Histological Inflammation in Human Ureter either Healthy or Fitted with Double-Pigtail Stent or a Thin 0.3 F Suture Thread: A Preliminary Study

Outcomes of a non-randomised audit of single pigtail suture stents in urolithiasis management of Asian patients in Singapore

Objective

Double-J (DJ) ureteric stents are commonly placed perioperatively for semirigid or flexible ureteroscopic renal surgery. It is believed that lesser stent material within the bladder mitigates stent-related symptoms. This study aimed to evaluate the J-Fil ureteral stent, a single pigtail suture stent compared with conventional DJ stent in relation to stent symptoms in an Asian population undergoing ureterorenal intervention.

Methods

Based on internal audit committee recommendation approval, the records of 50 patients retrieved, available data of 41 patients who were prospectively enrolled into two groups (Group 1 [J-Fil stent group], n=21 and Group 2 [DJ stent group], n=20) between August 2020 to January 2021, were analysed. Parameters compared were nature of procedure, stone location and size, ease of deployment or removal, and complications. A modified universal stent symptom questionnaire was used to assess morbidity of stent symptoms within 48 h of insertion and at removal.

Results

Both groups had similar median age, distribution in male to female ratio, and stone size. The overall median universal stent symptom questionnaire score at insertion was similar for bladder pain, flank or loin pain, and quality of life between Group 1 and 2; however, at removal Group 1 fared significantly better than Group 2, especially for flank or loin pain and pain at voiding. Both groups had similar ease in insertion with no hospital readmissions.

Conclusion

Our audit favoured the single pigtail suture stent in Asian ureters in mitigating stent-related issues. It showed a good safety profile with easy deployment and removal. It promises a new standard in stenting.

Patients undergoing double J substitution with a pigtail suture stent report a significant decrease of stent-related symptoms. Results from a prospective multicenter longitudinal trial

PURPOSE

To compare stent-related symptoms (SRS) in patients with double J (DJ) undergoing substitution with a pigtail suture stent (PSS) after ureteroscopy (URS), through the Ureteral Stent Symptom Questionnaire (USSQ).

MATERIALS AND METHODS

Patients with DJ undergoing URS for stone treatment were enrolled in this prospective multicenter longitudinal study. The USSQ was submitted thrice: 2 weeks after DJ, 2 weeks after PSS and 4 weeks after PSS removal (baseline).

PRIMARY ENDPOINT

to compare Urinary Symptom Index Score and the rate of patients with pain 2 weeks after DJ and PSS. Secondary endpoints: to compare other USSQ scores and single answers 2 weeks after DJ and PSS, and DJ and PSS USSQ scores with baseline.

RESULTS

93 patients were enrolled. 2 weeks Urinary Symptom Index Score (p < 0.001) and the percentage of patients complaining of pain (60.2% vs 88.2%, p < 0.001) were significantly in favour of PSS compared to DJ. 2 weeks scores were significantly improved with PSS compared to DJ: Pain Index (p < 0.001), VAS (p < 0.001), General Health Index (p < 0.001) and Work Performance Index (p < 0.001). All urinary symptoms were significantly decreased with PSS, including renal pain during micturition and pain interfering with life. Pain Index Score (p = 0.622) and VAS (p = 0.169) were comparable to baseline with PSS, while differed with DJ.

CONCLUSIONS

Patients undergoing DJ substitution with PSS after URS report a significant decrease of SRS. Urologists may consider positioning PSS after URS in pre-stented patients to reduce the impact of SRS.

Indwelling stents cause severe inflammation and fibrosis of the ureter via urothelial-mesenchymal transition

To explore the pathways and mechanisms driving inflammation and fibrosis in stented ureters. In total, six healthy female pigs underwent cystoscopic unilateral ureteral stent insertion (6 Fr). After 14 days indwelling time, ureteral tissue was harvested in three pigs, while the remaining three pigs had their stents removed, and were recovered for 7 days. Three separate pigs served as controls. Tissue from stented and contralateral ureters was analysed histologically to evaluate tissue remodelling and classify the degree of inflammation and fibrosis, while genome, proteome and immunohistochemistry analysis was performed to assess changes at the transcriptional and translational levels. Finally, immunofluorescence was used to characterize the cell composition of the immune response and pathways involved in inflammation and fibrosis. Statistical analysis was performed using GraphPad Prism and RStudio for Welch ANOVA, Kruskal-Wallis and Dunnett's T3 multiple comparison test. Stents cause significant inflammation and fibrosis of ureters. Gene set enrichment analysis confirmed fibrotic changes and tissue proliferation and suggests that epithelial-mesenchymal transition is a driver of fibrosis. Moreover, IL-6/JAK/STAT and TNFα via NF-κB signalling might contribute to chronic inflammation promoting a profibrotic environment. Immunostaining confirmed epithelial-mesenchymal transition in the urothelium and NF-κB expression in ureters stented for 14 days. Tissue alterations do not fully recover after 7 days. Histological evaluation showed that contralateral, unstented ureters are affected by mild inflammation. Our study showed that stenting has a significant impact on the ureter. Chronic inflammation and epithelial-mesenchymal transition are drivers of fibrosis, potentially impairing ureteral functionality in the long term. Furthermore, we observed mild inflammation in contralateral, unstented ureters.

