Exploring Quality of Endoscopic Ultrasonography in Clinical Practice

Two questions regarding use of endoscopic ultrasonography (EUS) have led to the studies described in this thesis. The first question “why are not all bile duct stones, diagnosed at endoscopic ultrasonography, detected during subsequent endoscopic therapy (ERCP)?” has led to the work described in chapters two, three and four. These chapters describe the use of endoscopic ultrasonography in patients with suspected bile duct stones in clinical practice, the interobserver variability amongst endosonographers evaluating video’s of EUS in these patients, and the prevalence of bile duct sludge.
The second question “why is the pathologist unable to make a diagnosis based on the EUS-guided tissue acquisition specimen of a solid pancreatic lesion I provided?” led to the work described in chapters five to eight. In chapters five and seven, the initiation and progression of a multidisciplinary multicenter collaboration, aiming to improve the outcome of EUS guided tissue acquisition, and it’s positive results are described. Chapter six zooms in on different specimen preparation techniques in the cytopathology lab. In chapter eight, nationwide practice variation regarding use and outcome of EUS guided tissue acquisition in pancreatic cancer patients in the Netherlands is described.
The work described in this thesis can provide a starting point for nationwide quality improvement initiatives aiming for reduction of practice variation and improvement of outcome of EUS and EUS-guided tissue acquisition in the Netherlands.