A 57-year-old woman presents to the emergency department for severe, constant, right upper quadrant abdominal pain for the past week. Over this time period, she reports inability to pass bowel movements or flatus, and she endorses nausea with a few episodes of non-bloody, non-bilious vomiting. She has a history of recurrent cholelithiasis but has declined surgery in the past. Vital signs are within normal limits except for a heart rate of 110 beats/min. Physical examination reveals that her abdomen is diffusely tender and distended with hypoactive bowel sounds. Abdominal X-ray shows free air in the biliary tree.
Which of the following describes the pathophysiology of the most likely complication of the patient's gallstone condition?
C) Gallstone passage through a fistula between the gallbladder and small bowel causing impaction at the ileocecal valve
The vignette most likely describes gallstone ileus, a relatively uncommon complication of cholelithiasis that occurs due to an aberrant connection between the gallbladder and small bowel. The combination of fever and right upper quadrant abdominal pain with signs of a small bowel obstruction (SBO) point toward impaction of the gallbladder within the gastrointestinal tract. The presence of free air in the biliary tree (pneumobilia) is a supportive feature of gallstone ileus.
Answer choice A: Acute inflammation of the gallbladder due to calculous deposits at the cystic duct, is incorrect. This describes acute cholecystitis, which presents with fever and right upper quadrant pain without jaundice. Pneumobilia may be present in cases of emphysematous cholecystitis if there is infection with gas-forming organisms, though air is typically trapped in the gallbladder itself rather than the greater biliary tree. Additionally, cholecystitis classically does not present with signs of SBO.
Answer choice B: Common hepatic duct obstruction due to extrinsic compression from an impacted gallstone in the cystic duct, is incorrect. This descriptor fits the diagnosis of Mirizzi syndrome, which classically presents with fever, jaundice, and right upper quadrant abdominal pain. Mirizzi syndrome is less likely in this case due to the absence of jaundice. Additionally, it classically does not present with signs of SBO.
Answer choice D: Obstruction of the common bile duct due to dislodged gallstone, is incorrect.
This describes ascending cholangitis, a serious inflammation of the common bile duct that presents with a triad of fever, jaundice, and right upper quadrant abdominal pain as in Mirizzi syndrome. Pneumobilia may be present in cases of infection with gas-producing organisms such as C. perfinges. However, ascending cholangitis classically does not present with signs of SBO.
Answer choice E: Obstruction of the pancreatic duct due to dislodged gallstone, is incorrect.
This describes gallstone pancreatitis. Although fever and nausea may be present, this more classically presents with epigastric pain. Additionally, gallstone pancreatitis classically does not present with signs of SBO.
Key Learning Point
Gallstone ileus is a relatively uncommon complication of cholelithiasis that occurs due to an aberrant connection between the gallbladder and small bowel.
