Ureteral stent infections: a prospective study

Bridging the knowledge gap: past, present and future of antibiotic use for ureteral stents

OBJECTIVE

To evaluate the available literature on ureteric stent-related infections, the use of antibiotics and bacterial colonisation to identify the current incidence of stent-related infections, unveil knowledge gaps and generate potential hypotheses for future research.

METHODS

A literature review was conducted using PubMed, Cochrane and urological association websites identifying relevant English literature published between 1983 and January 2024.

RESULTS

There is a worldwide lack of guidelines for antibiotic prophylaxis for stent placement, exchange or extraction. In patients with a negative preoperative urine culture undergoing ureteroscopy and stent placement, it may be considered to only provide prophylaxis in presence of risk factors. However, in pre-stented patients a preoperative urine culture is important to guide prophylaxis during endourological surgery. During stent indwell time, antibiotic prophylaxis does not show any advantage in preventing urinary tract infections (UTIs). There is no strong evidence to support the use of antibiotics at time of stent removal. In the absence of any clear evidence, management strategies for treating UTIs in patients with ureteric stents vary widely. Stent exchange could be considered to remove the biofilm as a potential source of bacteria. Stent culture can help to guide treatment during infection as urine culture and stent culture can differ.

CONCLUSION

In terms of good antibiotic stewardship, urologists should be aware that unnecessary use of antibiotics provokes bacterial resistance. There is a great need for further research in the field of antibiotic prophylaxis and stent-related infections to develop evidence that can help shape clear guidelines for this very common urological practice.

Microbial Colonization Pattern of Indwelling Double J Stents in Children

Background

Indwelling double-J-stent (DJ stent) kept post-urological procedures may cause urinary tract infections (UTIs) due to polymicrobial biofilm formation and colonisation.

Aims

To determine the incidence and microbiological characteristics of DJ stent related UTIs in a paediatric population.

Methods and Material

Patients under the age of 18 admitted for DJ stent removal following pediatric urological procedures were enrolled into the study. Prior to surgical removal of the DJ stent, a urine sample was collected and the stent was cystoscopically removed under anesthesia. The ends of the stent were inoculated into culture media and incubated up to 48 hours. When growth was observed, an antibiogram was obtained using a panel of anti-microbial agents.

Results

The study group consisted of 27 patients (M: F = 23:4) with a mean age of 4.3 years (1 month - 13 years). The commonest indication for stent placement was Pyeloplasty, 19 (70%). Stent colonisation was found in 8 out of 27 patients (29.6%; CI 12-51%) and E.Coli (33%) was the commonest organism. Polymicrobial growth was noted in 4 patients. Organisms were sensitive to Cephaerazone/ Sulbactam and Amikacin, and resistant to other Cephalosporins. All 8 culture positive patients were asymptomatic and a repeat urine culture revealed no growth. Colonisation did not lead to active UTI and post stent removal the urine became sterile.

Conclusions

Microbial colonisation was noted in 30% of patients with indwelling DJ stents. Prior knowledge of culture & sensitivity pattern helps to cover the patients with appropriate antibiotic on the day of stent removal.

Antireflux Ureteral Stent Improves Stent-Related Symptoms and Quality of Life: A Prospective Randomized Controlled Trial

Objectives: To compare the effectiveness of antireflux ureteral stents on improving symptoms and quality of life of patients with ureteral stents. Materials and Methods: We randomized 120 patients with ureteral stone who required ureteral stent placement after ureteroscopic lithotripsy, of which 107 (56 in standard ureteral stent group and 51 in antireflux ureteral stent group) entered the final analysis. Severity of flank pain and suprapubic pain, visual analog scale (VAS), analgesic used after hospitalization, back soreness during micturition, gross hematuria, creatinine abnormality, hydronephrosis grade, symptomatic urinary tract infection (UTI), and quality of life were compared between the two groups. Results: There were no serious complications after operation in all 107 cases. The antireflux ureteral stent group had less flank pain and suprapubic pain (p < 0.05), analgesic used after hospitalization (p < 0.05), back soreness during micturition (p < 0.05), and lower VAS (p < 0.05). The health status index scores (p < 0.05), dimensions of usual activities, and pain/discomfort (p < 0.05) in the antireflux ureteral stent group were statistically better than those in the standard ureteral stent group. There were no significant differences between the groups in creatinine abnormality, hydronephrosis grade, gross hematuria, and symptomatic UTI. Conclusions: The antireflux ureteral stent has the same safety and efficacy as the standard ureteral stent, and is significantly better than the standard ureteral stent in flank pain and suprapubic pain, VAS, analgesic used after hospitalization, back soreness during micturition, and quality of life.

