Association between ureteric stent dwell time and urinary tract infection

MAGnetic REtriaval Device for Minimally Invasive Ureter Stent Removal

Purpose: To assess the effectiveness and pain intensity associated with magnetic ureteral stent removal using a retriever, without the aid of ultrasound guidance. Methods: We prospectively enrolled 100 patients who underwent retrograde rigid and flexible ureterorenoscopy with or without laser lithotripsy for ureteronephrolithiasis treatment from September 2021 to June 2023. These patients were assigned in two groups. Group 1 underwent the traditional ureteral stent insertion, while Group 2 underwent magnetic ureteral stent insertion. Both insertion and removal times were documented. The indwelling time for ureteral stents was 14 days. One group underwent stent removal via flexible cystoscopy using grasping forceps and the other group using just a magnetic retriever, without the aid of ultrasound guidance. The numeric pain rating scale, recommendation rate, and a standardized self-answered ureter stent symptoms questionnaire (USSQ) were obtained directly after stent removal. Results: Both groups presented comparable characteristics in factors such as age, body mass index, history of stone treatments, procedure type, and complication rates during and post-surgery. Time taken for ureteral stent insertion did not differ significantly between the groups (131.2 seconds for Group 1 vs 159.1 seconds for Group 2). However, the stent removal time (152.1 seconds for Group 1 vs 35.4 seconds for Group 2) and pain intensity (6 for Group 1 vs 2 for Group 2) were significantly lower for Group 2. Furthermore, five out of the six sections of the USSQ showed significantly better results for Group 2. Conclusions: The use of magnetic ureteral stents, as a safe and efficient alternative to conventional ureteral stents, not only eliminates the need for cystoscopy but also conserves resources and reduces patient discomfort.

Comparing the effect of peri-operative antibiotic prophylaxis only with continuous low-dose antibiotic treatment on the incidence of urinary tract infection and stent related-symptoms in patients undergoing Double-J (DJ) stent insertion following transurethral lithotripsy (TUL)

PURPOSE

There are some controversial data about the peri operative use of antibiotics after double-J (DJ) insertion. This study aimed to compare the rates of urinary tract infections (UTI) and stent-related symptoms (SRSs) in patients who received only perioperative antibiotic prophylaxis and those given continuous low-dose antibiotic therapy for the entire stent-indwelling time following transurethral lithotripsy (TUL).

METHODS

In this randomized clinical trial 178 patients received intravenous antibiotic prophylaxis (ciprofloxacin 400 mg) before the TUL and then randomly divided into two groups to either receive no antibiotic treatment after procedure (group A, 90 patients) or to additionally receive a continuous low-dose antibiotic treatment with one ciprofloxacin 500 mg every 12 h for 3 days and then ciprofloxacin 250 mg once daily for the entire stent-indwelling time (group B, 88 patients). The rates of UTIs, SRSs and incidence of drug side-effects were evaluated in groups.

RESULTS

A total of 7 patients had positive urine culture [group A: 4 (4.4%) vs. group B: 3 (3.4%); P = 0.722]. Only 1 patient in group B had febrile UTI in the mean duration of indwelling stent in situ. The rate of SRSs was 92.2% and 89.8% in Group A and B, respectively, with no significant difference (P = 0.609). A total of 4 patients in Group B complained of gastrointestinal side effects of ciprofloxacin.

CONCLUSION

Continuous low-dose antibiotic treatment has no role in reducing the incidence of UTIs and SRSs during the indwelling time of ureteral stents compared with the peri-operative antibiotic prophylaxis only.

Safety and effectiveness of magnetic ureteric stent removal under ultrasound control: a randomized single center trial

PURPOSE

To assess the safety and effectiveness of magnetic ureteric stent removal with a special magnet retriever under ultrasound guidance.

METHODS

A total of 60 male patients, who underwent ureteroscopy from October 2020 to March 2022, were prospectively enrolled and randomized into two groups. Group A patients underwent conventional double-J (DJ) stent insertion and subsequent stent removal via flexible cystoscopy. Group B patients underwent stent insertion using magnetic ureteric stent [Blackstar, Urotech (Achenmühle, Germany)] and stents were removed using a special magnet retriever under ultrasound guidance. Stents were left in situ for 30 days in both groups. All patients had follow-ups with a ureter stent symptoms questionnaire at 3- and 30-days post stent insertion. Visual analog scale (VAS) was assessed immediately after stent removal.

