A New Technique for Ureteral Defect Lesion Reconstruction Using an Autologous Vein Graft and a Biodegradable Endoluminal Stent

Abstract

Ureteral defect lesions are severe complications caused by iatrogenic lesions or trauma. For ureteral defect lesions elaborate surgical intervention is needed, such as autotransplantation or ureteral replacement with small bowel. Thus, we developed a new technique for ureteral defect reconstruction in a pig model using an autologous vein graft splinted by an endoluminal biodegradable poly-L-lactic acid stent (Institute of Textile Technology and Process Engineering, Denkendorf, Germany). In 42 pigs we removed the external jugular vein and used it as an autologous vein graft. After median laparotomy a 3 cm segment was resected from the proximal ureter and replaced by the vein with or without an endoluminal biodegradable poly-L-lactic acid stent. As controls, we used 14 pigs. We observed survival, kidney function, and neoureteral and kidney morphological changes for 7 days and for 6 months. After 6 months the stent material was completely broken down and the vein graft was relined with urothelium. It resembled native ureter with cytokeratin-7 positive columnar epithelium and newly formed capillaries in the ureteral wall. All animals had normal kidney function without renal pelvis congestion. This new technique for ureteral defect reconstruction using an autologous vein graft and a biodegradable endoluminal stent is feasible. It is an interesting alternative in the clinic due to the preservation of physiological urine passage and the antireflux mechanism.