Gallstones occur as small solid stones that form in the gallbladder, also known as the gallbladder, due to a higher concentration of cholesterol in the bile.
What is gallstones
Gallstones is a very widespread disease in the Western world, present in percentages ranging from 5% to about 25% in the adult population of various American and European countries (especially Northern Europeans). In Europe, the latest data speak of a prevalence of biliary lithiasis ranging from 9 to 19% (about 19% in women and 9.5% in men). The Italian data, deriving from studies conducted in the 1980s, were able to ascertain that:
- stones are present in 10% of the general population;
- female subjects are more affected, in double percentages compared to males (15% VS 7%);
- with advancing age, the prevalence of the disease in both sexes increases significantly.
What are Gallstones
Gallstones are essentially of three types: cholesterol, pigmentary and mixed and can be present in the gallbladder, biliary tract, or both of these anatomical structures.
The stone formation process is slow and has been studied especially with regard to cholesterol stones. Initially there is an increased concentration of cholesterol in the bile (due to congenital abnormalities of the hepatic metabolism of endogenous fats, due to an incorrect diet or, again, due to a reduction in cholesterol-solubilizing bile agents), aggregation in nuclei and subsequently in cholesterol crystals, which are then the basis for subsequent calculations.
Practically a bile supersaturated in cholesterol and with a composition of the bile secreted by the hepatocyte in non-ideal proportions of the various types of bile acids necessary and useful for normal digestive function, and perhaps in a framework of metabolic syndrome and incorrect diet: this, therefore, is the pathogenesis for cholesterol stones.
Different and more complex is the question relating to pigmentary gallstones, which have a different pathogenesis. The gallbladder is the point where stones can most easily form, precisely because there is stagnation of bile in its interior when you are fasting and there is time for the nucleation and crystallization of a bile richer in cholesterol. If the gallbladder presents, due to intrinsic pathologies, a delayed, slow or ineffective emptying, stones are more easily formed.
The pigmentary calculations represent a minority of gallstones (about 20-25% in feedback workers) and are so named for their dark color. They consist of a mixture of cholesterol, phosphate and calcium carbonate and a particular pigment, bilirubin.
They are generally associated with chronic haematological diseases capable of inducing hemolysis (ie destruction of red blood cells) and release of the hemoglobin contained within the red blood cells, which is then degraded to form bilirubin. This type of stone is more common in the elderly and in advanced chronic liver disease.
Causes of gallstones
- Obesity is an established risk factor , especially in women: in this condition, genetic or incongruous diet is made this increased synthesis and biliary excretion of cholesterol.
- Another risk factor is certainly the infection of the biliary tract, particularly important for the genesis of pigmentary stones.
- Age can also be considered a risk factor as the prevalence of calculosis is markedly increased in the elderly, probably due to the higher concentration of cholesterol in the bile and the hypomobility of the gallbladder. In light of these data, considering the progressive increase in the average age of the Italian population, it is conceivable that gallstones will become a growing health problem in the coming years.
- The pregnancy (especially multiple pregnancies) determines a stagnation of bile in the gallbladder with incomplete emptying and ease the formation of cholesterol crystals, calculations precursors. Pregnancy associated with obesity further increases the risk.
- The use of oral contraceptives is also associated with an increased risk of gallstones.
- Finally, the eating behaviors most at risk for the development of gallstones are essentially identified in a diet low in fiber and rich in cholesterol and triglycerides.
Other favoring factors to mention are also the following:
- the composition in quantity and quality and the proportion between them of the various components of bile and cholesterol;
- a deficit of gallbladder motility, the sluggish, not very mobile gallbladder, which determines biliary stasis and therefore aggregation of cholesterol crystals;
- a motor defect of the digestive system, such as slowed transit or alteration of peristalsis;
- the hydrops of the gallbladder dangerous for possible various complications, including serious ones (abscess, perforation, etc.)
What are the symptoms of gallstones?
Gallstones can give rise to specific symptoms (such as typical pain, the so-called biliary colic or complications of the disease) or their presence can remain silent (asymptomatic lithiasis). From these two eventualities a completely different decision-making approach arises.
Biliary colic is defined as pain in the right epigastrium / hypochondrium sometimes radiating posteriorly and to the right shoulder lasting about 30 minutes and which does not go away with defecation. In addition, there may be nausea and vomiting or dyspepsia (postprandial sense of weight, belching, epigastric swelling, etc.), but the latter are generic symptoms that can also occur in many other situations that do not properly characterize the so-called biliary colic and may be present. in lithiasic and non-lithiac populations.
Important complications, to be brought to the operating table, can be acute, lithiasic and non-lithiasic cholecystitis, or bilio-enteric fistulas or stenosis of the ab extrinsic choledochus due to large calculus of the cystic duct. Often the small stones that easily take the path of the cholecoco up to the sphincter of Oddi can be responsible for acute pancreatitis and also require cholecystectomy.
Asymptomatic patients may have no specific symptoms for many years ; in them the probability of developing biliary pain is about 10% at 5 years and 20% at 15-20 years, with an annual risk of having biliary colic that decreases with the passage of time.
In some studies in which it was possible to monitor patients for a long time, it was found that in these patients the annual probability of developing a major complication is about 1%. Based on these data, there is no rationale for the indication for elective, prophylactic cholecystectomy surgery in patients with asymptomatic stones.
Of course, the matter is completely different in the presence of symptomatic stones, where a therapeutic decision is needed. The disease can present with pain, usually due to the passage of stones in the cystic duct or in the choledochus duct, or with complications of great clinical importance such as acute cholecystitis with the possibility of infection up to the abscess or perforation of the gallbladder, acute infections of the bile ducts, obstruction of the choledochus duct with jaundice, acute pancreatitis.
These are all clinical occurrences which, if not recognized and treated quickly, can lead to serious, sometimes fatal, complications.
Diagnosis of gallstones
A good anamnestic and clinical investigation already sufficiently leads to the correct diagnosis. Confirmation comes from laboratory data (increase in so-called biliary stasis investigations) and above all from imaging techniques.
Ultrasound is the technique of choice , as it is diagnostic in over 90% of cases, it is non-invasive, relatively inexpensive and reproducible. In the case of gallstones, the ultrasound allows to have other useful information for the general evaluation of the disease and of the patient (thickness of the gallbladder, dilation of the bile ducts, associated hepatic and / or pancreatic diseases, etc.).
Direct radiography of the abdomen and cholecystography add little to the ultrasound data and are required only in special cases.
Computed axial tomography (CT) is inferior to ultrasonography in gallstones and may be useful in demonstrating the degree of calcification of stones in patients attempting stone dissolution treatment with drugs.
If the stones are in the biliary tract, the diagnostic problem may not be solved by ultrasound and other more sophisticated investigations such as nuclear magnetic resonance (MRI) cholangiography or endoscopic retrograde cholangiography must be used, techniques that generally require the hospitalization.