Microbial composition associated with biliary stents in patients undergoing pancreatic resection for cancer.

Malignant bile duct obstruction is typically treated by biliary stenting, which however increases the risk of bacterial infections. Here, we analyzed the microbial content of the biliary stents from 56 patients finding widespread microbial colonization. Seventeen of 36 prevalent stent species are common oral microbiome members, associate with disease conditions when present in the gut, and include dozens of biofilm- and antimicrobial resistance-related genes. This work provides an overview of the microbial communities populating the stents.

Effect of co-trimoxazole and N-acetylcysteine alone and in combination on bacterial adherence on ureteral stent surface.

To assess the effect of co-trimoxazole and N-acetylcysteine (NAC), alone and in combination, on bacterial adherence to biofilm formed on ureteral stent surfaces. This prospective randomized study was conducted on 636 patients who underwent double J ureteral stent insertion after variable urological procedures. Patients were randomized into four groups: A (n = 165), no antibiotics or mucolytics during stent indwelling; B (n = 153), oral NAC (200 mg/day for children aged < 12 years old and 600 mg/day for adults) during stent indwelling; C (n = 162), oral co-trimoxazole (2 mg TMP/kg/day) during stent indwelling; and D (n = 156), both oral NAC and co-trimoxazole during stent indwelling. Two weeks following double J stent (JJ stent) insertion, urinalysis was performed on all patients and urine culture was done for all the patients at the day of double J stent removal. The stent was removed 2 weeks postoperatively, and a stent segment sized 3-5 cm from the bladder segment of the stent was sent for culture. Positive stent cultures were found in 63.6% (105/165), 43.1% (66/153), 37% (60/162), and 19.2% (30/156) patients of groups A, B, C, and D, respectively. E. coli was the organism most commonly isolated from the stent culture in all groups. The combination of co-trimoxazole and NAC was more effective in reducing bacterial adherence on ureteral stent surfaces than either alone.

Periocular Infection With Nocardia nova Following Dacryocystorhinostomy With Silicone Stent Intubation.

Nocardia species are aerobic, rod-shaped, Gram-positive bacteria that are ubiquitous throughout the environment. Nocardia nova has been reported as the second most prevalent Nocardia species. However, reports of ocular and periocular infection caused by this organism are rare. The authors present a case of a 58-year-old woman with a medical history of acquired nasolacrimal duct obstruction of the left eye who underwent a revision dacryocystorhinostomy with silicone stent intubation and developed a surgical site infection that was culture-positive for N. nova . Treatment consisted of removal of the silicone stent and a prolonged course of oral antibiotics, resulting in the patient's full recovery. This is the second reported case of postoperative periocular N. nova infection after dacryocystorhinostomy and silicone stent intubation.

Degradable Antimicrobial Ureteral Stent Construction with Silver@graphdiyne Nanocomposite.

In the surgical treatment of urinary diseases, ureteral stents are commonly used interventional medical devices. Although polymer ureteral stents with polyurethane as the main constituent are widely used in the clinic, the need for secondary surgery to remove them and their propensity to cause bacterial infections greatly limit their effectiveness. To satisfy clinical requirements, an electrospinning-based strategy to fabricate PLGA ureteral stents with silver@graphdiyne is innovated. Silver (Ag) nanoparticles are uniformly loaded on the surface of graphdiyne (GDY) flakes. It is found that the incorporation of Ag nanoparticles into GDY markedly increases their antibacterial properties. Subsequently, the synthesized and purified Ag@GDY is homogeneously blended with poly(lactic-co-glycolic acid) (PLGA) as an antimicrobial agent, and electrospinning along with high-speed collectors is used to make tubular stents. The antibacterial effect of Ag@GDY and the porous microstructure of the stents can effectively prevent bacterial biofilm formation. Furthermore, the stents gradually decrease in toughness but increase in strength during the degradation process. The cellular and subcutaneous implantation experiments demonstrate the moderate biocompatibility of the stents. In summary, considering these performance characteristics and the technical feasibility of the approach taken, this study opens new possibilities for the design and application of biodegradable ureteral stents.

Ureteral Stents Harbor Complex Biofilms With Rich Microbiome-Metabolite Interactions.

