Cholelithiasis

The exact cause of cholelithiasis is not entirely clear, and may be a result of multiple factors. Cholelithiasis most commonly results from a chemical imbalance within the contents of the gallbladder in which the bile contains too much cholesterol or bilirubin. The two most common types of gallstones are cholesterol gallstones and pigment gallstones. 

Cholesterol gallstones are the most common type of gallstone and may develop when the amount of cholesterol excreted by the liver exceeds what the bile can dissolve, leading to excess cholesterol depositing into yellow cholesterol stones. Additional risk factors associated with the development of cholesterol gallstones include high cholesterol; diabetes; high fat and low fiber diets; obesity; pregnancy;  sedentary living; rapid weight loss; medications used to lower cholesterol, such as statins; medications that increase estrogen levels in the body, such as oral contraceptives; being assigned female at birth; being Native American; being over the age of 60; and having a personal or family history of gallstones.

Cholelithiasis is typically not characterized by any signs or symptoms, unless there is an obstruction of the cystic duct, bile ducts, or both. Additionally, the signs and symptoms of cholelithiasis can vary depending on the size and location of the gallstone. Small gallstones are more likely to exit the gallbladder and block the cystic or bile ducts, while large gallstones are more likely to stay in the gallbladder and not cause any symptoms.

The most common signs and symptoms of cholelithiasis include gallbladder attacks, or biliary colic, characterized by severe, rapidly intensifying abdominal pain localized to the upper right or central abdomen. It is typically triggered at night after a fatty meal. Abdominal pain associated with biliary colic may radiate to the upper back, between the shoulder blades and to the right shoulder, and may last anywhere from 15 minutes to several hours. Other abdominal symptoms, such as clay-colored stools, bloating, indigestion, belching, and gas, may also occur.

 Temporary blockage of the cystic duct by a gallstone usually involves short-term pain, while persistent blockage of the cystic duct may increase pressure within the gallbladder, thereby leading to more severe, long-lasting pain and acute cholecystitis, or inflammation of the gallbladder. Gallstones that pass the cystic duct and block the common bile duct may result in choledocholithiasis, which is characterized by itchy skin and/or yellowing of the skin and eyes, also known as jaundice. Persistent blockage of the bile ducts may also result in pancreatitis or serious infection, which may be characterized by high fever, sweating, chills, rapid heartbeat, nausea, vomiting, and diarrhea.

Cholelithiasis and any potential complications are diagnosed by a medical professional upon a thorough review of symptoms, medical history, and physical examination.

Cholelithiasis is commonly diagnosed through a variety of imaging techniques, including abdominal ultrasound, endoscopic ultrasound, and other imaging tests. An abdominal ultrasound is most often completed as it is painless and the least invasive.  However, it may not visualize all biliary ducts in detail.

Endoscopic retrograde cholangiopancreatography (ERCP) is a diagnostic and potential treatment procedure involving the insertion of a long, thin, and flexible tube with a camera attached (i.e., an endoscope) through the mouth, down toward the small intestine. During an ERCP, an imaging dye is injected into the body to highlight the ducts of the biliary system. If gallstones are present in the bile ducts, they may be removed by the endoscope; however, the endoscope cannot remove stones inside the gallbladder.

Magnetic resonance cholangiopancreatography (MRCP) is a diagnostic procedure in which the bile ducts are examined with magnetic resonance imaging. This procedure provides a detailed image, is less invasive, and is a safer alternative for most individuals. In urgent cases (e.g., ascending cholangitis), ERCP may be done before MRCP. In an endoscopic ultrasound (EUS), an endoscope is passed through the mouth, down toward the common bile duct and gallbladder region, to screen for gallstones not visible in an abdominal ultrasound. An ERCP may follow MRCP or EUS in order to remove the visualized gallstones from the bile ducts.

Other imaging tests that may be used to diagnose cholelithiasis include oral cholecystography, a hepatobiliary iminodiacetic acid (HIDA) scan, and CT scan.

In addition, blood samples may be drawn to screen for infections, jaundice, or pancreatitis.

Treatment options for cholelithiasis depend on the age of the individual; overall health; medical history; severity of symptoms; as well as the size, location, and quantity of gallstones.

In asymptomatic individuals, cholelithiasis may not require treatment. In those with symptoms, cholelithiasis may be treated with medications used to dissolve gallstones; through certain diagnostic procedures; or through gallbladder removal surgery, also known as a cholecystectomy. Medications used to dissolve gallstones, such as ursodiol, may be used if an individual cannot undergo an invasive procedure; however, this approach is limited in efficacy, involves lengthy treatment periods, and has a high risk of gallstone recurrence once the medication is no longer in use. Extracorporeal shockwave lithotripsy is a procedure that uses shock waves to pulverize gallstones. Remnants can subsequently flow through the bile ducts without blockages. ERCP is an effective procedure used to remove gallstones from the bile ducts, provided they are not inside the gallbladder. A sphincterotomy, another procedure which can be completed during an ERCP, occurs when tight rings of muscle around the openings of bile ducts are cut to increase the width of bile ducts when open and allow the gallstones to pass into the intestine.

Gallbladder removal surgery is commonly performed when the gallstones are located inside the gallbladder. A cholecystectomy eliminates the risk for recurrent cholelithiasis and subsequently allows for bile to flow directly from the liver into the small intestine. Consequent diarrhea can occur. A laparoscopic cholecystectomy is the most commonly performed cholecystectomy as it is minimally invasive and involves the use of a laparoscope, or a narrow tube with a camera. The laparoscope is inserted through one of several small incisions in the abdomen to visualize and remove the gallbladder. If a laparoscopic cholecystectomy is not successful or an individual experiences complications of cholelithiasis, an open cholecystectomy may be performed, which involves one large incision to the abdomen and a longer healing period. 

In situations where a cholecystectomy is not a viable option due to illness, a percutaneous drainage may be performed in which a drainage tube is inserted into the gallbladder through the abdomen to allow for drainage of any infection until a cholecystectomy can be performed. After a cholecystectomy, certain individuals may require antibiotics, such as ciprofloxacin and metronidazole, to prevent or treat residual infection.