Regenerative Endoscopy in Refractory Perianal Crohn's Disease (REPAIR-pCD)

Autologous Mechanical tSVF Injection in Refractory Perianal Fistulizing Crohn's Disease: A Single Arm Pilot Feasibility Study

Perianal fistulizing Crohn's disease (pCD) represents a severe phenotype of Crohn's disease, affecting approximately 20-30% of patients and resulting in chronic drainage, recurrent sepsis, impaired continence, and reduced quality of life. Despite optimization of biologics, antibiotics, and surgical drainage, durable healing remains difficult to achieve. Conventional surgical approaches such as curettage or seton management alone yield modest remission rates, and repeated procedures may compromise sphincter integrity.

Autologous mechanically processed tissue stromal vascular fraction (tSVF) is derived from adipose tissue using non enzymatic methods and can be prepared and reinjected during the same operative session. Unlike culture-expanded or enzymatically isolated cell products, mechanical tSVF retains a native adipose micro architecture containing stromal cells, perivascular elements, endothelial progenitors, extracellular matrix components, and bioactive cytokines. This heterogeneous microenvironment is hypothesized to exert immunomodulatory, pro angiogenic, and regenerative effects that may enhance tract healing while preserving sphincter function.

Mechanical processing avoids enzymatic digestion, cell expansion, and complex laboratory infrastructure, making it potentially more feasible and cost effective in real world settings. However, high quality prospective data evaluating mechanically processed autologous tSVF specifically in refractory complex pCD remain limited, and feasibility data are required before undertaking a large randomized trial.

This single arm pilot feasibility study is therefore designed to evaluate procedural feasibility, safety, and preliminary signals of clinical and radiological healing following mechanical tSVF injection in refractory complex perianal Crohn's disease. The results will inform design parameters, outcome variability, and sample size estimation for a future definitive multicenter trial.

Study Overview

• Status: Recruiting
• Conditions: Crohn Disease (CD); Perianal Crohns Disease
• Intervention / Treatment: Procedure: Autologous Mechanical Tissue Stromal Vascular Fraction (tSVF) Injection

Detailed Description

All participants receive a single session of autologous mechanical tSVF injection following the standardized standard operating procedure.

1. Removal of existing setons where applicable (documented in CRF 3)
2. Tumescent liposuction: harvest of 60-120 mL adipose tissue from lower abdomen or flank under tumescent anaesthesia (Klein formula)
3. Mechanical emulsification and filtration to obtain tSVF using the specified device and Standard operating procedure - minimum acceptable yield ≥5 mL
4. Intraoperative tSVF product quality check: Gram stain from final product; viability assessment by Trypan Blue exclusion where feasible; flow cytometry sample aliquot (sub-study, see Appendix D)
5. Fistula preparation: examination under anaesthesia (EUA), curettage of tract, and identification/closure of internal opening
6. tSVF injection (6-12 mL total): circumferentially around internal opening region in 0.1-0.3 mL blebs; along tract length avoiding sphincter penetration
7. Standard postoperative wound care and antibiotics per unit protocol

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Rajendra Patel, MBBS, DNB, DrNB; Phone Number: +918152049069; Email: doc.rajendrapatel@gmail.com
• Study Contact Backup: Name: Goutham R Katukuri, MBBS, MD, DM; Phone Number: +919902305703; Email: goutham.mge@gmail.com

Study Locations

• India
  • Telangana
    • Hyderabad, Telangana, India, 500032
      • Recruiting
      • AIG Hospitals
      • Contact: Rajendra Patel, MBBS, DNB, DrNB; Phone Number: +918152049069; Email: doc.rajendrapatel@gmail.com
      • Principal Investigator: Rajendra Patel, MBBS, DNB, DrNB
      • Sub-Investigator: Goutham R Katukuri, MBBS, MD, DM

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18-65 years
• Crohn's disease with complex perianal fistula (≥1 secondary tract or internal opening involvement)
• Refractory to ≥1 biologic and/or ≥1 prior sphincter sparing procedure
• No abscess on screening MRI
• Mild or no proctitis on endoscopic assessment
• CDAI <220
• Stable IBD therapy ≥8 weeks
• Able to provide informed consent

Exclusion Criteria:

• Rectovaginal fistula
• Severe active proctitis requiring urgent escalation
• Malignancy in tract or pelvic region
• Pregnancy or lactation
• ASA IV status or bleeding disorder
• MRI contraindications

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Autologous tSVF Injection for Perianal Crohn's Disease; Participants with refractory complex perianal fistulizing Crohn's disease will undergo adipose tissue harvesting by tumescent liposuction, mechanical processing to obtain tissue stromal vascular fraction (tSVF), and local injection of tSVF around the internal opening and along the fistula tract, with standard postoperative care and continuation of stable background IBD therapy.

Procedure: Autologous Mechanical Tissue Stromal Vascular Fraction (tSVF) Injection; Autologous adipose tissue harvest by tumescent liposuction followed by same-session mechanical processing to obtain tissue stromal vascular fraction (tSVF) and local injection into the perianal fistula tract and internal opening region

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility and Preliminary Efficacy at Week 24	•Assess feasibility (recruitment rate, retention to Week 24, protocol adherence, and tSVF processing success rate) and generate preliminary efficacy estimates for mechanical tSVF injection in refractory complex pCD.	Week 24

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cessation of fistula drainage	Time to cessation of drainage; Change in Perianal Disease Activity Index (PDAI) from baseline; MRI tract volume and signal intensity changes (quantified centrally); Vaizey continence score change; Short Inflammatory Bowel Disease Questionnaire (SIBDQ) change; Recurrence and fistula related interventions; Safety: procedure related and systemic adverse events	Week 24 & 52

Collaborators and Investigators

• Sponsor: Asian Institute of Gastroenterology, India
• Investigators: Principal Investigator: Rajendra Patel, MBBS, DNB, DrNB, AIG Hospitals

Study record dates

Study Major Dates

• Study Start (Actual): April 20, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): March 1, 2028

Study Registration Dates

• First Submitted: June 5, 2026
• First Submitted That Met QC Criteria: June 11, 2026
• First Posted (Actual): June 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 17, 2026
• Last Update Submitted That Met QC Criteria: June 11, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: tSVF; REPAIR-CD
• Additional Relevant MeSH Terms: Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Gastroenteritis; Inflammatory Bowel Diseases; Crohn Disease; Therapeutics; Drug Administration Routes; Drug Therapy; Injections
• Other Study ID Numbers: tSVF 1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Hospital policy

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No