Transcript for Gallbladder diseases
The gallbladder is a small, pouch-like organ that stores the bile produced by the liver.
After a fatty meal, the gallbladder contracts and releases bile to help break down fats in the diet.
Bile is made up mostly of water, bile salts, bilirubin and fats, as well as cholesterol.
Now, the most common gallbladder diseases have to do with an imbalance in bile fluid composition, which leads to the formation of stones either in the gallbladder or somewhere along the biliary tree.
The biliary tree is made up of the left and right hepatic duct which come together and form the common hepatic duct, as well the cystic duct, which unites with the common hepatic duct to form the common bile duct, also known as choleducus duct.
Finally, the common bile duct joins with the main pancreatic canal to open in the second part of the duodenum.
Now, most gallbladder diseases are related to either the presence of stones in the gallbladder or in the common bile duct, and whether those locations are infected as the result of an obstruction caused by the gallstones.
A gallstone in the gallbladder is called cholelithiasis, and a gallstone in the common bile duct is called choledocolithiasis, and both are associated with mild inflammation. But, if the gallstones block the normal bile flow this can cause severe inflammation in the biliary tree.
When there’s a lot of inflammation, the gallbladder and common bile duct tissue becomes extremely susceptible to infection. An infection of an obstructed gallbladder is called cholecystitis, and an infection of an obstructed common bile duct is called cholangitis, or ascending cholangitis.
In cholelithiasis, gallstones often develop from an imbalance in bile composition.
For example, if there’s too much cholesterol, cholesterol gallstones form, and that happens mostly in female individuals during the reproductive period, especially over the age of forty. Other risk factors include being overweight and native American.
In some cases mixed gallstones may appear, made up of variable amounts of both cholesterol and pigments. But in practice, there’s no way to know the exact composition of the stone until the gallbladder is surgically removed.
Typically, gallstones happily remain in the gallbladder for months to years without ever being noticed, because they may not cause any symptoms. In fact, gallstones that are smaller than 5 millimeters, can pass through the cystic duct and reach the small intestine and be eliminated.
So in individuals with gallstones, but without symptoms, the gallstones may be discovered incidentally during an ultrasound - and that’s called cholelithiasis.
Now, if the individual is symptomatic, then we’re talking about gallstone disease rather than simply cholelithiasis.
These individuals might have biliary colic, which is abdominal pain in the right upper quadrant or epigastric region that can radiate to the shoulder or back, and typically lasts for less than an hour. Pain occurs because the gallbladder contracts against a bunch of stones, and that can temporarily compress the cystic duct. This often worsens after a high-fat meal.
Now, although it’s called biliary colic, the pain is usually constant, rather than colicky.
Associated symptoms include nausea, vomiting, and sweating.
The first and most accurate test for diagnosing cholelithiasis is an ultrasound of the right upper quadrant, which shows a distended gallbladder with stones inside. On an ultrasound, the gallstones cast an acoustic shadow below the gallbladder, and they also move freely when the individual turns from one side to the other, which helps distinguish them from other conditions, such as carcinoma. In some cases, the gallstones are so small that on the ultrasound they appear as a so called “sludge” which doesn’t cast an acoustic shadow.
Ok, now for most asymptomatic individuals, the usual plan is watchful waiting. However, for symptomatic individuals or those at high risk for developing symptoms, treatment is necessary.
High risk individuals include those with hemolytic disorders like sickle cell disease, morbidly obese individuals who undergo gastric bypass or individuals who have risk factors for developing gallbladder cancer, like gallstones bigger than 3 centimeters, a calcified gallbladder wall, also called a porcelain gallbladder, and gallbladder adenomas.
Initially gallstone disease is treated with spasmolytics such as butylscopolamine or in severe cases with opioids such as buprenorphine to stop the gallbladder from contracting in order to ease the pain. After that, a cholecystectomy - which is surgical removal of the gallbladder - can be done. Cholecystectomy is curative, meaning that once it’s done, no further medication is needed.
However, some individuals are not eligible for surgery, like those who can’t tolerate anesthesia. In that situation, a medication like ursodeoxycholic acid can be used.
Ursodeoxycholic acid decreases cholesterol absorption and that prevents new gallstones from forming, as well as dissolve the existing ones.
Another option for those that don’t have a cholecystectomy is a technique called extracorporeal shock-wave lithotripsy, or ESWL. ESWL is a machine that uses high-energy sound waves that produce shock waves to break gallstones into smaller fragments which then can be dissolved in the bile.
ESWL is a non-invasive procedure that’s usually used to break down kidney stones, but it works in individuals with a normal body mass index who have less than 3 gallstones between 4 to 30 millimeters.
There are some contraindications for ESWL like pregnancy, cholecystitis, choledocolithiasis, pancreatitis, and coagulapathies.
In choledocolithiasis - try saying that three times fast - a stone gets stuck in the common bile duct. Most frequently, this happens when a stone spontaneously passes through the cystic duct which is wider in some individuals and gets stuck in the common bile duct. However, in rare situations, gallstones can also form directly in the common bile duct. Those are typically made mainly of bilirubin and are called pigment gallstones.
The risk factors for choledocolithiasis are similar to the ones for cholelithiasis.
In choledocolithiasis, bile accumulates behind the obstruction, which blocks the flow of the entire biliary tree and, in some cases, can back up into the liver resulting in jaundice.
Other symptoms include abdominal pain in the right upper quadrant that lasts for more than one hour, nausea and vomiting.
On clinical examination, Courvoisier’s sign may be present, meaning there’s a palpable gallbladder. This happens as a result of the obstruction of the common bile duct which makes the gallbladder dilate.
Courvoisier’s sign is usually associated with malignant common bile duct obstruction, but it can also appear in choledocolithiasis.
Blood tests will show leukocytosis, and because of cholestasis, meaning something- in this case, a stone- is blocking the flow in the common bile duct to the duodenum, total bilirubin is high, and especially direct or conjugated bilirubin, also alkaline phosphatase and gamma glutamyl transferase levels are high.
Some individuals have an associated reactive pancreatitis, which happens because the stones compress the main pancreatic duct.
Pancreatitis can cause have pain in the upper abdomen which radiates in the shoulder and back, as well as abdominal tenderness, and blood tests will show high amylase and lipase levels.
Other individuals have an associated hepatitis, because bile accumulates in the intra and extrahepatic ducts.