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Dear stent friends, once again a newsletter of our ureteral stents series. I have chosen from the most recent scientific literature three very interesting papers. 

The first one focuses on an aspect that is often overlooked in patients, namely how ureteral stents affect them psychologically, with interesting results and, above all, a very clear message: education and information are key to reducing this psychological effect. 

On the other hand, the second selected manuscript focuses on an aspect of great importance that, despite research, is still relevant today: the impact of ureteral stent indwelling duration on encrustation degree and how this encrustation affects stent removal techniques. This manuscript provides crucial information for decision-making and avoiding major complications. 

Finally, the last selected paper is a comparative study in patients with an anti-encrustation coated stent, where we can see the industry's advances in producing stents that reduce complications associated with stents, and understand that in selected patients or in prolonged stenting times, coated stents have a clear indication.

I hope you enjoy this selection and have a nice summer holidays¡¡

3'

In this paper, the authors address an interesting but rarely assessed aspect of ureteral stents: the psychological impact on patients. Despite the bias inherent in the study group being from a single hospital and of a single nationality, it shows interesting results that should make us think about the patients. It is important to note that approximately 2 million ureteral stents are used annually worldwide. This provides insight into the importance of assessing associated complications and adverse effects. While physical complications are well-documented, psychological impacts remain understudied. 

The authors recruited patients who underwent ureteral stent placement following ureteroscopic lithotripsy, developing a prospective observational study. Psychological assessments using the Chinese version of the Perceived Stress Scale and Emotional Distress scale were performed at two time points: immediately before stent insertion and during the stent indwelling period.

A total of 82 patients with indwelling ureteral stents were enrolled in this study, comprising 55% males and 45% females. 11% of patients had bilateral stents. Gender emerged as a strong determinant of perceived stress, with female patients reporting significantly higher scores than male patients in both perceived helplessness and perceived tension. Notably, retired people reported the highest levels of stress in both dimensions. The duration of stent placement significantly influenced perceived helplessness, with patients having stents for ≥1 month experiencing greater feelings of helplessness compared to those with stents for <1 month. Interestingly, neither stent position (left, right, or bilateral) nor age group demonstrated significant associations with either dimension of perceived stress. Comparative analysis of patients' perceived stress levels before and during ureteral stent placement revealed substantial increases in all measured dimensions. The total perceived stress score increased by 66%. Similarly, the perceived helplessness dimension showed a considerable increase to a 56.5% rise.

For individuals identified as high risk, symptoms of anhedonia should be integrated into routine urological care, particularly prevalent among female patients. Specific psychological support and interventions should focus on anhedonia, while urologists can alleviate psychological distress through patient education and addressing their concerns. Greater collaboration with mental health professionals can better mitigate psychological distress in patients with permanent stents. Once again, an issue of great importance that has been described many times by other authors comes to the fore: educating patients with ureteral stents is one of the key points in reducing their stress and even their pain. Patients who understand where their pain comes from show fewer stent-related symptoms.

Clinicians should proactively address patients’ psychological needs through targeted patient education, especially for high-risk populations, to improve patient experience during the stent indwelling period.

3'

Further exploring encrustation, a manuscript has recently been published with a interesting objective: assess the association between ureteral stent indwelling time and encrustation level, as well as the procedural difficulty of stent extraction. The retrospective study included 33 patients who underwent ureteral stent placement either as an emergency procedure (for obstructive ureteral lithiasis) or electively (for ureteral strictures or retroperitoneal fibrosis). Only patients with neglected ureteral stents or stents associated with complications were included. The stents used were polyurethane double-J, with calibers ranging from 4.7 to 7 Fr.

The correlation between the degree of encrustation and the associated pathologies reported (obesity, retroperitoneal fibrosis, and antiplatelet treatment) showed statistically significant results in cases of low encrustation. However, no statistically significant correlation was observed in cases of moderate or severe encrustation.

