Cholecystitis
Cholecystitis describes the inflammation of the gallbladder. It is primarily caused by cystic duct obstruction, due to gallstones. However, it can also result from other factors such as gallbladder tumors, bile duct strictures, or infections without gallstones (acalculous cholecystitis).
Aetiology
Acute Cholecystitis:
Gallstones play a predominant role, accounting for approximately 90-95 % of acute cholecystitis cases. Cholesterol stones, being the predominant type of stones found in the gall bladder, are commonly associated with hypercholesterolemia, while bilirubin stones are more prevalent in conditions where haemolysis takes place such as: sickle cell disease, liver cirrhosis etc. However, the presence of gallstones, known as cholelithiasis, does not necessarily lead to cholecystitis manifestation. For cholecystitis to occur, it is crucial that gallstones occlude the cystic duct, resulting in gallbladder emptying dysfunction, which consequently can lead to inflammation due to increased intraluminal pressure and related ischemia. Another mechanism which leads to cholecystitis involves bacterial infection. In fact, in 50 to 85% of cases, bacteria such as Escherichia coli, Klebsiella, Streptococci, and Clostridia can be identified in the patient’s bile. In approximately 5 to 10% of acute cholecystitis cases, gallstones are not involved, in these cases the condition is termed as acalculous cholecystitis.
Causes of acalculous cholecystitis are:
Prolonged fasting, leading to bile stasis
Prolonged total parenteral nutrition, causing bile stasis
Trauma, burns, or major surgeries in the gallbladder region
Sepsis or infections, especially in immunosuppressed individuals
Tumors obstructing gallbladder emptying, like adenocarcinoma of the bile ducts or tumors of adjacent organs
Chronic Cholecystitis:
Chronic cholecystitis typically stems from recurrent acute episodes, primarily caused by gallstones. Persistent inflammation can lead to distinctive changes in the gallbladder wall, which can be seen in sonography. While other causes, such as gallbladder motility disorders, can also contribute to chronic cholecystitis, they are less common than gallstones.
Risk Factors
The 5 Fs describe the risk factors for gallstones, the most common cause for cholecystitis:
Female Gender
Forty: higher prevalence in individuals older than 40
Fertile: associated with pregnancy and hormonal changes, including oral contraception
Fat (Obesity)
Fair: linked to ethnicity, particularly fair or lighter skin
An additional 6th F is Family history.
Signs and symptoms
Signs and symptoms of acute and chronic cholecystitis can vary. Here are the typical features associated with each:
Acute Cholecystitis
Acute cholecystitis manifests with a sudden onset of symptoms, characterized by upper right quadrant abdominal pain and tenderness, potentially radiating to the back or right shoulder. Fever, nausea, and vomiting are also common symptoms.
A typical sign for acute cholecystitis is Murphy's Sign, which involves palpating the right subcostal area while instructing the patient to inspire. The presence of sharp pain or discomfort during this manoeuvre suggests cholecystitis. Although typically more prominent in acute cholecystitis, Murphy's Sign can also be positive in chronic cholecystitis.
Chronic Cholecystitis
Chronic cholecystitis can remain asymptomatic for extended periods or present with intermittent abdominal pain and tenderness, but typically these symptoms are less pronounced compared to acute cases. Some individuals may report discomfort or bloating, particularly following fat-rich meals, along with increased flatulence or belching. Eventually, an acute-on-chronic presentation can occur, which is marked by an exacerbation of symptoms.
Complications
Gallbladder perforation
Covered Perforation: Typically covered by the omentum majus can lead to localized abscess formation, peritonitis, and fistula development due to the containment of bile and inflammatory material within a localized area.
Free Perforation: In contrast, free gallbladder perforation results in diffuse peritonitis, a more severe and rapidly progressing condition, due to the widespread release of bile and infectious material into the abdominal cavity.
Empyema
Empyema typically arises from acute cholecystitis with prolonged cystic duct obstruction, leading to bacterial superinfection. It presents similarly to acute cholecystitis but with more severe symptoms. Empyema requires emergency surgical intervention, accompanied by antibiotic therapy and adequate hydration, due to the high risk of sepsis.
Hydrops
Similar to empyema, hydrops also results from prolonged cystic duct obstruction, leading to gallbladder enlargement. Unlike empyema, hydrops is often asymptomatic due to the absence of bacterial superinfection, though a palpable bulge in the right upper quadrant may be present. Despite the lack of infection, hydrops carries a higher risk of perforation or necrosis.