RESULTS

Stent removal time (142.5 s vs 142.5 s, group A vs group B, p < 0.0001) and VAS scores (4 vs 1, group A vs group B, p = 0.0008) were significantly lower in Group B. There were no statistically significant differences between both groups in the "urinary symptoms" (p = 0.3471) and "sexual matters" (p = 0.6126) in the USSQ domains. There was marginal statistical significance favoring Group A in the "body pain" (p = 0.0303), "general health score" (p = 0.0072), "additional problems" (p = 0.0142), and "work performance" (p < 0.0001) domains.

CONCLUSIONS

Magnetic ureteric stent can be considered as a safe and efficient alternative to conventional DJ stent. This approach avoids the need for cystoscopy, saving resources while minimizing patient discomfort.

Analysis of Bacterial Stent Colonization: The Role of Urine and Device Microbiological Cultures

In this study, we explored the incidence of double J (JJ) contamination of patients who underwent an endourological procedure for urinary stones and ureteral stenosis. We developed a prospective study between January 2019 and December 2021. Ninety-seven patients, 54 male and 43 female, were enrolled. Urine culture was taken during four steps: before stent insertion, a sample from selective renal pelvis catheterization, a sample two days after the JJ insertion and finally, after the stent removal procedure. At the time of the stent removal, 1 cm of proximal and distal ends were cut off and placed in the culture for bacterial evaluation. Cohen's kappa coefficient value (k) and concordance rates of microbiological culture results were evaluated. The study group comprised 56% of male patients. Proximal and distal stent cultures were positive in 81 and 78 patients. The concordance rate of microbiological cultures between proximal and distal double J stent is 88% (k 0.6). The most common pathogens isolated from urine and stent cultures were Enterococcus spp. in 52 cases and Klebsiella spp. in 27 cases.

Effect of operative times in bariatric surgery on outcomes: a matched analysis of the MBSAQIP database

BACKGROUND

The implications of operative time (OT) have been studied in different surgical specialties, showing a correlation with higher incidence rates of postoperative complications. However, the impact of OT on bariatric surgery complications is not well elucidated.

METHODS

A retrospective review of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database between 2015 and 2019 was performed. A total of 358,382 SG patients and 123,357 RYGB patients were included. The median OT was 68 min (10-720) and 113 min (10-640) for the sleeve gastrectomy (SG) group and the Roux-en-Y gastric bypass group, respectively. The groups were subdivided into two subgroups based on OT in comparison to the median time of each group. The subgroups were compared for surgical complications and outcomes. To reduce selection bias and risk of confounders, we performed a propensity score matching (PSM) for 22 variables.

RESULTS

In the PSM-matched cohort, 18,915 SG and 6,495 RYGB patients were included in each subgroup. The SG cohort showed higher rates of Clavien-Dindo Class 1, 2, 3a, 4, and 5 complications as well as higher rates of readmission, reoperation, and reintervention in the longer OT group before matching. After PSM, the subgroup with longer times continued to have higher rates of Clavien-Dindo Class 2 complications and higher rates of readmission and reoperation. Similarly, there were higher rates of all Clavien-Dindo class complications as well as readmission, reoperation, and reintervention in the RYGB group with higher OT. After PSM, there were still higher rates of Clavien-Dindo Class 3a complications as well as readmission and reintervention in the RYGB subgroup with prolonged OT.

CONCLUSION

In both SG and RYGB, longer OT was associated with increased rates of complications as well as readmission, reoperation, and reintervention. Surgeons should be cognizant of the increased rates of complications when operative times are longer.

Impact of eliminating urethral catheterization following ureterorenoscopic lithotripsy

OBJECTIVES

To show that elimination of a urethral catheter in ureterorenoscopic lithotripsy cases is not disadvantageous.

METHODS

We reviewed 164 non-catheterized patients (experimental group) and 656 catheterized patients (control group) with renal or ureteral stones treated at our institution. Inclusion criteria were initial operation, patient age 18 to 75 years, no dysuria, and no preoperative febrile urinary tract infection due to calculi. The primary areas of evaluation were patient background, stone characteristics, perioperative factors, and postoperative evaluation results.

