Febrile Complications Following Insertion of 100 Double-J Ureteral Stents

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.

Effects of Continuous Catheterization on Reducing Postoperative Urinary Tract Infection in Cervical Cancer Patients with Double J Stent Placement

This study aims at exploring the effect of continuous catheterization on reducing postoperative urinary tract infection in cervical cancer patients with double J tube placement. To be specific, a retrospective analysis was performed on 120 cases of cervical cancer patients who underwent laparoscopic or open radical hysterectomy in Shengjing Hospital of China Medical University from January to December 2019. They were divided into a persistent group (n = 70) and a short-term group (n = 50) according to indwelling catheter time. The incidence of postoperative complications and the positive rate of bacterial culture in bladder urine and double J tube bacterial culture were compared between the two groups. As a result, it was found that the incidence of postoperative fever and urinary tract infection in the short-term group was significantly higher than that in the persistent group (P < 0.05). There was no significant difference in the incidence of postoperative hematuria, bladder stimulation, and urinary system injury between the two groups. The positive rate of double J tube bacterial culture in both groups was also proved to be higher than that in bladder culture, and the difference was statistically significant (P < 0.05). And in the short-term group (P < 0.05), the difference in the positive rate of bladder culture between the two groups was not statistically significant. To conclude, we found that continuous catheterization can reduce the incidence of postoperative urinary tract infection in cervical cancer patients with double J tube placement, which might be helpful for the treatment of cervical cancer.

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.

Urolithiasis in pregnancy: a cost-effectiveness analysis of ureteroscopic management vs ureteral stenting

OBJECTIVE

The purpose of this study was to determine the cost-effectiveness of serial stenting vs ureteroscopy for treatment of urolithiasis during pregnancy as a function of gestational age (GA) at diagnosis.

STUDY DESIGN

We built decision analytic models for a hypothetical cohort of pregnant women who had received a diagnosis of symptomatic ureteral calculi and compared serial stenting to ureteroscopy. We assumed ureteral stent replacement every 4 weeks during pregnancy, intravenous sedation for stent placement, and spinal anesthetic for ureteroscopy. Outcomes were derived from the literature and included stent infection, migration, spontaneous kidney stone passage, ureteral injury, failed ureteroscopy, postoperative urinary tract infection, sepsis, and anesthetic complications. Four separate analyses were run based on the GA at diagnosis of urolithiasis. Using direct costs and quality-adjusted life years, we reported the incremental costs and effectiveness of each strategy based on GA at kidney stone diagnosis and calculated the net monetary benefit. We performed 1-way and Monte-Carlo sensitivity analyses to assess the strength of the model.

RESULTS

Ureteroscopy was less costly and more effective for urolithiasis, irrespective of GA at diagnosis. The incremental cost of ureteroscopy increased from -$74,469 to -$7631, and the incremental effectiveness decreased from 0.49 to 0.05 quality-adjusted life years for a kidney stone diagnosed at 12 and 36 weeks of gestation, respectively. The net monetary benefit of ureteroscopy progressively decreased for kidney stones that were diagnosed later in pregnancy. The model was robust to all variables.

CONCLUSION

Ureteroscopy is less costly and more effective relative to serial stenting for urolithiasis, regardless of the GA at diagnosis. Ureteroscopy is most beneficial for women who received the diagnosis early during pregnancy.

Percutaneous insertion of double-J ureteral stent in children with ureteral obstruction: our experiences

OBJECTIVE

Ureteral obstruction (UO) is usually treated by surgical or endoscopic approaches. We investigated whether percutaneous anterograde treatment with insertion of double-J ureteral stent (DJ) is a feasible alternative technique for the management of UO in selected cases, where traditional approaches are not possible or too risky.

PATIENTS AND METHODS

The DJ was percutaneously inserted into 10 children (mean age 9 years) who suffered from UO. Three children had already been treated surgically for complex urotract congenital anomalies; six children had restenosis/reocclusion or stenosis of ureteropelvic junction; and one girl suffered migration of an intraoperatively placed DJ with stenosis of the distal ureter.

