Table 2.

Technical procedural differences in performing EUS and ERCP in a patient with situs inversus totalis

Procedure steps	EUS with normal anatomy	ERCP with normal anatomy	EUS with SIT	ERCP with SIT
Position	Left lateral decubitus	Prone position	Left lateral decubitus	Prone position
Scope maneuver to enter the second portion of the duodenum	Move the tip of the scope to the right and upward	Move the tip of the scope to the right and up	Move the tip of the scope to the left and down	Move the tip of the scope to the left and down
Cannulation of the bile duct	N/A	The bile duct direction is usually at 11–12 o'clock position at the ampulla.	N/A	The bile duct direction is usually at 12–1 o'clock position at the ampulla.
Visualization of the bile duct	Pull the tip of the scope close to the wall at the duodenal bulb	If the contrast is injected into the ampulla, expect the cholangiogram to fill from the ampulla upward and slightly to the patient's right.	Pull the tip of the scope close to the wall at the duodenal bulb	If the contrast is injected into the ampulla, expect the cholangiogram to fill from the ampulla upward and slightly to the patient's left.
Visualization of the pancreas	Pull the scope slowly turning the scope clockwise	If the contrast is injected into the ampulla, expect the pancreatogram to fill from left to right.	Pull the scope turning the scope counterclockwise	If the contrast is injected into the ampulla, expect the pancreatogram to fill from right to left.

ERCP, endoscopic retrograde pancreatography; EUS, endoscopic ultrasound; SIT, situs inversus totalis.