The total and the core diameters measured were both significantly different from the advertised diameter in all fibers (p<0.00001). If one considers the advertised diameter as the total diameter, none of the fibers had a measured diameter within the 10% tolerance range. The median increase between total diameter and advertised diameter was 85.3% (range 50.7-116.7%), with four of the fibers being more than double as thick as promoted.
If the advertised diameter corresponds to the fiber core diameter, only one fiber respected the 10% margin, the rest of the fibers having a median increase in core diameter of 30.9% (range 16.7-80.1%). The measurement of core diameters of fibers with a supposed equal diameter revealed differences of up to 100 m in core diameter between manufacturers.
"Due to the ever increasing miniaturization of the instruments today, small differences in laser fiber diameter have repercussions on flexibility, irrigation flow and indirectly on visibility and operating time of ureterorenoscopy," commented Kronenberg on the findings. "And we detected differences in all fibers tested, sometimes well over 100%."
Additionally, in the enquiry, 4 out of 12 representatives said the advertised diameter to be the core diameter, acknowledging that the total fiber diameter was thicker than advertised. Only 1 of those 4 representatives admitted that the core diameter of his fibers was in fact bigger than advertised. The majority of representatives promoted the advertised diameter as the total diameter.
Referring to the implications of the study, Kronenberg explained that such large discrepancies found in
European Association of Urology