By: Dr. James Lee
The gallbladder is a sac-like organ that is pear-shaped and sits under the liver in the upper right side of the abdomen. It functions to store bile, which our body uses to digest the dietary fats that we take in. Bile is produced in the liver and collected in a system of tiny ducts that ultimately lead to the larger hepatic ducts and eventually the common bile duct which empties into the duodenum (first part of the small intestine). At the junction of the common bile duct and the duodenum, there is a circular muscle called the Sphincter of Oddi. When bile is not needed to help digest dietary fat, this muscle is contracted closing up the opening and leading to bile being backed up in the common duct, through the cystic duct and into the gallbladder where it is stored. While in the gallbladder, bile is concentrated which greatly increases its potency and intensifies its effects on dietary fat.
When we take in food that has fat in it, it goes through the stomach into the duodenum, where there are cells that sense the presence of fat and send a signal (called cholecystokinin, or CCK) to the gallbladder and the sphincter of Oddi. The gallbladder then contracts which propels bile out of the gallbladder into the cystic and common bile duct. This same signal (CCK) causes the muscle of the sphincter of Oddi to relax and bile is delivered to the intestine to aid in the digestion of dietary fat.
There are several ways that the gallbladder can cause problems in humans, including symptoms caused by gallstones, complications from gallstones, and poor function of the gallbladder. Gallstones are formed in the gallbladder due to supersaturation of bile salts. There is a chemistry experiment where you heat water and dissolve more sugar into a solution than it could take when cold. After allowing the solution to slowly cool, you add a crystal of sugar and see all the excess sugar form a precipitate and crystallize out of the solution. This is how gallstones are formed. Certain concentrations of the components of bile allow for the formation of stones. Once formed, gallstones can then go on to cause symptoms. Clinically, gallstones are best diagnosed by ultrasound.
Gallstones can cause many problems, from pain alone to acute cholecystitis, cholangitis, pancreatitis, and more. However, the presence of gallstones alone is not an indication to remove the gallbladder. The presence of gallstones must be accompanied by symptoms or complications of gallstones to be candidates for removal of the gallbladder. The classic symptoms of biliary colic (pain from gallstones) include pain in the upper right abdomen radiating to the back between the shoulder blades and is associated with nausea and sometimes vomiting. They begin usually within 30-45 minutes after eating a meal containing fried, fatty, or greasy food and can last for 1 – 6 hours. These symptoms are due to these mobile stones occasionally getting temporarily stuck at the narrow neck of the gallbladder. Once stuck there the gallbladder continues to try to squeeze the bile out, but is unable to do so due to the temporary blockage. Just like if you squeeze a balloon that has been tied off, the wall stretches; when the wall of the gallbladder stretches, pain is produced.
If the pain lasts longer than 6 hours, then the stone is more than temporarily stuck and this may be a case of acute cholecystitis. In acute cholecystitis, swelling occurs from the blockage of the outlet of the gallbladder by the stones. Inflammatory changes then occur and pressure builds up in the gallbladder leading to further swelling and pain, but also accompanied by fevers, chills, and an elevated white blood cell count indicating the body is trying to fight off infection. If not treated this can lead to a bad infection and even rupture of the gallbladder, much like in appendicitis.
If the stones are small enough then they can get outside of the gallbladder and into the common duct leading to blockage and infection of the common duct (cholangitis). This can be life-threatening and in addition to the gallbladder being removed, the stone must be removed from the common duct usually with a special endoscope called an ERCP or surgery.
The smaller stones can also get lodged at the sphincter of Oddi, or go through the sphincter of Oddi creating trauma and swelling of the area which can lead to pancreatitis, as the pancreas duct shares the opening of the sphincter of Oddi with the common bile duct. Pancreatitis is caused by the reflux of bile and pancreatic secretions back into the pancreatic duct due to swelling or stones blocking its outlet. Pancreatitis is also a potentially life-threatening condition.
Gallbladder disease is best diagnosed with an ultrasound. This is the best test to definitively confirm gallstones in the gallbladder. It can also show evidence of wall thickening (indicating an inflammatory or infectious process like acute cholecystitis), dilation of the common bile duct (indicating a possible stone or obstruction of the duct) and even the actual stones in the duct are sometimes seen. Although CT is helpful in excluding other causes of abdominal pain and can be helpful in suggesting problems in the gallbladder, confirmation by an Ultrasound is recommended before treatment is undertaken.
Just because stones are not seen in the gallbladder, it does not mean that the gallbladder is definitively excluded from the causes of symptoms. Another disease of the gallbladder is biliary dyskinesia, literally “abnormal motion”. Biliary dyskinesia can result from abnormal or ineffective contractions of the gallbladder, narrowing of the cystic duct leading out from the gallbladder, or failure of the sphincter of Oddi to relax when the gallbladder is contracting. The symptoms caused by biliary dyskinesia can be similar to those seen with gallstones, but the ultrasound is negative. To diagnose Biliary dyskinesia, a HIDA scan is performed.
HIDA scan is a nuclear medicine test that quantitates the degree of gallbladder function. It is a safe, non-invasive study that is often done in the x-ray department of the hospital. A radiotracer is introduced and gets concentrated in the liver and associates with bile. As bile flows toward the larger ducts, the radiotracer follows and can be seen going into the common duct and backing up as normal bile does into the gallbladder. There are several outcomes to the HIIDA scan. If the gallbladder is not visualized this means that something, usually a stone, is blocking the bile from getting into the gallbladder. This most commonly means cholecystitis, whereas you remember a stone blocks the outlet of the gallbladder creating symptoms. Once the gallbladder has the radiotracer in it, a second medicine (CCK) is given which causes the gallbladder to contract, much like it would with a normal fatty meal. The amount of radiotracer that is ejected from the gallbladder is then measured. If this is less than 30-35%, then the gallbladder is said to be poorly functioning. If it is above 35%, it is said to be normally functioning. Finally, the injection of the second medicine can cause symptoms. If the symptoms are similar to the symptoms that brought the patient in to get the test, then this is noted. The best indicators that surgery will relieve the symptoms a patient is experiencing from biliary dyskinesia are a low ejection fraction ( < 35%) and reproduction of symptoms with the injection of CCK.
The treatment for gallstones, their complications, and biliary dyskinesia is the surgical removal of the gallbladder. The preferred approach is laparoscopic with four small incisions, however, patients often consent to the traditional open surgery as it is sometimes necessary for patient safety. If the surgeon is able to do the surgery laparoscopically, patients can often leave the hospital on the same day. If the open procedure must be done the hospital stay is generally 3-5 days.
Dr. James Lee serves as the Coroner of Winn Parish. He is a General Surgeon and Surgical Oncologist who has been practicing in Winnfield for over ten years. Dr. Lee attended the University of Colorado for his medical degree. He completed his residency in Surgery at the University of Oklahoma before completing a fellowship in Surgical Oncology and Endoscopy at Roswell Park Cancer Institute in Buffalo, NY. Dr. Lee and his wife Scarlett live in Winnfield with their son and are active in the community.
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