Urinary Stents Research Articles

THE INDONESIAN LINGUISTIC VALIDATION OF THE URINARY STENT RELATED HEALTH QUESTIONNAIRE

Objective: To validate the Indonesian version of the urinary stent related health (UriSteRH) questionnaire. Material & Methods: The Indonesian version of the UriSteRH was developed with multistep process by urologist, two nursing lecturers and two independent translators. A total 13 patients with indwelling DJ Stent completed the Indonesian UriSteRH questionnaires on the 30th day after Stenting. The reliability of the Indonesian version was evaluated using Cronbach’s alpha test. Domain structures were examined by using Pearson correlation coefficient (R). Results: Urinary pain, body pain, physical activity, social life, mental health, sexual activity and quality of life showed good internal consistency. There were strong correlations of physical activity (r=0.851) and social life (r=0.815) with the quality of life (r=0.736). In addition, there were moderate correlation of mental health general (r=0.676) related to urinary pain (r=0.612) and body pain (r=0.567). However, sexual activity had a lower correlation (r=0.456). Conclusion: The Indonesian version of UriSteRH is a reliable and valid instrument to evaluate health and quality of life in patients with indwelling DJ Stent. Keywords: DJ Stent, indonesian validation, questionnaire, urinary stent related health .

Preoperative parent education and postoperative nurse-led care for boys versus routine hospital care for urethroplasty for hypospadias in Western China: a retrospective study.

Urethroplasty is the preferred treatment for hypospadias but is affected by the severity of anomalies, making it a complex procedure with potential postoperative complications. Following surgery, parents receive instructions and recommendations, whether from nurses or physicians, regardless of complication rates. However, nurses play a crucial role in educating caregivers before surgery and providing postoperative care during follow-up. The study aims to assess parents' knowledge and practices, as well as the frequency of complications in boys who underwent urethroplasty for hypospadias and received postoperative nurse-led care and whose parents received preoperative education against those of boys who underwent urethroplasty under routine hospital care. In this retrospective study, Han Chinese boys aged 21-41 months in Western China who underwent urethroplasty for hypospadias were divided into two groups: the NI cohort (n = 103), where they received postoperative nurse-led care and their parents received preoperative education, and the RH cohort (n = 142), where boys underwent routine hospital care. After urethroplasty, higher numbers of caregivers with satisfactory knowledge (96 (93%) vs. 80 (56%), p < 0.0001) and practice (102 (99%) vs. 132 (93%), p = 0.0276) were reported in the NI cohort compared to the RH cohort. Additionally, a higher number of boys in the RH cohort experienced adverse effects such as moderate bleeding (13 (9%) vs. 1 (1%), p = 0.0052), wound infection (17 (12%) vs. 4 (4%), p = 0.0356), urinary obstruction (35 (25%) vs. 10 (10%), p = 0.0049), burning sensation (47 (33%) vs. 15 (15%), p = 0.0019), and urinary stent fall (32 (23%) vs. 6 (6%), p = 0.0008) compared to those in the NI cohort. Preoperative instructions enhance caregivers' knowledge and practices following urethroplasty, while postoperative nurse-led care reduces immediate postoperative complications associated with hypospadias in boys.

Complications Subsequent to Urinary Tract Stent Placement: An Overview Focusing on the Imaging of Cancer Patients.

Ureteral involvement by a tumor is common, and both partial and complete obstructions can result in symptoms that are distressing and debilitating, especially in cancer patients for whom the resection of the primary tumor is not considered an option. Maintaining ureteric patency in these patients is a challenge. In addition, in cases where a patient has undergone nephroureterectomy due to primary transitional cell cancer, it becomes necessary to decompress the urinary tract to preserve the contralateral kidney from irreversible damage. This is possibly due to ureteral stenting, both retrograde and anterograde, and percutaneous nephrostomy (PCN). Since imaging plays an important role in the routine monitoring of stents, their more and more increasing use requires radiologists to be familiar with these devices, their correct position, their potential complications, and their consequences. The aim of this review is to offer a comprehensive review of the imaging features of some urinary stents and to show the complications encountered in cancer patients as a direct consequence of an invasive diagnostic or therapeutic procedure. Specifically, we focus on ureteral stents and PCN.