PURPOSE: We sought to determine microbe-metabolite composition and interactions within indwelling ureteral stent biofilms, determine their association with patient factors including infection, and reconstitute biofilm formation on relevant surface materials in vitro. MATERIALS AND METHODS: Upon ureteral stent removal from patients, proximal and distal ends were swabbed. Samples were analyzed by 16S next-generation sequencing and metabolomics. A continuous-flow stir-tank bioreactor was used to reconstitute and quantify in vitro biofilm formation from stent-isolated bacteria on stent-related materials including silicone, polytetrafluoroethylene, polyurethane, polycarbonate, and titanium. Diversity, relative abundance, and association with clinical factors were analyzed with ANOVA and Bonferroni t-tests or PERMANOVA. Biofilm deposition by microbial strain and device material type were analyzed using plate counts and scanning electron microscopy following bioreactor incubation. RESULTS: All 73 samples from 37 ureteral stents harbored microbiota. Specific genera were more abundant in samples from stents wherein there was antibiotic exposure during indwelling time (Escherichia/Shigella, Pseudomonas, Staphylococcus, Ureaplasma) and in those associated with infection (Escherichia/Shigella, Ureaplasma). The enriched interaction subnetwork in stent-associated infection included Ureaplasma and metabolite 9-methyl-7-bromoeudistomin. Strains identified as clinically relevant and central to interaction networks all reconstituted biofilm in vitro, with differential formation by strain (Enterococcus faecalis most) and material type (titanium least). CONCLUSIONS: Ureteral stent biofilms exhibit patterns unique to stent-associated infection and antibiotic exposure during indwelling time. Microbes isolated from stents reconstituted biofilm formation in vitro. This work provides a platform to test novel materials, evaluate new coatings for anti-biofilm properties, and explore commensal strain use for bacterial interference against pathogens.

Ureteral Stent Colonization and Urinary Tract Infection in Children Undergoing Minimally Invasive Pyeloplasty.

INTRODUCTION: Minimally invasive pyeloplasty (MIP), namely, laparoscopic and robot-assisted interventions, has gained popularity in recent years. Double-J ureteral stents are frequently inserted during surgery. Foreign bodies in the urinary tract are considered as risk factor for developing urinary tract infection (UTI). This study aimed to specify the bacteria cultured from urine and stents responsible for UTI in children with indwelling ureteral stents undergoing MIP. PATIENTS AND METHODS: We retrospectively reviewed medical records of 30 children (22 boys and 8 girls) who had undergone MIP between 2014 and 2017. Median age at surgery was 2.7 years (interquartile range [IQR]: 0.5-7.9). Urine cultures were obtained before surgery, before stent removal, 1 month after stent removal, and if UTI was suspected. Stents were removed 4 to 8 weeks after surgery and cultured. Patients' demographics, types of stents, and surgical details were recorded. RESULTS: Median stent indwelling time was 5.09 weeks (IQR: 4-6). Postoperative febrile UTI developed in 4/30 (13%) patients. Afebrile UTI occurred in another 4/30 (13%) patients. Stent cultures were positive in 19/30 (63%) patients. Stent and urinary cultures were identical in only one patient. Three of four patients with preoperative asymptomatic bacteriuria developed postoperative UTI. There was no association between UTI, gender, stent diameter, and duration of indwelling catheter. CONCLUSION: After MIP, febrile UTI and afebrile UTI occurred in about one quarter of patients. Pathogens isolated postsurgically from urinary cultures were unrelated to those colonizing the stents. Therefore, routine stent culturing is of low clinical significance. Moreover, small-caliber stents and longer indwelling periods were not risk factors for UTI. Optimizing antibiotic treatment for children with preoperative UTI may potentially prevent morbidity after surgery.

Mussel-Inspired Clickable Antibacterial Peptide Coating on Ureteral Stents for Encrustation Prevention.

