Review Question - QID 104551

Artificial cardiac valves can lead to longstanding hemolysis that results in the generation of pigmented, black gallstones due to reabsorption of elevated bilirubin.

The cause of acute cholecystitis is usually a gallstone obstructing the cystic duct resulting in subsequent inflammation and infection. Few patients with gallstones develop acute cholecystitis. Pain in acute cholecystitis is caused by gallbladder wall inflammation. It often persists for several days and may radiate to the right shoulder or scapula. Patients may have nausea, vomiting, and appetite loss. On physical examination, the key findings are right upper quadrant tenderness, rebound tenderness, and a positive Murphy sign (inspiratory arrest during deep palpation of the right upper quadrant) though this feature is not always present. Patients may also have a low grade fever and elevated white count. The cornerstone of diagnosis is the right upper quadrant ultrasound, not a CT scan. A radionuclide scan (HIDA scan) may be used when the ultrasound is inconclusive. Cholecystectomy within the first 24 to 48 hours of symptoms is the preferred treatment. On examination of the stones after resection, black stones may indicate chronic hemolysis caused by sickle cell disease, thalassemia, hereditary spherocytosis, or cardiac valves, while brown stones are more often found in alcoholic cirrhosis.

Kiewiet et al. conduct a systematic review and meta-analysis of diagnostic imaging in acute cholecystitis. Although ultrasonography is often prized for its high sensitivity and specificity, the sensitivity of cholescintigraphy was found to be 96%, while that of ultrasonography was 81% and magnetic resonance imaging 85%.

Figure A demonstrates a surgically removed gallbladder and several associated black stones, consistent in appearance with pigmented gallstones.

Incorrect Answers:
Answer 2: Crohn disease affecting the terminal ileum increases the risk of cholelithiasis due to impaired bile acid reabsorption. However, these patients develop cholesterol stones. Pigmented stones are not associated with Crohn disease.

Answer 3: Cystic fibrosis can lead to the development of cholelithiasis due to impaired excretion of bile acids. However, these patients develop cholesterol stones. Pigmented stones are not associated with cystic fibrosis.

Answer 4: Diabetes mellitus, especially when uncontrolled, may lead to impaired immune function and worsening outcomes in cholecystitis such as emphysematous cholecystitis. However, diabetes mellitus is not associated with pigmented gallstones.

Answer 5: Hyperlipidemia may predispose to the development of cholelithiasis due to over-saturation of cholesterol in bile. However, patients would be expected to develop cholesterol stones as opposed to pigmented stones.

Bullet Summary:
Patients with artificial heart valves often have chronic hemolysis, which may predispose to the development of pigmented gallstones and cholecystitis as a result.