Effect of Stent Duration on Ureteral Healing Following Endoureterotomy in an Animal Model

Abstract

Ureteral strictures were created in 18 minipigs. Six weeks after stricture inducement, endourologic incision with a balloon cutting device was performed and a 7 F internal polyurethane stent was placed. After this step, 14 pigs remained in the study and were randomized into three different groups depending upon the time when the stent was removed: 1, 3 or 6 weeks. Twelve weeks after stricture incision, the pigs were killed, the status of the incised ureteral segment was evaluated histologically, and a healing score was determined. There were no statistically significant overall differences among the mean values of the overall healing score throughout the three different groups. However, when the one-week and the six-week groups (p < .05) were compared with respect to strictures requiring more than one incision due to stricture length greater than 2 centimeters, a more favorable outcome occurred in the 1 week group. Based on these findings it may be reasonable to remove ureteral stents as early as 1 week after endoureterotomy and endopyelotomy.

Antegrade Percutaneous Endoluminal Treatment of Non&ndash;Malignant Ureterointestinal Anastomotic Strictures following Urinary Diversion

“…According to our results, stenting may be advocated for 6–8 weeks, which is also widely accepted in the literature (table 3). However, in animal models, a direct association between stent duration and outcome of endoureterotomy has not been found [29]. Similarly, Wolf et al [24]proved statistically that the duration of stenting (≤4 vs. ≥4 weeks) did not influence the short– and long–term success rate of endoureterotomy in cases of benign ureter stricture and also in cases of ureteroenteric ones.…”

Endoscopic ureteral incision using the holmium:YAG laser

“…17 The utility of leaving stents in place for this length of time is being reviewed, since some authors have reported similar success rates with shorter stenting periods. 13,18 Based on an animal study, Kerbl et al suggested that ureteral stents could be reasonably removed as early as 1 week after endoscopic ureteral incision. 18 Thus, the stent size and duration of stenting are still controversial issues.…”

“…13,18 Based on an animal study, Kerbl et al suggested that ureteral stents could be reasonably removed as early as 1 week after endoscopic ureteral incision. 18 Thus, the stent size and duration of stenting are still controversial issues. The guide wire was cut accidentally by the holmium laser ablation in one case of ureteroenteroanastomotic stricture.…”

Evaluation of Optimal Stent Size after Antegrade Endopyelotomy: An Experimental Study in the Porcine Model

“…In our experimental study, we have adopted a 1-week period of postendopyelotomy stenting. This choice was based on the results of a recent experimental study by Kerbl et al [ 13] using a porcine ureteral stricture model. These authors have demonstrated that after endoureterotomy, stenting durations of 1, 3 and 6 weeks were not statistically different in terms of ureteral healing.…”

“…Nevertheless it would be difficult to evaluate wheth er urine extravasation is less severe with a large caliber indwelling stent that with a 7 F stent. [13].…”