Comparison of ureteral stent-related symptoms in high-inserted stents with conventional ones

Objective: To assess whether high-inserted urinary stents (HIUS) provide substantial enhancements in patient comfort and overall quality of life, we compared the stent-related symptoms of HIUS and conventional ureteric stents (CUS). Methodology: We randomly assigned 54 patients who received simple ureteroscopic lithotripsy to a high-inserted or standard stent group. Baseline Ureteral Stent Symptom Questionnaire (USSQ) and visual analogue scale pain levels were assessed 2 weeks postoperatively and 4 weeks following stent removal. Also contrasted was subdomain analysis of all Stent-Related Symptoms (SRS) and stent problems. Results: Significant intergroup differences were seen in urinary symptoms, pain index on VAS, and overall health domain scores (p&lt;0.001). No significant difference was seen in the work performance index (p=0.077) or sexual matter score (p=0.064). The HIUS group had significantly higher scores on USSQ subdomains, including frequency, urgency, incomplete emptying, burning at voiding, hematuria grade, difficulties with heavy physical activity, feeling comfortable, resting in bed due to symptoms, decreasing routine activities, and sexual intercourse pain (p&lt;0.001). Patients in both groups who quit sex life owing to stents were similar (p=0.745). Complication rates were similar in both groups. Conclusion: HIUS dramatically reduced stent-related urine discomfort and pain. Thus, HIUS can be employed in clinical practice, especially for short-term stent implantation after simple ureteroscopic lithotripsy.

A Study of Factors Affecting Febrile Urinary Tract Infection Following Ureterorenoscopic Lithotripsy

Febrile urinary tract infection (f-UTI) is a common complication after ureterorenoscopic lithotripsy (URSL) but is sometimes lethal. In this article, we analyzed the factors of post URSL f-UTI. We retrospectively evaluated the association between the development of f-UTI and patients, stones, and perioperative factors in 695 cases in which URSL was performed at our institution from September 2015 to 2018. Seventy-six of the 695 patients (10.9%) had postoperative f-UTI. Elderly (p＝0.013), female (p＝0.02), and hypertension (p＝0.001) patients had significantly higher rates of f-UTI. Renal stone (p＝0.001) cases showed significantly higher rates of f-UTI. Preoperative urine positive culture (p＝0.045), preoperative f-UTI (p＜0.001), URSL procedure using flexible ureteroscopy (p＝0.048), non-stone-free (p＝0.006), long operation time (p＝0.011), preoperative urinary stent insertion due to preoperative f-UTI (p＜0.001), were factors associated with post-operative f-UTI. Multivariate analysis revealed that hypertension (OR＝2.08, p＝0.008) and preoperative f-UTI (OR＝3.739, p＝0.033) were independent factors of postoperative f-UTI. Patients with hypertension or preoperative f-UTI should be managed more carefully during the perioperative period, suspecting that they are more likely to develop postoperative f-UTI.

REVIEW ON COMPLICATIONS AND ADVERSE EFFECTS OF METALLIC URINARY STENTS.

Urinary stents, be it urethral or ureteral, polymeric, metallic or biodegradable, are one of the most frequently used tools in urology and they have been used for decades in prophylactic and therapeutic setting. Although relatively low invasive, they are prone to complications and adverse effects so much that complication rates up to 100% have been described. Many reviews have focused either on specific groups of patients or particular stent types, materials or designs but so far, no comprehensive review on complications has been published. To tackle this issue, a working group was set up within ENIUS (European Network of multidisciplinary research to Improve Urinary Stents) tasked with literature search in order to screen for and systematically review published stent complications in urethra (male only) and ureters (polymeric and metallic ureteral stents in both sexes) when used in obstructed systems. In this paper, we review, catalogue and summarize complications published for metallic urethral and ureteral stents.

