1.04] Analysis of encrustation of double-J catheters with optical coherence tomography (OCT)

Abstract

Objective Encrustation of pigtail catheters with crystalline deposit of urine components is a well-known problem and in addition to lower urinary tract infection, the most common complication of any material placed in the urinary tract. There is neither any data about the beginning of encrustation in literature, nor about location or progression. The aim of this study is to make an analysis of the level of encrustation and to document the longitudinal progression with OCT. Material and methods Fourteen double-J (DJ) catheters (Neomedical Ch 7/28 cm) with different indwelling times were compared with a new DJ catheter as a reference, after removal. The external surfaces of the catheters were examined using endoscopic surface OCT (Imalux) and the intraluminal surfaces with endoluminal-radial OCT (LightLab Imaging) with regard to possible encrustation or crystalline sedimentation. The resolution of OCT was 20 μm. The pullback mode of the endoluminal radial OCT allowed the documentation in 6 μm sequences. Results The median indwelling time was 100 days (19–27 days; n =12 female and n =2 male patients). Firstly, the external encrustation was macroscopically rated in “low”, “medium” and “high”. The macroscopic and the extraluminal OCT results were correlated. With the help of endoluminal OCT, the dimension of intraluminal encrustation could be expressed as a percentage relating to the reference catheter. The luminal reduction caused by encrustation is significant higher at the proximal end of the pigtail. An encrustation at the distal end of the pigtail was only present when there was also an encrustation at the proximal end. Only 2 stents showed an encrustation in the middle part. Conclusion OCT made it possible to detect the encrustation of DJ catheters and express the degree of encrustation quantitatively. The encrustation started at the proximal side and seemed to expand antegrade. Further studies have to be carried out in order to answer the question if an encrustation expands from intra- to extraluminal or vice versa. With the help of OCT, the effect of surface modification of the implanted material could be examined in order to reduce encrustation.