Cholelithiasis

© Reed Group

Risk: The risk of cholelithiasis increases with age, with individuals over age 50 at increased risk (Caddy); the condition is rare in individuals under age 20 (Brunetti). Other factors that increase the risk of gallstones include consuming a diet high in animal fats, high intake of carbohydrates (i.e., consuming foods with high glycemic index), elevated body mass index (BMI), diabetes mellitus, and a family history of gallstones. Women are at higher risks than men, and women who have more than one child are at greater risk. Pregnancy, use of oral contraceptives, and estrogen replacement therapy also are known to increase risk for developing gallstones. Gallbladder stasis is a risk factor for stones, and may be seen when there is rapid weight loss, a history of dieting, or after gastric bypass surgery. Individuals receiving tube or intravenous feeding (total parenteral nutrition) are also at increased risk for developing gallstones.

Incidence and Prevalence: Cholelithiasis is found in about 10% to 20% of adults, with increased incidence in women, Native Americans, Hispanics, and fair-skinned people of Northern European descent (Chiang). Blacks are less likely to get gallstones, except for those with sickle cell disease, who generally develop gallstones early in life (Chiang). Every year about 1% to 3% of people with gallstones become symptomatic

History: In up to 80% of cases, gallstones are asymptomatic; the individual will not experience any symptoms that prompt a visit to the physician (Chiang). When symptoms do occur, the individual often complains of pain (biliary colic) that begins abruptly, occurring often after consuming a large, fatty meal. The pain is usually located in the right upper, upper central (epigastrium), or middle abdomen, and may radiate into the shoulder, scapula or back. The pain is steady and can be quite intense, subsiding gradually over a period of minutes to several hours. The individual may describe the feeling as indigestion. It may be accompanied by nausea and/or vomiting. Other symptoms that are not specific to gallstones may include belching and bloating. A family history of gallstones or gallbladder surgery may be reported upon questioning.

Physical exam: The exam is usually normal, except for possible tenderness in the right upper abdomen. Rarely, an enlarged gallbladder may be felt when pressing (palpating) the abdomen. Fever, rapid heart rate (tachycardia) and low blood pressure (hypotension) may suggest complications including infection of the biliary tree (cholangitis) or inflammation of the gallbladder (cholecystitis) with secondary infection. Jaundice may be observed if gallstones cause obstruction of the common bile duct.

Tests: Transabdominal ultrasound imaging is a highly sensitive, non-invasive, and relatively less expensive diagnostic study that will detect most cases of cholelithiasis. X-rays only detect the minority of stones that contain radiopaque material such as calcium, limiting their usefulness to confirm this diagnosis. However, x-rays are often obtained to rule out other causes of symptoms (e.g., intestinal obstruction, kidney stones). Cholecystography may be performed. This requires the individual to drink a solution containing radiopaque media that will allow gallstones and possible blockage of the cystic duct by stones to be visualized. CT scans are somewhat less sensitive than ultrasound for detecting gallstones, although CT can assist with identifying stones in the common bile duct and in detecting other conditions accounting for symptoms. Technetium Tc-99m hepatoiminodiacetic acid (HIDA) scintigraphy may be of use to detect cystic duct obstruction with infection (acute cholecystitis), but is not used to evaluate non-obstructing stones. Patients with uncomplicated gallstones often have normal lab studies; however, complete blood count, liver function studies, and amylase and lipase may be of benefit to screen for complications.