When Hyperbaric Oxygen Therapy May Support Compromised Incisions, Grafts, Flaps, and Complex Postoperative Wounds
Most surgical wounds heal without hyperbaric oxygen therapy. When blood supply is adequate, the incision is mechanically stable, infection is controlled, and the patient has sufficient physiologic reserve, the body can progress through inflammation, tissue formation, and remodeling using standard postoperative care.
Some wounds do not follow this expected course. An incision may separate, a skin flap may become ischemic, irradiated tissue may fail to heal, or infection may increase local oxygen demand while damaging the microcirculation. These complications can place tissue, reconstruction, function, and sometimes the patient’s life at risk.
Hyperbaric oxygen therapy, commonly abbreviated as HBOT, may be considered when a surgical wound is compromised by a recognized hypoxic, ischemic, infectious, or radiation-related condition. It is not a routine recovery treatment for every operation, and it does not replace surgical correction of the problem causing the wound to fail.
How Surgical Wounds Normally Heal
Surgical wound healing is a coordinated process involving clot formation, inflammation, new tissue production, collagen deposition, wound contraction, epithelial coverage, and gradual remodeling.
Immediately after surgery, platelets and clotting factors help control bleeding and establish a temporary wound matrix. Inflammatory cells then remove damaged tissue and microorganisms. Fibroblasts begin producing extracellular matrix and collagen, while endothelial cells support the development of new capillaries. Epithelial cells migrate across the surface, and the wound gradually gains tensile strength.
Healing depends on several conditions:
- Adequate arterial inflow and microvascular perfusion
- Sufficient oxygen delivery
- Mechanical stability and appropriate wound closure
- Control of bacterial burden and infection
- Removal of devitalized tissue
- Adequate protein, calories, vitamins, and minerals
- Appropriate glucose management
- Control of edema and excessive pressure
- Management of tobacco exposure and other systemic risks
Standard wound care aims to support rapid healing without infection or other complications while restoring the best possible function and appearance. (ACS)
Oxygen is essential throughout this process. It supports cellular energy production, collagen maturation, angiogenesis, epithelial activity, and oxygen-dependent microbial killing by leukocytes. When perfusion falls or edema increases the distance between capillaries and cells, tissue oxygen tension may become inadequate even when systemic oxygen saturation is normal.
Why a Surgical Wound May Fail to Heal
A nonhealing surgical wound is a clinical finding, not a diagnosis. The team must determine why healing has slowed or stopped before adding an adjunctive treatment.
Common causes include:
- Inadequate arterial blood flow
- Venous congestion
- Excessive tension on the incision
- Hematoma or seroma
- Surgical site infection
- Retained foreign material
- Devitalized tissue
- Radiation-associated vascular damage
- Pressure, shear, or repeated trauma
- Uncontrolled edema
- Poor glucose control
- Malnutrition
- Tobacco or nicotine exposure
- Immunosuppressive medications
- An unrecognized fistula, abscess, or deeper structural problem
A wound may also separate because the fascia, muscle, subcutaneous tissue, or skin did not gain sufficient strength before mechanical stress was applied. Superficial skin separation is clinically different from deep fascial dehiscence, which may require urgent surgical intervention.
New or worsening pain, swelling, erythema, heat, purulent drainage, fever, tissue discoloration, malodor, or an incision that begins opening should prompt clinical evaluation. The CDC notes that new or worsening pain outside the expected postoperative pattern may be relevant to surgical site infection assessment. (CDC)
HBOT should not be used to obscure these warning signs or postpone evaluation by the operating surgeon.
How HBOT Changes Oxygen Delivery
During HBOT, the patient breathes oxygen while exposed to increased atmospheric pressure inside a medical hyperbaric chamber. Increased pressure raises arterial oxygen tension and substantially increases the amount of oxygen dissolved directly in plasma.
The resulting oxygen-rich plasma can move through functioning vessels and create a stronger diffusion gradient into hypoxic tissue. Oxygen may reach viable cells located farther from a capillary than it could under ordinary atmospheric conditions.
In a compromised surgical wound, this may support:
- Cellular energy production in hypoxic but viable tissue
- Fibroblast activity and collagen formation
- Angiogenic signaling
- Epithelial migration
- Leukocyte oxidative microbial killing
- Edema reduction through hyperoxic vasoconstriction
- Modulation of ischemia-reperfusion injury
- Survival of threatened graft or flap tissue
These effects require at least some functioning circulation. HBOT cannot deliver oxygen effectively to tissue that has no blood supply, and it cannot revive tissue that is already irreversibly necrotic.
A major arterial obstruction, twisted flap pedicle, constricting hematoma, thrombosed anastomosis, undrained abscess, or unstable wound closure requires direct correction. Oxygen therapy may support viable tissue after that correction, but it is not a substitute for it.
