Cholecystitis: Causes, Symptoms, and Treatments

Overview

Cholecystitis is an inflammatory condition of the gallbladder, often resulting from a secondary bacterial infection following bile duct obstruction. This obstruction can lead to infection within the bile, causing inflammation in the gallbladder.

Medical Specialty

Related Departments: Gastroenterology, Surgery
Primary Organ Affected: Gallbladder

Definition

Acute cholecystitis typically arises when gallstones, surgical scarring, or tumors cause partial or complete blockage of the bile ducts. This blockage allows bacteria to proliferate within the bile, leading to inflammation of the gallbladder. If gallstones continue to irritate the gallbladder wall, chronic cholecystitis can develop. While acute cholecystitis may eventually lead to chronic conditions, many patients with chronic cholecystitis have no history of acute episodes, often experiencing nonspecific or no symptoms.

Causes

Around 90% of cholecystitis cases are caused by gallstones, with other factors including trauma, congenital abnormalities, diabetes, or parasitic infections. When a gallstone blocks the bile duct entrance, it can initiate inflammation of the gallbladder wall and lead to bile stasis, followed by a secondary bacterial infection. The most common bacteria involved are Escherichia coli (E. coli), along with Staphylococcus, Streptococcus, and Klebsiella.

In approximately 5-10% of acute cholecystitis cases, no gallstones are found during surgery, with about half of these instances lacking a clear cause. Diagnosing and managing such cases can be more complex compared to typical gallstone-related cholecystitis.

Symptoms

About 75% of patients with acute cholecystitis have a history of biliary colic—a type of intense pain caused by gallbladder contractions against a blockage. The condition often begins with this type of pain, which intensifies over time, concentrating in the upper right abdomen. Patients may also experience nausea, vomiting, mild fever, and occasionally, high fever with chills.

Approximately 25% of cases involve an enlarged gallbladder that can be felt during a physical examination. A key sign of acute cholecystitis is Murphy's sign, where pressing the upper right abdomen below the ribcage causes sharp pain when the patient takes a deep breath. This pain can cause the patient to stop inhaling abruptly. Symptoms of chronic cholecystitis range from no symptoms to nonspecific discomfort, biliary colic, or even sudden complications.

Diagnosis and Testing

A diagnosis of acute cholecystitis is typically based on its characteristic symptoms, including upper right abdominal tenderness, fever, and an increased white blood cell count. Confirmation is achieved through blood tests, ultrasound, or CT scans.

Blood tests often reveal leukocytosis (elevated white blood cells), with about 50% of cases showing hyperbilirubinemia (bilirubin levels below 5 mg/dL). Additionally, about 25% of patients show a 2-5 fold increase in aminotransferase levels, along with a slight rise in amylase. If severe hyperbilirubinemia or high amylase levels are present, other conditions like choledocholithiasis (bile duct stones) or gallstone pancreatitis may be suspected.

Treatment

The primary approach to managing acute cholecystitis includes fasting, antibiotics, and fluid replacement. However, the most definitive treatment is cholecystectomy (surgical removal of the gallbladder). If the patient's condition is too unstable for immediate surgery due to severe inflammation, procedures like percutaneous gallbladder drainage or endoscopic ultrasound-guided drainage may be performed as interim measures.

Prognosis and Complications

About 75% of patients respond to non-surgical treatment, but complications can occur in others. Even among those who initially improve, about 25% will experience a recurrence of acute cholecystitis within a year. For this reason, early surgical intervention is often recommended.

Potential complications of acute and chronic cholecystitis include emphysematous cholecystitis (where gas-forming bacteria infect the gallbladder), gallbladder abscess (bacterial buildup within the gallbladder), hydrops (accumulation of clear fluid and mucus in the gallbladder), perforation, fistula formation, gallstone ileus, porcelain gallbladder (calcification of the gallbladder wall), and Mirizzi syndrome (compression of the common bile duct by a gallstone lodged in the gallbladder neck or duct).