Adipose-derived stromal vascular fraction injection for radiation-induced bladder fibrosis: a first-in-human pilot study

Pelvic radiotherapy can lead to loss of bladder compliance, detrusor overactivity, and superficial vascular proliferation. Animal studies have demonstrated a reduction in radiation-induced inflammation and fibrosis following administration of mesenchymal stem cell products. We performed a first-in-human pilot study to assess the safety and feasibility of intravesical adipose stromal vascular fraction injection in an 82-year-old man with a history of brachytherapy for prostate cancer. Following FDA and IRB approval, subcutaneous adipose tissue harvested under local anesthesia was immediately processed using the SVF-2 device (GID Bio). The cell product, consisting of 4.58 × 107 stromal vascular fraction cells resuspended in 20 cc/s of lactated ringers, was injected into the bladder wall using a flexible cystoscope. Urinary symptoms, urologic flow parameters, repeat cystoscopy with bladder biopsy, and MRI were employed during the 16-month follow-up period. There were no postprocedural complications. The patient reported expected symptoms of self-limited dysuria, hematuria, and flank bruising in the 2 weeks following the procedure. Urinary symptoms and flow parameters remained stable for 6 months but progressed slightly at 15 months. A repeat cystoscopy with biopsy showed stabilization of disease without concern for secondary malignancy. The patient's 12-month postprocedural MRI and 15-month urodynamics study were unchanged from prior. This study demonstrates the safety and feasibility of adipose harvest under local anesthesia, followed by point-of-care isolation and administration of an adipose-derived cell product via cystoscopic-guided intravesical injection. This pilot is foundational for further clinical studies to elucidate effective dosing and patient selection in the treatment of bladder fibrosis with cell therapy.