Microsurgical urology: A silicone cover to protect the ureter from induced retroperitoneal fibrosis in rats

Retroperitoneal fibrosis was induced in 30 rats by placing a paraffin pellet containing 5 mg of phenol‐mandelic acid behind the left ureter. In an additional 15 rats, the left urinary tract was transposed into a silicone sheath before the pellet of phenol‐mandelic acid was placed behind the ureter in an attempt to protect the urinary tract from retroperitoneal fibrosis. In all 30 animals without the sheath, hydronephrosis of the left side occurred, and in the 15 animals with the sheath, lateral and anterior displacement of the left tract occurred, but function was not impaired. It is concluded that the silicone‐sheath technique may represent a new therapeutic approach to retroperitoneal fibrosis.