P8.141: Prevalence and Outcome of Kidney Transplant Recipients Infected With BK Polyoma Virus at National Kidney And Transplant Institute From 2016 to 2021

Background: BK polyoma virus (BKV) infection is an evolving challenge in kidney transplant recipients as untreated infections often lead to allograft dysfunction or graft loss. The virus is ubiquitous with viruria and viremia being detected in 30% and >10% of patients, respectively. Decreasing the immunosuppression has been established as the mainstay of treatment, however, screening protocols vary between institutions. Objective: This study aims to describe the prevalence and outcomes of kidney transplant recipients with BKV at the National Kidney and Transplant Institute (NKTI) for the last 5 years. Methods: This is a retrospective study conducted at the NKTI wherein chart review was performed. Age, gender, native kidney disease, viral loads (urine and blood), graft biopsy results were reviewed. Clinical outcomes such as graft failure, early complications, and readmission were also determined. Results: There were 1057 kidney transplants and 12 BKV cases from 2016-2021 with a prevalence of 1.1%. The mean age of recipients was 39 (range 17-66) years, majority of which were males (58%) (Table 1). Half of the recipients had chronic glomerulonephritis with anti-thymocyte globulin being the most common induction agent (67%). Majority (88%) did not have urinary stents. Of the identified cases, viruria (41%) and viremia (33%) were present with 50% having biopsy-proven BKV nephropathy. Most cases presented >6 months from transplant (66%) and viral loads were above 500 copies/ml in 83% of cases. One patient was highly sensitized (8%) and two patients had graft loss (17%). No graft loss and retransplants were done for BKV. Conclusion: The low prevalence of BKV infection in our center reflects the varying practice of clinicians in the management of transplant recipients. Reduction of immunosuppression remains to be the treatment of choice. Early detection may prevent morbidity and graft loss. Routine screening for BKV has been recommended however, it has yet to gain acceptance among our transplant physicians.

Assuring the Biofunctionalization of Silicone Covalently Bonded to Rhamnolipids: Antibiofilm Activity and Biocompatibility.

Silicone-based medical devices composed of polydimethylsiloxane (PDMS) are widely used all over the human body (e.g., urinary stents and catheters, central venous catheters stents) with extreme clinical success. Nevertheless, their abiotic surfaces, being prone to microorganism colonization, are often involved in infection occurrence. Improving PDMS antimicrobial properties by surface functionalization with biosurfactants to prevent related infections has been the goal of different works, but studies that mimic the clinical use of these novel surfaces are missing. This work aims at the biofunctional assessment of PDMS functionalized with rhamnolipids (RLs), using translational tests that more closely mimic the clinical microenvironment. Rhamnolipids were covalently bonded to PDMS, and the obtained surfaces were characterized by contact angle modification assessment, ATR-FTIR analysis and atomic force microscopy imaging. Moreover, a parallel flow chamber was used to assess the Staphylococcus aureus antibiofilm activity of the obtained surfaces under dynamic conditions, and an in vitro characterization with human dermal fibroblast cells in both direct and indirect characterization assays, along with an in vivo subcutaneous implantation assay in the translational rabbit model, was performed. A 1.2 log reduction in S. aureus biofilm was observed after 24 h under flow dynamic conditions. Additionally, functionalized PDMS lessened cell adhesion upon direct contact, while supporting a cytocompatible profile, within an indirect assay. The adequacy of the biological response was further validated upon in vivo subcutaneous tissue implantation. An important step was taken towards biofunctional assessment of RLs-functionalized PDMS, reinforcing their suitability for medical device usage and infection prevention.

Assessment of a Coated Mitomycin-Releasing Biodegradable Ureteral Stent as an Adjuvant Therapy in Upper Urothelial Carcinoma: A Comparative In Vitro Study

A major limitation of the treatment of low-grade upper tract urothelial carcinoma is the difficulty of intracavitary instillation of adjuvant therapy. Therefore, the aim of this in vitro study was to develop and to assess a new design of biodegradable ureteral stent coated with a silk fibroin matrix for the controlled release of mitomycin C as a chemotherapeutic drug. For this purpose, we assessed the coating of a biodegradable ureteral stent, BraidStent®, with silk fibroin and subsequently loaded the polymeric matrix with two formulations of mitomycin to evaluate its degradation rate, the concentration of mitomycin released, and changes in the pH and the weight of the stent. Our results confirm that the silk fibroin matrix is able to coat the biodegradable stent and release mitomycin for between 6 and 12 h in the urinary environment. There was a significant delay in the degradation rate of silk fibroin and mitomycin-coated stents compared to bare biodegradable stents, from 6–7 weeks to 13–14 weeks. The present study has shown the feasibility of using mitomycin C-loaded silk fibroin for the coating of biodegradable urinary stents. The addition of mitomycin C to the coating of silk fibroin biodegradable stents could be an attractive approach for intracavitary instillation in the upper urinary tract.

