Cholelithiasis or gallstones are hardened deposits of digestive fluid that can form in your gallbladder. The gallbladder is a small organ located just beneath the liver. The gallbladder holds a digestive fluid known as bile that is released into your small intestine.
Causes and risk factors
There are three main pathways in the formation of gallstones:
- Cholesterol supersaturation: Normally, bile can dissolve the amount of cholesterol excreted by the liver. But if the liver produces more cholesterol than bile can dissolve, the excess cholesterol may precipitate as crystals. Crystals are trapped in gallbladder mucus, producing gallbladder sludge. With time, the crystals may grow to form stones and occlude the ducts which ultimately produce the gallstone disease.
- Excess bilirubin: Bilirubin, a yellow pigment derived from the breakdown of red blood cells, is secreted into bile by liver cells. Certain hematologic conditions cause the liver to make too much bilirubin through the processing of breakdown of hemoglobin. This excess bilirubin may also cause gallstone formation.
- Gallbladder hypomotility or impaired contractility: If the gallbladder does not empty effectively, bile may become concentrated and form gallstones.
Depending on the etiology, gallstones have different compositions. The three most common types are cholesterol gallstones, black pigment gallstones, and brown pigment gallstones. Ninety percent of gallstones are cholesterol gallstones.
Each stone has a unique set of risk factors. Some risk factors for the development of cholesterol gallstones are obesity, age, female gender, pregnancy, genetics, total parenteral nutrition, rapid weight loss, and certain medications (oral contraceptives, clofibrate, and somatostatin analogs).
Approximately 2% of all gallstones are black and brown pigment stones. These can be found in individuals with high hemoglobin turnover. The pigment consists of mostly bilirubin. Patients with cirrhosis, ileal diseases, sickle cell anemia, and cystic fibrosis are at risk of developing black pigment stones. Brown pigments are mainly found in the Southeast Asian population and are not common in the United States. Risk factors for brown pigment stones are intraductal stasis and chronic colonization of bile with bacteria.
Patients with Crohn disease and those with ileum disease (or resection) are not able to reabsorb bile salts and this increases the risk of gallstones.
Symptoms of gallstones
The symptoms of gallstones can vary based on the size of the gallstone. Most gallstones do not cause any symptoms at all. These gallstones are known as silent stones and require no treatment. When the gallstones cause symptoms, they may include:
- Pain in the upper mid abdomen or upper right abdomen.
- Associated pain in the right shoulder.
- Chest pain.
- Nausea and vomiting.
- Repeated similar episodes.
- Jaundice (a yellow tint to the skin and eyes).
Pain is the main symptom most people experience with gallstones. This pain is steady and can last from around 15 minutes to several hours. The episodes, which can be severe, generally subside after one to three hours or so. People who have these painful attacks, while uncomfortable, are not in any medical jeopardy. Gallstones can cause acute cholecystitis, which is a more serious condition when the gallbladder is actually inflamed. This happens if a stone blocks off the cystic duct, which increases the pressure within the gallbladder. This condition may require antibiotics, hospitalization and even urgent surgery. Stones that pass out of the gallbladder and into the common bile duct can cause a complete blockage of the duct with jaundice, infection and pancreatitis. You may feel pain in several places, including:
- Upper part of the abdomen, on the right side.
- Between the shoulder blades.
- Under the right shoulder.
When people experience pain with gallstones, it is sometimes referred to as a gallbladder attack or biliary colic. There are two special conditions that could mimic gallstone symptoms. First, some gallbladders contain a thick sludge, which has not formed into actual stones. Sometimes sludge is felt to cause symptoms similar to actual gallstone pain. Secondly, there is an uncommon condition called acalculous cholecystitis, when the gallbladder becomes inflamed, but no stones are present. This is generally treated by surgical removal of the gallbladder.
Nonsteroidal anti-inflammatory drugs (eg, diclofenac 50–75 mg intramuscularly) can be used to relieve biliary pain.
Laparoscopic cholecystectomy is the treatment of choice for symptomatic gallbladder disease. Pain relief after cholecystectomy is most likely in patients with episodic pain (generally once a month or less), pain lasting 30 minutes to 24 hours, pain in the evening or at night, and the onset of symptoms 1 year or less before presentation. Patients may go home within 1 day of the procedure and return to work within days (instead of weeks for those undergoing open cholecystectomy). The procedure is often performed on an outpatient basis and is suitable for most patients, including those with acute cholecystitis.
Conversion to a conventional open cholecystectomy may be necessary in 2–8% of cases (higher for acute cholecystitis than for uncomplicated cholelithiasis). Bile duct injuries occur in 0.1% of cases done by experienced surgeons, and the overall complication rate is 11% and correlates with the patient’s comorbidities, duration of surgery, and emergency admissions for gallbladder disease prior to cholecystectomy.
There is generally no need for prophylactic cholecystectomy in an asymptomatic person unless the gallbladder is calcified, gallstones are 3 cm or greater in diameter, or the patient is a Native American or a candidate for bariatric surgery or cardiac transplantation.
Cholecystectomy may increase the risk of esophageal, proximal small intestinal, and colonic adenocarcinomas because of increased duodenogastric reflux and changes in intestinal exposure to bile.
In pregnant patients, a conservative approach to biliary pain is advised, but for patients with repeated attacks of biliary pain or acute cholecystitis, cholecystectomy can be performed—even by the laparoscopic route—preferably in the second trimester. Enterolithotomy alone is considered adequate treatment in most patients with gallstone ileus. Cholecystectomy via natural orifice translumenal endoscopic surgery (NOTES) has been performed on a limited basis.
Ursodeoxycholic acid is a bile salt that when given orally for up to 2 years dissolves some cholesterol stones and may be considered in occasional, selected patients who refuse cholecystectomy. The dose is 8–13 mg/kg in divided doses daily. It is most effective in patients with a functioning gallbladder, as determined by gallbladder visualization on oral cholecystography, and multiple small “floating” gallstones (representing not more than 15% of patients with gallstones). In half of patients, gallstones recur within 5 years after treatment is stopped.
Ursodeoxycholic acid, 500–600 mg daily, and diets higher in fat reduce the risk of gallstone formation with rapid weight loss. Lithotripsy in combination with bile salt therapy for single radiolucent stones smaller than 20 mm in diameter was an option in the past but is no longer generally used in the United States.