Managing Hemorrhagic Cystitis with Hyperbaric Therapy

A Clinical Approach to Bleeding Control, Bladder Evaluation, Patient Selection, and Tissue Repair

Hemorrhagic cystitis is characterized by inflammation and bleeding from the bladder lining. Its severity ranges from microscopic hematuria to persistent gross bleeding with clot retention, urinary obstruction, anemia, transfusion dependence, and hemodynamic instability.

Pelvic radiation is one of the most clinically significant causes of chronic hemorrhagic cystitis. The condition may also occur after exposure to urotoxic chemotherapy, particularly cyclophosphamide or ifosfamide, and after viral reactivation in immunocompromised patients, including those who have undergone hematopoietic stem cell transplantation. The cause matters because hyperbaric oxygen therapy, or HBOT, has its strongest evidence base in delayed radiation-induced hemorrhagic cystitis. Evidence for chemotherapy-associated or viral disease remains more limited and is largely observational. (PubMed Central (PMC))

HBOT should not be viewed as an emergency replacement for bladder drainage, clot evacuation, transfusion, infection treatment, or stabilization. Its primary role is restorative. By improving oxygen delivery to damaged tissue, HBOT may help the bladder develop a healthier microvascular supply and become less vulnerable to recurrent bleeding.

Determining the Cause of Hemorrhagic Cystitis

Hematuria in a patient with a history of cancer treatment should not automatically be attributed to radiation or chemotherapy. Other causes may include urinary tract infection, bladder or upper urinary tract malignancy, recurrent cancer, kidney or bladder stones, renal disease, prostatic bleeding, trauma, recent instrumentation, and medication-associated bleeding.

The clinical assessment should document:

• The onset, frequency, and approximate volume of bleeding
• Passage of clots or difficulty emptying the bladder
• Pelvic pain, dysuria, urgency, or frequency
• Previous pelvic radiation and chemotherapy exposure
• Stem cell or solid-organ transplantation history
• Anticoagulant and antiplatelet use
• Recent urinary procedures
• Fever, immunosuppression, or infection symptoms
• Previous treatments for hemorrhagic cystitis

Laboratory evaluation commonly includes a complete blood count, renal function testing, coagulation studies, urinalysis, and urine culture. Additional infectious testing may be required in immunocompromised patients when BK polyomavirus, adenovirus, or another infectious cause is suspected. (PubMed Central (PMC))

Cystoscopy is important when bleeding is persistent, recurrent, severe, or inadequately explained. It allows direct inspection of the bladder, clot evacuation, treatment of focal bleeding, and evaluation for suspicious lesions. Upper urinary tract imaging may also be appropriate, especially in patients with gross hematuria or risk factors for urinary tract malignancy. (PubMed Central (PMC))

Stabilizing Active Bladder Bleeding

Patients with heavy bleeding, urinary retention, symptomatic anemia, or cardiovascular instability require immediate stabilization. HBOT should not delay interventions needed to restore urinary drainage or control acute blood loss.

Initial management may include:

• Intravenous access and hemodynamic assessment
• Serial hemoglobin measurement
• Fluid resuscitation and blood-product support when indicated
• Correction of a clinically significant coagulopathy
• Placement of a large-bore three-way urinary catheter
• Manual clot irrigation
• Continuous bladder irrigation
• Cystoscopic clot evacuation and fulguration

Persistent or life-threatening bleeding may require intravesical therapies, selective arterial embolization, urinary diversion, or surgery. The most appropriate intervention depends on bleeding severity, bladder integrity, renal function, comorbidities, prior treatments, and the underlying cause. (PubMed Central (PMC))

The presence of significant hematuria does not necessarily exclude HBOT. It does mean that the patient must first be stable enough to tolerate transport, chamber compression, and a series of scheduled treatments.

Why Radiation Causes Recurrent Hemorrhagic Cystitis

Late radiation cystitis is driven by progressive injury to the small blood vessels supplying the bladder wall. Radiation damages vascular endothelial cells and may lead to narrowing, thrombosis, and eventual loss of portions of the microcirculation.

The bladder tissue becomes relatively hypoxic, fibrotic, and less capable of normal repair. The mucosa may become thin and ulcerated, while fragile telangiectatic vessels form within the damaged tissue. These vessels can rupture repeatedly as the bladder fills, empties, or is exposed to minor irritation. (PubMed Central (PMC))

This process explains why focal cauterization may provide incomplete or temporary control. Fulguration can treat an identifiable bleeding vessel, but it does not necessarily correct the broader vascular insufficiency affecting the surrounding bladder.

