The clinical presentation of cases with chronic cholecystitis may be insidious, and a slowly progressive development of symptoms is observed. Symptoms are generally mild and patients are not significantly impaired, which is why patient history often reveals that the duration of symptoms is months or even years. Recurrent biliary colic, which occurs as a result of transient obstruction of the biliary ducts by gallstones can be manifested as either epigastric or right hypochondrial abdominal pain and is the most common manifestation. Nausea, vomiting, significant discomfort when eating fatty foods may also be reported. Fever may be present in some cases, but it usually indicates an acute process, and it is not uncommon for episodes of acute cholecystitis to occur.

Patients with recurrent abdominal pain and suspected development of gallstones should be evaluated through various imaging techniques [10]. Abdominal ultrasonography is the initial diagnostic procedure of choice, as it can clearly show the presence of gallstones, while changes in gallbladder shape can be detected by this method as well. Other imaging techniques, such as, computed tomography (CT), magnetic resonance imaging (MRI) or hepatobiliary scintigraphy (HIDA) may be used as well if ultrasound shows inconclusive results. 

In addition to imaging techniques, blood levels of amylase, lipase, bilirubin, liver transaminases (including ALT and AST), lactate dehydrogenase, alkaline phosphatase (ALP) should be determined, together with a complete blood count (CBC). Because recurrent abdominal pain may resemble pyelonephritis, urinalysis should be performed, and abdominal ultrasound should include examination of the kidneys, to rule out infection of the renal system as a possible cause of symptoms.

Surgical treatment is the method of choice for chronic cholecystitis, primarily because of the complications it may cause, but also to prevent recurrent development of symptoms [11]. Laparoscopic cholecystectomy is recommended over open cholecystectomy primarily because mortality rates were shown to be significantly higher when performing open cholecystectomy [12], but also because patients with additional comorbidities may not be suitable for open surgery [13]. Moreover, early surgical treatment was established to provide significantly better recovery rates, reduced mortality rates, and shorter duration of hospital stay [14]. Additional procedures may include endoscopic retrograde cholangiopancreatography (ERCP), which is used to remove gallstones from the biliary ducts.

Having in mind its slowly progressive course, which can present as a significant challenge for the physician, this disorder may cause significant morbidity to patient. Numerous complications may arise [9]:

• Super infection by bacterial organisms, which may lead to cholangitis or life-threatening sepsis.
• Gallbladder perforation, local abscess formation, or rupture that may lead to peritonitis.
• Formation of cholecystenteric fistulas, that consequently drain bile into adjacent organs, or may present as a mean of bacterial entry into the biliary tree.
• Further progression of pre-existing conditions, such as liver cirrhosis, heart failure and chronic kidney disease.

For these reasons, it is imperative to obtain a diagnosis while chronic cholecystitis is in its early stages, to prevent these complications and provide significant benefit to the patient.

Presumably, chronic cholecystitis almost exclusively occurs because of gallstone formation, while preceding acute cholecystitis plays a minor role in its development. In rare cases, chronic cholecystitis may also develop without the presence of gallstones (acalculous cholecystitis), in which case other causes may be responsible. Bacterial pathogens, primarily Helicobacter pylori [2], but also Escherichia coli and enterococcal species have been associated with disorders of the biliary system and are supposedly involved in both acute and chronic inflammation of the gallbladder. 

Chronic cholecystitis occurs in the setting of cholelithiasis in the vast majority of cases, and it is described as the most important risk factor for the development of this disease. Both genetic and geographic factors are deemed to be important determinants for the development of gallstones [3]. Prevalence of gallstones has been established to be very high in certain ethnic groups such as Native and Mexican Americans, and people living in Northern Europe, while lowest prevalence rates are observed in the African populations [4]. Epidemiological studies indicate that between 10-20% of people living in the United States have gallstones and are at increased risk for chronic cystitis, while similar rates are observed in Central Europe and Asia. Significant gender predilection toward females has been established, with a 2:1 or 3:1 ratio. Additional risk factors for gallstone formation, thereby chronic cholecystitis include advanced age, hyperlipidemic syndromes (either metabolic defects or dietary habits), obesity and bile stasis [5].

The pathogenesis of chronic cholecystitis generally starts with gallstone formation and they exert significant damage to the gallbladder epithelium [6]. However, other factors are also involved in the onset of inflammation and its persistence throughout time, such as bile super saturation, while infections have been hypothesized to contribute as well. Various bacterial pathogens have been cultured in patients suffering from cholecystitis, including Helicobacter pylori, Escherichia coli and other species that are known to reside in bile ducts, implying that they also play a role in the pathogenesis of this condition [7]. 

