Advanced techniques in ERCP

Endoscopic Retrograde Cholangiopancreatography (ERCP), first described over 50 years ago, has fundamentally remained unchanged. Despite the potential for technical and clinical innovations in the x-ray field, their implementation has progressed at a slow pace. ERCP is a common procedure that is both cost- and resource-intensive but there is a notable absence of tools to assist with scheduling, and the topic of ERCP duration remains largely unexplored. The technique of implanting multiple plastic stents side by side in the pancreatic duct has been well known for nearly 20 years, yet its role remains ambiguously defined. The 4 projects described in this thesis investigated clinically relevant yet scientifically insufficiently explored topics in ERCP with the goal of advancing the technique and improving clinical care.

In Studies I and II, we aimed to adapt the use of advanced imaging techniques for ERCP. Study I assessed radiation doses during ERCP with cone beam computed tomography (CBCT) and discussed lessons learned from early clinical experiences with this technique. We showed that, although CBCT requires more radiation, doses were moderate, and highlighted the importance of appropriate case selection. Study II is the first-ever description of image fusion technique used during ERCP which proved feasible and helpful in most cases.

In Study III, we created and validated the first specific tool for estimating ERCP duration using large datasets from a national database. A simple addition score achieved estimation of the expected ERCP duration with a mean absolute error of 17 min.

Study IV focused on treating pain in chronic pancreatitis with multiple plastic stents in the pancreatic duct. We demonstrated that ERCP with multiple plastic stents is safe and effective for pain relief in patients with co-morbidities in which the risk of standard treatment with surgical resection of the pancreatic head is high. However, our results also highlighted that pain relapse is common in the long- term.

Our studies demonstrate that an open-minded approach to established techniques might lead to new knowledge and could help paving the way for broader clinical use of advanced ERCP techniques in the future.

List of scientific papers

I. Radiation dose in cone beam CT guided ERCP Alexander Waldthaler, Marcus Reuterwall Hansson, Urban Arnelo, Nils Kadesjö European Journal of Radiology 2020; 123.108789
https://doi.org/10.1016/j.ejrad.2019.108789

II. Bimodal ERCP, a new way of seeing things Marcus Reuterwall Hansson, Alexander Waldthaler, Jeanne Lubbe, Nils Kadesjö, Raffaella Pozzi Mucelli, Marco Del Chiaro, Johannes-Matthias Löhr, Urban Arnelo Endoscopy International Open 2020; 8: E368-E376
https://doi.org/10.1055/a-1070-8749

III. Predicting ERCP procedure time - the SWedish Estimation of ERCP Time (SWEET) tool Alexander Waldthaler, Anna Warnqvist, Josefine Waldthaler Miroslav Vujasinovic, Poya Ghorbani, Erik von Seth, Urban Arnelo, Johannes-Matthias Löhr, Annika Bergquist Endoscopy 2025; 57: 31-40
https://doi.org/10.1055/a-2371-1367

IV. Multiple plastic stents for treatment of obstructive chronic pancreatitis Alexander Waldthaler, Ebba Asplund, Paula Steiner, Laura Vossen Engblom, Erik von Seth, Miroslav Vujasinovic, Urban Arnelo, J .- Matthias Löhr, Annika Bergquist [Manuscript]