Factors predisposing to urinary tract infection after J ureteral stent insertion

Purpose: We determined the group of patients most likely to have bacterial infection or colonization of J stents inserted to relieve ureteral obstruction. Materials and Methods: Midstream urine from 250 consecutive patients who required indwelling J stent insertion obtained before stent insertion and on the day of stent removal was analyzed by microbiological testing. At stent removal 3 to 5 cm. of the stent tip located inside the bladder was also sent for culture. Patient sex, duration of stent insertion and systemic disease, such as diabetes mellitus, chronic renal failure or diabetic nephropathy, were recorded. Patients without systemic disease were classified as normal. The rates of bacteriuria, stent colonization and symptomatic urinary tract infection were compared in patients with and without systemic disease. Results: Of the 250 patients studied 180 (72%) were men and 70 (28%) were women, while 152 (60.8%) had no systemic disease, 27 (10.8%) had diabetes mellitus, 53 (21.1%) had chronic renal failure and 18 (7.2%) had diabetic nephropathy. The bacteriuria rate was 4.2% for stents removed within 30 days and 34% for stents removed after 90 days (p <0.001). Overall the bacteriuria rate in women was 24.3% compared with 13.9% in men (p <0.06). The rate of bacteriuria in normal patients was significantly lower (3.3%) than in patients with diabetes mellitus, chronic renal failure and diabetic nephropathy (33.3%, 39.6% and 44.4%, respectively, p <0.001). The colonization rate of the tip of the stent was higher in women (64.3%) than in men (34.7%). The stent was removed prematurely in 9 of the 250 patients (3.6%) because of septicemia, including 7 women (77.8%) with systemic disease. Conclusions: The risk of bacteriuria and colonization of the J stent tip is significantly enhanced by the duration of stent retention, patient sex and the systemic disease, such as diabetes mellitus, chronic renal failure and diabetic nephropathy. These categories of patients should undergo shorter stent retention, antimicrobial prophylaxis and careful followup to minimize infectious complications.