RESTOREGI Study: Regenerative Endoscopic Stromal Therapy: Outcomes and Risk Factor Evaluation in GI Fistulas

RESTOREGI Study Benign gastrointestinal fistulas are abnormal communications between the gastrointestinal tract and adjacent organs or the skin. Chronic fistulas are often difficult to treat because of persistent inflammation, fibrosis, impaired vascularity, and defective tissue regeneration. Endoscopic regenerative therapy using mechanically processed autologous total stromal vascular fraction-enriched microfragmented adipose tissue (tSVF-EM) has emerged as a novel therapeutic approach that may promote tissue repair through angiogenesis, immunomodulation, and regenerative signaling. Although early clinical experience suggests promising healing outcomes, factors predicting successful fistula closure remain poorly understood. The RESTOREGI study is a prospective, single-center observational cohort study designed to identify patient-related, fistula-related, and procedural factors associated with successful healing following endoscopic tSVF-EM therapy in benign gastrointestinal fistulas. The study will also evaluate treatment safety, time to healing, recurrence rates, and the impact of procedural variables on outcomes.

Inclusion Criteria: * Age ≥18 years * Confirmed benign gastrointestinal fistula involving the luminal gastrointestinal tract * Fistula accessible for endoscopic evaluation and treatment * Planned treatment with endoscopic tSVF-EM therapy, with or without adjunctive endoscopic therapies (argon plasma coagulation \[APC\], tract abrasion/curettage, clips, over-the-scope clips \[OTSC\], endoscopic suturing, or stent placement) * Ability and willingness to provide written informed consent * Willingness to comply with scheduled follow-up visits and study assessments Exclusion Criteria: * Perianal fistulas of any aetiology * Inflammatory bowel disease-associated fistulas, including fistulas related to Crohn's disease or ulcerative colitis * Malignancy-related fistulas * Fistulas requiring primary oncologic surgical management * Uncontrolled sepsis or undrained abscess at baseline (patients may become eligible following adequate drainage and clinical stabilisation) * Contraindication to adipose tissue harvest, sedation, anaesthesia, or therapeutic endoscopy * Pregnancy or lactation * Severe coagulopathy not correctable prior to intervention * Inability to provide informed consent * Anticipated inability to complete study follow-up * Participation in another interventional study that may influence fistula healing outcomes