Single-use ureteroscope yields high-quality images

Findings from preclinical studies evaluating the performance of an investigational single-use digital flexible ureteroscope (Lithovue, Boston Scientific) support it as a viable alternative to current non-disposable flexible digital and fiberoptic ureteroscopes, said Brian H. Eisner, MD, at the World Congress of Endourology and SWL in London.

London-Findings from preclinical studies evaluating the performance of an investigational single-use digital flexible ureteroscope (Lithovue, Boston Scientific) support it as a viable alternative to current non-disposable flexible digital and fiberoptic ureteroscopes, said Brian H. Eisner, MD, at the World Congress of Endourology and SWL in London.

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Dr. EisnerDr. Eisner, co-director of the Kidney Stone Program, Massachusetts General Hospital, and assistant professor of surgery, Harvard Medical School, Boston, presented data showing that the single-use ureteroscope provided comparable or better image quality and comparable performance characteristics relative to commercially available instruments.

“There is good rationale for developing a single-use ureteroscope since reusable instruments are expensive, costly to repair, and although not substantiated, may carry a risk for infection transmission. Previously developed single-use or disposable flexible ureteroscopes, however, have not been able to match the performance of reusable devices, and there are no such devices on the market in the United States,” Dr. Eisner said.

“The investigational device we evaluated shows promise. However, our research involved ex vivo and in vivo studies in porcine models, and it remains to be seen if this single-use ureteroscope performs as well in humans and provides the anticipated success with stone removal.”

Image quality of the single-use ureteroscope was compared with that of five digital ureteroscopes and three fiberoptic models. Renal papilla images during ex vivo ureteroscopy in porcine kidneys were captured using each device. Then, in a blinded evaluation, 13 experienced endourologists were asked to rate the quality of each image on a 5-point scale (1=poor, 5=excellent).

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The investigational single-use ureteroscope had the highest mean image quality score (4.59), and in statistical analyses, its score was comparable to that of the best-scoring comparator (a digital ureteroscope, mean score of 4.53) and significantly better than all other tested models (mean score range, 1.69 to 4.25).

Next: Feasibility examined in animal model

Feasibility examined in animal model

A second study examined the feasibility of ureteroscopy using the single-use device in anesthetized pigs. Three experienced endourologists each performed flexible ureteroscopy with and without an access sheath and carried out a laser papillotomy using both the single-use device and a reusable fiberoptic ureteroscope.

Using the single-use instrument, it was possible to access all of the calyces, including the lower calyx, and the endourologists’ assessments showed that it worked well with the basket and the laser, Dr. Eisner reported.

“The pig urinary system can often be more challenging to access with a ureteroscope than in humans because the ureters may be narrower and the renal pelvis tends to be elongated, requiring greater ureteroscope deflection to enter the lower calyces,” he said.

“The single-use ureteroscope was able to enter the lower calyces of each of the pigs, and instruments (baskets, lasers) were deployed in these lower calyces. As in the previous study, the single-use digital instrument also provided superior image quality compared with the fiberoptic scope. Although we must take into account that our study has the limitations of being conducted in a laboratory animal model, these results were encouraging and suggested a high level of performance for this scope.”

Dr. Eisner is a consultant to Boston Scientific and other companies that manufacture ureteroscopes.