Long-term indwelling catheters or stents often cause complications like infection, encrustation, hematuria, pain, and so on. The source of these problems is bacteria, which can form biofilms on the stents to reduce antibiotic sensitivity and produce urease to form encrustation by increasing the urine pH. Urinary tract infection (UTI) can aggravate the body damage and even seriously endanger lives, and the encrustation will block the stents, which can cause hydronephrosis and renal function damage. Therefore, the prevention of UTI and encrustation represents a great challenge in clinical ureteral stent uses. In this work, a clickable mussel-inspired peptide and antimicrobial peptide (AMP) were used to functionalize the commercial stents' surfaces to inhibit long-term infection and encrustation caused by bacteria. Copper (Cu) ions were used to coordinate the mussel-inspired peptide to improve the stability. The AMP with an azido group was clicked to the mussel-inspired Cu-coordinated peptide coating through click chemistry. The bio-inspired antibacterial coating was constructed with excellent stability, bactericidal properties, and improved biological compatibility. In in vitro and in vivo experiments, it was further found that the coating showed bactericidal and encrustation reduction abilities. This study thus developed an effective, safe, and stable AMP coating on urinary stents/catheters capable of long-term antibacterial and encrustation inhibition.

A multicenter, double-blind, placebo-controlled parallel study to evaluate the role of Yinhua Miyanling tablets in the prevention of bacterial biofilm formation on ureteral stents: a randomised trial.

BACKGROUND: Yinhua Miyanling tablet (YMT) not only has the functions of clearing away heat and toxin, dredging drenching and diuresis, but also has antibacterial activity. The formation of bacterial biofilm in ureteral stent and its related infection have plagued the clinic. Antibacterial traditional Chinese medicine is a potential method. METHODS: This multicenter, randomized, double-blind, placebo-controlled study was designed to enroll patients who underwent ureteroscopic lithotripsy associated with indwelling ureteral stents at six centers between March 2019 and June 2020. The eligible patients were randomly assigned to the experimental group to take YMT 2 g qid orally or the control group to take dummy YMT 2 g qid orally from the first day after the operation according to a random number table. The unused drugs were recalled 14±3 days after the operation and record the body temperature. Relevant laboratory tests (urinalysis and urine culture) were performed before extubation. The ureteral stent was removed. The specimen was collected for scanning electron microscopy (SEM). Biofilm formation, USSQ scores, postoperative infectious complications, stone formation, and adverse drug reactions were compared between the two groups. RESULTS: Of the 211 patients enrolled, 165 were included in the per-protocol set (PPS), including 86 in the control group and 79 in the experimental group. No significant difference was found between the two groups in baseline parameters (P>0.05). The prevalence of biofilm formation in the control group (47%) was significantly higher than that in the experimental group (22.7%, P=0.001). There was no significant difference in total USSQ score and domain score between the two groups (all P>0.05). There were more patients with symptomatic urinary tract infection (UTI) in the control group (12.9%) than in the experimental group (2.6%, P=0.017). The incidence of other complications did not show a significant difference between the two groups (all P>0.05). The incidence of stone formation on the ureteral stent surface and adverse drug reactions did not show a significant difference between the two groups (all P>0.05). CONCLUSIONS: YMT is helpful to reduce the formation of bacterial biofilms on ureteral stents and the incidence of symptomatic UTIs related to ureteral stenting after surgery for ureteral calculi. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000041399.

Microbial Metagenomics of the Extubated Lacrimal Stents Following Dacryocystorhinostomy: The Lacriome Paper 4.

PURPOSE: To study the metagenome of the microbes present on the extubated lacrimal stents following a dacryocystorhinostomy. METHODS: A prospective study was performed on 10 consecutive extubated lacrimal stents obtained for the metagenomic analysis from the patients following an endoscopic dacryocystorhinostomy. The stents were extubated at 4 weeks postoperatively under endoscopic guidance and immediately transported on ice to the laboratory. Following DNA extraction and library preparation, a whole shotgun metagenome sequencing was performed on the Illumina platform. The downstream processing and bioinformatics of the samples were performed using multiple software packaged in SqueezeMeta pipeline or MG-RAST pipeline. RESULTS: The taxonomic hit distribution across the stent samples showed that bacteria were the most common isolates (mean, 69.70%), followed by viruses (mean, 0.02%) and archaea (0.003%). The 3 major phyla identified were Firmicutes, Actinobacteria, and Proteobacteria. The prevalent organisms include Pseudomonas aeruginosa, Staphylococcus aureus, Corynebacterium accolens, Dolosigranulum pigrum, Citrobacter koserii, Staphylococcus epidermidis, E. coli, and Hemophilus influenza . The functional subsystem profiling demonstrated microbial genes associated with metabolism, cellular, and information processing. The functional subsystem categories were metabolism involving carbohydrates, amino acids, DNA and RNA, cell wall or cell capsule biogenesis, membrane transport, virulence, and defense mechanisms. CONCLUSIONS: The present study is the first whole metagenome sequencing of the microbes isolated from the extubated lacrimal stents. The stents harbor diverse microbial communities with distinct ecosystem dynamics. Further studies on microbes-host interactions in the early postoperative period would provide valuable insights.