RESULTS

Percutaneous insertion of the DJ was successful on the first attempt in 8 and on the second in 2 children. Adverse events after the procedure, all successfully treated, included one pyelonephritis and one migration of DJ, and 3 children had bacteriuria and 3 hematuria. Mean duration of insertion of the DJ was 6.4 months. After removal of the DJ, 7 children did not need any further interventions, but 2 children needed surgical correction and 1 reinsertion of the DJ.

CONCLUSION

In selected cases, percutanous insertion of a DJ should be considered as an alternative to surgery or endoscopic treatment in the management of children with UO.

Ureteroscopic holmium laser ablation of a knotted ureteral stent

Ureteral stents are commonly used in urologic practice and have a number of well recognized complications. A rare complication is knotting with associated difficult removal having been reported in only 15 previous cases. Various methods of removal have been described. We report an additional case in which a ureteroscopic holmium laser was successfully used to remove a knotted ureteral stent. A literature review of all previous cases of this rare complication is also presented.

Update on ureteral stent technology

Ureteral stents are commonly used in urology but are frequently associated with patient discomfort, stent encrustation and stent-related infection. New biomaterials, coatings and designs have been designed to attempt to reduce these problems. This article reviews coatings to reduce bacterial adhesion and encrustation. In addition, metal ureteral stents, the triclosan and ketorolac drug eluting ureteral stents, and biodegradable ureteral stents are discussed. In summary there is no perfect ureteral stent that avoids all morbidity but there have been significant advances in the last few years in stent technology.

A sealed bladder cuff technique during laparoscopic nephroureterectomy utilizing the LigaSure electrosurgical device: laboratory and clinical experience

INTRODUCTION

Laparoscopic nephroureterectomy (LNU) is a safe, minimally invasive approach for management of upper tract urothelial tumors. Controversy exists over the optimal technique for the distal ureter and bladder cuff (DUBC) excision. We examined the novel technique of using the LigaSure bipolar electrosurgical device in laboratory investigations and during clinical LNU to manage the DUBC.

PATIENTS AND METHODS

Initial investigations were undertaken in the porcine model. Areas of both normal porcine ureters and bladders, and ex vivo human ureters from radical nephrectomy specimens were sealed with the LigaSure and stained with nicotinamide adenine dinucleotide (NADH) and hematoxylin and eosin to examine the length of treatment effect and the viability of the ablated tissue. Clinically, we performed 22 LNU for proximal urothelial tumors using the LigaSure for the management of the DUBC. Intraoperative cystoscopy assessed cuff resection and bladder leakage. On postoperative day 10, a cystogram was performed.

RESULTS

In the porcine model, the technique sealed the bladder effectively with a mean burst pressure of 14 mm Hg. Cellular staining revealed no viable urothelial tissue in the seal area and an additional 2 mm outside this area. Eighteen patients had a successful seal/ablation intraoperatively. Cystoscopy revealed cautery artifact and blanching over the former position of the ureteral orifice.

CONCLUSION

The LigaSure device ablates and seals urothelial tissue with no viable cells in the clamped and adjacent blanched tissue. Our technique is technically feasible, removes an adequate bladder cuff, typically maintains a closed urinary system, and adheres to sound oncological principles. This procedure could be performed in both laparoscopic and open nephroureterectomy for proximal upper tract transitional cell tumors.

Next generation biodegradable ureteral stent in a yucatan pig model

PURPOSE

Ureteral stents are commonly used to facilitate kidney drainage but they may produce significant stent symptoms and morbidity, and require a secondary procedure for removal. Previous biodegradable stents showed bio-incompatibility or inconsistent degradation, requiring extra procedures to remove undegraded stent fragments. We previously reported a first generation biodegradable stent composed of suture-like material that required placement through the lumen of a sheath and degraded by 10 weeks. We now report second and third generation biodegradable stents that degrade more rapidly and can be placed directly over a polytetrafluoroethylene guidewire.

