Platelet‐rich fibrin matrix as treatment for complex anal fistulae: A 3‐year experience at a tertiary centre

AIM: Treatment of complex anal fistulae remains a significant challenge for physicians and patients. A sphincter-preserving technique with bioactive platelet-rich fibrin matrix is one option. This three-year study aimed to evaluate the efficacy of bioactive platelet-rich fibrin matrix in treating complex anal fistulae. METHOD: This retrospective study analysed data from 2019 to 2022 of patients diagnosed with complex anal fistulae treated with a platelet-rich fibrin matrix at a tertiary centre. Endoanal ultrasound was used to morphologically characterize fistulas using Park's classification. Pearson's chi-squared and Kaplan-Meier (log-rank) analyses were used to evaluate between-group differences. RESULTS: A total of 213 patients were included in the study (181 with cryptoglandular fistulae and 32 with Crohn's disease-associated fistulae) with a median follow-up of 6.6 months (range 0.5-67.1 months). Cavities and secondary tracts were identified in 14.6% and 34.7% of the patients, respectively. External opening closure occurred in 32% after one procedure and 43% cumulatively after a second intervention. Healing rates did not differ statistically by aetiology or fistula location. Cavities and secondary tracts were associated with failure. During follow-up, 23% of the secondary tracts healed, whereas cavities derived no significant benefit from the intervention. No serious complications were reported. CONCLUSION: Platelet-rich fibrin matrix is a simple and safe sphincter-preserving technique that achieves reasonably good results in the treatment of cryptoglandular and Crohn's disease-associated fistulae. While secondary tracts may respond well, further research is required to optimize the management of fistulae associated with cavities.