Addition of Platelet-Rich Plasma to Endorectal Advancement Flap Repair Does Not Enhance the Healing of Cryptoglandular Transsphincteric Fistulas.

BACKGROUND: The endorectal advancement flap repair is often performed for the treatment of cryptoglandular transsphincteric fistulas. However, this procedure fails in approximately one out of four patients. Based on its supposed healing properties platelet-rich plasma might enhance the outcome of this procedure.

OBJECTIVE: To evaluate and to compare the short- and long-term outcomes after endorectal advancement flap repair with and without platelet-rich plasma injection in patients with a cryptoglandular transsphincteric fistula.

DESIGN: Retrospective cohort study.

SETTING: Tertiary referral hospital for proctology in the Netherlands.

PATIENTS: Consecutive patients with a cryptoglandular transsphincteric fistula. Inverse propensity score-weighted comparison was used to adjust for confounding and selection bias.

INTERVENTIONS: Endorectal advancement flap repair with and without platelet-rich plasma injection.

MAIN OUTCOME MEASURES: Clinical fistula closure within one year without need for a re-intervention (primary healing), clinical fistula closure within one year corrected for re-interventions (secondary healing), overall fistula healing within one year and long-term outcomes assessed by a questionnaire.

RESULTS: In total, 219 patients underwent an endorectal advancement flap repair. In 88 patients (40.2%) platelet-rich plasma was injected. No significant difference was observed in primary healing (67.0% vs. 69.5%, p = 0.71), secondary healing (37.5% vs. 43.5%, p = 0.60), and overall healing (73.9% vs. 77.1%, p = 0.58) between patients with and without platelet-rich plasma injection, respectively. Long-term follow-up was available in 67.1% of the patients with a mean follow-up of 6.8 years (standard deviation: 3.7 years). Within all patients who reached fistula healing, both primary and secondary, within one year and had available long-term follow-up data, recurrence rates also were not significantly different (6.3% vs. 2.9%, p = 0.37). Propensity-scored weighted analysis showed that patients treated with an platelet-rich plasma injection were not more likely to achieve primary healing (odds ratio [OR] 1.0; 95% confidence interval [CI] 0.5 - 1.9), secondary healing (OR 1.1; 95% CI 0.2 - 3.2), overall healing (OR 0.9; 95% CI 0.5 - 1.7) or recurrence at long-term follow-up (OR 1.1; 95% CI 0.4 - 18.8) as compared to patients without platelet-rich plasma injection.

LIMITATIONS: Retrospective design, lack of postoperative imaging and assessment of long-term follow-up using a questionnaire.

CONCLUSION: Addition of platelet-rich plasma injection does not improve the short- and long-term outcome of endorectal advancement flap repair in patients with a cryptoglandular transsphincteric fistula treated in a tertiary referral center. See Video Abstract.