OBJECTIVES: Ureteral stents all share one general goal, drainage, and one major drawback, irritative symptoms in the kidney and bladder. In an effort to preserve drainage while minimizing irritation, a lightweight, self-expanding mesh stent was designed. Herein, we compare the in vivo tissue reaction and flow characteristics of the mesh stent to a standard 7F double-pigtail polyurethane stent. METHODS: Eight female Yucatan minipigs had bilateral stents placed: a mesh stent on one side and a standard 7F stent on the opposite side. Imaging and flow measurements were obtained in 4 pigs at 1 week and in another 4 pigs at 6 weeks. Following this procedure, the stents were removed, and the kidneys, ureters, and bladder were harvested en bloc for a blinded histopathologic analysis. RESULTS: The degree of stent-related tissue reactivity was low for both stents and appeared similar for the ureter and bladder. Overall, the mesh stent resulted in a decrease in inflammation along the urinary tract at 1 week, but this result was statistically insignificant (P = 0.55). Flow rate through the mesh stent tended to be greater than for the polyurethane stent both at 1 week and at 6 weeks. CONCLUSIONS: Overall, the mesh stent appeared to be well tolerated and provided for excellent flow.
OBJECTIVES: Ureteral stents all share one general goal, drainage, and one major drawback, irritative symptoms in the kidney and bladder. In an effort to preserve drainage while minimizing irritation, a lightweight, self-expanding mesh stent was designed. Herein, we compare the in vivo tissue reaction and flow characteristics of the mesh stent to a standard 7F double-pigtail polyurethane stent. METHODS: Eight female Yucatan minipigs had bilateral stents placed: a mesh stent on one side and a standard 7F stent on the opposite side. Imaging and flow measurements were obtained in 4 pigs at 1 week and in another 4 pigs at 6 weeks. Following this procedure, the stents were removed, and the kidneys, ureters, and bladder were harvested en bloc for a blinded histopathologic analysis. RESULTS: The degree of stent-related tissue reactivity was low for both stents and appeared similar for the ureter and bladder. Overall, the mesh stent resulted in a decrease in inflammation along the urinary tract at 1 week, but this result was statistically insignificant (P = 0.55). Flow rate through the mesh stent tended to be greater than for the polyurethane stent both at 1 week and at 6 weeks. CONCLUSIONS: Overall, the mesh stent appeared to be well tolerated and provided for excellent flow.