Sham_comparator: Control group

The surgeon trained to lipoaspiration procedure will perform lipoaspiration for the ADSVF cryopreservation under local anesthesia with sedation.~The patients of the control group benefices to urethrotomy (standard care) under general anesthesia. The surgical surgical technique necessitates performing three incisions with a cold endoscopic knife in the stenosis to obtain enlargement of urethral lumen on the length of the fibrosis at 3, 9 and 12 o' clock.~For patients randomised in the control group, lippoaspiration will be performed for cryopreservation of the autologous ADSVF and potential second administration of ADSVF in case of UrS recurrency. UrS recurrence or primary failure is defined as a recurrence without a period of post procedure improvement). Recurrence incoming before 21 months post experimental treatment will be treated according to the study in order to have a minimum follow-up of 3 months.

Experimental: Experimental group

The surgeon trained to lipoaspiration procedure will perform lipoaspiration for the ADSVF cryopreservation under local anesthesia with sedation.~The patients of the control group benefices to urethrotomy (standard care) under general anesthesia. The surgical surgical technique necessitates performing three incisions with a cold endoscopic knife in the stenosis to obtain enlargement of urethral lumen on the length of the fibrosis at 3, 9 and 12 o' clock.~For theses patients -randomised in the experimental group - the experimental cell drug will be customised-made to each patient's lesion and included a dose between 16 and 56 million\* viable nucleated cells (VNCs) of fresh or thawed autologous Adipose-derived -Stromal Vascular Fraction, resuspended in saline (0, 9%) - 5% human serum albumin (50 mg/mL) final packaged in 2 to 7 syringes of 1 mL at a concentration of 8 million CNV / mL, individually closed with a tamper-proof Luer Lock cap and labelled to ensure double-blindness.