PURPOSE: To evaluate the suitability of a bioabsorbable stent as a partial internal catheter after percutaneous endopyelotomy in ureteropelvic junction (UPJ) obstruction therapy. PATIENT AND METHODS: The material for the helical spiral stents was a copolymer of polylactide and glycolide (PLGA; L:G ratio 80/20). The self-reinforcement (SR) was accomplished by heating and drawing by Bionx Implants Ltd, Tampere, Finland. The stents were horn shaped, with an initial outside diameter 6 to 3.0 mm +/- 0.2 mm and a length of 90 mm. The stent was partially degraded before insertion so it would degrade faster from the distal end, proceeding gradually to the proximal end. According to in vitro estimation, the degradation time of the material was 2 to 2.5 months. The railroaded cold-knife technique was used for antegrade endopyelotomy. After relief of the UPJ obstruction, the stent was pushed to the upper ureter. RESULTS: The 37-year-old male patient had under open pyeloplasty 5 years previously. He had a pelvic stone 32 mm in diameter and tight restenosis of the UPJ. Percutaneous lithotripsy, incision of the stenosis, and application of the SR-PLGA helical horn-shaped spiral stent was without early or late complications. Eighteen months after the operation, retrograde pyelography showed the UPJ to be totally unobstructed. CONCLUSIONS: The bioabsorbable horn-shaped SR-PLGA helical spiral stent proved a suitable alternative for stenting of the UPJ after antegrade endopyelotomy, bringing a reduced need for postoperative percutaneous kidney drainage and no need for subsequent stent removal. The bioabsorbable helical stent works as a partial catheter, which prevents vesicoureteral reflux and reduces the risk of postoperative renal infection.
PURPOSE: To evaluate the suitability of a bioabsorbable stent as a partial internal catheter after percutaneous endopyelotomy in ureteropelvic junction (UPJ) obstruction therapy. PATIENT AND METHODS: The material for the helical spiral stents was a copolymer of polylactide and glycolide (PLGA; L:G ratio 80/20). The self-reinforcement (SR) was accomplished by heating and drawing by Bionx Implants Ltd, Tampere, Finland. The stents were horn shaped, with an initial outside diameter 6 to 3.0 mm +/- 0.2 mm and a length of 90 mm. The stent was partially degraded before insertion so it would degrade faster from the distal end, proceeding gradually to the proximal end. According to in vitro estimation, the degradation time of the material was 2 to 2.5 months. The railroaded cold-knife technique was used for antegrade endopyelotomy. After relief of the UPJ obstruction, the stent was pushed to the upper ureter. RESULTS: The 37-year-old male patient had under open pyeloplasty 5 years previously. He had a pelvic stone 32 mm in diameter and tight restenosis of the UPJ. Percutaneous lithotripsy, incision of the stenosis, and application of the SR-PLGA helical horn-shaped spiral stent was without early or late complications. Eighteen months after the operation, retrograde pyelography showed the UPJ to be totally unobstructed. CONCLUSIONS: The bioabsorbable horn-shaped SR-PLGA helical spiral stent proved a suitable alternative for stenting of the UPJ after antegrade endopyelotomy, bringing a reduced need for postoperative percutaneous kidney drainage and no need for subsequent stent removal. The bioabsorbable helical stent works as a partial catheter, which prevents vesicoureteral reflux and reduces the risk of postoperative renal infection.