Magnetic Microswarm and Fluoroscopy-Guided Platform for Biofilm Eradication in Biliary Stents.

Biofilm eradication from medical implants is of fundamental importance, and the treatment of biofilm-associated pathogen infections on inaccessible biliary stents remains challenging. Magnetically driven microrobots with controlled motility, accessibility to the tiny lumen, and swarm enhancement effects can physically disrupt the deleterious biostructures while not developing drug resistance. Magnetic urchin-like capsule robots (MUCRs) loaded with magnetic liquid metal droplets (MLMDs, antibacterial agents) are designed using natural sunflower pollen, and the therapeutic effect of swarming MUCR@MLMDs is explored for eradicating complex mixtures of bacterial biofilm within biliary stents collected from patients. The external magnetic field triggers the emergence of the microswarm and induces MLMDs to transform their shape into spheroids and rods with sharp edges. The inherent natural microspikes of MUCRs and the obtained sharp edges of MLMDs actively rupture the dense biological matrix and multiple species of embedded bacterial cells by exerting mechanical force, finally achieving synergistic biofilm eradication. The microswarm is precisely and rapidly deployed into the biliary stent via endoscopy in 10 min. Notably, fluoroscopy imaging is used to track and navigate the locomotion of microswarm in biliary stents in real-time. The microswarm has great potential for treating bacterial biofilm infections associated with medical implants.

Urine versus stent cultures and clinical UTIs.

PURPOSE: Current American Urological Association guidelines recommend pre-operative antimicrobial therapy based on prior urine cultures (UC); however, the role of stent culture (SC) in urologic practice is unclear. We examined whether UC and SC differed at the time of stent removal, as well as the association, microbiology, and timing of subsequent UTIs as related to SC. METHODS: This was a retrospective review of 159 patients with ureteral stents for indications of urolithiasis, benign stricture, malignant obstruction, and kidney transplant. UC and SC were analyzed at the time of stent removal. Patients were followed for 12 months after stent removal for development, concordance, and timing of clinical UTIs. RESULTS: In 159 patients, 15% had positive UC and 45% had positive SC. Of patients who had positive SC, 66% had negative UC. All patients with positive UC had identical micro-organisms on SC; however, 33% of these had SC with additional micro-organisms. Relative to those with both negative UC and SC, patients with negative UC and positive SC had a 5.7 odds, and those with both positive UC and SC had a 13.6 odds of developing a clinical UTI within 12 months. Concordance of SC and future UTI was highest in those with post-operative sepsis, and those with Candida species on SC. CONCLUSIONS: SC was a unique risk factor for development of UTI within 12 months of stent removal. Clinicians should consider SC results when empirically treating those with post-operative sepsis or those with UTI after Candida on SC.

Surface analysis of ureteral stent before and after implantation in the bodies of child patients.

The aim of this work was to determine which part of a double-J ureteral stent (DJ stents) showed the highest tendency to crystal, calculi, and biofilm deposition after ureterorenoscopic-lithotripsy procedure (URS-L) to treat calcium oxalate stones. Additionally, the mechanical strength and the stiffness of DJ stents were evaluated before and after exposure to urine. Obtained results indicated that the proximal (renal pelvis) and distal (urinary bladder) part is the most susceptible for post-URS-L fragments and urea salt deposition. Both, the outer and inner surfaces of the DJ ureteral stents were completely covered even after 7 days of implantation. Encrustation of DJ stents during a 31-day period results in reducing the Young's modulus by 27-30%, which confirms the loss of DJ stent elasticity and increased probability of cracks or interruption. Performed analysis pointed to the need to use an antibacterial coating in the above-mentioned part of the ureteral stent to prolong its usage time and to prevent urinary tract infection.