10-Year Experience with Reinforced Ureteral Stents for Malignant Ureteral Obstruction

Introduction

Malignant ureteral obstruction (MUO) hinders the management of malignant diseases. Indwelling stent is a common method to release renal obstruction, but stent failure with obstruction is frequent. The studies conclude that stent obstruction divides survival by 2 or even 4. We carried out the present study in order to evaluate drainage efficiency and overall survival by using stents with distinctive degrees of stiffness.

Materials and Methods

We performed an analysis of 156 patients with MUO drainage at a single institution from June 2009 to June 2019.

Results

Of the 156 patients, 128 (82.1%) died with a mean survival time of 15.3 ± 14.4 months after the first ureteral stent procedure (USP). In order to study stent failure and overall survival, the patients were divided into 3 groups. Group 1 with patients died soon after only one USP (n=37). Group 2 with patients had more than one USP and no obstruction (n=41). Patients in Group 3 had more than one USP and at least one stent obstruction (n=62). During the study period, 556 USPs were analysed separately. The stent failure with obstruction occurred in 23.0% (128/556) of USP at a mean of 4.4 ± 3.6 months. In case of stent failure, a progressive choice of stents was shaped to overcome each failure by focusing on the criterion of increasingly stiff stents. Patients in Group 1 died soon at mean of 4.9 ± 4.8 months. The mean survival time of patients in Groups 2 and 3 were, respectively, 19.4 ± 11.2 and 21.5 ± 16.3 months (P = 0.19).

Conclusion

MUO is a serious disease but this study is the first to prevent survival rate from falling by choosing the stent stiffness suitable for the patient. The active detection of stent failure has been shown to be essential for preserving survival.

The reasons of unsatisfactory results of extracorporeal shock wave lithotripsy in patients with ureterolithiasis

The article dedicate to the problem of failure of extracorporeal shockwave lithotripsy in patients with ureterolithiasis and reveal the changes which appear in the ureter in the location of the stone.The aim. Analysis of the results of treatment in patients, suffering ureteric stones, using the ureterolithotripsy procedure after failure extracorporeal shockwave lithotripsy. Materials and methods. In 137 patients with ureteric stones, whom ureterolithotripsy procedure after failure extracorporeal shockwave lithotripsy was conducted, the symptoms of the disease, the diagnostic methods value, efficacy of surgical treatment and reasons of the failure of previous method of treatment were analyzed. Results. In 135 patients endoscopic removal of stones has been succeeded, in 2 patients because of total obliteration of the ureter, uretero-ureteral anastomosis has been performed. If the symptoms, with are characteristic of ureterolithiasis, persists up to one week stones don’t cause significant macroscopic changes to the ureter wall. If the stone persists in the ureter longer than a week we identified local appearing of oedema. Long–term (more than two months) ureteric stone persistence increase the risk of intramucosal “ingrowth” of the calculi greatly. Conclusion. The URS and ESWL are high effective and minimal invasive methods of surgical intervention for patients with ureterolithiasis, guaranteeing high level of postoperative “stone free rate”. Prolongation of the stone insertion time in the ureter causes the ureteric wall changes, complicating performance of minimal invasive interventions (ureterolithotripsy and extracorporeal shock–wave lithotripsy) and reduce its efficacy.

Characterization of Sonic Hedgehog/Gli1 Signal Expression in Human Ureter Either Un-Stented or Fitted with Double-Pigtail Stent or a Thread

Introduction

The Sonic Hedgehog/Gli1 signal is involved in smooth muscle activity. An experiment showed that the double-pigtail stent caused ureteral inflammation and decreased Gli1 expression in smooth muscle cells. The innovative pigtail-suture stent (JFil^® or MiniJFil^®) with a thin 0.3F suture thread significantly decreased stent-related symptoms. Fortuitously, a dilation of the ureter containing the sutures was discovered, and a previous study confirmed that the sutures caused less ureteral inflammation than the double-pigtail stent. However, the mechanisms involved in the ureteral dilation are still unknown. In this study, we assessed ureteral Gli1 expression in the human ureter when it was un-stunted or when fitted with a double-pigtail stent or a suture thread.

Material and Methods

After consent and inclusion of patients in the protocol, nine segments of ureters were collected during cystectomy procedures for bladder cancers. There was no selection or exclusion, and patients with large tumors were included. Gli1 expression was assessed on the histological section to control the reflection of an active hedgehog signal. The expression of Gli1 in smooth muscle cells of the stented ureter was subjectively compared to un-stented ureter.

Results

A decrease in the intensity of Gli1 expression of smooth muscle cells was observed in all cases of ureter fitted with a double-pigtail stent. For the un-stunted ureters and the ureters fitted with the thin 0.3F suture thread, Gli1 staining of smooth muscle cells was heterogeneous, and the small number of cases did not allow us to conclude.

Conclusion

Apart from the cases of ureters fitted with the double-pigtail stent, Gli1 expression of smooth muscle was heterogeneous. The Shh/Gli1 pathway may not be involved in ureteral dilation by the thread. A broader exploration of molecular mechanisms could make it possible to obtain the mechanisms involved in the dilation of the ureter by the thread.