Cell-assisted lipotransfer in treating uncontrollable sepsis associated perianal fistula: a pilot study.

Purpose: Surgeons can treat debilitating conditions of uncontrollable complex anorectal fistulas with sepsis, even after repeated fistula surgeries, for curative intention. Adipose-derived stem cells have shown good outcomes for refractory Crohn fistula. Unfortunately, cell therapy has some limitations, including high costs. We have therefore attempted immediate cell-assisted lipotransfer (CAL) in treating refractory complex anal fistulas and observed its outcomes.

Methods: In a retrospective study, CAL, using a mixture of freshly extracted autologous stromal vascular fraction (SVF) and fat tissues, was used to treat 22 patients of refractory complex anal fistula from March 2018 to May 2021. Preoperative and postoperative assessments were performed with direct visual inspection, digital palpation, and endoanal ultrasonography. A fistula was considered completely healed if (1) the patient had no symptoms of discharge or inflammation; (2) there were no visible secondary openings of fistula tract inside and outside of the anorectal unit and even in the perineum; and (3) there was no primary opening in the anus. The endpoint of complete remission was wound healing without signs of inflammation 3 months after CAL treatment.

Results: In a total of 22 patients who received CAL treatment, 19 patients showed complete remission, 1 patient showed partial improvement, and 2 patients showed no improvement. One of the 2 patients without improvement at primary endpoint showed complete remission 9 months after CAL. There were no significant adverse effects of the procedure.

Conclusion: We found that the immediately-collected CAL procedure for refractory complex anal fistula showed good outcomes without adverse side effects. It can be strongly recommended as an alternative surgical option for the treatment of complex anal fistula that is uncontrollable even after repeated surgical procedures. However, considering the unpredictable characteristics of SVF, long-term follow-up is necessary.