Acute pancreatitis (AP) is an inflammatory condition with a mild course in most patients, but 20-30% evolve to single or multiple organ dysfunction and pancreatic/peripancreatic necrosis, with potentially infected collections. In the first weeks of disease, a systemic inflammatory syndrome (SIRS) dominates the clinical setting, and early management decisions in this precocious phase can change the course of the disease. Imaging is crucial in the diagnosis, and since the adoption of the revised Atlanta classification, four different types of pancreatic/peripancreatic collections have been defined. The management of the complicated forms of AP has been defined by several treatment guidelines, and the main indication for intervention is local infection, preferably in walled-off necrosis. Open surgery necrosectomy is associated with a very high rate of morbimortality, giving a place to different multidisciplinary methodologies, emphasizing drainage and necrosectomy techniques in a "step-up" approach starting from mini-invasive endoscopic drainage and moving, if needed, to progressively more invasive techniques, including interventional radiology and mini-invasive surgery. With the advent of several new technologies in the specialties involved, the complicated AP cases which need drainage and necrosectomy benefit from a new era of multidisciplinary cooperation, permitting higher efficacy with lower levels of morbimortality and reducing hospital stay and costs.
Keywords: acute pancreatitis; drainage; haemorrhage; infection; necrosectomy.