Clinical Practice Guideline
Developed for the
Aerospace Medical Association
by their constituent organization
Overview: Gallstone disease is one of the most common and expensive gastrointestinal diseases in the United States; it the most common abdominal cause for hospital admission, with more than 250,000 hospitalizations and a median charge of $11,584 per admission. It is estimated that there are 6.3 million men and 14.2 million women aged 20 to 74 years with the disease, and others state that the disease affects up to 12 percent of the US population. Ethnically, there appear to be higher rates of disease in Caucasian, Hispanic, and Native American populations, and lower rates in African American and Japanese populations. Recognized risk factors include: increased age; gender – females have a higher prevalence by a factor of 3.0 in some cases, and this is most likely a result of pregnancy and estrogen, both of which are known risk factors; family history; obesity; rapid weight loss; diabetes mellitus; cirrhosis; gallbladder stasis; decreased physical activity (those who are physically active have a decreased risk of symptomatic cholelithiasis); and finally, disease prevalence is increased in patients with Crohn’s disease. Regarding Crohn’s disease, gallbladder disease incidence can be over twice that in non-affected individuals; interestingly, there is no increased incidence in ulcerative colitis patients. The mechanism of disease in Crohn’s disease is postulated to be a decreased intestinal reabsorption of bile salts with subsequent secretion of supersaturated bile.
Gallstones form when the solubility of bilirubin or cholesterol is exceeded in the bile. Pigment stones arise from the bilirubin process and cholesterol stones arise due to an imbalance in the mechanisms maintaining cholesterol in solution. In the US cholesterol stones are the most common type of gallstone (about 80% of all stones) with pigmented stones occurring less often. The majority of asymptomatic gallstone patients (who make up a majority of all gallstone patients) will remain asymptomatic for many years. It has been estimated that around 10 percent of patients with gallstones will develop symptoms in the first five years after diagnosis. Symptomatic patients may complain of severe right upper quadrant pain (biliary colic), nausea, vomiting, and fever; occasionally jaundice. In general, the first, and often the only, imaging study recommended in patients with suspected biliary pain is ultrasound of the RUQ.
Many options are available for the management of symptomatic gallstone disease. Improvements in endoscopic, radiologic, and chemical therapies for gallstones have enhanced the overall management of patients with gallstones. Nonetheless, surgery remains the most important therapeutic option, and laparoscopic cholecystectomy has become the standard method for the elective management of patients with biliary pain and complications of gallstone disease, such as acute cholecystitis, gallstone pancreatitis, and choledocholithiasis. The indications for laparoscopic cholecystectomy are symptomatic gallstones manifesting as biliary colic, acute or chronic cholecystitis, and pancreatitis (caused by a stone migrating into the common bile duct). In most cases, the procedure is done on an out-patient basis and the recovery is days to a week or two. Approximately 700,000 procedures are performed annually in the US and it is one of the more common surgeries performed by general surgeons. An interesting observation in the past decade is that the increase in the rate of elective cholecystectomy procedures after the introduction of the laparoscopic technique in the early 1990s has been associated with an overall reduction in the incidence of severe gallstone disease.
Interest in non-surgical therapies for gallstone disease has decreased over the past two decades due to the popularity and safety of the laparoscopic surgical approach. The primary candidates for such therapies are symptomatic patients who are not good surgical risks. Most of the medical therapies are directed toward management of cholesterol-rich gallstones; two methods are available, used alone or in combination. These are oral bile salt dissolution therapy or extracorporeal shock wave therapy (lithotripsy). Smaller stones (less than 5 mm) are better candidates for dissolution and larger stones are more likely to respond best to lithotripsy. Two bile acids, chenodeoxycholic acid and ursodeoxycholic acid (UCDA) have been used in gallstone treatment. UDCA has significantly fewer side effects such as diarrhea, increased serum cholesterol and hepatotoxicity. Treatment should continue until stone dissolution is documented by two consecutive negative ultrasonograms performed at least 1 month apart. Lithotripsy is more effective in patients with a single gallstone. Centers with great experience in this modality have a 90 to 100 percent clearance rate for a single gallstone and 67 percent for two or more stones. As with other medical therapies, stone recurrence remains a major problem. Some newer medical approaches to reduce the incidence of gallbladder disease include the use of medications such as ezetimibe to reduce intestinal cholesterol absorption and biliary cholesterol secretion.
