BACKGROUND: Further development of sphincter-preserving techniques in the treatment of complex anal fistula disease is needed. OBJECTIVE: To study anal fistula closure achieved exclusively with autologous platelet-rich plasma in a large cohort. DESIGN: Retrospective cohort study. SETTINGS: Referral center for anal fistula disease, Sweden. PATIENTS: Cohort of 90 consecutive patients with complex anal fistulas at a referral center between October 2021 and June 2025. Patient age was from 14 to 72 years. No patient group or fistula-type was excluded. Intervention treatment sequence: (a) Clinical fistula and incontinence evaluation including endoanal 3D-ultrasound at surgical outpatient clinic; (b) outpatient surgery fistula examination under anesthesia including endoanal 3D-ultrasound and seton placement; (c) Outpatient surgery fistula occlusion with autologous platelet-rich plasma after three months; (d) follow-up at surgical outpatient clinic with clinical examination, endoanal 3D-ultrasound and incontinence evaluation. Endoanal 3D-ultrasound has completely replaced MRI in this setting. MAIN OUTCOME MEASURES: Primary outcome was closure rate, assessed both clinically and with endoanal 3D-ultrasound. Secondary outcomes were complication rate, anal continence and whether or not patient age has effect on the healing rate. RESULTS: Fistula healing was achieved in 57 patients (63%) after a single closure-operation. Ten patients (11%) healed after a second closure-operation and a further six patients (7%) after a third procedure. We saw no complications or postoperative anal incontinence. Statistical analysis showed that age is a weak predictor of healing outcome in this dataset lacking significance. LIMITATIONS: Retrospective study; no control group. All patient contacts and operations carried out by a single surgeon. CONCLUSIONS: The technique is relatively easy to learn, safe and effective. Because of its very low destructiveness it can easily be repeated until fistula closure is achieved. Sixty-three percent of patients had successful fistula closure after one operation. Eighty-one percent after one or two additional operations. These are very promising results in a difficult-to-treat patient group. See Video Abstract .
Ihle et al. (Mon,) studied this question.