Pancreatic fistula is a highly morbid complication of pancreatitis. External pancreatic fistulas result when pancreatic secretions leak externally into the percutaneous drains or external wound (following surgery) due to the communication of the peripancreatic collection with the main pancreatic duct (MPD). Internal pancreatic fistulas include communication of the pancreatic duct (directly or via intervening collection) with the pleura, pericardium, mediastinum, peritoneal cavity, or gastrointestinal tract. Cross-sectional imaging plays an essential role in the management of pancreatic fistulas. With the help of multiplanar imaging, fistulous tracts can be delineated clearly. Thin computed tomography sections and magnetic resonance cholangiopancreatography images may demonstrate the communication between MPD and pancreatic fluid collections or body cavities. Endoscopic retrograde cholangiography (ERCP) is diagnostic as well as therapeutic. In this review, we discuss the imaging diagnosis and management of various types of pancreatic fistulas with the aim to sensitize radiologists to timely diagnosis of this critical complication of pancreatitis.

Acute pancreatitis (AP) is an inflammatory disease of the pancreas, which can progress to severe AP, with a high risk of death. It is one of the most complicated and clinically challenging of all disorders affecting the abdomen. The main causes of AP are gallstone migration and alcohol abuse. Other causes are uncommon, controversial and insufficiently explained. The disease is primarily characterized by inappropriate activation of trypsinogen, infiltration of inflammatory cells, and destruction of secretory cells. According to the revised Atlanta classification, severity of the disease is categorized into three levels: Mild, moderately severe and severe, depending upon organ failure and local as well as systemic complications. Various methods have been used for predicting the severity of AP and its outcome, such as clinical evaluation, imaging evaluation and testing of various biochemical markers. However, AP is a very complex disease and despite the fact that there are of several clinical, biochemical and imaging criteria for assessment of severity of AP, it is not an easy task to predict its subsequent course. Therefore, there are existing controversies regarding diagnostic and therapeutic modalities, their effectiveness and complications in the treatment of AP. The main reason being the fact, that the pathophysiologic mechanisms of AP have not been fully elucidated and need to be studied further. In this editorial article, we discuss the efficacy of the existing diagnostic and therapeutic modalities, complications and treatment failure in the management of AP.

This is to incorporate the recent trends in chronic pancreatitis. Extensive literature search was done from Pubmed and Ovid SP. Full text articles and abstracts related to chronic pancreatitis were reviewed and the article was prepared. Chronic pancreatitis is evolving fast on its etiology and treatment areas. The main etiological factors are pointing towards genetic, alcohol, and smoking. Autoimmune has also been added as a cause. Endoscopic ultra sound (EUS) becoming the standard diagnostic procedure. Surgery is becoming the treatment of choice for pain and mechanical complications and not the endotherapy in the long-term follow-up. The numbers of surgeries are getting narrowed down. The two etiological groups of chronic pancreatitis namely alcohol + smoking and genetic getting clearer, where the later group present at an early age. Endoscopic ultrasound and imaging with secretin is diagnostic of chronic pancreatitis before the structural changes. Endotherapy is found to be inferior to surgery in long-term pain relief. Diagnostic criteria for autoimmune pancreatitis are established. Pancreaticogenic diabetes (Type3c) and its problem associated with fat malabsorption are being understood.

Severe acute pancreatitis (SAP), which is the most serious type of this disorder, is associated with high morbidity and mortality. SAP runs a biphasic course. During the first 1-2 wk, a pro-inflammatory response results in systemic inflammatory response syndrome (SIRS). If the SIRS is severe, it can lead to early multisystem organ failure (MOF). After the first 1-2 wk, a transition from a pro-inflammatory response to an anti-inflammatory response occurs; during this transition, the patient is at risk for intestinal flora translocation and the development of secondary infection of the necrotic tissue, which can result in sepsis and late MOF. Many recommendations have been made regarding SAP management and its complications. However, despite the reduction in overall mortality in the last decade, SAP is still associated with high mortality. In the majority of cases, sterile necrosis should be managed conservatively, whereas in infected necrotizing pancreatitis, the infected non-vital solid tissue should be removed to control the sepsis. Intervention should be delayed for as long as possible to allow better demarcation and liquefaction of the necrosis. Currently, the step-up approach (delay, drain, and debride) may be considered as the reference standard intervention for this disorder.

To report an uncommon method of managing pancreatic fistulas and retroperitoneal abscess.

A 50-year-old man was admitted with fever, abdominal pain, periumbilical fistula and pus in stool. Five months before admission, he underwent urgent necrosectomy (7 days after onset of pain) and subsequently two more surgeries for necrotizing pancreatitis. Ultrasound revealed fluid collection in the retropancreatic space. After evacuation of pus, contrast medium instilled through a catheter showed a retroperitoneal abscess cavity, retroperitoneal-periumbilical and retroperitoneal-sigmoidal fistulas. After percutaneous drainage and iodine irrigation, the abscess collection and fistulas disappeared.

In this case, percutaneous drainage was a successful option in the management of pancreatic fistulas and a retroperitoneal abscess.

Most gastrointestinal fistulae commonly occur following surgery. A minority is caused by a myriad of other etiologies and is termed by some as "uncommon fistulae". The aim of this study was to review these fistulae and their treatment.

A literature review was carried out. Searches were conducted in Pubmed and related references reviewed.

Except for Crohn's disease and diverticulitis, "uncommon fistulae" are described in case reports or very small case series. Most of the patients were treated by surgery.

The anatomic features of the fistula and the etiology usually dictate the approach. Most patients will eventually need surgery to resolve this pathology.