Aeromedical Concerns: In patients with symptomatic gallstone disease, biliary colic may present abruptly as a sharp, incapacitating abdominal pain that is frequently accompanied with intense nausea and emesis. Asymptomatic gallstones do not appear to present a significant risk for aviation safety and can be followed on an annual basis with the PHA. Patients undergoing a surgical technique need to stay grounded until cleared by the surgeon to resume unrestricted activities, at which time they can be returned to flying duties without a waiver.
Medical Work-up: The waiver request for an aviator with cholelithiasis should include a complete discussion of the history and etiology of the condition and how it was discovered, a detailed G.I. history noting any abdominal pains, and address concerns of underlying pathology and gallbladder function. A consultation report by a gastroenterologist or surgeon may also be useful. Important documentation would include: Imaging studies: discussion of the exams that discovered the condition, nature of the cholelithiasis, and the indication for the original exam, and Lab studies: CBC and liver function tests.
Air Force: The diagnosis of cholelithiasis is disqualifying for all classes of aviation in the US Air Force. For UAS duties, acute, recurrent or chronic cholecystitis is disqualifying, but not specifically cholelithiasis.
Army: Cholelithiasis is considered disqualifying, IAW AR 40-501 Standards of Medical Fitness. The Gallstones APL discusses the work-up and disposition of aviators with this condition. Asymptomatic gallstones found incidentally and with no evidence of cholecystitis on ultrasound examination are routinely granted a waiver in rated aviation personnel. Initial applicants are considered for exception to policy on a case-by-case basis. Aviators with symptoms are grounded until the stones are removed. A history of cholecystectomy, if uncomplicated, does not require a waiver and will be filed for information only.
Navy: Waivers are recommended for aviators and applicants with incidentally noted asymptomatic stones. Aviators with symptoms should be grounded until the stones are removed. Aviators who have undergone extracorporeal shock wave lithotripsy (ESWL) may apply for a waiver after a 6-month period free of biliary colic. A history of cholecystectomy, either open or laparoscopic, is NCD in all aviation personnel. No evidence of cholecystitis on ultrasound examination should be present. A nuclear medicine study may be necessary to assure proper function of the gall bladder.
1. Confirmation that the patient is symptom-free
2. All radiology and/or nuclear medicine studies
3. GI consult (if applicable)
4. Documentation that bile duct stones are absent
Civilian: Acute cholecystitis that has resulted from gallstones disease will require that the airman be treated and stable for medical certification to occur. Once the gallbladder has been removed an authorization for special issuance with incidental gallstones with no prior symptoms will not result in denial or even a waiver.
Air Force: AIMWTS review revealed a total of 56 aviators with waiver submissions containing the diagnosis of cholelithiasis. Of the total, 2 were FC I/IA (both s/p lap choly), 40 were FC II and 14 were FC III. Two cases were disqualified, both FC II, and each for a medical problem not related to gall bladder disease. Of the total of 56 cases, 29 were identified as asymptomatic, 21 were treated with a laparoscopic cholecystectomy, 3 with a cholecystectomy (not specifically described), and 3 treated via other procedures. The 27 treated cases would not necessarily have required a waiver assuming they recovered well and did not require a waiver for any other diagnosis.
Army: Over a recent two year period there were 1,741 unique rated aircrew encounters filed in the Army Aeromedical Epidemiological Data Repository . Among these five were coded for cholelithiasis leading to one suspension.
Navy: Not available at this time
Civilian: Statistical data are not maintained for this medical condition.
ICD 9 code for Gallstones
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Prepared by Dr. Dan Van Syoc