| objective:To research ideal replacement material to reconstructe long ureteral defect, experimental Beagle dog models were established. Reconstruction of the new ureter was performed by inversive folding intestinal sero-muscular segment. The survival,unobstruction,absorption of urine and histologic examination of substitute ureter were observed postoperatively. This animal study provided the basic ground for further clinical application of substitute ureter.Methods:12 Beagle dogs were randomly divided into 2 groups, and their body weight was 6.2kg-8.6kg. In group A,a 6 centimeter artificial ureter segment was constructed by inversive folding intestinal seromuscular segment.2weeks,4weeks and 6weeks after operations, biochemical criterion and histologic examination of the constructed artificial ureter was carried out, and six weeks after oprations,intravenous urography(IVU) of the dogs was conducted. In groups B,a 10 centimeter artificial ureter was constructed as group A.2weeks,4weeks and 6weeks after operations, biochemical criterion and histologic examination of the constructed artificial ureter was conducted, six weeks after operations, IVU of the constructed artificial ureter was also performed.Results:none of the dogs died after operation, and necrosis of artificial ureter didn't occur. Serious complications were two ureteral strictures, one urinary tract infection and one stent shedding. In group A,2weeks after operations, histological examination showed there were 1-2 layers of transitional cells growing along the serosal surface of the 2 ends of artificial ureter.In the 4weeks postoperative day, the surface of artificial ureter were covered by 3-4 layers of transitional cells.6weeks after opration,histologic examination of the reconstructed ureter was as similar as the normal ureter. In group B,2weeks after operations, histological examination showed there were 1-2 layers of transitional cells growing along the serosal surface of the 2 ends of artificial ureter.In the 4weeks postoperative day,the surface of artificial ureter were covered by 2-3 layers of transitional cells. But six weeks after operations, in histologic examination,the structure of the reconstructed ureter was as similar as the normal ureter. IVU showed good visualization of the reconstructed ureter, there were no anastomotic leakage or hydronephrosis found. There were no difference in BUN, Cr, and electrolytes in preoperation and postoperation.Conclusion:Transitional epithelium may creep and grow in intestinal seromucular segment. Reconstruction short defect of ureter by inversive folding intestinal seromucular segment is as similar as the normal ureter in structure and function. We might use it to substitute long defect of ureter cautiously because study of the modus operandi is initial. The results might provide an experimental basis for clinical use. |
