severity of AP.

Forty patients without pancreatic disorders were retrospectively analyzed to observe the normal transverse mesocolon using MRI; 210 patients with AP confirmed by clinical and laboratory tests were retrospectively analyzed using MRI to observe transverse-mesocolon involvement (TMI). The severity of TMI was recorded as zero points (no abnormalities and transverse-mesocolon vessel involvement), one point (linear and patchy signal in the transverse mesocolon) or two points (transverse-mesocolon effusion). The AP severity was graded by the MRI severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation II (APACHE II) scoring system. The correlations of TMI with MRSI and APACHE-II were analyzed.

In a normal transverse mesocolon, the display rates of the middle colic artery, the middle colic vein and the gastrocolic trunk on MRI were 95.0%, 82.5% and 100.0%, respectively. Of the 210 patients with AP, 130 patients (61.9%) had TMI. According to the TMI grading, 40%, 39% and 20% of the patients were graded at zero, one and two points, respectively. TMI was strongly correlated with the MRSI score (r = 0.759, P = 0.000) and the APACHE-II score (r = 0.384, P = 0.000).

MRI could be used to visualize transverse-mesocolon involvement. The severity of TMI could reflect that of AP in the clinical setting and imaging. TMI might be a supplementary indicator of the severity of AP.