Moreover, the presence of associated pathologies was found to promote the occurrence of urinary tract infections, particularly in cases involving E. coli, Klebsiella, and Enterococcus species. Additionally, stent discoloration, specifically black pigmentation was significantly associated with the presence of these pathogens. The duration of ureteral stent indwelling influences the occurrence of low encrustations. Among patients who received stents with a planned duration of 3 months, a significant positive association was observed between low encrustations and stent indwelling for 45–90 days, as well as for more than 90 days. No statistically significant correlations were identified between the presence of urinary tract infections and the degree of ureteral stent encrustation. An interesting finding is that as the duration of stent retention increased, black discoloration became more frequent.

Patients recluted in this study with stents maintained for longer periods, particularly those exceeding 90 days or those classified as neglected, more frequently required complex surgical procedures. In contrast, patients with stents retained for less than 45 days most commonly underwent standard cystoscopic removal. These findings suggest that prolonged stent retention increases the likelihood of requiring more invasive or technically demanding surgical interventions, and provide information about a cut-off date.

The findings of this study suggest that shorter indwelling times tend to result in encrustations limited to the distal segment, whereas neglected stents are more frequently associated with extensive, multi-site encrustations involving the shaft and proximal loop.

The conclusions of this manuscript help us in our clinical practice. The duration of stenting plays a key role, with prolonged periods of stent indwelling (over 45 days) being strongly associated with low encrustation, particularly in patients with stents neglected for over 90 days. The presence of urinary tract infections, particularly with E. coli and Klebsiella pneumoniae, was correlated with black coloration of the stents,which was also found to be a strong indicator of encrustation. Furthermore, encrustation was observed across all stent diameters used, emphasizing that the material composition of polyurethane stents is prone to biofilm formation, leading to varying degrees of encrustation. 

2'

It is well known that prolonged indwelling stents are at increased risk of infection, encrustation and dysfunction. These stents can become calcified and brittle, leading to stent blockage, infection, and worsening symptoms.
For this reason, the authors of the study aim to determine whether there are differences in technical performance or patient-reported outcomes between the new Tria™ (Boston Scientific Corporation) stent and non-Tria stents. The Tria™ stent was designed to decrease the accumulation of Mg and calcium salts on the stent surface. This is thought to decrease the encrustation processes when exposed to urine. The stent softens by 40% at body temperature in an attempt to improve patient tolerability and comes in a firm and soft durometer.

A multicenter study was performed with 359 patients. Of the 359 patients, 271 patients had a single ureteric stent placed for stone management. 154 patients had a Tria Stent (109 Tria Soft and 45 Tria Firm). Post-operative prescriptions for Tria and non-Tria included alpha-blockers (52% vs. 46%), antibiotics (54% vs. 38%), and analgesics (60% vs. 80%). The stent indwell times were similar: 11.8 Tria vs. 9.9 non-Tria days.

Technical success between the two groups was Tria 98.7% vs. non-Tria 98.3%. The stent migration rate was low in both groups, Tria 0% vs. non-Tria 1.7%. Overall, there were low and not significantly different rates of encrustation; Tria 1.3% vs. non-Tria 0%, and infection; Tria 1.9% non-Tria 3.4%. About the changes in pain scores, there was no significant difference in pain intensity or interference scores for either group.However, from stent removal to post-stent removal visit, the non-Tria group had significantly greater changes in both domains due to this group having higher pain scores at time of stent removal. The Tria group had lower pain interference scores in the week prior to stent removal and pain intensity scores approached statistical significance. 

As the authors mention, there are likely to be no differences between the two stents in terms of encrustation due to the short stenting time used. In fact, the only encrusted stent was in 53 days, significantly longer than the median indwell times. In relation to encrustation, stenting time is one of the most important factors, as well as infection and the characteristics of each patient's urine. Therefore, this type of coated stent should be selected for longer ureteral stent indwelling times.

An important aspect of this study relates to the lower pain interference scores in the Tria group, in the week prior to removal and post-stent removal. This may be explained by the fact that Tria softens by 40% at body temperature.