6

Pancreas

Acute Pancreatitis

Overview

The two most common causes are gallstones and alcohol

Other etiologies include iatrogenic (endoscopic retrograde cholangiopancreatography [ERCP]), drugs, trauma, neoplasm, hypercalcemia, hypertriglyceridemia, infections, idiopathic

Signs and Symptoms

Epigastric pain radiating to the back accompanied with nausea and vomiting

May develop classic signs of Grey Turner’s sign (flank ecchymosis) or Cullen’s sign (periumbilical ecchymosis); suggests hemorrhagic pancreatitis

Pancreatitis may lead to acute respiratory distress syndrome (ARDS) or systemic inflammatory response (SIRS) with resultant hypotension, tachycardia, tachypnea, etc.

Diagnosis

Elevated amylase and lipase—no correlation between the serum level and the prognosis or the severity of the disease process

Ranson’s criteria:

• Upon admission:

Age >55 years

White blood cell count >16,000 cells/mm³

Glucose >200 mg/dL

Serum lactate dehydrogenase >350 IU/L

Aspartate aminotransferase >250 IU/L

• At 48 hours:

Hematocrit decrease >10%

Blood urea nitrogen elevation >5 mg/dL

Calcium <8 mg/dL

Arterial PO₂ <60 mmHg

Base deficit >4 mEq/L

Estimated fluid sequestration >6 L

• Number of Ranson’s signs: Risk of mortality

0–2: 0%

3–4: 15%

5–6: 50%

>6: 70%–90%

Complications

Pancreatic pseudocyst

Necrotizing pancreatitis

Infected pancreatic necrosis

Visceral pseudoaneurysm

Treatment

Supportive measures: IV fluid resuscitation, bowel rest to limit pancreatic enzyme secretions, TPN or postpyloric nasojejunal feeding, pain control, alcohol withdrawal prophylaxis, antibiotics for infected or necrotizing pancreatitis

If pancreatitis is caused by gallstones, then patient should undergo a semielective cholecystectomy with intraoperative cholangiogram during the same hospitalization

Surgical treatment is usually reserved for patients with infected or necrotizing pancreatitis who are not improving despite maximal medical management

• Involves necrosectomy, drain placement, and possible serial abdominal washouts

RADIOLOGY

Pancreatitis with Surrounding Fluid

Plain film findings

• Duodenal ileus may be seen

• Sentinel dilated loop of transverse colon can be seen with acute pancreatitis

• Effacement of the psoas fat plane

• Chronic pancreatitis may show pancreatic calcifications

US findings

• Chronic pancreatitis shows main pancreatic duct dilatation beyond the normal 3 mm

• Acute pancreatitis will manifest as a diffuse or focal hypoechogenicity of the pancreas with or without surrounding peripancreatic fluid

CT findings (Fig. 6.1)

• Diffuse or focal pancreatic edema with peripancreatic fat stranding

• May be associated with surrounding fluid collections

• Areas of non-enhancement of the pancreas would be concerning for necrotizing pancreatitis

• Areas of high attenuation fluid within the pancreas would be concerning for hemorrhagic pancreatitis

• May see associated complications including pseudocyst, splenic vein thrombosis, or splenic artery pseudoaneurysm

MRCP findings

• Chronic pancreatitis is characterized by dilatation or multifocal stenosis of main pancreatic duct sometimes with narrowing of the intrapancreatic segment of the common bile duct

• Acute pancreatitis may manifest as a diffuse or focal T2 hyperintense signal within and/or surrounding the pancreas

FIGURE 6.1

A. Liver

B. Kidney

C. Vertebra

D. Descending aorta

E. Spleen