Adipose Mesenchymal Stem Cells Are Effective for Complex Perianal Fistulas in Crohn Disease

Adipose-derived mesenchymal stem cells were effective in improving perianal fistulas in early studies.

In a multicenter, industry-funded trial in Europe and Israel, 212 patients with complex perianal fistulas (defined as high intersphincteric, high transsphincteric, extrasphincteric, or suprasphincteric, or with at least 2 external openings, or associated collections) with ≤2 internal and ≤3 external openings were randomized to treatment with stem cells versus saline placebo. Participants were refractory to antibiotics, immunomodulators, or anti–tumor necrosis factor agents.

Randomized patients received adequate drainage and, in the majority, seton placement. Two weeks or more later, the internal opening was stitched closed. A surgeon, unblin…