PMC9110104_01
Coronal T2 single-shot fast spin echo (SSFSE)-weighted magnetic resonance imaging (MRI) of the abdomen demonstrating small amount of hyperintense ascites surrounding the liver (blue star), and a large heterogeneous, predominantly T2 hypointense signal likely within the duodenal bulb which represents a very large gallstone (red arrow; identified on imaging retrospectively only after endoscopy).
10-1055-s-0041-1739541-i210028-1.jpg
PMC9110104_01_10-1055-s-0041-1739541-i210028-1.jpg
FI210028-1
The gallbladder could not be identified ( Fig. 1 ).
Coronal, orally- and intravenously enhanced computed tomography (CT) of the abdomen demonstrates a large calculus (red arrow) with a few foci of air as well as air within the biliary system (green arrow), suggesting cholecystoenteric fistula. A small amount of ascites surrounds the liver. Subcutaneous air within the right abdominal wall and adjacent to the gluteal muscles due to recent laparoscopy is noted.
10-1055-s-0041-1739541-i210028-2.jpg
PMC9110104_01_10-1055-s-0041-1739541-i210028-2.jpg
FI210028-2
A computed tomography (CT) scan of abdomen with intravenous (IV) contrast confirmed a cholecystoduodenal fistula along with pneumobilia of a nondilated biliary tree ( Fig. 2 ). 
A very large gallstone was found in the bulb.
10-1055-s-0041-1739541-i210028-3.jpg
PMC9110104_01_10-1055-s-0041-1739541-i210028-3.jpg
FI210028-3
 On postop day seven, esophagogastroduodenoscopy (190HD, Olympus) revealed a 5-cm brown, smooth, oval and hard stone along with a 1 to 2 cm stone in the duodenal bulb ( Fig. 3 ).
Fistulous tract opening in the bulb (yellow arrow). Note the epithelization of the tract as well as a stone in the tract or the gallbladder.
10-1055-s-0041-1739541-i210028-4.jpg
PMC9110104_01_10-1055-s-0041-1739541-i210028-4.jpg
FI210028-4
Fig. 4 ). Further advancement of the scope beyond the stones was unsuccessful.
Fragmentation of the large stone using a stiff snare.
10-1055-s-0041-1739541-i210028-5.jpg
PMC9110104_01_10-1055-s-0041-1739541-i210028-5.jpg
FI210028-5
Due to the lack of specialized lithotripsy equipment, a large snare with a stiff wire (Captivator 27 mm; BostonSicentific, MA) was used to break it down by first confirming that only stone was grasped with the snare ( Fig. 5 ), then forcefully and quickly pulling it against the plastic tip of the snare.
Some fragments of the large stone after retrieval. Largest fragment is approximately 3 cm long.
10-1055-s-0041-1739541-i210028-6.jpg
PMC9110104_01_10-1055-s-0041-1739541-i210028-6.jpg
FI210028-6
A total of 15 fragments were retrieved using a roth net, leaving no fragments behind ( Fig. 6 ).