Ureteral Access Sheath Influence on the Ureteral Wall Evaluated by Cyclooxygenase-2 and Tumor Necrosis Factor-α in a Porcine Model

Abstract

Objective: To examine the effect of ureteral access sheath (UAS) on the expression of the pro-inflammatory mediators cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) in the ureteral wall.Material and Methods: In 22 pigs an UAS was inserted and removed after 2 minutes on one side and 2 hours on the contralateral side. Postoperatively ureters were excised in vivo, and tissue samples from the distal (2 minutes/2 hours) and proximal ureter (2 minutes/2 hours) were snap-frozen before quantitative polymerase chain reaction analysis of COX-2 and TNF-α. Five unmanipulated ureteral units from other pigs served as the control group.Results: Compared to controls COX-2 mRNA was significantly upregulated in all UAS treated ureteral groups. Similarly, TNF-α mRNA was upregulated in all groups except the 2-minute proximal ureteral group. Both COX-2 and TNF-α expression were significantly higher in the distal than in the proximal ureter in the UAS treated ureters. After UAS insertion for 2 minutes, expression levels in the distal ureter were increased 6.5- and 8-fold for COX-2 and TNF-α, respectively; and after 2 hours of UAS placement COX-2 and TNF-α mRNA expression levels were increased 9- and 9.5-fold, respectively.Conclusion: The pro-inflammatory mediators COX-2 and TNF-α were significantly upregulated in the ureteral wall by the influence of UAS. These findings may have implications for postoperative pain, drainage, and complications.

Histopathological correlations to ureteral lesions visualized during ureteroscopy

“…During histopathological scoring of lesions, other observations were made, such as profound ureteral dilatation sometimes accompanied by total epithelial denudation but without lesion of the muscular coat; de-epithelialization with luminal fibrin casts; sub-mucosal edema and hematoma; acute neutrophil inflammation often with angiocentric location; and focal necrosis. These findings correspond with previous findings demonstrating a marked up-regulation of proinflammatory mediators in the ureteral wall following UAS usage [ 5 ]. Interestingly, we also saw varying degrees of focal eosinophilia, at times very profound and located under the mucosal or deep in the muscular layers.…”

Histopathological correlations to ureteral lesions visualized during ureteroscopy

“…During histopathological scoring of lesions, other observations were made, such as profound ureteral dilatation sometimes accompanied by total epithelial denudation but without lesion of the muscular coat; de-epithelialization with luminal fibrin casts; sub-mucosal edema and hematoma; acute neutrophil inflammation often with angiocentric location; and focal necrosis. These findings correspond with previous findings demonstrating a marked up-regulation of proinflammatory mediators in the ureteral wall following UAS usage [ 5 ]. Interestingly, we also saw varying degrees of focal eosinophilia, at times very profound and located under the mucosal or deep in the muscular layers.…”

Comparison of Frictional Forces Among Ureteral Access Sheaths and Urinary Tract Dilators in a Novel Ex Vivo Porcine Ureteral Model

“…20 Although UAS design has evolved significantly, the risk of ureteral injury and subsequent stricture formation persists. 6,[21][22][23][24][25][26] Previous studies conducted by Loftus et al and Elsaga et al comparing the Cook Flexor ® and the Boston Scientific NavigatorÔ HD noted no significant difference in ureteral injury rates. 5,26 However, in neither study was the force of UAS placement measured, and both studies were marred by relatively small sample sizes.…”

Does ureteral access sheath have an impact on ureteral injury?

