ERCP 2.0 : A solution to determine guidewire localization before stent placement, in patients with malignant peri-hilar stricture

Aims Endoscopic retrograde cholangiopancreatography (ERCP), in the setting of peri-hilar malignant stricture, is a complex procedure. Adequate stent placement relies on the identification of the intrahepatic branch(s) which will allow optimal biliary drainage. Thus, comprehension of the biliary anatomy and knowing the localization of the guidewire (i.e. which intra-hepatic branch) before stent placement is of paramount importance. The aim of this study was to create and evaluate a novel tool to determine the guidewire localization, usable per ERCP.

Methods We used 3D segmentation-reconstruction of biliary trees of patients having undergone an MRCP, followed by ERCP for biliary drainage, in the setting of a malignant peri-hilar stricture, between 2018 and 2024, in Saint Antoine and Henri Mondor, Paris Academic hospitals. The 3D-segmentation-reconstruction technique is described in a prior publication of our group [1]. Fluoroscopic images pertaining to the ERCP procedures and post ERCP-CT scans were collected as well. A solution based on a 3D/2D (reconstruction and fluoroscopy) projection and registration was implemented. It consisted in determining in which intra-hepatic branch (3D) the segmented guidewire (2D) had the highest probability of being localized. The diagnostic performances of the solution (sensitivity) were determined and compared to the expert opinion when available (a group of 11 experts reviewed the images of the first 11 cases in a single session). Post ERCP CT scans were analyzed to determine the guidewire localization by extrapolation, based on the location of the stent. This was considered as the ground truth.

Results 3D reconstructions were available for 25 cases. 10 patients were excluded due to the absence of fluoroscopic images or post ERCP CT scan. A total of 15 patients were included for analysis. The mean age was 68.2 (+ /-13.3) years-old, 60% of patients were female, 60% of patients had hilar cholangiocarcinoma. The mean pre ERCP total bilirubin level was 11.58 mg/dL (+ /- 7.7). Unilateral plastic stenting was performed in 14 patients (93%) and bilateral stenting in 1 patient (7%). 16 guidewire localizations were analyzed. The sensitivity of the localization solution was 87.5%. The sensitivity was 100% (4/4) in simple cases and 83% (10/12) in cases of complex biliary trees, with overlapping intrahepatic branches. Comparatively, the expert's sensitivity was 72.7% (8/11).

Conclusions In this pilot study, we analyze the performances of a novel guidewire localization solution in the setting of complex ERCPs. The overall sensitivity was 87.5%, higher than that of experts. Further development is needed to increase performances in complex biliary trees with overlapping branches, before this solution is tested in real time during ERCP procedures.

Publication History

Article published online:
27 March 2025

• References

• 1 Becq A, Szewczyk J, Salin G, Chartier M, Chaput U, Leenhardt R, Dray X, Arrive L, Camus M.. ERCP 2.0: Biliary 3D-reconstruction in patients with malignant hilar stricture Clin Res Hepatol Gastroenterol. 2023; 47 (7) 102172 doi:10.1016/j.clinre.2023.102172. Epub 2023 Jun 26. PMID: 37379653.