<div>A 70-year-old male patient presented to the Emergency Department with a
history of dyspnea, anorexia, and fever. While waiting for observation,
the patient had a syncope with loss of sphincter control. He was
hypotensive, and tachycardic, had signs of poor peripheral perfusion and
abdominal distension. Laboratory findings showed elevated inflammatory
parameters, acute kidney injury, and metabolic acidemia.</div><div>The patient underwent an abdominal and pelvic computed tomography (CT)
study (Figure 1), which revealed exuberant gastric distention and wall
thickening of the pylorus</div><div>A nasogastric tube was placed, draining 1 liter of gastric content. On
endoscopy the stomach was found to remain filled with abundant content
and the scope could not be passed through the pylorus due to
non-distensibility of its wall.</div><div>A thorough review of the CT study revealed the existence of pneumobilia,
which raised the suspicion of a colecystoenteric fistula. A subtle dense
image was seen inside the pylorus.</div><div>The CT study was repeated with oral contrast material (Figure 2), which
confirmed the presence of a gallstone lodged in the pylorus surrounded
by oral contrast material.</div><div>The patient showed a good clinical evolution after conservative
treatment and was discharged with a referral to a gastroenterologist
appointment for follow-up.</div><div>Gastric outlet obstruction caused by gallstone impaction in the distal
stomach or proximal duodenum is designated Bouveret syndrome. It occurs
most frequently in elderly women. Probably due to the patient’s advanced
age and comorbidities, mortality is still high. Clinical presentation
and laboratory findings are nonspecific. Symptoms may include nausea,
vomits, and epigastric pain. <sup>1</sup></div><div>The presence of the Rigler triad (bowel obstruction, pneumobilia, and an
ectopic gallstone) on the abdominal radiography can be the clue to the
diagnosis. Ultrasound may also suggest the diagnosis, although findings
can be difficult to interpret. CT can demonstrate the Rigler triad and
also the fistula, if it is filled with oral contrast material or air.
The identification of the gallstone may be challenging if it is
radiolucent. As in our case, oral contrast material can be very helpful
because a gallstone surrounded by oral contrast material will be more
easily visualized. In patients unable to take oral contrast material,
Magnetic Resonance cholangiopancreatography may be very helpful for the
detection of radiolucent gallstones. <sup>2</sup></div><div>The preferred therapy approach is endoscopy because patients are
commonly poor surgical candidates. If endoscopic treatment fails,
surgery is needed.<sup>1</sup></div><div>Fast removal of an obstructing stone is important because this condition
causes significant morbidity and mortality. For that reason, prompt
diagnosis is crucial.<sup>2</sup></div><div>References</div><div>[1]Nickel F, Müller-Eschner MM, Chu J, von Tengg-Kobligk H,
Müller-Stich BP. Bouveret’s syndrome: presentation of two cases with
review of the literature and development of a surgical treatment
strategy. BMC Surg. 2013;13:33. Published 2013 Sep 4.
doi:10.1186/1471-2482-13-33</div><div>[2]Brennan GB, Rosenberg RD, Arora S. Bouveret syndrome.
Radiographics. 2004;24(4):1171-1175. doi:10.1148/rg.244035222</div>