Long-term outcomes of metallic endobronchial stents in lung transplant recipients are not affected by bacterial colonization.

OBJECTIVES: We evaluated associations of endobronchial stenting with airway bacterial colonization, the antimicrobial resistance profile, hospitalizations for pneumonia and survival in lung transplant recipients. METHODS: This is a retrospective single-centre study of 582 recipients of lung transplant during 2002-2018. We compared outcomes of 57 patients (9.7%) who received endobronchial stents (intervention group) to a control group of 57 patients without stents who were matched one to one for age, sex, year of transplantation, unilateral/bilateral transplantation and underlying disease. RESULTS: For the intervention compared to the control group, airway colonization was more common for Pseudomonas (86% vs 35%, P < 0.001), Acinetobacter (21% vs 7%, P = 0.05), Klebsiella (21% vs 5%, P = 0.02) and Staphylococcus species (11% vs 0%, P = 0.02). The respective proportions of patients with positive bronchoalveolar lavage cultures on the third post-transplantation day, the day of stent insertion and 6-month post-stent insertion were 47.4%, 50.9% and 65.4% for Pseudomonas sp.; 15.8%, 12.3% and 3.8% for Klebsiella sp.; and 8.8%, 5.3% and 5.8% for Acinetobacter sp. The mean number of hospitalizations for pneumonia per patient was higher, without statistical significance, in the intervention than the control group (1.5 ± 1.7 vs 0.9 ± 1.5, P = 0.1). Kaplan-Meier survival curves did not show a statistically significant difference between the intervention group and the entire group without endobronchial stents (n = 525) (P = 0.4). CONCLUSIONS: Lung transplant recipients with endobronchial stents were more likely to be colonized with pathologic bacteria and having pneumonia; however, stent placement was not associated with increased long-term mortality with appropriate stent maintenance.

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.

Antimicrobial susceptibility of biliary stents do not predict infectious complications after whipple.

BACKGROUND: Postoperative infectious complications after a pancreaticoduodenectomy remain a significant cause of morbidity. Studies have demonstrated that a preoperative biliary stent increases the risk of postoperative infectious complications. Few studies have investigated the specific preoperative biliary stent bacterial sensitivities to preoperative antibiotics and the effect on infectious complications. The goal of this study was to investigate if the presence of a preoperative biliary stent increases the risk of postoperative infectious complications in patients undergoing a pancreaticoduodenectomy. Additionally, we aimed to investigate biliary stent culture sensitivities to preoperative antibiotics and determine if those sensitivities impacted postoperative infectious complications after a pancreaticoduodenectomy. METHODS: A retrospective chart review of patients who had undergone a pancreaticoduodenectomy at a single institution tertiary care center from 2007 to 2018 was performed. Perioperative variables including microbiology cultures from biliary stents were collected and analyzed. RESULTS: A total of 244 patients underwent a pancreaticoduodenectomy. A preoperative biliary stent was present in 45 (18%) patients. Infectious complications occurred in 25% of those patients with a preoperative biliary stent, and 19% of those without (P = .37). Of those patients with a stent that was cultured intraoperatively, 92% grew bacteria and 61% of those were resistant to the preoperative antibiotics administered. Of the patients with a preoperative biliary stent and bacteria resistant to the preoperative antibiotics, 17% developed a postoperative infectious complication, compared with 20% if the bacteria cultured was susceptible to the preoperative antibiotics (P = .64). CONCLUSION: Infectious complications after pancreaticoduodenectomy are a significant cause of morbidity. Stent bacterial sensitivities to preoperative antibiotics did not reduce the postoperative infectious complications in the preoperative biliary stent group suggesting a multifactorial cause of infections.

Does duration of stenting increase the risk of clinical infection?

