Clinical Study on the Integration of Traditional Chinese Medicine Virtual Hanging Therapy With Mesenchymal Stem Cells for the Treatment of Crohn's Disease-Associated Anal Fistula.

Prior treatment

• Presence of abscess \>2 cm unless treated ≥2 weeks prior to the trial.
• History of fistula surgery (except drainage or seton placement), concurrent need for perianal surgery unrelated to fistula, or anticipated need for such surgery within 24 weeks post-treatment.
• Systemic steroid therapy within 4 weeks prior to screening.
• Major surgery or severe trauma within the past 6 months.
• History of alcohol/drug abuse within 6 months prior to enrollment.
• Use of investigational drugs within 12 weeks (84 days) prior to screening.

Other illness

• Current or history of malignancy (including fistula-related carcinoma).
• Severe, progressive, or uncontrolled hepatic, hematologic, gastrointestinal (excluding CD), endocrine, pulmonary, cardiac, neurologic, psychiatric, or cerebral diseases.
• HIV/syphilis antibody positivity, active HCV/HBV infection, or active tuberculosis.
• Intolerance to anesthesia or contraindications to MRI scanning (e.g., pacemaker, hip prosthesis, severe claustrophobia, gadolinium allergy).
• Inability to comply with the study protocol or other conditions deemed unsuitable by investigators.

Lab values

• Abnormal laboratory results:
• Liver function: Total bilirubin ≥1.5×ULN; aspartate aminotransferase (AST) or alanine aminotransferase (ALT) ≥2.5×ULN.
• Renal function: Creatinine clearance \<60 mL/min or serum creatinine ≥1.5×ULN (measured or calculated by Cockcroft-Gault formula).
• Known allergy to antibiotics or trial-related agents (e.g., penicillin, streptomycin, gentamicin, aminoglycosides, human serum albumin, human platelet lysate, DMEM cell culture medium, or bovine-derived materials).

Other

• CDAI \>220 or requiring immediate treatment for active CD.
• Patients with rectal/anal stenosis or active proctitis (due to procedural limitations).
• Pregnancy, lactation, or refusal to use effective contraception during and for 6 months post-trial.

• Signed informed consent form.
• Diagnosis of Crohn's disease (CD) confirmed at least 6 months prior to screening, based on the Chinese Consensus on Diagnosis and Treatment of Inflammatory Bowel Disease (2018, Beijing).
• Crohn's Disease Activity Index (CDAI) score ≤220, indicating inactive or mildly active CD.
• Presence of complex anal fistula confirmed by clinical and MRI evaluation.
• Age 18-60 years (inclusive), regardless of sex.
• Negative serum/urine pregnancy test for women of childbearing potential; all participants must agree to use effective contraception during and for 6 months after the trial.
• Good general health status confirmed by medical history and relevant examinations.