Bladder histological changes associated with chronic indwelling urinary catheter

Chronic urinary catheters induce histological changes in the bladder with time. The exact etiology of these changes is postulated to arise from inflammation and local tissue response. We elucidate the incidence of nonmalignant histological change in bladder biopsies of patients with chronic indwelling urinary catheters.

During 7 years 208 spinal cord injured patients underwent bladder biopsies as part of a surveillance program for vesical malignancy. All patients had chronic (more than 8.5 years) indwelling urethral or suprapubic catheters as definitive management for neurogenic voiding dysfunction. Biopsies were obtained from 4 to 6 sites within the bladder, including areas that were visually abnormal. All samples were routinely fixed with hematoxylin and eosin staining, and interpreted by an experienced pathologist.

A total of 17 patients were identified with malignancy, including 10 with squamous cell carcinoma, 5 with transitional cell carcinoma and 2 with adenocarcinoma. Nonmalignant changes occurred in 48 patients (23%) with keratinizing squamous metaplasia or cystitis glandularis, each of which is considered a premalignant lesion.

To our knowledge our study represents the largest group of spinal cord injured patients to undergo biopsy evaluation after chronic catheter use. A spectrum of inflammatory and proliferative pathological conditions were identified, which were predominantly inflammatory and squamous. The need to survey ongoing transitional mucosal changes in this population is underscored by the spectrum of histological abnormalities and the significant occurrence of malignant pathologies in our patients.