A Drug-Coated Balloon Treatment for Urethral Stricture Disease: Three-Year Results from the ROBUST I Study

Deep Phenotyping the Anterior Urethral Stricture: Characterizing the Relationship Between Inflammation, Fibrosis, Patient History, and Disease Pathophysiology

PURPOSE

Anterior urethral stricture disease (aUSD) is a complex, heterogeneous condition that is idiopathic in origin for most men. This gap in knowledge rarely affects the current management strategy for aUSD, as urethroplasty does not generally consider etiology. However, as we transition towards personalized, minimally invasive treatments for aUSD and begin to consider aUSD prevention strategies, disease pathophysiology will become increasingly important. The purpose of this study was to perform a deep phenotype of men undergoing anterior urethroplasty for aUSD. We hypothesized that unique biologic signatures and potential targets for intervention would emerge based on stricture presence/absence, stricture etiology, and the presence/absence of stricture inflammation.

MATERIALS AND METHODS

Men with aUSD undergoing urethroplasty were recruited from one of 5 participating centers. Enrollees provided urethral stricture tissue and blood/serum on the day of surgery and completed patient-reported outcome measure questionnaires both pre- and postoperatively. The initial study had 3 aims: (1) to determine pediatric and adult subacute and repeated perineal trauma (SRPT) exposures using a study-specific SRPT questionnaire, (2) to determine the degree of inflammation and fibrosis in aUSD and peri-aUSD (normal urethra) tissue, and (3) to determine levels of systemic inflammatory and fibrotic cytokines. Two controls groups provided serum (normal vasectomy patients) and urethral tissue (autopsy patients). Cohorts were based on the presence/absence of stricture, by presumed stricture etiology (idiopathic, traumatic/iatrogenic, lichen sclerosus [LS]), and by the presence/absence of stricture inflammation.

RESULTS

Of 138 enrolled men (120 tissue/serum; 18 stricture tissue only), 78 had idiopathic strictures, 33 had trauma-related strictures, and 27 had LS-related strictures. BMI, stricture length, and stricture location significantly differed between cohorts (P < .001 for each). The highest BMIs and the longest strictures were observed in the LS cohort. SRPT exposures did not significantly differ between etiology cohorts, with > 60% of each reporting low/mild risk. Stricture inflammation significantly differed between cohorts, with mild to severe inflammation present in 27% of trauma-related strictures, 54% of idiopathic strictures, and 48% of LS strictures (P = .036). Stricture fibrosis did not significantly differ between cohorts (P = .7). Three serum cytokines were significantly higher in patients with strictures compared to stricture-free controls: interleukin-9 (IL-9; P = .001), platelet-derived growth factor-BB (P = .004), and CCL5 (P = .01). No differences were observed in the levels of these cytokines based on stricture etiology. However, IL-9 levels were significantly higher in patients with inflamed strictures than in patients with strictures lacking inflammation (P = .019). Degree of stricture inflammation positively correlated with serum levels of IL-9 (Spearman's rho 0.224, P = .014).

CONCLUSIONS

The most common aUSD etiology is idiopathic. Though convention has implicated SRPT as causative for idiopathic strictures, here we found that patients with idiopathic strictures had low SRPT rates that were similar to rates in patients with a known stricture etiology. Stricture and stricture-adjacent inflammation in idiopathic stricture were similar to LS strictures, suggesting shared pathophysiologic mechanisms. IL-9, platelet-derived growth factor-BB, and CCL5, which were elevated in patients with strictures, have been implicated in fibrotic conditions elsewhere in the body. Further work will be required to determine if this shared biologic signature represents a potential mechanism for an aUSD predisposition.

Comparative analysis of holmium: YAG laser internal urethrotomy versus Cold-Knife optical internal urethrotomy in the management of urethral stricture - a systematic review and meta-analysis

OBJECTIVE

Urethral stricture management has posed enduring challenges in urology, demanding innovative and effective treatment modalities. This study addresses the persistent issues associated with urethral strictures, focusing on the comparative evaluation of two contemporary treatment modalities: Ho: YAG Laser Internal Urethrotomy (HIU) and Cold Knife Optical Internal Urethrotomy (CIU).