MATERIALS AND METHODS

Two groups of 16 Yucatan pigs each were unilaterally stented endoscopically with a control nondegradable (biostable) stent or a second generation degradable Uriprene stent. Blood studies, renal ultrasound and excretory urography were done throughout the study to determine renal function, hydronephrosis and stent degradation. Genitourinary organs were harvested at necropsy for pathological analysis. A third generation stent designed to improve degradation time was bilaterally implanted endoscopically into 4 Yorkshire Farm pigs (total of 8 stents), followed by excretory urography weekly to assess degradation and kidney function. Biomaterial parameters were tested.

RESULTS

Second generation stents began degrading at 2 weeks and were completely degraded by 10 weeks. All third generation stents were degraded by 4 weeks. Hydronephrosis was considerably less in the Uriprene group than in control biostable stented kidneys. Biostable stented ureters showed an average higher degree of inflammation, uropathy and nephropathy. Physical characteristics indicate that Uriprene stents are significantly more resistant to stent compression and have markedly higher tensile strength and coil strength comparable to that of other commercially available plastic stents.

CONCLUSIONS

Our study confirms that Uriprene stents are biocompatible and provide good renal drainage. They hold promise for decreasing the need for a secondary procedure and stent related morbidity, such as infection and irritative symptoms.

Ureteral stent symptoms and associated infections: a biomaterials perspective

Ureteral stents are commonly used in the field of urology, and, given their indwelling nature, are often a nidus for infection and a cause of discomfort. To minimize symptoms, the urologic surgeon should first consider whether a stent needs to be placed at all. Softer stents do not seem to improve patient comfort. Stents that are too long, specifically those that cross the midline of the bladder, significantly increase the frequency of stent-related symptoms. Administering alpha blockers while the stent is indwelling can reduce these symptoms. Antibiotic prophylaxis or concomitant antibiotic administration does not seem to reduce the incidence of stent-related urinary tract infection. At present, drug-eluting stents have shown the most promise for inhibiting bacterial adhesion and biofilm formation. Future stent designs that maintain drainage of the kidney and ureter while minimizing inflammation and contact with the urothelium will improve patient outcomes. By better understanding the basic pathways of bacterial adhesion to biomaterials, new stents and medications that target these mechanisms can be developed to eliminate bacterial adhesion and infection in patients with ureteral stents.

Investigation of a novel degradable ureteral stent in a porcine model

PURPOSE

Ureteral stents often result in patient morbidity and the potential for a forgotten stent. When the suture tether is detached, a secondary procedure is required for removal. Previous attempts at developing biodegradable ureteral stents have been unsuccessful since those stents were not biocompatible or they failed to degrade in timely fashion. We evaluated a new biodegradable Double-J stent in a porcine model.

MATERIALS AND METHODS

A total of 36 Yorkshire pigs were stented unilaterally with a biodegradable Uriprene stent or a standard biostable control stent. Excretory urograms, and blood and urine tests were performed at weeks 2, 3, 4, 5, 7 and 10. Four animals per group were sacrificed after 2, 4, 7 and 10 weeks to determine stent degradation and obtain samples for pathological evaluation.

RESULTS

Degradable ureteral stents began to degrade at 3 weeks. By weeks 7 and 10, 60% and 100% of the stents, respectively, were fully degraded. There was no significant difference in laboratory parameters or the amount of hydronephrosis between the 2 groups. However, ureteral dilatation was significantly more pronounced in the control group than in the Uriprene group. The novel stent was biocompatible on histological evaluation and it led to significantly less urinary tract infections than in controls.

CONCLUSIONS

The novel Uriprene stents provided drainage similar to that of regular stents and they were completely degraded by 10 weeks. Moreover, these stents resulted in less ureteral dilatation and fewer positive urine cultures. Biocompatibility was good and human trials will be forthcoming.

