Clinical Pancreatology for Practising Gastroenterologists and Surgeons

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30 30 Hollemans RA, Bakker OJ, Boermeester MA, et al. Superiority of step‐up approach vs open necrosectomy in long‐term follow‐up of patients with necrotizing pancreatitis. Gastroenterology 2019; 156(4):1016–1026.

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Muhammad F. Dawwas1 and Kofi W. Oppong2

1 Jewish Hospital and St. Mary’s HealthCare, Louisville, KY, USA

2 Freeman Hospital, and Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK

The development of pancreatic fluid collections may complicate all forms of pancreatic disease, including acute pancreatitis, chronic pancreatitis, pancreatic duct injury by abdominal surgery or blunt trauma, and even pancreatic malignancy. The Revised Atlanta Classification ( Table 17.1) has categorized pancreatic fluid collections into four subgroups according to the length of time since onset of pancreatic injury, presence of a mature encapsulating wall, and magnitude of solid necrotic component [1]. Pancreatic pseudocysts are walled‐off fluid collections with no or minimal solid component usually developing in the setting of chronic pancreatitis, or at least four weeks after the onset of acute pancreatitis or other pancreatic duct injury. Pathologically, pancreatic pseudocysts are surrounded by a wall of fibrous or inflammatory tissue and lack an epithelial lining. The contents are dependent on communication or otherwise with the pancreatic duct. If there is communication, the cyst will contain pancreatic juice rich in amylase, lipase, and zymogens. If there is no communication, the fluid is serous and protease‐free. Pancreatic pseudocysts are more common in chronic pancreatitis than acute pancreatitis, complicating 20–40% of cases of chronic pancreatitis compared with 5–16% of episodes of acute pancreatitis. This chapter focuses on the management of pancreatic pseudocysts; the management of other types of pancreatic fluid collections is discussed in Chapter 16.

Critical appraisal of the patient’s history, physical examination findings, laboratory profile, and imaging abnormalities is a fundamental prerequisite for appropriate management of pancreatic pseudocysts and exclusion of their mimics. A multidisciplinary approach, enlisting the expertise of interventional endoscopists, interventional radiologists, and pancreatico‐biliary surgeons in the evaluation of this complex patient population is highly desirable. Because an interventional approach to management is not risk‐free and a significant proportion of pseudocysts can regress or even resolve spontaneously, only patients with sizeable (>6 cm diameter) pseudocysts causing significant symptoms or complications, such as intractable abdominal pain, nausea, vomiting, malnutrition, other evidence of gastric outlet obstruction, sepsis, gastrointestinal bleeding, biliary obstruction, compression of major peripancreatic vasculature and/or features of abdominal compartment syndrome, require drainage therapy [2–7] ( Figure 17.1). In contrast, it is reasonable to withhold or delay intervention in the setting of asymptomatic or minimally symptomatic pancreatic pseudocysts, following them up with serial cross‐sectional imaging instead as there is no immediate clinical benefit to be gained by the patient and the risk of intervention may outweigh the risk of developing a complication due to the pseudocyst. Patient comorbidity is particularly relevant in this context. In cases of diagnostic uncertainty as to whether a small pseudocyst is symptomatic, it is possible to simply needle‐aspirate the pseudocyst to dryness under endoscopic ultrasound (EUS) guidance and evaluate the subsequent clinical course. In general, the larger the pseudocyst, the greater the incidence of compressive symptoms, and the lower the probability of not only spontaneous resolution but, in our experience, also that of intervention‐related complications. Conversely, transluminal stent‐assisted drainage of collections smaller than 6 cm in diameter potentially increases the procedural risk of perforation and pseudocyst wall dehiscence and is therefore discouraged. Spontaneous resolution is more common in pseudocysts secondary to acute pancreatitis. Factors associated with a reduced likelihood of spontaneous resolution include communication with the main pancreatic duct, presence of multiple cysts, increase in size during follow‐up, and presence of a pancreatic duct stricture. Additionally, pseudocysts occurring in the setting of chronic pancreatitis with imaging evidence of calcification are unlikely to spontaneously resolve.

Table 17.1 Revised definitions of morphological features of acute pancreatitis.

Figure 17.1 CT scan of 12‐cm collection causing a degree of gastric outflow obstruction, associated portal vein occlusion, and varices in stomach wall.