Epidemiology and risk factors for febrile ureteral stent-associated urinary tract infections: A prospective observational cohort study

OBJECTIVES

We aimed to determine the incidence and risk factors of febrile ureteral stent-associated urinary tract infections (FUSAUTI).

METHODS

Hospitalized adult patients with ureteral stent (US) placement or exchange were prospectively enrolled. Patients with kidney transplantation of less than one year were excluded. Patients were followed until US removal/exchange or six months after inclusion.

RESULTS

Out of 663 patients included in the study, 48 had at least one FUSAUTI (cumulative incidence 7.24%; 95% confidence interval [CI] 5.39-9.48). The incidence rate of FUSAUTI was 9.04 (95% CI 6.67-12.2) per 10,000 US-days. Ten patients (20.8%) experienced sepsis or septic shock. The most frequently isolated microorganisms were Escherichia coli (38%), Enterococcus spp. (14.5%), Candida spp. (9%) and Pseudomonas aeruginosa (9%). In multivariable logistic regression analysis, female gender, an age adjusted Charlson comorbidity index score> 3, an urethral stent placement concomitant with US placement, and a history of urinary tract infection within three months were significantly associated with a higher risk of FUSAUTI.

CONCLUSION

After US placement, 7.24% of patients developed at least one FUSAUTI and, in a quarter of cases, a serious infection. Urethral stent placement was the only modifiable risk factor identified. Future interventional studies are needed to reduce FUSAUTI in these patients.

Prevention of device-related infections in patients with cancer: Current practice and future horizons

Over the past several years, multifaceted advances in the management of cancer have led to a significant improvement in survival rates. Throughout patients' oncological journeys, they will likely receive one or more implantable devices for the administration of fluids and medications as well as management of various comorbidities and complications related to cancer therapy. Infections associated with these devices are frequent and complex, often necessitating device removal, increasing health care costs, negatively affecting quality of life, and complicating oncological care, usually leading to delays in further life-saving cancer therapy. Herein, the authors comprehensively review multiple evidence-based recommendations along with best practices, expert opinions, and novel approaches for the prevention of diverse device-related infections. The authors present many general principles for the prevention of these infections followed by specific device-related recommendations in a systematic manner. The continuous involvement and meaningful cooperation between regulatory entities, industry, specialty medical societies, hospitals, and infection control-targeted interventions, along with primary care and consulting health care providers, are all vital for the sustained reduction in the incidence of these preventable infections.

Determination of microbiological characteristics and risk factors associated with bacteriuria and symptomatic urinary tract infection in patients with retained ureteral stents: an observational study

Background

The maintenance of ureteral stents is vital in patients with severe ureteral stricture or ureteral obstruction. This study aimed to identify microbiological characteristics and factors associated with bacteriuria and symptomatic urinary tract infection (UTI) in these patients.

Methods

This study is an observational cross-sectional study. From August 2018 to January 2021, urine samples from 307 consecutive patients who required stent indwelling and had replaced ureteral stents more than once were collected before the replacement procedure and analyzed by microbiological testing. Patient demographics, laboratory test results, and data on dependent functional capacity and indwelling urethral catheter use were collected from all patients. Additionally, ureteral stenting duration and number of previous ureteral stent replacements were reviewed. The primary endpoint was the incidence rate of bacteriuria and extended-spectrum beta-lactamase (ESBL)-producing bacteria. The secondary endpoint was the factors predisposing patients with ureteral stents to bacteriuria, ESBL-producing bacteria, and the development of symptomatic UTIs.

