Stone formation on polypropylene suture.

Polypropylene is a relatively new suture material with many advantages, which has been demonstrated in experimental studies to be a safe material for urologic operations. However, recently, 2 patients had polypropylene suture at the matrix of urinary calculi. Symptoms from the calculi developed in both patients in the late postoperative period and both had large amounts of fibrosis around the sutured urothelium.