Sandbox:pancreatic abscess

Overview

Pancreatic abscess is an unusual and rare, but life threatening complication of acute pancreatitis. It develop 5 weeks after the onset of pancreatitis and after onset of symptoms and subsidence of the acute phase of pancreatitis.

Causes

Common Causes

Common organisms causing pancreatic abscess are as follows:

Aerobic bacteria

• Enterococcus
• Escherichia coli
• Klebsiella pneumoniae
• Pseudomonas aeruginosa
• Staphylococcus aureus

Anaerobic bacteria

• Bacteriodes fragilis
• Clostridium perfringens

Differentiating Pancreatic Abscess from other Diseases

Pancreatic abscess should be diagnosed early and treat promptly not only to reduce morbidity and mortality, but also it is important to differentiate from other pancreatic disesases such recurrent pancreatitis, pancreatic psuedocysts etc. as the undrained abscess carreies high risk of mortality.

• Recurrent pancreatitis

Pancreatic necrosis CT findings: Well marginated zones of non-enhanced pancreatic parenchyma Pancreatic abscess CT findings: Absent or limited necrosis Infected pseudocyst

Characteristics	Pancreatic abscess		Infected pancreatic pseudocyst			Infected necrotic pancreas				Recurrent pancreatitis
Definition	Pancreatic abscess is defined as a localized collection of pus surrounded by a more or less distinct capsula in inflamed pancreas.		Necrotic pancreas defined as a diffuse bacterial inflammation of necrotic pancreatic and peripancreatic tissue, but without any significant pus collections
Presentation	Present after onset of symptoms and after subsidence of the acute phase of pancreatitls		clinically evident during the early phase of acute pancreatitis with signs of sepsis
Prognosis			Mortality is high compared to pancreatic abscess

Epidemiology and Demographics

Incidence

Incidence of pancreatic abscess is unknown, but McClave et al reported it as 2-5% among patients hospitalized for pancreatitis.

Case Fatality Rate

Mortality rate of pancreatic abscess is varies depending upon the severity of pancreatitis with range of 10-59%.

Risk Factors

• History of alcoholic pancreatitis who fails to respond to medical therapy

Natural History, Complications and Prognosis

Complications

• Intra abdominal sepsis

Gastric complications

• GI bleeding
• Gastric outlet obstruction

Colon complications Other complications

• Pancreatic fistula
• Pancreaticocolocutaneous fistula
• Wound infection
• Recurrent abdominal pain
• Duodenal fistula

Diagnosis

History and Symptoms

Common Symptoms

Presenting symptoms of pancreatic abscess are vague and variable, but common symptoms include:

• Abdominal pain
• Back pain
• Nausea and vomiting
• Weight loss

Less common symptoms

• Melena
• Diarrhoea

Vital signs

• High grade fever (greater than 37.8°C)
• Upper abdominal pain
• Failure to thrive

Physical Examination Findings

• Abdominal tenderness
• Abdominal mass
• Abdominal distention

Lab Findings

• Leukocytosis (range between 10,500 to 35,00O/mm³)

Imaging

Imaging studies are crucial in the diagnosis and treatment of pancreatic abscess.

X-ray

• Shows extraluminal (pancreas or lesser sac) gas bubbles suggesting abscess

Ultrasound

• Shows fluid filled sac suggesting abscess

Treatment

Endoscopic Drainage

Indications

• Patients who are unfit for surgical drainage.

Advantages

• Less invasive
• Potentially safe