OBJECTIVE: We investigated when an indwelling ureteral catheter should be withdrawn for infection and evaluated the importance of urinary cultures in identifying colonized microorganisms and define the bacterial flora encountered in the study. Moreover, this study tried to determine the clinical role of stent culture in clinical practice. MATERIALS AND METHODS: The study was conducted between June 2018 and February 2019. Patients with ureteral stent implantation after endoscopic ureteral stone treatment were divided into two groups and each group consisted of 45 patients. Ureteral catheter was removed 15 and 30 days after ureteral stone treatment in group 1 and 2, respectively, and transferred for microbiological examination. The urine culture was obtained before and after ureteral stent implantation. The groups were compared in terms of demographics, urine and catheter cultures results. Urine analysis and catheter culture results were also compared. RESULTS: Demographic data of patients were similar in both groups. 3 patients in group 1 and 12 patients in group 2 had positive urine culture before catheter retraction; 2 of 45 and 6 of 45 patients had positive catheter culture in group 1 and 2, respectively. Although 2 patients in group 1 and 4 patients in group 2 had urine culture sterile, they had growth in catheter culture. In Group 1, 1 of the microorganisms was E. fecalis and 1 was E. coli. In Group 2, 2 cases were E. fecalis, 3 were E. coli and 1 was MRSE. There was no significant difference between the urine analysis results of the patients before catheter retraction and catheter culture positivity. CONCLUSIONS: Pre-operative urine culture does not exclude catheter colonization, and the prolonged duration of the catheter associated with greater colonization and may be associated urinary tract infection. Ureteral catheter should be removed as early as possible.

Detection of microbial colonization of the urinary tract of patients prior to secondary ureterorenoscopy is highly variable between different types of assessment: results of a prospective observational study.

This study compares the findings of different detection methods for microorganisms in patients with ureteral stents undergoing secondary ureterorenoscopy including the use of a novel validated examination pipeline for biofilms on ureteral stents. Of the included 94 patients, 21.3% showed bacteriuria in preoperative urine cultures. Intraoperative urine culture showed bacteriuria in four (4.3%) of the patients. Stent biofilm cultures were positive in 12.9% and qPCR detected bacterial DNA in 18.1%. The findings of the different examinations were poorly correlated with each other. Detection of microorganisms in the urinary tract of patients with indwelling ureteral stents is highly dependent on timing (i.e. pre- vs intraoperative) and method of assessment. Preoperative routine urine cultures are not predictive for intraoperative urine- and stent culture. These results cast doubt on the clinical relevance of enterococcal species, staphylococci, and streptococci if identified preoperatively prior to stent removal. The timing of oral preoperative antibiotic prophylaxis might need to be reconsidered.

Symptoms Associated With Long-term Double-J Ureteral Stenting and Influence of Biofilms.

OBJECTIVE: To assess the symptoms associated with long-term Double-J ureteral stenting including the influence of biofilms on ureteral stents. METHODS: Patients with long-term (>8 weeks) uni- or bilateral ureteral stents completed the Ureteral Stent Symptoms Questionnaire (USSQ) at the day of stent exchange. Repeated assessment of patients was possible to allow for analysis of intraindividual changes. Assessment of biofilm mass on the stents was performed according to a validated method, its correlation with the USSQ total score was defined as primary outcome. Secondary outcomes included further analyses of stent-associated symptoms and their temporal course. RESULTS: A total of 87 stent indwelling periods in 35 patients were investigated. Median USSQ total score did not differ significantly between unilateral and bilateral stenting (42 vs 39 points; P = .17). An increasing total stent treatment time up to study inclusion did not correlate with the USSQ total score, but was significantly correlated with less urinary symptoms and a better quality of life. USSQ total score and subscores within individual patients did not significantly increase or decrease over the sequence of stent indwelling periods. Higher total biofilm masses were not associated with higher USSQ total scores or subscores. CONCLUSION: Long-term Double-J stenting provides a valuable treatment option, if stent-associated symptoms are low during the initial indwelling period. Thus, symptoms remain stable over the long-term course and the majority of patients are satisfied with the treatment. Furthermore, biofilm formation on ureteral stents does not seem to be the relevant driver of symptoms.

The First Report of Purulent Pericarditis Associated with Aortic Stent-graft Infection Caused by Methicillin-susceptible Staphylococcus aureus.

We herein report the first case of purulent pericarditis associated with aortic stent-graft infection in an 80-year-old Japanese man that was caused by methicillin-susceptible Staphylococcus aureus, which appropriate antibiotics failed to treat. The detailed clinical course and autopsy images revealed that purulent pericarditis associated with aortic stent-graft infection caused cardiac tamponade and eventually led to mortality. We therefore suggest that surgical procedures, including drainage, should be introduced for such cases.