Information conveyed to urologists regarding laser fiber diameter is incorrect, says new study

Neither the total nor the core diameters of laser fibers correspond to the advertised laser fiber diameter, revealed a new study investigating lasers used for urological surgery. Furthermore, there are serious differences between manufacturers of fibers with a supposedly equal diameter.

The new study, conducted by Dr. Peter Kronenberg of Hospital Fernando Fonseca in Amadora, Portugal, and Prof. Olivier Traxer of the Hôpital Tenon in Paris, France, aimed to objectively confirm the between of supposed equal thickness by different brands.

According to Dr. P. Kronenberg, who recently presented the findings at the 2nd Meeting of the EAU Section of Urolithiasis (EULIS) in Copenhagen, Denmark, urologists need to know the exact technical specifications of the material they use.

"If the information conveyed to them, whether written on a product label or transmitted by an industry representative, is incorrect, their judgments and the decisions they make based on this knowledge may have surgical repercussions," he explained.

"And yet our measurements and survey suggest that most information conveyed to urologists regarding laser fiber diameter is incorrect and that the large majority of industry representatives are not aware of the real diameter of the laser fibers they represent."

The findings should warrant attention from the urological community, as larger than advertised laser fibers influence irrigation flow, visibility, scope and stone retropulsion.

In the course of the study 14 different brand-new laser fibers of 6 leading brands (with advertised diameters of 200, 270, 272, 273, 365, and 400 µm, including single use and re-usable fibers) were assessed through . Multiple measurements of both the total diameter (including fiber coating) and the fiber core diameter were performed and compared to their respective advertised diameter. A 10% diameter deviation was considered as the maximum tolerance margin to be acceptable due to manufacture procedures. In addition to that, representatives of those brands at the top two major urology congresses were questioned on what the real diameter of their fibers were and if said diameter was the total diameter or only its core.

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 µm in core diameter between manufacturers.

"Due to the ever increasing miniaturization of the instruments today, small differences in laser fiber diameter have 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 the course of the study might warrant the researchers to look into other technical specifications of these and other materials used in endourology.

"It is highly necessary to see if the materials we use are in conformity with the provided information and if there are significant inter-manufacturer differences between materials with supposedly equal characteristics."

The study won the Clinical Research Award at the 2nd EULIS.

More information: Reference: P. Kronenberg and O. Traxer; The truth about laser fiber diameters, Abstract E60, 2nd Meeting of the EAU Section of Urolithiasis (EULIS).

add to favorites email to friend print save as pdf

Related Stories

Data highway for quantum information

Jun 12, 2013

Researchers at the Vienna University of Technology quantum mechanically couple atoms to glass fiber cables. Now, they have shown that their technique enables storage of quantum information over a sufficiently ...

Recommended for you

Were clinical trial practices in East Germany questionable?

10 hours ago

Clinical trials carried out in the former East Germany in the second half of the 20th century were not always with the full knowledge or understanding of participants with some questionable practices taking place, according ...

Schumacher's doctor sees progress after injury

Oct 23, 2014

A French physician who treated Michael Schumacher for nearly six months after the Formula One champion struck his head in a ski accident says he is no longer in a coma and predicted a possible recovery within three years.

User comments