Discussed August 18th, 2006.
The quest for improved endourologic therapies continues as evident in presentations at the 24th World Congress of Endourology meeting. Two independent research groups reported on the effects of ketorolac on the ureter.
(BR2-01 and BR2-10) Nakada and his group showed that pieces of pig ureter, suspended in ketorolac solutions, demonstrated inhibition of ureteral contractility which was directly related to the solution concentration. Denstedt’s research team showed that when ketorolac solutions were instilled intraluminally in rabbit ureters the drug was absorbed into local tissues and blood and this caused minimal urethelial inflammation. Both these studies suggest that ketorolac is safe when applied topically to the ureter and may facilitate acute local treatment of ureteral obstruction associated with stones. This raises the interesting potential of ketorolac impregnated on the surface of ureteral stents for the management of ureteral obstruction.
The research group from the New Jersey Medical School evaluated a common practice of urologists with TUR loops. (BR2-03) They showed that when the resectoscope loop was manipulated to an angle off the manufactured perpendicular position the tensile strength of the loop was reduced by 90 % with one manipulation. Almost 50% of the manipulated loops failed to meet minimum industry required standards. Therefore, surgeon manipulated resectoscope loops reduced the quality of the surgical resection even with only 15 degrees of loop repositioning. These results indicate that surgeons should choose loops with the appropriate manufactured angle prior to their use in TUR cases and avoid manipulation of the loops intraoperatively.
Leveillee’s research team from the University of Miami showed that retropulsion of stones could be reduced by installation of a novel phased transition polymer (PTP) from Pluromed (Woburn, MA). (BR2-05) This polymer solution is a free-flowing fluid at room temperature, but turns into a transparent gelatinous phase at body temperature. In this invitro study, when instilled behind the stone the 1 ml of 20% PTP significantly reduced stone retropulsion and improved stone fragmentation, during holmium laser lithotripsy with a 400 micron fiber. Further in vivo animal studies will be necessary to determine if this stone stabilization with PTP is safe and efficacious before clinical trials can be pursued, but this technology holds promise!
