key: cord-015957-vimq6qs7 authors: Casillas, Javier; Sleeman, Danny; Ahualli, Jorge; Ruiz-Cordero, Roberto; Echenique, Ana title: Acute Pancreatitis (AP) date: 2015-03-31 journal: Multidisciplinary Teaching Atlas of the Pancreas DOI: 10.1007/978-3-662-46745-9_14 sha: doc_id: 15957 cord_uid: vimq6qs7 All of these conditions can be associated with acute pancreatitis, except ? Acute pancreatitis defi nition: • Acute infl ammatory process of the pancreas with a wide range of manifestations and clinical variation, ranging from local infl ammation to systemic manifestations such as organ failure. • The frequency of acute pancreatitis varies among different countries. • In the USA, the frequency of pancreatitis is higher in patients older than 65 years. • The rate of pancreatitis in black Americans is 3 times higher than in white Americans. • The frequency of pancreatitis is approximately equal in men and women. Acute pancreatitis is classifi ed into two types. • Acute edematous interstitial pancreatitis Total score : points are given on a scale from 0 to 10 to determine the grade of pancreatitis and treatment 0-2 mild, 4-6 moderate, 8-10 severe • Computed tomography (CT) and magnetic resonance imaging (MRI) are the preferred imaging modalities. • Contrast-enhanced CT (CECT) is currently the gold standard for evaluating patients with suspected acute pancreatitis. • The role of this modality is to confirm or exclude the clinical diagnosis, to establish the cause, to determinate the severity, to detect complications of the acute pancreatitis, and to provide guidance for therapy. • Very useful to predict clinical outcome. • MR imaging is particularly useful in pregnant patients and in patients who cannot receive iodinated contrast material due to allergic reactions or renal insuffi ciency. • Abdominal ultrasound is an inexpensive, convenient imaging modality helpful to evaluate the presence of gallbladder and/or common duct stones in acute pancreatitis. • Many scoring systems have been reported, but none has proven to be perfect. • They are superior to clinical judgment for triaging patients to more intensive and aggressive therapy. • Acute interstitial pancreatitis (AIP) (Figs. 14.20 -14.29 ) -Homogeneous or heterogeneous pancreatic parenchymal enhancement (diffuse or focal due to interstitial parenchymal edema) -Normal or mild to severe peripancreatic and retroperitoneal infl ammatory changes (fatty stranding) depending on the severity of the acute pancreatitis -Varying amounts of peripancreatic fl uid -Thickening of the retroperitoneal fascia • Interstitial pancreatitis (Figs. 14.50 -14.52 ) -Diffuse or focal enlargement of the pancreas. -Pancreatic boundaries are blurred. -Normal or hypointense signal intensity of the pancreas relative to the liver on T1-weighted images and hyperintense on T2-weighted images. -Threadlike, interlobular, hyperintense structures (interlobular septal infl ammation). -Peripancreatic and/or pancreatic edema or fl uid collections. • Pancreatic necrosis (Figs. 14.53 -14.54 ) -Focal pancreatic necrosis is characterized by spotted, patchy, non-enhancing pancreatic parenchyma on contrast-enhanced MR images. -Diffuse pancreatic necrosis is characterized by non-enhancing pancreatic parenchyma on dynamic contrast-enhanced MRI. • Infected pancreatic necrosis Findings -Focal or diffuse, non-enhancing segments in the pancreatic parenchyma of low signal intensity associated with signal void areas (pockets of air in the pancreatic parenchyma) • Patients with organ failure at admission have a higher mortality. • The highest mortality is among those patients with multisystem organ failure and sustained organ failure for >48 hours. • Patients with signs of organ failure require admission in an intensive care unit or stepdown unit. • Organ failure (acute pancreatitis) -Approximately 10 % of patients. Mostly transient with very low mortality. -Median prevalence of organ failure in necrotizing pancreatitis is 54 % (more common in infected necrosis). • Vital signs, oxygen saturation, and fl uid balance should be carefully monitored. -Aggressive IV fl uid replacement is the cornerstone of therapy. -250 -500 ml/h × 24-48 hours, with frequent reevaluations during that time. • Patients should have the head of the bed elevated. • Lactate Ringer's solution reduces the incidence of SIRS compared to saline solution. • Nutritional support -In mild pancreatitis , oral intake is restored within 3-7 days, when patient is hungry and does not have nausea or vomiting and pain is controlled without medications -Low-fat diet is recommended to start. -In severe pancreatitis , nutritional support should be initiated when it becomes clear that the patient will not be able to consume nourishment by mouth for several weeks. -Enteral feeding is preferable to total parenteral nutrition (stabilizes gut barrier function, is safer and less expensive than TPN). ○ Nasogastric (NG), nasoduodenal (ND), or nasojejunal (NJ) tube feedings are equivalent. ○ Unless patient is retching and vomiting in which case NJ is more reasonable. • Organ dysfunction (management) -Pressor agents for sustained hypotension -Intubation and assisted ventilation for respiratory failure -Renal dialysis for intractable renal failure • Respiratory failure is the most common form of organ dysfunction. • There is evidence that early aggressive fl uid resuscitation prevents or minimizes pancreatic necrosis and improves survival. • Lactate Ringer's solution is associated with positive effects on acid-base homeostasis. • Enteral feeding is associated with a reduction in mortality, systemic infection, and multiorgan dysfunction. • Most patients with infected necrosis have systemic toxicity, fever, and leukocytosis. -CT-guided percutaneous aspiration with gram stain and culture is indicated when infected necrosis is suspected. -If gram-negative organisms are isolated, the antibiotics recommended are: ○ Carbapenem, a fl uoroquinolone plus metronidazole, or a third-generation cephalosporin plus metronidazole pending results of culture sensitivity. • Percutaneous external lavage of infected necrosis has signifi cantly lower morbidity and mortality than surgical necrosectomy. • Best suited for the stable patient. • Its success depends on the close interdisciplinary approach between the surgeon and the interventional radiologist. • Retained common bile duct stone could lead to organ failure. -Absence of fl ow in the vein(s) involved -Partial or complete venous intraluminal fi lling defect in vein(s) involved (partial thrombosis) -Lack of identifi cation of the splenic vein associated with multiple local venous collaterals is diagnostic of splenic vein thrombosis. -Conservative -The use of anticoagulants is controversial. mild peripancreatic infl ammatory changes in the rest of the pancreas. Note the prominence of the short gastric veins, multiple venous collateral in the territory of the left gastric vein ( arrowheads ), and the lack of identifi cation of the splenic vein 14.14.7 Pseudoaneurysms (Figs. 14.70 -14.71 ) • Rare complication of acute pancreatitis • More common in chronic pancreatitis. • Most frequently associated with pseudocysts. • Rupture of pseudoaneurysm is rare; however, the mortality rate is high when it occurs. • Autodigestion of the arterial walls by the pancreatic enzymes • Direct damage from severe infl ammation • Vascular wall erosion from pancreatic enzymes within the pseudocyst or direct vascular compression or ischemia • In those rare patients where it is diffi cult to catheterize the artery involved, the alternative is to access the artery percutaneously for treatment with vascular coils or direct thrombin injection. or Bowel Obstruction • Rare complication of acute pancreatitis • Secondary to the compression of the stomach, small bowel, or colon by a pancreatic fl uid collection Acute pancreatitis: assessment of severity with clinical and CT evaluation Classifi cation of acute pancreatitis-2012: revision of the Atlanta classifi cation and defi nitions by international consensus MR imaging of the pancreas: a pictorial tour Imaging of acute pancreatitis and its complications A modifi ed CT severity index for evaluating acute pancreatitis: Improved correlation with patient outcome Predicting the severity of acute pancreatitis Disconnection of the pancreatic duct: An important but overlooked complication of severe acute pancreatitis Percutaneous lavage as primary treatment for infected pancreatic necrosis The revised atlanta classifi cation of acute pancreatitis: its importance for the radiologist and its effect on treatment Tailored helical CT evaluation of acute abdomen Clinical management of patients with acute pancreatitis • Dilatation of the biliary system secondary to a compression of the common bile duct by pancreatic collection or by a pseudocyst • Percutaneous or endoscopic decompression of the pancreatic fl uid collection or pseudocyst. Patient went to an outside facility with increased abdominal pain and was found to have evidence of hemorrhage into the pseudocyst. Patient was referred to the interventional radiology service for diagnostic visceral angiogram and possible embolization of splenic artery. Axial image ( a ) from CECT initially done at outside institution reveals a small area of low attenuation in the tail of the pancreas ( arrow ) associated with mild peripancreatic infl ammatory changes. In the follow-up CECT ( bc ) performed 4 weeks later, axial images reveal a large collection with high density in the tail of the pancreas extending into the lesser sac ( arrows ). Finding suggestive of acute hemorrhage into the known pancreatic pseudocyst. A selective angiogram of the splenic artery performed the same day ( d ) shows a small pseudoaneurysm of the splenic artery in the body of the pancreas ( arrow ). This pseudoaneurysm was successfully treated with multiple endovascular coils ( e ) ( arrow )