Impact of hyperbaric oxygen therapy on complex perineal fistula healing

Complex perineal fistulas frequently recur after surgery. Hyperbaric oxygen therapy (HBOT) augments tissue oxygenation and may enhance healing.

In this retrospective matched cohort study, we reviewed 53 consecutive patients who received HBOT during repair of perianal, rectovaginal, or pouch-vaginal fistulas (2012-2024). Each was matched 1:3 to controls treated without HBOT by age, sex, body mass index, and fistula type. Demographics, operative history, healing, recurrence and stoma reversal were compared. Healing was defined as complete clinical closure confirmed at examination. Kaplan-Meier (KM) curves assessed time-to-fistula recurrence.

HBOT patients had longer median fistula duration than controls (2.7 vs. 1.5 years, p < 0.001), higher diversion rates (89% vs. 47%, p < 0.001), and were more likely to have undergone more than two prior surgeries (70% vs. 34%, p = 0.001). At 6 months follow-up, 45 (84.9%) patients in the HBOT group achieved fistula healing compared with 122 (76.3%) patients in the control group (p = 0.18). After a median follow-up of 1.4 and 2.7 years for HBOT and non-HBOT groups (p = 0.55), respectively, 4 (9%) HBOT patients and 20 (16.4%) controls developed fistula recurrence (p = 0.38). The Kaplan-Meier estimated recurrence-free survival of healed fistulas was numerically higher with HBOT at 6, 12 and 18 months: 83%, 78% and 74% versus 75%, 68% and 65% (p = 0.20). After stoma reversal, recurrence was lower with HBOT 5.9% versus 26.5% (log rank p = 0.035). Among patients with three or more repairs (n = 90), healing at last follow-up was 85% after HBOT versus 66% in controls (p = 0.04).

HBOT was associated with lower recurrence after stoma reversal and with more durable healing in fistulas that had already failed multiple prior repairs, without changing stoma reversal rates. These data suggest that HBOT may be a useful adjunct in the reconstructive strategy for complex recurrent perineal fistulas.