Results

Bacteriuria was observed in 187 patients (60.9%). Among the bacteria identified in urine, Escherichia coli was the most commonly isolated microorganism, followed by Enterococcus, Candida species, Staphylococcus species, Klebsiella, and Pseudomonas. Using multivariate analysis, bacteriuria was significantly associated with old age, female sex, presence of diabetes mellitus, impaired renal function, and longer duration of ureteral stenting. ESBL-producing bacteria were detected in 52 isolates (27.8%). The incidence of ESBL-producing bacteria in urine culture was associated with old age and longer ureteral stenting duration. Additionally, symptomatic UTIs developed in 22 patients (7.2%). Dependent functional capacity, impaired renal function, and longer ureteral stenting duration were significantly associated with symptomatic UTIs.

Conclusions

Infections related to ureteral stents showed a specific microorganism profile and resistance pattern compared to community-acquired UTIs. Additionally, we identified the factors associated with bacteriuria and symptomatic UTI in patients with retained ureteral stents and deduced that these may be associated with better outcomes in patients with retained ureteral stents.

Peri-Ureteral Abscess Formation Following Ureteroscopic Laser Lithotripsy: A Case Report

We report the case of a patient with a previous history of obstructive renal calculus disease who initially presented with a symptomatic calculus in her right mid-ureter, requiring ureteroscopy with laser lithotripsy and ureteral stent placement. Shortly after the removal of the stent, the patient was found to have a peri-ureteral abscess, necessitating percutaneous drainage by interventional radiology, and placement of an additional ureteral stent. Adverse reactions to these procedures are rare and, to our knowledge, this is the only documented case of peri-ureteral abscess as a complication of ureteroscopic laser lithotripsy or of ureteral stenting. In addition to developing a peri-ureteral abscess, this patient also experienced deep vein thrombosis (DVT) and subsegmental pulmonary embolism (PE), which also have not been found to be a common complication of laser lithotripsy or ureteral stent placement in any of the studies that we reviewed for this article. The complications that were previously rare are unfortunately on the rise, possibly in the setting of both increased access to invasive therapies as well as the increased rates of diabetes and obesity. Survivability hinges on prompt recognition and treatment of these complications. In the event that a peri-ureteral abscess is discovered, prompt treatment with broad-spectrum antibiotics is recommended in addition to interventional radiology and urology consultation. Antibiotics should cover conventional intra-abdominal and urologic abscess regimens.

Risk factors in bacterial colonization of internal ureteral stent

A ureteral stent is most broadly used to manage upper urinary tract disorders such as obstruction and prevent post-endoscopic complications. However, the stent may become a niche for bacterial colonization. This study aimed to determine the rate of bacterial colonization and type of bacteria in internal ureteral stents and the risk factors associated with bacterial colonization. This prospective cross-sectional study included 100 consecutive adult patients who had temporary ureteral stenting as preparation for a secondary ureterorenoscopy at Al-Yarmook Hospital/ Baghdad. All included patients were negative for bacterial culture before stenting. Stent and urine culture were performed at the time of stent removal. The colonization rate and bacteriuria in patients with internal ureteral stent were 19% and 9%, respectively. The most common bacteria in-stent and urine were E. coli accounting for 31.58% and 33.33%. Pseudomonas aeruginosa was common in stent culture, representing 21.05%. Positive bacterial culture was confirmed in 19 stents and 9 urine samples. All cases with positive urine samples were also positive for culture. Thus, the sensitivity and specificity of urine culture for detection of stent colonization were 47.37% and 100%, respectively. Diabetes mellitus, chronic renal failure, and prolonged stenting were significantly associated with increased stent colonization. The ureteral stent could be a source of urinary tract infection. The most pathogenic bacteria associated with the ureter stent are E. coli and Pseudomonas aeruginosa. Risk factors associated with stent colonization are diabetes mellitus, chronic renal failure, and prolonged indwelling time.