Importance of the gynecologic oncologist in management of cesarean hysterectomy for Placenta Accreta Spectrum (PAS)

ObjectivePlacenta Accreta Spectrum (PAS) is an invasive placental disorder characterized by significant maternal and fetal morbidity. Utilization of multidisciplinary teams has been shown to optimize patient outcomes. Our objective was to assess the impact of cesarean hysterectomy performed by gynecologic oncologists versus Ob/Gyn specialists in maternal morbidity. MethodsA retrospective cohort study was performed of singleton, non-anomalous pregnancies complicated by PAS University of Texas Health San Antonio Placenta Accreta program from 2010 to 2021. Our primary outcome was a maternal morbidity composite of any of the following: estimated blood loss >2 L, ICU admission, intraoperative acidosis and post-operative length of stay >4 days. In addition, demographic and pregnancy data were obtained. Univariate and multivariate analyses were performed to identify the individual impact of variables such as general anesthesia, episodes of vaginal bleeding, uterine artery embolization, emergent delivery and placenta percreta pathology. Results122 pregnancies complicated by PAS who underwent cesarean hysterectomy were identified from 2010 to 2021. Gynecologic oncologists were the primary surgeons for 62 (50.8%) of these cases. The involvement of gynecologic oncologists increased over the time period from 16% to 80%. Gynecologic oncologists were more like to be involved in cases with an antenatal diagnosis of placenta percreta (11.7 vs 37.1%, p = 0.001) and these cases were characterized by increased composite maternal morbidity (65 vs 83.9%, p = 0.02). These cases were also significantly longer (151 vs 271 min, p < 0.0001), involved greater usage of urinary stents (36.7 vs 66.1%, p = 0.002) and had longer post-operative lengths of stay (3 vs 4 days, p < 0.0001). PAS cesarean hysterectomies by gynecologic oncologists were less likely to be supracervical (25 vs 3.2%, p = 0.0005). Multivariate analysis controlling for placenta percreta, uterine artery embolization, vaginal bleeding and emergent delivery showed no difference in composite maternal morbidity (aOR = 0.95, 95%CI [0.35–2.52]) and lower rates of intraoperative acidosis (aOR = 0.36, 95%CI [0.14–0.93]) or post-operative length of stay >4 days (aOR = 0.37, 95%CI [0.15–0.91]). ConclusionsGynecologic oncologists play a critical role in the surgical management of PAS cesarean hysterectomies. When compared to Ob/Gyn specialists, gynecologic oncologists are more likely to act as primary surgeons in complex cases similar morbidity and greater post-operative outcomes.

Urinary Stent Development and Evaluation Models: In Vitro, Ex Vivo and In Vivo-A European Network of Multidisciplinary Research to Improve Urinary Stents (ENIUS) Initiative.

Background: When trying to modify urinary stents, certain pre-clinical steps have to be followed before clinical evaluation in humans. Usually, the process starts as an in silico assessment. The urinary tract is a highly complex, dynamic and variable environment, which makes a computer simulation closely reflecting physiological conditions extremely challenging. Therefore, the pre-clinical evaluation needs to go through further steps of in vitro, ex vivo and in vivo assessments. Methods and materials: Within the European Network of Multidisciplinary Research to Improve Urinary Stents (ENIUS), the authors summarized and evaluated stent assessment models in silico, in vitro, ex vivo and in vivo. The topic and relevant sub-topics were researched in a systematic literature search in Embase, Scope, Web of Science and PubMed. Clinicaltrials.gov was consulted for ongoing trials. Articles were selected systematically according to guidelines with non-relevant, non-complete, and non-English or Spanish language articles excluded. Results: In the first part of this paper, we critically evaluate in vitro stent assessment models used over the last five decades, outlining briefly their strengths and weaknesses. In the second part, we provide a step-by-step guide on what to consider when setting up an ex vivo model for stent evaluation on the example of a biodegradable stent. Lastly, the third part lists and discusses the pros and cons of available animal models for urinary stent evaluation, this being the final step before human trials. Conclusions: We hope that this overview can provide a practical guide and a critical discussion of the experimental pre-clinical evaluation steps needed, which will help interested readers in choosing the right methodology from the start of a stent evaluation process once an in silico assessment has been completed. Only a transparent multidisciplinary approach using the correct methodology will lead to a successful clinical implementation of any new or modified stent.