All of these factors result in structural and morphological changes in the gallbladder wall, including extensive fibrosis and development of calcifications ("porcelain gallbladder"), while chronic inflammatory cells have been identified in many patients. Still, the exact mechanism of its occurrence remains incompletely understood.

Additionally, cholecystitis has implications in the development of preneoplastic lesions, and eventual development of gallbladder cancer [8].

The burden of chronic cholecystitis may be significantly reduced on a global basis through several preventive measures. Since hyperlipidemia and obesity have been brought into connection with this disease, proper dietary habits should be instated. Additionally, patients in whom a diagnosis of cholelithiasis (gallstones) has been established, proper therapeutic regimens should be carried out and regular follow-ups should be conducted to prevent the onset of chronic and irreversible damage to the gallbladder, especially if symptoms are present.

Chronic cholecystitis is a term that describes persistent, long-standing inflammation of the gallbladder, which almost always occurs on pre-existing gallstone formation and sometimes recurrent bouts of acute cholecystitis. Additionally, bacterial pathogens such as Helicobacter pylori, and gram-negative bacteria have also been found associated with the condition in a significant number of patients, implying an infectious component in the disease pathogenesis [1]. Changes that are observed include extensive calcification and fibrosis (termed "porcelain gallbladder"), while absence of acute inflammatory infiltrates distinguishes this condition from acute cholecystitis. Cholecystitis is one of the most common indications for abdominal surgery throughout the world and several risk factors have been established. Significant predilection toward female gender has been observed, due to much more common rates of cholelithiasis among females, and this ratio is the largest among middle-aged adults. Additionally to gender, obesity, hyperlipidemia, pregnancy, but also genetic and geographic factors may contribute to development of this disorder. Chronic forms of cholecystitis tend to have a very slow progression and may be without symptoms in its early stages. Symptoms, when present, include nausea, vomiting, epigastric and right upper quadrant pain. The diagnosis is made through various laboratory tests and abdominal ultrasonography. Because numerous complications may arise from chronic cholecystitis, some of them even life-threatening, such as bacterial superinfection, perforation or rupture of gallbladder, or formation of biliary enteric fistulas, surgical treatment is indicated. In most cases, laparoscopic cholecystectomy is recommended.

Chronic cholecystitis implies prolonged inflammation of the gallbladder, which most commonly occurs in patients with gallstones. The main function of the gallbladder is to store bile and release it into the gastrointestinal tract to facilitate food digestion.

In most cases, gallstones contribute to chronic irritation and inflammation of the gallbladder by mechanical irritation of its wall and bile ducts and induce scarring and fibrosis of the gallbladder wall (in which case the term "porcelain gallbladder" is used). Certain bacterial microorganisms, such as Helicobacter pylori, which are the cause of acute gastritis, and other pathogens such as Escherichia coli, have been implicated in the development of chronic cholecystitis. Chronic cholecystitis almost universally occurs in patients with gallstones. The common risk factors associated with cholecystitis are obesity, increased amount of fat in circulation and a female gender predilection predisposing individuals to this disorder. Pregnancy and use of oral contraceptives have been associated with gallstone formation in females.

Chronic cholecystitis is characterized by a slow onset of symptoms that are usually recurrent, which include abdominal pain, usually below the ribs or in the right upper corner, in the projection of gall bladder and most commonly occurs due to transient passage of gallstones through the bile ducts (known as biliary colic). Other symptoms include nausea, vomiting and intolerance to foods that are rich in fat, while patients who report fever are more likely suffering from acute cholecystitis. The diagnosis of this condition can be made by performing abdominal ultrasonography, which can provide a clear view into the contents of the gallbladder and its wall, while additional tests that evaluate liver and gallbladder function should be performed as well.

Because various complications can arise in patients suffering from cholecystitis, such as sepsis, gallbladder perforation or rupture and subsequent leakage of bile into other organs, surgical removal of gallbladder, known as cholecystectomy, is indicated in all patients. More specifically, laparoscopic cholecystectomy is recommended, because this method is less invasive than open cholecystectomy, and shows much better results in terms of lower mortality rates and shorter time of recovery. It is established that surgical treatment of this disease significantly improves outcomes in patients, which is why an early diagnosis of chronic cases of cholecystitis may be life-saving. Significant steps in prevention of this disease can be made, such as restriction of food that is high in fat and regular monitoring of fat content in blood. Patients in whom gallstones are already diagnosed should be regularly followed-up, while symptoms should be reported immediately after their appearance.

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