Epidemiology and risk factors for ureteral stent-associated urinary tract infections in non-transplanted renal patients: a systematic review of the literature

PURPOSE

Pathophysiology and risk factors for Ureteral Stent-Associated Urinary Tract Infection (USAUTI) have been poorly investigated. This situation results in highly diverse practices regarding USAUTI prevention, diagnosis and treatment. The aim of the present study was to describe the epidemiology and risk factors for USAUTI in non-transplanted patients.

METHODS

We conducted a systematic literature review based on a comprehensive PubMed® bibliographic strategy, between October 1998 and March 2020. The methodological quality of the studies included was analyzed according to dedicated grids. The main endpoints were the correlation between different potential risk factors and infection ureteral stent-associated urinary tract infection or colonization rate. Conclusions and their level of evidence were reported on the basis of a critical analysis of the best available scientific evidence. This work has been submitted to a national review, which enabled the potentially divergent opinions of experts to be collected, thereby ensuring adequate quality of data.

RESULTS AND CONCLUSION

Twenty-six studies out of the 505 articles identified, were included in the final analysis. Staphylococcus spp, E. coli, Klebsiella spp, Pseudomona aeruginosa, Enterococcus spp. and Candida spp. were the microorganisms most often responsible for asymptomatic bacteriuria (ABU) or USAUTI. Longer indwelling time, diabetes mellitus, female gender, chronic renal failure, diabetic nephropathy and cancer were identified as risk factors for ABU and ureteral stent colonization. No specific risk factor for UTI was identified in the literature studied. A causal relationship between ureteral stent colonization and USAUTI or urosepsis remains to be demonstrated.

Association of acute pyelonephritis with double-J ureteral stenting: a nationwide population-based case control study

OBJECTIVE

Urinary Tract Infections (UTIs) due to ureteral catheters has been frequently seen. The risk factors of this include both timing and those of the female gender. However, the association of Acute Pyelonephritis (APN) with use of ureteral DJ stents has rarely been investigated.

Materials and Methods: This study enrolled a total of 6,459 patients who were being treated with a ureteral catheter over a 10 year period from the nationwide database of Taiwan's National Health Insurance Bureau. From these subjects, episodes of APN were found in a total of 500 patients. Additionally, 2,000 patients without APN were randomly enrolled as a control group in order to analyze the associated factors.

RESULTS

The results indicate that the percentage of those with regards gender, age, duration of implantation, ureteral stent type, hypertension, T2DM, presence of urinary tract infection, benign prostate hyperplasia and pregnancy status were significantly statistically higher in APN patients than non-APN patients. APN did not associate with the use of antibiotics, urolithiasis, chronic kidney disease, malignancy, or uric acid stone in patients with a ureteral catheter.

Conclusion: In conclusion, patients with a ureteral catheter associated with APN should be given close attention with regards to the above risk factors. Early removal of the catheter is the best policy for the prevention of APN.

Ureteral Stent Microbiota Is Associated with Patient Comorbidities but Not Antibiotic Exposure

Ureteral stents are commonly used to prevent urinary obstruction but can become colonized by bacteria and encrusted, leading to clinical complications. Despite recent discovery and characterization of the healthy urinary microbiota, stent-associated bacteria and their impact on encrustation are largely underexplored. We profile the microbiota of patients with typical short-term stents, as well as over 30 atypical cases (all with paired mid-stream urine) from 241 patients. Indwelling time, age, and various patient comorbidities correlate with alterations to the stent microbiota composition, whereas antibiotic exposure, urinary tract infection (UTI), and stent placement method do not. The stent microbiota most likely originates from adhesion of resident urinary microbes but subsequently diverges to a distinct, reproducible population, thereby negating the urine as a biomarker for stent encrustation or microbiota. Urological practice should reconsider standalone prophylactic antibiotics in favor of tailored therapies based on patient comorbidities in efforts to minimize bacterial burden, encrustation, and complications of ureteral stents.

