43 posters, 
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154 authors, 
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ePostersOnline®, by the PosterGenius® team

PP-04

A new design of anti-reflux ureteral stent versus double j ureteral stent. Comparative study on animal model

Saturday, 29 June, 2013 - 11:10
Board 1

Poster Presenter: F. Soriafsoria@ccmijesususon.com

Objective. Comparison of the effectiveness of a new ureteral stent design (pending patent) which does not cause vesicoureteral reflux (SARP) versus a double pigtail ureteral stent (JJ) in a porcine model.

Material and methods.A total of 12 pigs were used in this study. This study consisted of three phases: Phase I, after sonographic and contrast fluoroscopic evaluation, we proceed to measure the internal diameter of the ureteropelvic junction (UPJ) in both kidneys, and continued with the stenting in the right nefroureteral unit with the new design SARP (3Fr) and in it left nefroureteral unit a double pigtail ureteral stent (4Fr). Phase II, after 6 weeks repeated sonographic and fluoroscopic assessment, and removed both ureteral stents. Phase III, 5 months follow-up, which includes the aforementioned diagnostic methods and pathologic examination with histological score.

Results. We found statistically significant differences in the evolution of the internal diameter of the UPJ between Phase I vs. Phase II and III, but not between groups. 4 ureteral pigtail stents migrated versus 2 in the SARP group. There were not statistically significant differences in renal resistance index, or the variation of the degree of hydronephrosis between the two groups around the different phases. JJ Group has a 66.6% vesicoureteral reflux (filling phase) in Phase II and 16.6% in Phase III by 0% in both phases in SARP group. In Phase II, all animals shown near of the left ureteral orifice: hyperplastic inflammatory infiltrate with pseudopapillary surface structure in the bladder neck with dilated left ureteral orifice and hyperemic bladder neck mucosa. Not showing changes in right ureteral orifice (SARP group). After pathologic assessment not statistically significant differences were shown at UPJ level, however, if there were in the ureterovesical junction (UVJ) showed a greater degree of injury in the JJ group, with changes at the level of "fibrosis of the muscular layer" and "inflammation wall ".

Conclusions. In view of the results obtained in our study, the newly designed antireflux ureteral stent, achieved dilated upper urinary tract without changes in UVJ. The SARP group does not show any side effects associated with ureteral pigtail stents at UVJ level and bladder neck, so that their tolerance in patients will be presumably better to current designs. The design of this new stent is prepared to manufacture biodegradable material and evaluate it in endourologic therapeutic approach.