METHODS

A comprehensive search of PubMed, Embase, Web of Science, Cochrane Library, and ResearchGate was conducted to identify relevant studies up to November 2023. Inclusion criteria encompassed comparative studies evaluating HIU and CIU in patients with urethral stricture. Data extraction, quality assessment, and subgroup analyses were performed using standardized methods. Outcome measures included preoperative and postoperative mean the maximum urine flow rate (Qmax), mean surgical time, recurrence rates, and perioperative complications.

RESULTS

Nine articles met the inclusion criteria, and their data were analyzed using RevMan 5.4.1. Forest plots were generated for preoperative and postoperative mean Qmax, mean surgical time, recurrence rates, and perioperative complications. While postoperative mean Qmax (MD -0.06; 95% CI: -0.28-0.16; P =0.60, I2 =75%) and mean surgical time (MD 2.16; 95% CI: -1.66-5.99; P =0.27, I2 =98%) showed no significant differences between HIU and CIU, a trend towards lower recurrence rates (RR 0.71; 95% CI: 0.48-1.06; P =0.09, I2 =46%) was observed with HIU but without statistical significance. Perioperative complications, particularly bleeding (RR 0.21; 95% CI: 0.08-0.53; P =0.001, I2 =0%), favored HIU over CIU. The subanalysis indicates that for the treatment of complex urethral strictures, the two surgical methods differ in terms of mean Qmax at 6 months postoperatively (MD -2.51; 95% CI: -4.10--0.91; P =0.002, I2 =59%) and 12 months postoperatively (MD 2.62; 95% CI: 0.93-4.30; P =0.002, I2 =0%). The HIU group shows a significant decrease in recurrence rate at 12 months postoperatively (RR 0.44; 95% CI: 0.21-0.92; P =0.03, I2 =0%). For short-segment urethral strictures with a length ≤1.5 cm, CIU had a shorter operative time compared to the HIU (MD 4.49; 95% CI: 3.87-5.10; P <0.00001, I2 =44%).

CONCLUSION

Overall, both interventions demonstrated similar efficacy in improving postoperative mean Qmax, mean surgical time, and recurrence rates. However, subanalysis indicates that in the short-term, CIU is more effective than HIU in improving Qmax after complex urethral stricture surgery. In long-term Qmax follow-up after surgery, HIU is significantly higher than CIU, and HIU has a low recurrence rate. In addition, for short-segment urethral stricture (≤1.5 cm), CIU requires less time. In terms of complications, HIU has a lower risk of bleeding.

Minimal invasive treatment of urethral strictures: An experimental study of the effect of paclitaxel coated balloons in the wall of strictured rabbit's urethra

PURPOSE

The aim of this study is the evaluation of the distribution of paclitaxel (PTX) released by a coated balloon in the layers of rabbit's urethra.

METHODS

18 rabbits were included. A laser device was used for the stricture formation. After two weeks, dilation of the strictured urethra was performed by using Advance 35LP PTA balloons and Advance 18 PTX PTA balloons. The experimental models were divided into 3 groups. The group Α included two rabbits without any intervention except for the stenosis procedure. Group B compromised six rabbits that underwent dilation with Advance 35LP PTA balloons. Group C consisted of 10 rabbits to which dilation with both Advance 35LP PTA balloons and Advance 18 PTX PTA balloons was applied. Histological evaluation and Immunohistochemistry were performed on all specimens.

RESULTS

Inflammation, fibrosis and ruptures were detected in the specimens of the study. In specimens of Group C the decrease of inflammation and fibrosis rate was greater. Anti-PTX antibody was detected in the epithelium, lamina propria and smooth muscle layer of all specimens of urethras that have been harvested immediately and 1 day after the dilation with Advance 18 PTX PTA balloon and it was not observed in any layer of the urethral wall of the rest of the examined specimens of Group C.