HBOT is intended to address that underlying tissue environment. It is used within the recognized indication of delayed soft tissue radiation injury rather than as a nonspecific treatment for hematuria. Medicare’s national coverage determination includes soft tissue radionecrosis when HBOT is used as an adjunct to conventional treatment. (Centers for Medicare & Medicaid Services)

How Hyperbaric Oxygen Supports Bladder Tissue Repair

During HBOT, the patient breathes oxygen while exposed to increased atmospheric pressure inside a medical hyperbaric chamber. The elevated oxygen partial pressure substantially increases the amount of oxygen dissolved directly in plasma.

This oxygen-rich plasma can reach functioning vessels near the injured bladder tissue and create a stronger diffusion gradient into chronically hypoxic areas. Repeated exposures may stimulate biologic responses that continue beyond the temporary period of elevated tissue oxygen.

Potential therapeutic effects include:

• Increased oxygen delivery to hypoxic bladder tissue
• Angiogenic signaling and formation of new capillary networks
• Support for fibroblast activity and collagen remodeling
• Improved mucosal and epithelial repair
• Modulation of chronic inflammation
• Greater tissue resistance to recurrent ulceration and bleeding

HBOT is therefore different from an immediate hemostatic procedure. Its purpose is to improve the tissue’s long-term capacity to heal and maintain vascular integrity. Clinical improvement may begin during treatment, but symptom reduction may also continue after the course is completed. (AUANews)

Selecting Patients for Hyperbaric Therapy

HBOT may be considered when hemorrhagic cystitis is associated with delayed radiation injury and symptoms persist or recur after appropriate urologic evaluation and conventional care.

Potential candidates include patients with:

• Recurrent gross hematuria attributed to pelvic radiation
• Diffuse bladder telangiectasia that is difficult to treat focally
• Recurrent bleeding after cystoscopic fulguration
• Radiation-associated bladder ulceration
• Repeated clot-retention episodes
• Iron-deficiency anemia or transfusion requirements
• Persistent urinary urgency, frequency, pain, or dysuria
• A desire to preserve bladder function and avoid more destructive procedures

The Canadian Urological Association recommends considering HBOT relatively early after cystoscopy and fulguration have failed, rather than reserving it only for patients who have undergone every available invasive treatment. (PubMed Central (PMC))

The expected treatment target should be defined before therapy begins. For one patient, success may mean complete resolution of hematuria. For another, it may mean fewer bleeding episodes, elimination of transfusion requirements, fewer hospitalizations, improved urinary function, or avoidance of urinary diversion.

HBOT is less likely to correct symptoms caused primarily by an untreated tumor, severe bladder-neck obstruction, urethral stricture, large stone, fixed fistula, or markedly contracted bladder. These conditions require separate urologic or oncologic management.

HBOT for Non-Radiation Hemorrhagic Cystitis

Chemotherapy-associated hemorrhagic cystitis is frequently linked to cyclophosphamide or ifosfamide. Their metabolite acrolein can injure the bladder lining, particularly when protective measures are inadequate or high-dose therapy is used. Viral hemorrhagic cystitis, especially from BK polyomavirus, is an important complication after allogeneic stem cell transplantation. (PubMed Central (PMC))

Management of these conditions focuses on treating or reducing the underlying cause, maintaining hydration and urinary drainage, controlling pain, managing immunosuppression when appropriate, treating infection when a specific therapy is available, and supporting the patient through bleeding and cytopenias.

HBOT has been used in refractory chemotherapy-related and viral hemorrhagic cystitis, and retrospective studies have reported improvement in selected patients. The available evidence is substantially less mature than the evidence for delayed radiation injury, with small cohorts, heterogeneous populations, and no definitive randomized trials establishing routine use. (PubMed Central (PMC))

A hyperbaric referral in these cases should therefore involve close coordination with hematology, oncology, transplant medicine, infectious disease, and urology. The decision should reflect disease severity, response to conventional treatment, immune status, platelet count, transport safety, and the center’s ability to manage a medically complex patient under pressure.

What a Course of HBOT May Involve

Hyperbaric protocols vary according to the facility, chamber system, medical history, and treatment response. A common radiation cystitis course involves daily treatment, Monday through Friday, for several weeks.