HBOT Is Not Recommended for Routine Postoperative Recovery
HBOT is neither necessary nor recommended for a normal, uncompromised surgical incision, skin graft, or flap. The Undersea and Hyperbaric Medical Society specifically distinguishes threatened grafts and flaps from reconstructions that are healing normally. (UHMS)
The evidence for using HBOT broadly across acute surgical wounds is limited. A Cochrane review found no high-quality evidence establishing routine benefit for acute surgical wound healing. Two small studies suggested possible benefits in skin grafting and trauma, but both had important risks of bias. (PubMed)
This means a patient should not receive HBOT simply because they recently underwent surgery, want to heal faster, or are concerned about the appearance of a scar. Routine use adds cost, treatment burden, and medical risk without a clearly established benefit.
A clinically appropriate referral should identify a specific wound-threatening process that HBOT can plausibly address.
Compromised Skin Grafts and Surgical Flaps
The clearest surgical wound application involves a compromised graft or flap.
A skin graft depends initially on close contact with a vascular wound bed. Fluid accumulation, infection, movement, inadequate recipient-site perfusion, or poor tissue preparation can interfere with graft survival.
A flap carries its own blood supply, but that circulation can become compromised by arterial insufficiency, venous congestion, thrombosis, kinking, compression, excessive tension, or damage to the vascular pedicle. Free flaps may develop problems at the microsurgical arterial or venous anastomosis.
Warning findings may include:
- Increasing pallor or cyanosis
- Cool tissue
- Delayed capillary refill
- Progressive edema
- Dark or congested appearance
- Loss of Doppler signal
- Poor bleeding after pinprick
- Epidermolysis or tissue necrosis
Suspected vascular compromise requires immediate evaluation by the reconstructive surgeon. A hematoma may need evacuation, a tight dressing may need removal, and a thrombosed pedicle may require urgent return to the operating room.
HBOT may be added after correctable mechanical or vascular causes have been addressed. Its goal is to maximize survival of hypoxic but viable tissue and potentially reduce the extent of flap loss, regrafting, or repeat reconstruction. (UHMS)
Medicare covers HBOT for the preparation and preservation of compromised skin grafts, while explicitly stating that this coverage is not for the primary management of wounds. (Centers for Medicare & Medicaid Services)
Wounds in Previously Irradiated Tissue
Surgical wounds within a previous radiation field may heal poorly because radiation can progressively damage the small blood vessels supplying skin, muscle, mucosa, and bone.
Irradiated tissue may become hypovascular, fibrotic, and chronically hypoxic. Surgery introduces additional metabolic demand into tissue that may have little reserve. The incision can separate, soft tissue may break down, and exposed bone or hardware may become difficult to cover.
HBOT may be considered when the surgical problem meets the recognized indication of delayed radiation injury, including soft tissue radionecrosis or osteoradionecrosis. It may be delivered as part of treatment for an existing wound or coordinated with debridement and reconstruction in selected patients.
The treatment objective is to increase oxygenation and stimulate vascular remodeling in viable irradiated tissue. HBOT does not eliminate the need to exclude recurrent cancer, remove necrotic tissue, manage infection, or perform appropriate reconstruction. Medicare recognizes soft tissue radionecrosis and osteoradionecrosis as covered indications when HBOT is used alongside conventional treatment. (Centers for Medicare & Medicaid Services)
Surgical Wounds Complicated by Infection
A surgical site infection can involve the skin and subcutaneous tissue, the deeper incision, or an organ or space entered during surgery. Infection increases local oxygen demand while inflammatory edema, thrombosis, and tissue destruction impair oxygen delivery.
HBOT is not routinely indicated for an uncomplicated postoperative infection. Standard treatment may include:
- Opening or draining the wound
- Obtaining appropriate cultures
- Debridement of devitalized tissue
- Removal of infected material when necessary
- Targeted antimicrobial therapy
- Management of sepsis
- Delayed closure or reconstruction
HBOT may become relevant when the infection falls within a recognized hyperbaric indication, such as necrotizing fasciitis, gas gangrene, chronic refractory osteomyelitis, or a sufficiently advanced diabetic lower-extremity wound.
These are specific clinical conditions, not interchangeable labels for any infected incision. CMS lists progressive necrotizing infections, gas gangrene, chronic refractory osteomyelitis, and qualifying diabetic wounds among covered indications. (Centers for Medicare & Medicaid Services)
Even in these settings, source control remains essential. An undrained abscess, infected implant, necrotic fascia, or sequestrum cannot be treated adequately with oxygen alone.
Wound Dehiscence and Tissue Necrosis
Wound dehiscence occurs when the edges or deeper layers of a surgical wound separate. The clinical significance depends on which tissue layers are involved and why the failure occurred.