Factors influencing stone-free rate of Extracorporeal Shock Wave Lithotripsy (ESWL); a cohort study

Objective To evaluate the success rate of Extracorporeal Shock Wave Lithotripsy (ESWL) therapy and identify relevant treatment-specific factors affecting stone-free rate (SFR) after ESWL. Materials and methods All ESWL treatments in the years 2016–2019, in Ängelholm Hospital, Skåne, Sweden were analysed retrospectively. Primary outcome was stone-free rate (SFR) at 3 months. Univariate logistic regression was used followed by multivariable regression. Lasso analysis was made to adjust for treatment-specific factors such as age, stone size, skin-to-stone distance (SSD), stone attenuation, number of treatments, stone location and presence of a urinary stent. Results Factors affecting successful ESWL treatment were lower age (p < 0.001), smaller stone size and volume (both p = 0.001). SSD, stone attenuation, sex, laterality and drainage did not have an effect on SFR in this study. After the first ESWL treatment session, 46.7% of the patients were stone-free. Conclusion Results indicate that stone size and age are the most predictive factors for ESWL outcome. Based on this, we present a simple model for prediction of SFR after ESWL, to be used when counseling patients before ESWL treatment.

Bio-inspired antibacterial coatings on urinary stents for encrustation prevention.

Urinary tract infection (UTI) represents one of the most common nosocomial infections, which is mainly related to indwelling catheters or stents. In addition to the formation of biofilms to reduce antibiotic sensitivity, the urease-producing bacteria can also increase urine pH, causing Ca2+ and Mg2+ deposition and finally catheter obstruction. The prevention of UTIs and its complication (i.e., encrustation) thus is a great challenge in design of catheters and ureteral stents. In this work, a metal-catechol-assisted mussel chemistry (i.e., dopamine self-polymerization) was employed for surface functionalization of commercially available catheters with antimicrobial peptides (AMP), for the purpose of long-term anti-infection and encrustation prevention. To improve the stability of the polydopamine coating on polymeric stents, we used Cu2+-coordinated dopamine self-polymerization. Then, a cysteine-terminated AMP was introduced on the polydopamine coating through Michael addition. We found that the Cu2+-coordinated polydopamine coating showed improved stability and antibacterial effect. The cytotoxicity test confirmed that the bioinspired antibacterial coating showed good biocompatibility and no obvious toxicity. The results confirmed that the stents with AMP could in situ inhibit bacterial growth and biofilm formation, and finally reduce the deposition of struvite and hydroxyapatite crystals both in vitro and in vivo. We anticipate that this bioinspired strategy would develop a safe, stable and effective antibacterial coating on urinary tract medical devices for long-term bacterial inhibition and encrustation prevention.

Urinary Tract Infections in the First 6 Months after Renal Transplantation.

