Efficacy of Injection of Freshly Collected Autologous Adipose Tissue Into Complex Cryptoglandular Anal Fistulas

BACKGROUND: Treatment of cryptoglandular anal fistulas with injection of autologous or allogenic adipose tissue-derived mesenchymal stem cells has shown promising results. However, allogenic adipose tissue-derived mesenchymal stem cells are expensive and use of autologous adipose tissue-derived mesenchymal stem cells requires preceding liposuction and isolation of stem cells, time for cell culture, and laboratory facilities. Freshly collected autologous adipose tissue may be an easily available and inexpensive alternative.OBJECTIVE: This study aimed to investigate the efficacy of injection with freshly collected autologous adipose tissue into complex cryptoglandular anal fistulas.DESIGN: Prospective cohort study.SETTING: Single tertiary center for treatment of cryptoglandular fistulas in Denmark.PATIENTS: This study included 77 patients with complex cryptoglandular anal fistulas.INTERVENTIONS: The intervention included injections of freshly collected autologous adipose tissue. Patients not achieving healing after 8 to 12 weeks were offered a second injection.MAIN OUTCOME MEASURES: Primary outcome was fistula healing defined as no symptoms of discharge and no visible external and palpable internal opening by anorectal digital examination at clinical evaluation 6 months after final treatment. Secondary end points were combined clinical and MRI fistula healing, reduced fistula secretion and anal discomfort, and complications to the treatment.RESULTS: Thirty-nine patients (51%) achieved the primary outcome of fistula healing 6 months after their final treatment. Nine patients (12%) experienced reduced secretion and decreased anal discomfort. Thirty-seven patients (48%) achieved combined clinical and MRI fistula healing. Treatment was well tolerated; 5 patients (4%) experienced serious adverse events (infection or bleeding) requiring surgical intervention.LIMITATIONS: No control group was included.CONCLUSION: Injection of freshly collected autologous adipose tissue is a safe treatment of complex cryptoglandular anal fistulas and may be an easily accessible inexpensive alternative to cultured autologous and allogenic adipose tissue-derived mesenchymal stem cells.