RESULTS

The proportion of women was significantly lower (24.4% vs 37.2%; P = 0.01) and the proportion of multiple stone cases was significantly higher (34.9% vs 19.2%; P < 0.001) in the experimental as compared to the control group, while there were no significant differences for patient background or stone characteristics. The percentages of short-term preoperative stent insertion (72.0% vs 33.0%; P = 0.009) and negative preoperative urine culture cases (58.0% vs 23.0%; P < 0.001) were significantly higher in the experimental than in the control group, with no differences regarding other perioperative factors. There was no significant difference for complete stone clearance rate between the groups (P = 0.339), while only one patient underwent re-catheterization and there were no cases of urinary retention. Interestingly, the rate of postoperative febrile urinary tract infection was significantly lower (P = 0.024) in the experimental (5.7%) than in the control (9.0%) group.

CONCLUSION

Postoperative urethral catheterization can be eliminated in low-risk ureterorenoscopic lithotripsy cases, although additional studies are needed.

Post-Ureteroscopy Infections Are Linked to Pre-Operative Stent Dwell Time over Two Months: Outcomes of Three European Endourology Centres

Background: The aim of this study is to investigate outcomes of pre-operative stent dwell time on infectious complications following ureteroscopy and stone treatment to identify a time cut-off. Material and Methods: Three tertiary referral centres in Europe retrospectively collected outcomes of ureteroscopy and laser fragmentation (URSL) for all patients with pre-operative indwelling ureteric stents over a period of up to 5 years. Data was collected on patient details, stone demographics, stent dwell time, complications and stone free rate (SFR). Matching for age, sex, operative time, stone size and post-operative stent insertion. To examine for a threshold effect, monthly cut-offs were used to compare post-ureteroscopic febrile UTIs. Binomial logistic regression was used (SPSS v.24) with a significance level set at 0.0036. The risk ratio (RR) with a 95% confidence interval (CI) and the number needed to harm (NNH) are reported. Results: There were 467 patients with a pre-operative stent for analysis. These patients (n = 315) were matched to non-stented controls after excluding 152 patients to achieve adequate matching. There was a significant difference in rates of post-ureteroscopic febrile UTI between stented vs non-stented patients (RR = 2.67, 95% CI: 1.10–6.48, p = 0.03). On adjustment, a dwell time of more than two months was associated with an increased risk of post-ureteroscopic febrile UTI (RR = 3.94, 95% CI: 1.30–12.01, p = 0.02), this increased risk rose with longer dwell time. At stent time longer than four months was associated with a significantly increased risk of post-ureteroscopic febrile UTI (5% vs. 15%, RR = 3.09, 95% CI: 1.56–6.10, p = 0.001), with the number needed to harm at 10. Conclusions: Overall infectious complication rates from URSL are low. The risk of post-operative UTI after four months of dwell time is nearly tripled compared to less than four months.

The development and application of a triage system for urolithiasis during COVID-19

Purpose

To balance epidemic prevention with the therapeutic needs of patients with urolithiasis during the COVID-19 pandemic, we developed a triage system to guide medical staff in making priority decisions.

Methods

The study began with a review of the literature to propose a theoretical framework. Then, focus groups were assembled to develop, supplement, refine and form a consensus on the indications of the triage system. Finally, the system was implemented in the clinic. The validity and reliability of the system were tested by a content validity index and the interrater reliability kappa coefficient. Changes in patient characteristics and waiting time before and after the epidemic were compared.

Results

The theoretical framework was based on disease pathophysiology, including obstruction, infection, kidney dysfunction, and other symptoms. With this guide, a 28-item triage system with categories of T1–5 (low priority to urgent) was developed. The content validity index and the interrater reliability coefficient were 0.833 and 0.812, respectively. During clinical application, although the total number of patients remained steady, the proportion of T1 decreased significantly; even though the overall waiting time of patients did not change significantly, it increased for T1 and decreased for T2–4 in 2020 compared with 2019 (P < 0.05).

Conclusion

This triage tool based on the dimensions of obstruction, infection, kidney dysfunction, and other symptoms has good psychometric properties and significant utility for prioritizing patients with urolithiasis during times of crisis. With this system, patients of moderate to high priority were treated promptly during the COVID-19 pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-021-03871-7.