Management of Complex Perianal Fistulas Using Platelet-Rich Plasma and Adipose-Derived Mesenchymal Stem Cells: A Case Series.

Perianal fistulas have posed a medical and surgical problem since ancient times. The plethora of surgical operations described nowadays for anal fistula treatment is real proof that there is no ideal therapeutic procedure. The cornerstone of all approaches is the equilibrium between the definitive treatment of the fistula with the maintenance of the anal continence mechanism, i.e., anal sphincters. Especially complex anal fistulas (multiple tracts, high transphincteric fistulas, rectovaginal and Crohn disease-associated anal fistulas) are difficult to deal with to preserve this therapeutic balance. Contemporary experimental procedures include the use of autologous biological products such as platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs), either in their "raw" matrix (stromal vascular fraction, SVF) or after isolation and cultivation before delivered to the patient. Herein, we present a new experimental procedure that we implemented for four patients with perianal fistulas, which is safe and effective, easily reproduced, and cheap. It is a one-stage procedure that requires only simple means and could serve as a first-line approach in complex anal fistulas. In this article, we will present four indicative cases treated with this method, using different syringes for various patient conditions, while analyzing the corresponding clinical and imaging results.