An overview of walled-off pancreatic necrosis for clinicians.

INTRODUCTION: Walled of pancreatic necrosis (WOPN) is a new term coined for encapsulated fluid collection developing after acute necrotising pancreatitis (ANP). It is a heterogeneous collection containing varying amount of liquid as well as solid necrotic material. The literature on its natural history as well as appropriate management is gradually expanding thereby improving treatment outcomes of this enigmatic disease. Areas covered: This review discusses currently available literature on etiology, frequency, natural history, and imaging features WOPN. Also, updated treatment options including endoscopic, radiological and surgical drainage are discussed. Expert opinion: WOPN is alocal complication of ANP occurring in the delayed phase of ANP and may be asymptomatic (50%) or present with pain, fever, jaundice, or gastric outlet obstruction. Natural courses of asymptomatic WOPN have been infrequently studied, and it appears that the majority remain asymptomatic and resolve spontaneously. Magnetic resonance imaging and endoscopic ultrasound are the best imaging modalities to evaluate solid necrotic debris. Symptomatic WOPN usually needs immediate drainage, this can be done endoscopically, radiologically, or surgically. Current evidence suggests that endoscopic transluminal drainage is the preferred drainage technique as it is effective and associated with lower mortality, risk of organ failure, adverse effects, and length of hospital stay.