E-PTFE GRAFT AS A URINARY TRACT PROSTHESIS

The First Report: The Change of E-PTFE Graft and Bladder Wall after the Partial Replacement of Bladder Wall

Abstract

A piece of E-PTFE (expanded polytetrafluoroethylene) which has been clinically used as an artifical blood vessel and pericardium is recently investigated for its possibility as a prosthesis for urinary tract replacement.
The possible usability of an E-PTFE piece as an artificial ureter has been investigated. The main purpose of this study is to observe the water-proof ability, the adaptation of E-PTFE to tissue and the regeneration process of urinary tract.
Two kinds of E-PTFE sheet graft, Cardiovascular patch^® (fibril length; 30μ) and Pericardial sheet^® (fibril length; under 1μ) were implanted into the defected bladder walls in 8 dogs. Cystographic examinations were performed, and macroscopic and microscopic findings of E-PTFE graft and regenerated bladder walls were observed from 1 week to 6 months after the operation. The results were as followsed:
1) Cystographic examination showed no marked deformity of the bladder wall and no urinary leakage in an anastomotic line.
2) Macroscopically, E-PTFE graft showed the tendency of detachment from the bladder wall.
3) Histologically, granulation tissue was stretching from bilateral ends toward the mid portion of the graft, but there was no neointima 2 weeks after the operation. Thin neointima covered the whole length of the serosa site of the graft 1 month after the operation.
As time passed, neointima grew. And we could observe the regeneration of transitional cell epithelium with partial muscle regeneration 6 months after the operation. However, we could not see the regeneration tissue on the mucosa site of the graft at any time.
4) Cardiovascular patch and Pericardial sheet showed almost the same results.
5) E-PTFE graft made little injurious biological reaction and was useful to assist the regeneration of bladder wall for some period although it was eventually excluded.