The RICH-ART randomized trial used:

• 30 to 40 treatment sessions
• 100 percent oxygen
• Pressure of 240 to 250 kPa, approximately 2.4 to 2.5 atmospheres absolute
• 80 to 90 minutes of oxygen breathing per session

These parameters provide an evidence-based reference but are not a universal prescription for every patient. The hyperbaric physician selects the pressure, oxygen duration, air breaks, and number of treatments based on clinical circumstances. (PubMed)

A typical visit includes pre-treatment assessment, removal of prohibited items, gradual compression, oxygen exposure at the prescribed pressure, controlled decompression, and post-treatment reassessment.

During the treatment course, clinicians may monitor:

• Frequency and severity of hematuria
• Clot-retention events
• Hemoglobin and iron status
• Transfusion requirements
• Emergency visits and hospitalizations
• Need for irrigation or cystoscopy
• Urinary urgency, frequency, pain, and continence
• Treatment tolerance and adverse effects

The course should remain connected to urologic care. New obstruction, heavy bleeding, fever, declining hemoglobin, or worsening pain requires clinical evaluation rather than simply continuing scheduled chamber sessions.

What the Evidence Shows

A 2024 systematic review and meta-analysis included 556 patients treated with HBOT for radiation-induced hemorrhagic cystitis. Approximately 89.9 percent experienced some degree of symptom improvement, while the pooled complete remission rate for hematuria was 55 percent. The included studies differed in patient severity, treatment protocols, follow-up, and definitions of response, so these results should not be interpreted as a guaranteed individual outcome. (PubMed Central (PMC))

The RICH-ART randomized trial found that HBOT improved patient-reported urinary symptoms compared with standard care. Its five-year follow-up, published in 2025, found that improvement remained clinically meaningful among many initial responders. Of 70 patients included in the long-term analysis, 48, or 68.6 percent, met the study’s responder definition. Some patients received another HBOT course after symptoms recurred. (PubMed)

These findings support HBOT as a meaningful treatment option for selected patients with chronic radiation cystitis. They also show that response is not universal. Some patients improve partially, some relapse, and others ultimately require additional urologic intervention.

Anticoagulation and Bleeding Risk

Many patients with radiation-induced hemorrhagic cystitis also take anticoagulant or antiplatelet medications for atrial fibrillation, coronary artery disease, previous stroke, venous thromboembolism, or vascular disease.

These medications may increase bleeding from fragile irradiated vessels, but they may also be essential for preventing stroke, myocardial infarction, or recurrent thrombosis. They should not be discontinued without direction from the prescribing clinician.

Management may require coordination among urology, cardiology, hematology, primary care, and hyperbaric medicine to determine whether treatment interruption is acceptable, how long it can continue, and when medication should be restarted.

HBOT may improve the health of the bladder tissue, but it does not eliminate the need for an individualized assessment of thrombotic and bleeding risk.

Risks and Contraindications of HBOT

HBOT is generally well tolerated in appropriately screened patients, but it has recognized adverse effects.

Potential complications include:

• Middle-ear or sinus barotrauma
• Temporary myopic vision changes
• Claustrophobia or confinement anxiety
• Blood glucose instability
• Pulmonary oxygen effects
• Rare oxygen-induced seizure

An untreated pneumothorax is generally considered an absolute contraindication. Pulmonary air trapping, difficulty equalizing ear pressure, unstable heart failure, seizure risk, implanted medical devices, and medication concerns require individualized evaluation.

Cancer history is not itself a contraindication. HBOT treats the radiation-damaged bladder tissue, not the underlying malignancy. Appropriate cancer surveillance must continue, particularly when new hematuria, pain, obstruction, or suspicious cystoscopic findings develop.

Integrating HBOT into a Bladder-Preservation Strategy

The management of hemorrhagic cystitis is most effective when it follows a coordinated sequence rather than a disconnected series of procedures.

Immediate priorities are to stabilize the patient, maintain urinary drainage, remove clots, and control clinically significant bleeding. The next step is to identify the cause, exclude malignancy, and address infection, medication effects, obstruction, or other contributing factors.

HBOT becomes most relevant when chronic radiation injury is confirmed and recurrent bleeding reflects diffuse hypoxic tissue rather than one isolated lesion. Its purpose is to improve the condition of the bladder wall, reduce dependence on repeated procedures, and preserve urinary function when possible.

Living with recurrent hematuria can be frightening and exhausting. Patients may avoid travel, work, exercise, or social activities because they fear bleeding, clot retention, or another emergency visit. A clinically successful treatment plan should therefore measure more than whether the urine appears clear on one particular day. It should evaluate whether the patient is experiencing fewer crises, improved function, greater independence, and a meaningful reduction in the burden of disease.