Hyperbaric Oxygen Therapy for the Treatment of Perianal fistulas In Crohn’s disease

Patients will be recruited through the outpatient fistula clinic in the AMC. Patients that are willing to participate will be asked whether they want to receive hyperbaric oxygen therapy or if they want to serve as a controlgroup, continuing to receive standard care. If they choose to undergo hyperbaric oxygen therapy (n = 20) treatment will start directly at the beginning of the study and will last for 8 weeks (= 40 sessions). After 30 sessions the seton will be removed. Patients will be followed until 1 year after treatment, using the earlier mentioned parameters/outcomes. The control group will be followed for the same period of time, but without MRI or labwork. If patients refuse hyperbaric oxygen therapy or participation, they will be asked for their reasons for refusal (in regards to feasibility).

Hyperbaric Oxygen Therapy is an effective and feasible therapy option for therapy-refractory patients with perianal fistulas in Crohn's disease.

HBO therapy will start directly a the beginning of the study, week 0-8. Timepoints for HBO group:



PDAI: baseline, week 16, 34 and 60.

MRI: baseline, week 16 and 60.

FDA: baseline, week 16, 34 and 60.

Labwork: baseline, week 16, 34 and 60.

PROs: baseline, week 16, 34 and 60.



The parameters and timepoints for the control group are:

PDAI: baseline, week 16, 34 and 60.

FDA: baseline, week 16, 34 and 60.

PROs: baseline, week 16, 34 and 60.

Hyperbaric oxygen (HBO) group: a total of 40 sessions of HBO, 30 before the removal of the seton and 10 after. One session consists of a total of 80 minutes of 100% oxygen with 5-minute airbreaks, with a total session time of 110 minutes. The pressure that will be used is 2.4-2.5 atmosphere absolute.



Control group: standard care (medical or surgical) as deemed necessary by the primary physician (gastroenterologist and/or surgeon).