Purpose Urinary tract infections (UTIs) are common in the first 6 months after renal transplantation, and there are only limited data about UTIs after transplantation in Saudi Arabia in general. Methods A retrospective study from January 2017 to May 2020 with 6-month follow-up. Results 279 renal transplant recipients were included. Mean age was 43.4 ± 16.0 years, and114 (40.9%) were women. Urinary stents were inserted routinely during transplantation and were removed 35.3 ± 28 days postoperatively. Ninety-seven patients (35%) developed urinary tract infections (UTIs) in the first six months after renal transplantation. Of those who developed the first episode of UTI, the recurrence rates were 57%, 27%, and 14% for having one, two, or three recurrences, respectively. Late urinary stent removals, defined as more than 21 days postoperatively, tended to have more UTIs (OR: 1.43, P: 0.259, CI: 0.76–2.66). Age >40, female gender, history of neurogenic bladder, and transplantation abroad were statistically significant factors associated with UTIs and recurrence. Diabetes, level of immunosuppression, deceased donor renal transplantation, pretransplant residual urine volume, or history of vesicoureteral reflux (VUR) was not associated with a higher incidence of UTIs. UTIs were asymptomatic in 60% but complicated with bacteremia in 6% of the cases. Multidrug resistant organisms (MDROs) were the causative organisms in 42% of cases, and in-hospital treatment was required in about 50% of cases. Norfloxacin + Bactrim DD (160/800 mg) every other day was not associated with the lower risk of developing UTIs compared to the standard prophylaxis daily Bactrim SS (80/400 mg). Conclusion UTIs and recurrence are common in the first 6 months after renal transplantation. Age >40, female gender, neurogenic bladder, and transplantation abroad are associated with the increased risk of UTIs and recurrence. MDROs are common causative organisms, and hospitalization is frequently required. Dual prophylactic antibiotics did not seem to be advantageous over the standard daily Bactrim.

The Impact of Timing of Stent Removal on the Incidence of UTI, Recurrence, Symptomatology, Resistance, and Hospitalization in Renal Transplant Recipients.

Purpose To evaluate the impact of early (<3 weeks) versus late (>3 weeks) urinary stent removal on urinary tract infections (UTIs) post renal transplantation. Methods A retrospective study was performed including all adult renal transplants who were transplanted between January 2017 and May 2020 with a minimum of 6-month follow-up at King Abdulaziz Medical City, Riyadh, Saudi Arabia. Results A total of 279 kidney recipients included in the study were stratified into 114 in the early stent removal group (ESR) and 165 in the late stent removal group (LSR). Mean age was 43.4 ± 15.8; women: n: 114, 40.90%; and deceased donor transplant: n: 55, 19.70%. Mean stent removal time was 35.3 ± 28.0 days posttransplant (14.1 ± 4.6 days in the ESR versus 49.9 ± 28.1 days in LSR, p < 0.001). Seventy-four UTIs were diagnosed while the stents were in vivo or up to two weeks after the stent removal “UTIs related to the stent” (n = 20, 17.5% in ESR versus n = 54, 32.7% in LSR; p=0.006). By six months after transplantation, there were 97 UTIs (n = 36, 31.6% UTIs in ESR versus n = 61, 37% in LSR; p=0.373). Compared with UTIs diagnosed after stent removal, UTIs diagnosed while the stent was still in vivo tended to be complicated (17.9% versus 4.9%, p: 0.019), recurrent (66.1% versus 46.3%; p: 0.063), associated with bacteremia (10.7% versus 0%; p: 0.019), and requiring hospitalization (61% versus 24%, p: 0.024). Early stent removal decreased the need for expedited stent removal due to UTI reasons (rate of UTIs before stent removal) (n = 11, 9% in the early group versus n = 45, 27% in the late group; p=0.001). The effect on the rate of multidrug-resistant organisms (MDRO) was less clear (33% versus 47%, p: 0.205). Early stent removal was associated with a statistically significant reduction in the incidence of UTIs related to the stent (HR = 0.505, 95% CI: 0.302-0.844, p=0.009) without increasing the incidence of urological complications. Removing the stent before 21 days posttransplantation decreased UTIs related to stent (aOR: 0.403, CI: 0.218-0.744). Removing the stent before 14 days may even further decrease the risk of UTIs (aOR: 0.311, CI: 0.035- 2.726). Conclusion Early ureteric stent removal defined as less than 21 days post renal transplantation reduced the incidence of UTIs related to stent without increasing the incidence of urological complications. UTIs occurring while the ureteric stent still in vivo were notably associated with bacteremia and hospitalization. A randomized trial will be required to further determine the best timing for stent removal.

