Transurethral Injection of Autologous Micronized Adipose Tissue for Refractory Interstitial Cystitis/Bladder Pain...

Background/Objectives: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic condition characterized by pelvic pain, urinary symptoms, and reduced quality of life, with limited effective treatment options. Regenerative approaches using adipose-derived mesenchymal stromal cells (MSCs) have shown promising preclinical results. This study aimed to evaluate the feasibility, safety, and preliminary efficacy of transurethral implantation of autologous micronized adipose tissue (MAT) in patients with refractory IC/BPS. Methods: We conducted a single-center retrospective observational pilot study including 20 patients with refractory IC/BPS treated between April and October 2024. Adipose tissue was harvested via liposuction and mechanically processed using a closed system (Matrigen device) to obtain minimally manipulated micronized adipose tissue. The product was injected transurethrally into the bladder submucosa. Patients were evaluated at baseline and at 1, 3, and 6 months using validated questionnaires (ICSI/ICPI, SF-36, MOS Sexual Function), verbal rating scale (VRS) for pain and urgency, urodynamic parameters, and cystoscopic findings. Changes over time were assessed using paired non-parametric tests. Results: At 6 months, 65% of patients met responder criteria, defined as ≥50% improvement in pain and/or urgency or a positive global response. Significant improvements were observed in IC Problem Index, SF-36, MOS scores, and VRS urgency, while VRS pain improved significantly at 6 months. Urodynamic parameters showed increased bladder capacity (median 275 to 325 mL, p < 0.001) and reduced post-void residual volume (80 to 40 mL, p < 0.001). Cystoscopic findings demonstrated improvement in bladder mucosal appearance. The procedure was well tolerated, with no serious adverse events or immunological complications observed. Conclusions: In this exploratory pilot study, transurethral implantation of autologous micronized adipose tissue was associated with improvements in symptoms, bladder function, and cystoscopic findings in patients with refractory IC/BPS. These results support the feasibility and potential role of minimally manipulated adipose-derived therapies in this setting. Given the small sample size and absence of a control group, findings should be considered exploratory. Larger controlled studies are warranted to confirm efficacy and evaluate long-term outcomes.