Safety and Potential Effect of Innovative Treatment by Adjuvant Injection of Stromal Vascular Fraction From Autologous Adipose Tissue of URethral Stenosis With Endoscopic Urethrotomy

SURF is a randomised controlled, parallel group, single blind phase II study designed to assess the safety and potential efficacy of an innovative therapeutic strategy for urethral stenosis based on adjuvant injection of autologous Adipose-Derived Stromal Vascular Fraction of Adipose Tissue (ADSVF) during endoscopic urethrotomy (standard care).

Urethral stenosis (UrS) is a narrowing of the urethra's caliber. UrS results of ischemic fibrosis of the corpus spongiosum (spongiofibrosis). Fibrosis-induced retraction reduces the size of the urethral lumen. Spongiofibrosis may be due to infections, inflammation, trauma but remains mostly idiopathic.Endo-urethral treatment exposes to a high rate of recurrence (up to 60% depending on the site, length and etiology). The reconstruction treatment is more effective but more complex (use of oral mucosal flap or other substitution tissue, less mastered by the surgical community and more morbid.

The (ADSVF) is an easily accessible source of autologous mesenchymal stem cells. Obtention from lipoaspirates is safe, simple and standardized. Different animal models have demonstrated the pro-healing and anti-fibrotic properties of autologous ADSVF in the urethra corpus cavernous during erectile dysfunction, perineal fistulas during Crohn's disease and systemic sclerosis.

The main objective of this study is to assess the safety and tolerability of ADSVF, as add-on treatment to endoscopic urethrotomy for recurrent bulbar urethral stenosis during the follow-up.

Eligibility Criteria:
Inclusion Criteria:

* Signed informed consent
* Male, aged from 18 to 85 years
* Bulbar urethral stenosis ≤ 3 cm.
* At least one urethral dilatation or urethrotomy for the bulbar stenosis in the past 24 months before diagnosis of stenosis
* Ability to avoid corticoids or immunosuppressive drugs one month after treatment. For any patients with either corticoid or immunosuppressive treatment the physician in charge of this treatment will be contacted and asked to give a written approval for one month cessation of the therapy
* Good general health status according to clinical history and a physical examination
* BMI \> 18 to insure adequate access to abdominal or other subcutaneous adipose tissue for adipose tissue harvesting

Exclusion Criteria:

* Urethral stenosis of other location than bulbar
* Urethral stenosis length \> 3 cm
* Urethral stenosis on reconstructed penis (transgender, post amputation)
* Prior perineal or pelvic radiotherapy
* Concurrent urinary tract infection without treatment
* Concurrent perineal infection
* Penile cancer \< 5 years
* Current or recent history of abnormal, severe, progressive, uncontrolled infectious, hepatic, haematological, gastrointestinal (except CD), endocrine, pulmonary, cardiac, neurological, psychiatric, or cerebral disease
* Congenital or acquired immunodeficiencies
* Contraindication to the anaesthetic or surgical procedure
* Corticoids or immunosuppressive drugs \> 3 months
* Any active viral infection among the following: HIV, HTLV I and II, VHB, VHC and syphillis
* Administrative restricted rights
* Presence of signs of obstructive voiding symptoms not directly attributable to the stricture at the discretion of the physician
* Diagnosis of untreated and unresolved BPH benign prostatic hyperplasia or BNC bladder neck contracture
* Diagnosis of carcinoma of the urethra, bladder or prostate within the last two (2) years