The HEROES Trial: Hyperbaric Oxygen Therapy for Endometriosis-Related Pain

Endometriosis is caused when endometrial-like tissue is found outside of the uterus. It predominantly affects women of reproductive age, with an estimated prevalence of 10% worldwide. Chronic pain related to endometriosis is one of the primary manifestations that lead individuals to seek treatment, with many women reporting moderate to severe pain that can have serious consequences for mental health and quality of life.

Current therapeutic approaches for endometriosis include hormonal therapies (e.g. oral contraceptive pills, progestins, and Gonadotropin-Releasing Hormone agonists/antagonists). While these treatments may provide temporary symptom relief, they are often associated with serious side effects and preclude conception during treatment. The efficacy of other medical interventions remains controversial, therefore surgical procedures are often indicated. However, surgery also has associated risks, has long wait times (between 6 months and 3 years), and a considerable percentage of patients experience recurrence of pain following surgical resection.

Pathologically, endometriosis is characterized by angiogenesis, inflammation, and a chronic hypoxic state at the cellular level. Because of this, Hyperbaric Oxygen Therapy (HBOT), which suppresses inflammation and promotes tissue healing, offers promise as a novel therapeutic modality. This is supported by murine models, which demonstrate the ability of HBOT to reduce inflammation and inflammatory cytokines in the context of endometriosis in animals. However, there have not been any human studies investigating the use of HBOT for treatment of endometriosis and related pain.

This study aims to explore HBOT as a treatment for endometriosis related pelvic pain. Specifically, the investigators will test if HBOT, in addition to the standard treatments (e.g. hormonal and non-hormonal medical options), is more effective at treating endometriosis pain than the standard treatments alone.

Inclusion criteria

• Age ≥ 18 years old
• Patients having refractory pelvic pain (NRS≥4) secondary to endometriosis for >6 months
• May or may not be on traditional multi-modal treatment (pharmacological and/or non-pharmacological)
• On waitlist for surgical treatment

Exclusion criteria

• Patients with chronic pain resulting from disease processes unrelated to the pathophysiology of endometriosis-related symptoms (e.g. irritable bowel syndrome, migraine headache, fibromyalgia, chronic low back pain, and musculoskeletal injuries)
• Contraindications/medically unfit to receive hyperbaric treatments at an outpatient facility (e.g. pneumothorax, in-patients, requiring infusions to maintain hemodynamics, active and unstable coronary disease)
• Unlikely to comply with follow-up assessments (e.g. no fixed address, plans to move out of town)