Research and Reports in Urology (Apr 2022)
Imaging and Chemical Analysis of External and Internal Ureteral Stent Encrustation
Abstract
Tal Amitay-Rosen,1 Ishai Dror,2 Yaniv Shilo,3 Brian Berkowitz2 1Department of Physical Chemistry, Institute for Biological Research, Ness-Ziona, 7410001, Israel; 2Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel; 3Department of Urology, Kaplan Medical Center, Affiliated with the Hebrew University of Jerusalem, Rehovot, 7661041, IsraelCorrespondence: Brian Berkowitz, Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel, Tel +972-8-9342098, Fax +972-8-9344124, Email [email protected]: Ureteral stents are effective in alleviating flow disruptions in the urinary tract, whether due to ureteral stones, strictures or extrinsic ureteral obstruction. However, significant stent encrustation on the external and/or internal stent lumen walls can occur, which may interfere with stent functioning and/or removal. Currently, there is only limited, generally qualitative, information on the distribution, mineral structure, and chemical content of these deposits, particularly in terms of stent lumen encrustation.Objective: To quantify, in an initial investigation, external and internal encrustation in representative, intact ureteral stents. The study investigates possible correlations between patterns of external and internal encrustation, determines mineral structure and chemical composition, and examines the potential for stent lumen obstruction even in the absence of external stent wall encrustation.Study Design: High-resolution, laboratory micro-computed tomography (micro-CT) was used to non-destructively image external and internal stent encrustation in four representative stents. X-ray diffractometry (XRD) and scanning electron microscopy–energy dispersive x-ray spectroscopy (SEM-EDS) enabled parallel analysis of mineral structure and chemical content of samples collected from external and internal encrusted material along the distal, proximal and mid-ureteral stent regions.Results: Extensive stent lumen encrustation can occur within any region of a stent, with only incidental or minor external encrustation, along the entire length of the stent. External and internal encrusted materials in a given stent are generally similar, consisting of a combination of amorphous (mostly organic) and crystalline mineral deposits.Conclusion: Micro-CT demonstrates that significant stent lumen encrustation can occur, which can lead to partial or full stent lumen occlusion, even when the exterior stent wall is essentially free of encrusted material.Keywords: micro-computed tomography, stent deposition, mineral composition, obstruction, stent lumen
