The morphological, in situ effects of a self-reinforced bioabsorbable polylactide (SR-PLA 96) ureteric stent; An experimental study

Purpose: The present study was done to evaluate the biocompatibility of a n ew biodegradable double helical spiral self-reinforced poly-L,D-lactide cop olymer (L/D ratio 96/4, SR-PLA96) ureteric stent. Materials and Methods: In sixteen dogs, the right ureter was cut transversa lly, sutured and stented with a 50 mm. long SR-PLA 96 stent. In eight dogs, left ureter was similarly operated and stented with a double-J pigtail ste nt (C-Flex, Cook Urological Inc.), while eight remaining ureters served as plain controls. Urine was analyzed for signs of infection, The dogs were te rminated at 6, 12 and 24 weeks postoperatively and the ureters dissected to find persistent SR-PLA 96 particles or local ureteric changes. Histologic samples were taken at three levels of dissected ureters in contact with the stent. Results: C-Flex and SR-PLA 96 materials were well tolerated. Both of these induced only minimal ureteral wall edema, epithelial hyperplasia, epithelia l destruction and inflammatory cell reaction. In SR-PLA 96 stented ureters the tissue reaction subsided after the degradation of the device. Conclusions: SR-PLA 96 spiral stent is regarded highly compatible and SR-PL A 96 might be a suitable material for a partial ureteric stent. Biodegradat ion of a SR-PLA 96 stent makes stent removal unnecessary.