Effects of indwelling catheters on the urethral mucosa (polypoid urethritis).

Indwelling catheters are almost invariably associated with characteristic mucosal lesions of the urinary bladder, commonly referred to as polypoid cystitis. In the present study, 20 male patients with indwelling catheters (due to benign prostatic hyperplasia) for 1-12 months were studied. Three non-catheter bearing male patients served as controls. Biopsies were taken from the posterior urethra in all patients and from the bladder in 16 of the 20 patients with indwelling catheters. All patients with catheters had endoscopic lesions in the urethra. The lesions varied from polypoid to bullous or oedematous, with or without hemorrhagic discoloration. In 11 of 20 patients the urethral lesions were histologically almost identical to polypoid cystitis. In the remaining 9 patients the reaction was less pronounced, and oedema, with or without mucosal hemorrhage, dominated. Due to the similarity between the catheter associated bladder lesions and the urethral lesions we suggest the term polypoid urethritis for the urethral lesions. There was no correlation between type of catheter used or how long it was used and the mucosal lesions. The results suggest mechanical irritation and/or pressure exerted by the catheter on the mucosa is responsible for the development of polypoid urethritis.