Fistula Formation and Gallstone Ileus
Inflammation or adhesions can lead to fistula formation into adjacent organs, occurring in less than 1% of gallstone patients. Fistulas most commonly develop in the duodenum, facilitating the entry of bacteria from the intestine into the gallbladder, which can result in recurrent cholangitis. Another possible complication of fistulas is gallstone ileus, a rare type of mechanical ileus. A diagnostic sign characteristic of gallbladder fistulas is aerobilia (air within the biliary system), which can be detected through diagnostic imaging.
Porcelain Gallbladder and Shrunken Gallbladder
Calcium salt deposition can lead to a porcelain gallbladder, characterized by diffuse calcification of the gallbladder wall. This condition is considered precancerous as is the shrunken gallbladder. The latter is due to chronic inflammation, which can lead to atrophy. In both cases, a cholecystectomy is recommended to reduce the risk of gallbladder carcinoma.
Diagnosis
The diagnosis of acute cholecystitis is typically based on a characteristic clinical presentation with the above discussed signs and symptoms. Chronic cholecystitis though, may present with less distinct diagnostic indicators.
Laboratory Tests
Important laboratory tests for diagnosing cholecystitis include inflammatory markers, which are usually elevated:
leucocytosis (usually 10,000 - 15,000/µl with left shift)
elevated ESR
elevated CRP
Moreover, the so-called cholestasis parameters are usually also determined when cholecystitis is suspected. Their elevation is an indirect indicator of posthepatic bile stasis. The parameters include:
Conjugated bilirubin (less frequently elevated than AP and GGT)
alkaline phosphatase (AP)
gamma-glutamyl transferase (GGT)
Sonography
Sonography, or ultrasound imaging, is a crucial tool in the diagnosis of cholecystitis. It is non-invasive, widely available, and highly effective for visualizing the gallbladder and surrounding structures. In the case of cholecystitis, sonography can reveal several key features:
Gallstones: Detection of stones within the gallbladder or cystic duct.
Gallbladder Wall Thickening: A wall thicker than 3 mm suggests inflammation. Often also described as three-layered gallbladder. This presentation is more commonly seen in chronic cholecystitis.
Pericholecystic Fluid: The presence of fluid around the gallbladder indicates inflammation or infection.
When sonography yields inconclusive results or in complex cases, either CT (computed tomography) or MRCP (magnetic resonance cholangiopancreatography) can be employed.
Therapy
The therapy for cholecystitis typically involves medical management and surgical intervention. Medical management includes using NSAIDs for pain relief and empirical antibiotic therapy to address infection. The surgical intervention consists in the removal of the gallbladder also known as cholecystectomy. Its removal is crucial as the recurrence rate of gallbladder stones is very high if left untreated. Ideally surgery is performed within 24 to 72 hours to prevent complications and shorten hospital stays. The preferred surgical intervention is laparoscopic cholecystectomy, its minimally invasive nature results in quicker recovery times compared to open surgery. In cases involving stones in the bile ducts, endoscopic retrograde cholangiopancreatography (ERCP) may be necessary for their extraction.
References
Liu J, Yan Q, Luo F, Shang D, Wu D, Zhang H, Shang X, Kang X, Abdo M, Liu B, Ma Y, Xin Y. Acute cholecystitis associated with infection of Enterobacteriaceae from gut microbiota. Clin Microbiol Infect. 2015 Sep;21(9):851.e1-9. doi: 10.1016/j.cmi.2015.05.017. Epub 2015 May 27. PMID: 26025761.
Giles AE, Godzisz S, Nenshi R, Forbes S, Farrokhyar F, Lee J, Eskicioglu C. Diagnosis and management of acute cholecystitis: a single-centre audit of guideline adherence and patient outcomes. Can J Surg. 2020 May 8;63(3):E241-E249. doi: 10.1503/cjs.002719. PMID: 32386475; PMCID: PMC7828997.
Sharma R, Stead TS, Aleksandrovskiy I, Amatea J, Ganti L. Gallbladder Hydrops. Cureus. 2021 Sep 21;13(9):e18159. doi: 10.7759/cureus.18159. PMID: 34703693; PMCID: PMC8530502.