ENIUS. European Network of multidisciplinary research to Improve the Urinary Stents. COSTS Actions. CA16217. European Cooperation in Science &amp; Technology

ENIUS. European Network of multidisciplinary research to Improve the Urinary Stents. COSTS Actions. CA16217. European Cooperation in Science &amp; Technology

Biodegradation and Antimicrobial Properties of Zinc Oxide–Polymer Composite Materials for Urinary Stent Applications

Research advancements in the field of urinary stents have mainly been in the selection of materials and coatings to address commonly faced problems of encrustation and bacterial adhesion. In this study, polylactic acid (PLA) and polypropylene (PP) were evaluated with zinc oxide (ZnO) coating to assess its ability to reduce or eliminate the problems of encrustation and bacteria adhesion. PLA and PP films were prepared via twin screw extrusion. ZnO microparticles were prepared using sol-gel hydrothermal synthesis. The as-prepared ZnO microparticles were combined in the form of a functional coating and deposited on both polymer substrates using a doctor blade technique. The ZnO-coated PP and PLA samples as well as their uncoated counterparts were characterized from the physicochemical standpoints, antibacterial and biodegradation properties. The results demonstrated that both the polymers preserved their mechanical and thermal properties after coating with ZnO, which showed a better adhesion on PLA than on PP. Moreover, the ZnO coating successfully enhanced the antibacterial properties with respect to bare PP/PLA substrates. All the samples were investigated after immersion in simulated body fluid and artificial urine. The ZnO layer was completely degraded following 21 days immersion in artificial urine irrespective of the substrate, with encrustations more evident in PP and ZnO-coated PP films than PLA and ZnO-coated PLA films. Overall, the addition of ZnO coating on PLA displayed better adhesion, antibacterial activity and delayed the deposition of encrustations in comparison to PP substrates.

Biodegradable and Drug-Eluting Inorganic Composites Based on Mesoporous Zinc Oxide for Urinary Stent Applications.

Conventional technologies for ureteral stent fabrication suffer from major inconveniences such as the development of encrustations and bacteria biofilm formation. These drawbacks typically lead to the failure of the device, significant patient discomfort and an additional surgery to remove and replace the stent in the worst cases. This work focuses on the preparation of a new nanocomposite material able to show drug elution properties, biodegradation and eventually potential antibacterial activity. Poly(2-hydroxyethyl methacrylate) or the crosslinked poly(2-hydroxyethyl methacrylate)-co-poly(acrylic acid) hydrogels were prepared by the radical polymerization method and combined with a biodegradable and antibacterial filling agent, i.e., flower-like Zinc Oxide (ZnO) micropowders obtained via the hydrothermal route. The physico-chemical analyses revealed the correct incorporation of ZnO within the hydrogel matrix and its highly mesoporous structure and surface area, ideal for drug incorporation. Two different anti-inflammatory drugs (Ibuprofen and Diclofenac) were loaded within each composite and the release profile was monitored up to two weeks in artificial urine (AU) and even at different pH values in AU to simulate pathological conditions. The addition of mesoporous ZnO micropowders to the hydrogel did not negatively affect the drug loading properties of the hydrogel and it was successfully allowed to mitigate undesirable burst-release effects. Furthermore, the sustained release of the drugs over time was observed at neutral pH, with kinetic constants (k) as low as 0.05 h−1. By exploiting the pH-tunable swelling properties of the hydrogel, an even more sustained release was achieved in acidic and alkaline conditions especially at short release times, with a further reduction of burst effects (k ≈ 0.01–0.02 h−1). The nanocomposite system herein proposed represents a new material formulation for preparing innovative drug eluting stents with intrinsic antibacterial properties.

