Comparison of nitinol urethral stent infections with indwelling catheter-associated urinary-tract infections.
OBJECTIVE
To determine the efficacy of intraurethral metal stents in preventing or eradicating urinary-tract infections (UTI) during the management of bladder outlet obstruction (BOO) by comparing the frequency and nature of the infections with indwelling-catheter-associated UTI.


METHODS
The SAS relative-risk test was used to compare the risks of UTI in 76 patients with temporary urethral stents, 60 patients with BOO who had never been catheterized nor stented, and 34 patients with a permanent indwelling urethral catheter (PIUC). Infection was assessed 1 month after placement of the devices. Scanning electron microscopy (SEM) of the proximal and distal pieces of the stents removed from five patients with and five patients without UTI was carried out in a search for predisposing changes on the surfaces.


RESULTS
After insertion of the catheter, UTI developed in 79.4% of the patients who originally had sterile urine. However, after insertion of the stent, UTI developed in only 40.9% of the patients with sterile urine. In 21 (44.6%) of the catheterized patients who had infected urine, UTI was eradicated after stent insertion. The SEM analysis of the stents showed that a thick organic layer had formed only on the infected devices but with no sign of erosion.


CONCLUSIONS
Urinary infection is a significant problem in patients with PIUC but is significantly less frequent and less severe in patients with urethral stents. This advantage of stents over the conventional urethral catheter, in addition to their obvious convenience for the patient, make them good alternatives to reduce the risk of UTI.
Egilmez
Tulga
T
Department of Urology, Baskent University Faculty of Medicine, Adana Teaching & Medical Research Center, Adana, Turkey. tulgaegilmez@yahoo.com
Aridogan
I Atilla
IA
Yachia
Daniel
D
Hassin
David
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D015995:Prevalence; D011859:Radiography; D012307:Risk Factors; D015607:Stents; D014521:Urethra; D001748:Urinary Bladder Neck Obstruction / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000628:therapy*; D014546:Urinary Catheterization / Q000009:adverse effects*; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control*; D014554:Urination; D014555:Urination Disorders / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000628:therapy
D000497:Alloys; C013616:nitinol