Uropathogens Preferrentially Interact with Conditioning Film Components on the Surface of Indwelling Ureteral Stents Rather than Stent Material

Despite routine implementation in urology, indwelling ureteral stents pose as a nidus for infection. Conditioning film accumulates on stents, which prime pathogen adhesion, promoting infectious biofilm formation. However, the extent to which conditioning film components play a role in facilitating bacterial adhesion and biofilm formation remains largely unknown. Here, we examined the interaction of previously identified stent-bound conditioning film components (fibrinogen, uromodulin, and albumin) with bacterial uropathogens. Cytoscopically removed stents were incubated with common uropathogens (Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus). Immunofluorescent double staining was performed to study the localization of uropathogens relative to stent-bound conditioning film proteins. Conditioning film components were identified on the external stent surface with some deposition in the inner lumen. Bacteria co-localized with fibrinogen, uromodulin, and albumin, suggesting a potential mechanism for stent-associated infections. Here, we determine strong co-localization between common uropathogenic bacterial species with prominent conditioning film components on ureteral stents. Further functional validation of interactions amongst these uropathogens and conditioning film proteins may enhance clinical management for stent-associated infections and development of improved stent technologies.

Risk Factors of Urinary Tract Infection After Ureteral Stenting in Patients with Renal Colic During Pregnancy

Introduction: To investigate risk factors associated with urinary tract infection (UTI), following ureteral stenting, for patients with renal colic during pregnancy. Patients and Methods: Patients with renal colic during pregnancy who underwent ureteral stenting in The First Affiliated Hospital of Guangzhou Medical University between 2009 and 2019 were examined retrospectively. Ureteral stenting patients who had UTIs after hospital discharge and before delivery were classified as the infected group. Multivariate logistic regression analysis was used to assess the risk factors associated with UTI after ureteral stenting. Results: A total of 102 patients were enrolled into the study. Mean age was 30 years (interquartile range [IQR]: 26-33 years) and mean gestation age was 22 weeks (IQR: 18-28 weeks). UTI occurred in 21 patients (20.6%). Compared with noninfected patients, infected patients had a higher rate of positive urine culture (52.4% vs 13.6%, p = 0.000), kidney stones ≥10 mm (81% vs 35.8%, p = 0.000), residual stones after ureteral stenting (71.4% vs 43.2%, p = 0.021), and different surgical indications and gestational ages (18 vs 23 weeks, p = 0.00). Multifactor analysis showed that gestational age, positive urine culture (odds ratio [OR] = 6.233, 95% confidence interval [CI]: 1.830-21.227), and stones ≥10 mm (OR = 0.124, 95% CI: 0.031-0.495) were independent risk factors for UTI after ureteral stenting in patients with renal colic. In the infection group, Escherichia coli was the most commonly found organism (47.4%). Conclusions: Gestational age, positive urine culture before surgery, and stone ≥10 mm were risk factors for UTI after ureteral stenting in pregnant patients with renal colic. E. coli was the main pathogen of UTI after this procedure. Preoperative anti-infection treatment needs to be based on drugs that are sensitive to E. coli.

Ureteral stent-associated infection and sepsis: pathogenesis and prevention: a review

Ureteral stents are commonly used devices in hospital settings. However, their usage is often complicated by associated urinary tract infections as a result of bacterial adhesion onto the indwelling implant surfaces, followed by the formation of layers of biofilm. Once formed, the biofilm is exceedingly difficult to remove, potentially leading to further morbidity and even urosepsis. Urosepsis, where pathogens from the urinary tract enter the bloodstream, has a mortality rate of up to 50% of severely infected patients. Hence, it is important to understand its pathogenesis. In this review, ureteral stent-associated urinary tract infection and urosepsis will be addressed. In particular, the bacterial mechanisms involved, as well as the prevention and treatment of these infections will be discussed.