“…Two studies showed that the insertion of UAS increased the fibroblastic precursors. [ 4 5 ] The one study was performed in a rabbit model, either 2 or 3 Fr ureteral catheter was introduced to ureter for 1–4 h. The fibrotic activity in the ureters was investigated after a month. [ 4 ] Seventy-two ureter units were investigated.…”

“…The other study included 22 pigs, a 13–15 Fr UAS was inserted either for 2 min or for 2 h. The ureteral COX-2 and TNF-alpha levels were analyzed. [ 5 ] Higher preinflammatory mediators were found to be related to the presence of the UAS and longer indwelling periods (2 h).…”

Histopathological correlations to ureteral lesions visualized during ureteroscopy

“…During histopathological scoring of lesions, other observations were made, such as profound ureteral dilatation sometimes accompanied by total epithelial denudation but without lesion of the muscular coat; de-epithelialization with luminal fibrin casts; sub-mucosal edema and hematoma; acute neutrophil inflammation often with angiocentric location; and focal necrosis. These findings correspond with previous findings demonstrating a marked up-regulation of proinflammatory mediators in the ureteral wall following UAS usage [ 5 ]. Interestingly, we also saw varying degrees of focal eosinophilia, at times very profound and located under the mucosal or deep in the muscular layers.…”

Comparison of Frictional Forces Among Ureteral Access Sheaths and Urinary Tract Dilators in a Novel Ex Vivo Porcine Ureteral Model

“…20 Although UAS design has evolved significantly, the risk of ureteral injury and subsequent stricture formation persists. 6,[21][22][23][24][25][26] Previous studies conducted by Loftus et al and Elsaga et al comparing the Cook Flexor ® and the Boston Scientific NavigatorÔ HD noted no significant difference in ureteral injury rates. 5,26 However, in neither study was the force of UAS placement measured, and both studies were marred by relatively small sample sizes.…”

Does ureteral access sheath have an impact on ureteral injury?

“…Two studies showed that the insertion of UAS increased the fibroblastic precursors. [ 4 5 ] The one study was performed in a rabbit model, either 2 or 3 Fr ureteral catheter was introduced to ureter for 1–4 h. The fibrotic activity in the ureters was investigated after a month. [ 4 ] Seventy-two ureter units were investigated.…”

“…The other study included 22 pigs, a 13–15 Fr UAS was inserted either for 2 min or for 2 h. The ureteral COX-2 and TNF-alpha levels were analyzed. [ 5 ] Higher preinflammatory mediators were found to be related to the presence of the UAS and longer indwelling periods (2 h).…”

Histopathological correlations to ureteral lesions visualized during ureteroscopy

“…During histopathological scoring of lesions, other observations were made, such as profound ureteral dilatation sometimes accompanied by total epithelial denudation but without lesion of the muscular coat; de-epithelialization with luminal fibrin casts; sub-mucosal edema and hematoma; acute neutrophil inflammation often with angiocentric location; and focal necrosis. These findings correspond with previous findings demonstrating a marked up-regulation of proinflammatory mediators in the ureteral wall following UAS usage [ 5 ]. Interestingly, we also saw varying degrees of focal eosinophilia, at times very profound and located under the mucosal or deep in the muscular layers.…”

Comparison of Frictional Forces Among Ureteral Access Sheaths and Urinary Tract Dilators in a Novel Ex Vivo Porcine Ureteral Model

“…20 Although UAS design has evolved significantly, the risk of ureteral injury and subsequent stricture formation persists. 6,[21][22][23][24][25][26] Previous studies conducted by Loftus et al and Elsaga et al comparing the Cook Flexor ® and the Boston Scientific NavigatorÔ HD noted no significant difference in ureteral injury rates. 5,26 However, in neither study was the force of UAS placement measured, and both studies were marred by relatively small sample sizes.…”

Does ureteral access sheath have an impact on ureteral injury?

“…Two studies showed that the insertion of UAS increased the fibroblastic precursors. [ 4 5 ] The one study was performed in a rabbit model, either 2 or 3 Fr ureteral catheter was introduced to ureter for 1–4 h. The fibrotic activity in the ureters was investigated after a month. [ 4 ] Seventy-two ureter units were investigated.…”

“…The other study included 22 pigs, a 13–15 Fr UAS was inserted either for 2 min or for 2 h. The ureteral COX-2 and TNF-alpha levels were analyzed. [ 5 ] Higher preinflammatory mediators were found to be related to the presence of the UAS and longer indwelling periods (2 h).…”