Intraprocedural mixed‐reality hologram support in endoscopic retrograde cholangiography (ERC) for bile leaks

Endoscopic retrograde cholangiography (ERC) has been reported to be useful in the treatment of bile leaks.1 However, when the bile duct branches from the site of a bile leak are narrow, it is often difficult to identify a location of bile leak. Holograms, which are computer-generated graphics models, have recently been used with mixed reality (MR) techniques as a surgical navigation tool.2 We have previously reported a case using MR technology to project a three-dimensional (3D) hologram image of the bile ducts in space during interventional endoscopic ultrasound (EUS).3 We herein report a case in which navigation using MR technology was useful for identifying the location of a bile leak during ERC. The patient was a 53-year-old male. Seven days after undergoing emergency laparotomy for acute cholecystitis and perforation of the gallbladder, he developed a bile leak (Figure 1a). However, it was difficult to identify the location of a bile leak using magnetic resonance cholangiopancreatography (MRCP) (Figure 1b) of a two-dimensional (2D) image. A 3D hologram of the bile duct was created from MRCP images, and the 3D cholangiogram was projected onto the lenses of the operator and assistants wearing head-mounted displays. The location of the bile leak could thus be identified using a 3D cholangiogram (Figure 2a). Thereafter, we performed ERC (Figure 2b) wearing goggles (Video S1). It was challenging to identify the bile duct branch with a bile leak using 2D images of ERC. However, by referring to the 3D cholangiogram from various angles in real time, and comparing it with the ERC images, the location of the bile leak was successfully identified, thus allowing for the successful placement of the drainage tube in the targeted bile duct branch. The combined use of MR techniques can therefore be useful for identifying the location of a bile leak in small bile duct branches. There are no companies or organizations with which I have a conflict of interest related to the publication of this paper. Video S1. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.