Excision and Primary Anastomosis Reconstruction for Traumatic Strictures of the Pendulous Urethra

OBJECTIVES

To present a multi-institutional experience with functional and patient-reported outcomes among men undergoing excision and primary anastomosis (EPA) urethroplasty for pendulous urethral strictures.

METHODS

We describe the technique and present our experience with EPA for focal penile strictures. Patients undergoing urethroplasty (2004-2017) at 2 tertiary referral centers were reviewed, of whom 14 (0.7%) underwent EPA of radiographically confirmed pendulous urethral strictures. Validated questionnaires were utilized to evaluate overall improvement (Patient Global Impression of Improvement), urinary bother (International Prostate Symptom Score), and sexual function (International Index of Erectile Function-5). Treatment success was defined as urethral patency without need for subsequent reconstruction.

RESULTS

Among 14 men undergoing penile EPA, 13/14 (93%) had durable treatment success over a median follow-up of 43 months. No patient reported penile curvature postoperatively. Stricture etiology in most cases was posttraumatic (12/14), of which 4 had a history of urethral disruption secondary to penile fracture and 8 iatrogenic trauma. Median age was 51 years (IQR 30-60) and stricture length 1.0 cm (IQR 1.0-1.4). Erectile function was normal in 8/14 patients preoperatively, and postoperative median International Index of Erectile Function was 21. Most men reported significant global improvement in condition (median Patient Global Impression of Improvement 2, IQR 1-3) and most had only mild urinary bother (median International Prostate Symptom Score 4, quality of life 1). The single treatment failure had a history of hypospadias with multiple prior urethral procedures.

CONCLUSION

For men with short strictures of the pendulous urethra, EPA has a high success rate, without adverse sequelae such as erectile function or penile curvature.

Regenerative medicine for urological tissues: Updated review 2018

The focus of the present review on regenerative medicine is limited; first, on a few human clinical trials carried out thus far in the urology field, and second, on more basic but important biological progress that regenerative medicine has brought us. Clinical trials for the bladder, urethra and urethral sphincter have been carried out thus far. Reconstruction with autologous cell-seeded biomaterial failed in patients in need of bladder augmentation. The strategy succeeded for urethral reconstruction in patients who might not have required this approach. Sphincter function improvement was attained by cell therapy, but did not equal the conventional standard therapy - the artificial sphincter. The radical progress in regenerative medicine is reported in more basic stem cell technology. The strategy to induce therapeutic cells from inducible pluripotent stem cells has shed novel light on developmental biology. In vitro creation of novel kidney tissue from inducible pluripotent stem cells has been attained. Other kinds of therapeutic cells could also be induced from the inducible pluripotent stem cells. Research should be encouraged to fill the gap between patient needs and what current regenerative medicine can attain.

Repair of injured urethras with silk fibroin scaffolds in a rabbit model of onlay urethroplasty

BACKGROUND

Preclinical validation of scaffold-based technologies in animal models of urethral disease is desired to assess wound healing efficacy in scenarios that mimic the target patient population. This study investigates the feasibility of bilayer silk fibroin (BLSF) scaffolds for the repair of previously damaged urethras in a rabbit model of onlay urethroplasty.

MATERIALS AND METHODS

A focal, partial thickness urethral injury was created in adult male rabbits (n = 12) via electrocoagulation and then onlay urethroplasty with 50 mm² BLSF grafts was carried out 2 wk after injury. Animals were randomly divided into three experimental groups and harvested at 2 wk after electrocoagulation (n = 3), and 1 (n = 3) or 3 (n = 6) months after scaffold implantation. Outcome analyses were performed preoperatively and at 2 wk after injury in all groups as well as at 1 or 3 mo after scaffold grafting and included urethroscopy, retrograde urethrography (RUG), and histological and immunohistochemical analyses.

RESULTS

At 2 wk after electrocoagulation, urethroscopic and RUG evaluations confirmed urethral stricture formation in 92% (n = 11/12) of rabbits. Gross tissue assessments at 1 (n = 3) and 3 (n = 6) mo after onlay urethroplasty revealed host tissue ingrowth covering the entire implant site. At 3 mo post-op, RUG analyses of repaired urethral segments demonstrated a 39% reduction in urethral stenosis detected following electrocoagulation injury. Histological and immunohistochemical analyses revealed the formation of innervated, vascularized neotissues with α-smooth muscle actin+ and SM22α+ smooth muscle bundles and pan-cytokeratin + epithelium at graft sites.

CONCLUSIONS

These results demonstrate the feasibility of BLSF matrices to support the repair of previously damaged urethral tissues.

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.

[Application of buccal mucosa with Snodgrass procedure for repair of hypospadias]

Objective

To present method and experiences in using the buccal mucosa with the Snodgrass procedure for repair of hypospadias.

Methods

Between August 2012 and April 2015, 55 boys with hypospadias were treated with Snodgrass procedure combined with buccal mucosa. The age ranged from 1 to 7 years (mean, 4 years). There were 32 cases of distal penile type, 14 cases of proximal penile type, and 9 cases of coronal sulcus type. The buccal mucosa taking from inner cheek was fixed into the incised urethral plate. The urethral plate was tubularized over a catheter.

Results

All the patients were followed up 3-25 months (mean, 11 months). After operation, 1 patient had urethral stricture and fistula after repaired urethra was infected, and 5 patients had fistula. For the others, the urination was smooth, the appearance of penis was satisfying, the urethral stricture did not occur, and the penis was straightened completely.

Conclusion

Compared with traditional Snodgrass procedure, the application of buccal mucosa can increase the reconstruction material of urethral and reduce the stricture of the repaired urethra after operation.