Risk factors for lower urinary tract infection and bacterial stent colonization in patients with a double J ureteral stent

OBJECTIVE

We investigated the potential risk factors for lower urinary tract infection and bacterial stent colonization in patients with double-J stents.

PATIENTS AND METHODS

A total of 195 double-J stents from 190 patients (95 men and 95 women, mean age 40.22 years) were examined. In all patients, prophylactic antimicrobial therapy was administered at the time of stenting. The stents and urine samples were removed aseptically and the proximal and distal tip segments of the stents were obtained. Three culture specimens were obtained from each stent segment and urine sample. Chi-square tests, odds ratio, and relative risk were used for the statistical analysis.

RESULTS

Bacterial colonies were found in 24% (47 of 190) of the urine samples, 31% (61 of 195) of the proximal stent segments, and 34% (67 of 195) of the distal stent segments. Of the pathogens identified, Escherichia coli (34 of 47) was the most common. Diabetes mellitus (P < 0.01), chronic renal failure (P < 0.001), and pregnancy (P < 0.01) were found to be risk factors for lower urinary tract infection in patients with stents. An increased stent colonization rate was associated with implantation time, age, and female sex, but these were not statistically significant for lower urinary tract infection

CONCLUSION

Diabetes mellitus, chronic renal failure, and pregnancy are associated with a higher risk of lower urinary tract infection. Therefore, patients in these categories should be monitored carefully for infectious complications.

Minimizing symptoms in patients with ureteric stents

PURPOSE OF REVIEW

The current approaches for minimizing symptoms in patients with ureteric stents were reviewed utilizing a literature search on Pubmed using the keywords stent, symptom, and ureter.

RECENT FINDINGS

Ureteral stents are widely used in urological procedures for maintaining upper urinary tract drainage to relieve obstruction, pain, or infection. Indwelling stents, however, are associated with significant morbidity such as infection, encrustation, hematuria, and bothersome symptoms. Minimizing these issues has become paramount in the design of new ureteral stents. This article will review current and novel ways to minimize stent-related morbidity.

SUMMARY

Currently, there is no ideal stent that relieves obstruction, is resistant to infection and encrustation, and is comfortable for patients. Advances in biomaterials and design will result in a more biocompatible stent that also has patient comfort in mind.

Is there a role for alpha1-blockers in treating double-J stent-related symptoms?

OBJECTIVES

To evaluate the effect of alfuzosin in improving symptoms in, and quality of life of, patients with indwelling double-J ureteral stents.

METHODS

A total of 100 patients, 50 men and 50 women (mean age 54.2 years), with unilateral ureteral stone-related hydronephrosis, who had opted for conservative management with insertion of a double-J ureteral stent, were prospectively randomized into two groups. Group 1 included 50 patients who received 10 mg of alfuzosin, once daily for 4 weeks, and group 2 consisted of 50 patients who received placebo for the same period. All patients completed a validated Ureteral Stent Symptom Questionnaire (USSQ) 4 weeks after stent placement.

RESULTS

The mean urinary symptom index score was 21.6 in group 1 and 28.1 in group 2 (P < 0.001). Stent-related pain was reported by 44% of patients in group 1 and 66% of patients in group 2 (P = 0.027). The mean pain index score was 14.6 in group 1 and 17.4 in group 2 (P = 0.047). The mean general health index score was statistically greater (P < 0.001) in group 1 compared with in group 2 (8 versus 11.4, respectively). Among sexually active patients, the mean sexual score was 2.3 in group 1 and 2.9 in group 2 (P = 0.017).

CONCLUSIONS

Stent-related symptoms were present in 66% of the controls (group 2). Alfuzosin improved a subset of stent-related urinary symptoms and pain. Patients receiving alfuzosin had their sexual function and general health better preserved.