CONCLUSIONS

PTX's enrichment was detected in the smooth muscle layer of all specimens that have been harvested immediately and 24h after the dilation with Advance 18 PTX PTA balloons. PTX may play an inhibitive role in the recurrence of the stenosis.

Balloon dilation for the treatment of male urethral strictures: a systematic review and meta-analysis

OBJECTIVE

The use of minimally invasive endoluminal treatment for urethral strictures has been a subject for debate for several decades. The aim of this study was to review and discuss the safety, efficacy and factors influencing the clinical application of balloon dilation for the treatment of male urethral strictures.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Embase, Medline, Web of Science, Cochrane Library and Scopus were searched for publications published before 17 July 2022.

STUDY SELECTION

Two independent researchers screened and assessed the results, and all clinical studies on balloon dilation for the treatment of urethral strictures in men were included.

DATA EXTRACTION AND SYNTHESIS

The success rate, rate of adverse events, International Prostate Symptom Scores, maximum uroflow (Qmax) and postvoid residual urine volume were the main outcomes. Stata V.14.0 was used for statistical analysis.

RESULTS

Fifteen studies with 715 patients were ultimately included in this systematic review. The pooled results of eight studies showed that the reported success rate of simple balloon dilation for male urethral strictures was 67.07% (95% confidence interval [CI]: 55.92% to 77.36%). The maximum urinary flow rate at 3 months (risk ratio [RR]= 2.6510, 95% CI: 1.0681 to 4.2338, p<0.01) and the maximum urinary flow rate at 1 year (RR= 1.6637, 95% CI: 1.1837 to 2.1437, p<0.05) were significantly different after dilation. There is insufficient evidence to suggest that balloon dilation is superior to optical internal urethrotomy or direct visual internal urethrotomy (DVIU) (RR= 1.4754, 95% CI: 0.7306 to 2.9793, p=0.278).

CONCLUSION

Balloon dilation may be an intermediate step before urethroplasty and is a promising alternative therapy to simple dilation and DVIU. The balloon is a promising drug delivery tool, and paclitaxel drug-coated balloon dilation is effective in reducing retreatment rates in patients with recurrent anterior urethral strictures. The aetiology, location, length, previous treatment of urethral stricture may be associated with the efficacy of balloon dilation.

PROSPERO REGISTRATION NUMBER

CRD42022334403.

Durable benefit after treatment of obstructive benign prostatic hyperplasia with a novel drug-device combination product: 2-year outcomes from the EVEREST-I study

PURPOSE

To evaluate the safety and efficacy of the Optilume BPH Catheter System for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH).

METHODS

This open-label, single-arm study enrolled eighty subjects with LUTS secondary to BPH who were treated with the Optilume BPH Catheter System. Symptoms were recorded utilizing the International Prostate Symptom Score (IPSS) and Benign Prostatic Hyperplasia Impact Index (BPH-II). Functional improvement was measured utilizing peak urinary flow rate (Qmax) and post-void residual urine volume (PVR). Adverse events were systematically captured and reported at each follow-up visit.

RESULTS

Subjects treated with the Optilume BPH Catheter System experienced a significant improvement in LUTS from baseline through 2 years of follow-up, as measured by IPSS (22.3 vs 8.2, p < 0.001) and BPH-II (6.9 vs 2.3, p < 0.001). Functional improvement was also significant, with Qmax improving from an average of 10.9 mL/s at baseline to 17.2 mL/s at the 2-year follow-up and PVR improving from 63.1 to 45.0 mL. Treatment-related adverse events were typically minor, with none occurring between 1- and 2-year post-treatment.

CONCLUSIONS

The Optilume BPH Catheter System is a unique minimally invasive surgical therapy that combines mechanical and pharmaceutical aspects for the treatment of BPH. The functional and symptomatic improvements seen after treatment are significant and have been sustained through 2 years in this early feasibility study.

REGISTRATION

NCT03423979, registered February 6, 2018.