EMPHYSEMATOUS PYELONEPHRITIS IN RENAL TRANSPLANT RECIPIENT

Introduction: Emphysematous pyelonephritis (EPN) is a necrotizing infection caharacterized by the presence of gas in the renal parenchyma, collecting system and peri- renal tissues. It´s a life threatening disease, nonspecific presentation, extremely rare in transplant recipients. Associated factors are: Diabetes mellitus, female sex, inmunosuppresion, urinary tract obstruction, and impaired vascular supply. It´s typically caused by gas producing bacteria such as Escherichia coli and Klebsiella pneumonia. We report a case of EPN in a transplant recipients. Case Description: 63-year-old male patient with end-stage renal failure due to polycystic disease. Kidney transplant with deceased donor in December 2017. There is no history of urinary stent, diabetes, rejection or obstruction of the urinary tract. Urinary tract colonization with Klebsiella pneumoniae producing extended spectrum Betalactamases (BLEE). In January 2020 consulted for deterioration of the general state, vomiting, diarrhea, anuria. TA: 100/60 FC: 120 FR: 22 SAT 89% FIO2 21%. He had no fever, urinary symptoms, graft site pain or signs of peritoneal irritation. Immunosuppression with meprednisone and mycophenolate. Leukocytes 9100 103 / mm3, neutrophils 82%, Platelets 192000 103 / mm3, hb 7.3 g / dl. Creatinine 2.70 mg%. Urinary sediment: semi-covered leukocyte field. Start empirical treatment with Meropenen. Graft echodoppler without collections or urostasis, with normal arterial resistance indices. For the first 24 hours, afebrile continues, with pain in the right hypochondrium. Ultrasound with presence of air bubbles in upper and lower calyces. Tomography with densification of the perirenal fat and presence of bubbles at the level of the renal sinus. Nephrostomy is performed. Uroculture: Klebsiella pneumoniae BLEE, negative blood cultures, negative coproculture, negative Clostridium difficile toxin, CMV viral load <100 copies. Patient completed 3 weeks of intravenous treatment. Continue with ertapenem.He with clinical, laboratory parameters and imaging improvement. Discussion: Emphysematous pyelonephritis has a high mortality. Of 29 cases reviewed 93% were diabetic, the rest were observed obstructive uropathy and a case of rejection. The 58.6% required transplantectomy, 27.5% antibiotic treatment with percutaneous drainage, 13.7% antibiotic management. The 13.7% died, 44.8% entered hemodialysis and 41% recovered renal function. The predominant germ was Escherichia coli (41.3%) and Klebsiella pneumoniae (34.4%). In our case as a only risk factor was chronic colonization by Klebsiella pneumoniae. According to the staging of Geizawi corresponded to a stage 2, so it was managed with antibiotic therapy and percutaneous drainage with favorable evolution. For this reason we highlight the importance of knowledge of the microbiological colonization of the urinary tract for early diagnosis and targeted therapy.

Surface-Treated Pellethanes: Comparative Quantification of Encrustation in Artificial Urine Solution

Introduction: Encrustation of implanted urinary tract devices is associated with significant morbidity. Pellethane® is a polyether-based compound noted for its strength, porosity, and resistance to solvents. We assessed Pellethane thermoplastic polyurethane (TPU) with and without surface coatings 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethyl ether (TETRA) for the potential to resist encrustation in an artificial urine environment. Materials and Methods: Samples of Pellethane TPU, HEMA Pellethane TPU, TETRA Pellethane TPU, and hydrogel-coated ureteral stent (Cook®) were suspended in a batch-flow model with an artificial urine solution (AUS). Every 48 hours for 90 days, 40% of the solution was replaced with fresh AUS. All samples were stored in a 37°C incubator. Subsequently, the samples were thoroughly dried for 48 hours before weighing. Scanning electron microscopy was used to assess the degree of encrustation. Nu-Attom Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine the precise compositions of the encrustation specifically with regard to calcium, magnesium, and phosphate. Results: At the conclusion of the 90-day trial, the samples were analyzed, and the average mass changes were as follows: stent 63.78%, uncoated Pellethane TPU 11.50%, HEMA-coated Pellethane TPU 2.90%, and TETRA-coated Pellethane TPU 0.60%. Pellethane TPU products, and specifically those coated with HEMA and TETRA, exhibited less average mass increase and a lesser propensity to form encrustation than the traditional urinary tract stent. The mass increases noted on coated Pellethane devices were primarily ionic, whereas that of the stent was not. Conclusion: Pellethane, particularly with an HEMA-based preventative coating, may serve as a favorable alternative to traditional urinary stent material, providing its improved resistance to encrustation.