Management of urethral stricture: High‐pressure balloon dilation versus optical internal urethrotomy

Optilume drug-coated balloon for anterior urethral stricture: 2-year results of the ROBUST III trial

Objective

The aim of this study is to report the updated 2-year results of the intervention arm of the ROBUST III randomized trial evaluating the safety and efficacy of the Optilume drug-coated balloon (DCB) versus standard endoscopic management of recurrent male anterior urethral stricture.

Materials and Methods

Eligible patients included men with recurrent anterior urethral stricture ≤3 cm in length and ≤12Fr in diameter, International Prostate Symptom Score (IPSS) ≥11 and peak flow rate (Qmax) <15 mL/s. Patients were randomized to treatment with the Optilume DCB or standard-of-care endoscopic management. Primary efficacy endpoints measured at 2 years included freedom from re-intervention and changes in IPSS, Qmax and post-void residual (PVR). Secondary endpoint was impact on sexual function using the International Index of Erectile Function (IIEF). Primary safety endpoint was freedom from serious procedure- or device-related adverse events (AEs).

Results

A total of 127 patients enrolled at 22 sites in the United States and Canada (48 randomized to standard-of-care dilation and 79 to DCB dilation). Seventy-five patients in the DCB arm entered the open-label phase after 6 months. Participants averaged 3.2 prior endoscopic interventions (range 2-10); most (89.9%) had bulbar strictures with an average stricture length of 1.63 cm (SD 0.76). Significant improvements in IPSS, average Qmax and PVR were maintained at 2 years. Freedom from repeat intervention was significantly higher in the Optilume DCB arm at 2 years versus the Control arm at 1 year (77.8% vs. 23.6%, p < 0.001). During the follow-up period, there were 15 treatment failures and two non-study-related deaths. Treatment-related AEs were rare and generally self-limited (haematuria, dysuria and urinary tract infection).

Conclusion

The Optilume DCB shows sustained improvement in both objective and subjective voiding parameters at 2-year follow-up. Optilume appears to provide a safe and effective endoscopic treatment alternative for short recurrent anterior urethral strictures among men who wish to avoid or delay formal urethroplasty.

Evaluation of the Distribution of Paclitaxel After Application of a Paclitaxel-Coated Balloon in the Rabbit Urethra

INTRODUCTION

Urethral strictures are a common urologic problem that could require complex reconstructive procedures. Urethral dilatation represents a frequent practiced intervention associated with high recurrence rates. Drug-coated percutaneous angioplasty balloons (DCBs) with cytostatic drugs have been effectively used for the prevention of vascular restenosis after balloon dilatation. To reduce restenosis rates of urethral dilatation, these balloons could be used in the urethra. Nevertheless, the urothelium is different than the endothelium and these drugs may not be distributed to the outer layers of the urethra. Thus, an experiment was performed to evaluate the distribution of paclitaxel (PTX) in the rabbit urethra after the inflation of a PTX-coated balloon (PCB).

MATERIALS AND METHODS

Eleven rabbits underwent dilatation of the posterior urethra with common endoscopic balloons after urethrography. Nine of these rabbits were additionally treated with PCB. The urethras of the two control animals were removed along with three more dilated with PCB urethras immediately after the dilatation. The remaining of the urethras were removed after 24 (n = 3) and 48 hours (n = 3). The posterior segments of the urethras were evaluated with hematoxylin and eosin staining as well as with immunohistochemistry with polyclonal anti-PTX antibody.

RESULTS

The two control specimens showed denudation of the urothelium after balloon dilatations and no PTX was observed. All specimens from dilated PCB urethras showed distribution of PTX to all layers of the urethra. The specimens that were immediately removed exhibited denudation of the urothelium without any inflammation. The specimens removed at 24 and 48 hours showed mild acute inflammation.

CONCLUSION

PTX was distributed to the urothelial, submucosal, and smooth muscle layers of the normal rabbit urethra immediately after dilatation with a DCB. PTX and mild inflammation were present at the site 24 and 48 hours after the dilatation.

The use of S-curved coaxial dilator for urethral dilatation: Experience of a tertiary department

Objective:

Urethral strictures can be treated by urethral dilation, optical internal urethrotomy, or open surgical reconstruction (urethroplasty). Urethral dilation is done with filiforms and followers, balloons, or coaxial dilators inserted over a guidewire. The S-curved coaxial dilator (SCCD) was designed to facilitate the passage of the dilator through the stricture and the urethra because it imitates the curved anatomy of the male urethra. This study presents our experience with SCCD.

Materials and Methods:

We used this kind of dilation in 310 patients. The technique included the insertion of a hydrophilic floppy-tipped guidewire through the urethra directly into the bladder under fluoroscopic control. The SCCDs were then inserted over the guidewire. Dilators of gradually increased size from 8F to 20F were used. The follow-up of the patients includes uroflowmetry and measurement of postvoid residual at 4 weeks, 6 months, or in the case of a recurrence of symptoms.

Results:

The age of the patients were 69.08 ± 15.77 years. The causes of urethral stricture were iatrogenic (n = 114), traumatic (n = 35), infectious (n = 22), and of unknown origin (n = 139). The stricture length was 1.62 ± 0.85 cm. The mean number of dilations needed per case was 2 (range: 1–15), and the time between the dilations was 212.19 ± 253.9 days. We had seven failures.

Conclusion:

We propose the S-curved coaxial dilators for urethral dilation as a safe and effective technique because of their similarity to the shape of the male urethra and because of their hydrophilic coating.