A small superficial opening may be managed with local wound care or secondary-intention healing. Deep fascial separation, exposure of an implant, bowel evisceration, or rapidly expanding tissue necrosis may require urgent surgery.
Before considering HBOT, the team should determine whether dehiscence is being driven by:
- Infection
- Ischemia
- Excessive tension
- Hematoma or fluid collection
- Fascial failure
- Radiation damage
- Nutritional or metabolic impairment
- Repeated pressure or motion
- Medication-related suppression of healing
HBOT may support selected hypoxic wounds after the structural problem has been addressed, particularly when compromised flaps, radiation injury, severe ischemia, or another recognized indication is present.
It should not be described as a general treatment for every incision that opens. The clinical target is tissue hypoxia within a salvageable wound, not dehiscence as an isolated visual finding.
Standard Surgical Wound Care Must Continue
HBOT works best when it is added to a coordinated wound and surgical plan.
The plan may include:
- Surgical debridement
- Vascular assessment and revascularization
- Drainage of hematoma, seroma, or abscess
- Culture-directed antimicrobial therapy
- Pressure redistribution
- Negative-pressure wound therapy
- Moisture-balanced dressings
- Glucose management
- Nutritional optimization
- Tobacco and nicotine cessation
- Flap revision or reconstructive surgery
A wound that remains ischemic, infected, mechanically unstable, or exposed to repeated pressure is unlikely to heal simply because oxygen exposure has been increased.
CMS applies this principle explicitly to qualifying diabetic lower-extremity wounds. HBOT must be delivered in addition to standard wound care, which includes vascular evaluation, nutritional and glucose optimization, debridement, moist wound management, offloading, and treatment of infection. (Centers for Medicare & Medicaid Services)
The same clinical reasoning applies more broadly to complicated surgical wounds, even when the specific coverage pathway differs.
Which Surgical Patients May Merit a Hyperbaric Evaluation?
A referral may be reasonable when a postoperative wound involves a recognized hyperbaric indication or a clearly threatened reconstruction.
Potential referral scenarios include:
- A compromised skin graft or flap after correctable mechanical causes have been addressed
- A surgical wound within significantly irradiated tissue
- Progressive necrotizing soft tissue infection after urgent debridement
- Chronic refractory osteomyelitis associated with a surgical site
- Acute traumatic ischemia following limb reconstruction
- A qualifying advanced diabetic lower-extremity wound after surgery
- Threatened replanted or revascularized tissue
- Selected complex wounds with documented hypoxia and limited reconstructive options
The referral should include the operative history, wound chronology, vascular findings, infection evaluation, imaging, pathology, microbiology, previous reconstruction, and the specific clinical objective for HBOT.
The question should not be, “Will oxygen help healing?” Oxygen is involved in nearly every healing process. The more useful question is, “Is this wound failing because of a hypoxic condition that HBOT can address, after the correctable surgical problems have been treated?”
What an HBOT Course May Involve
The protocol depends on the indication, urgency, tissue response, and timing of surgery.
Compromised grafts and flaps are often treated urgently because salvageable tissue may deteriorate quickly. Treatment may be delivered more than once per day during the initial period, followed by a reduced schedule as perfusion and tissue viability improve.
Delayed radiation injury and chronic problem wounds generally require a longer course, often involving weekday treatments over several weeks. Pressure, oxygen duration, air breaks, and the total number of sessions are prescribed by the hyperbaric physician.
During treatment, the team may monitor:
- Wound dimensions
- Tissue color and temperature
- Capillary refill
- Doppler signals
- Graft or flap viability
- Drainage and infection findings
- Granulation and epithelialization
- Need for further debridement
- Progress toward closure or reconstruction
- Patient tolerance and adverse effects
A predetermined number of treatments should not replace clinical reassessment. Progressive necrosis, new infection, loss of vascular signal, worsening dehiscence, or systemic deterioration requires renewed surgical evaluation.
Measuring Meaningful Clinical Benefit
The objective of HBOT should be defined before treatment begins.
Depending on the wound, meaningful benefit may include:
- Preservation of a compromised flap or graft
- Reduction in the amount of tissue requiring debridement
- Improved granulation over exposed structures
- Progress toward definitive closure
- Reduced wound depth or surface area
- Successful healing within irradiated tissue
- Fewer repeat reconstructive operations
- Preservation of limb or function
- Control of a qualifying infection alongside standard treatment
Photography, wound measurement, perfusion testing, operative findings, and patient-reported function can help document response.
Scar appearance alone is generally not an appropriate indication. HBOT should not be marketed as a routine cosmetic method for producing a finer postoperative scar when the incision is otherwise healing normally.
Current Evidence Requires Careful Patient Selection
Evidence is strongest when HBOT is used for established indications and selected threatened tissue. Evidence is weaker for generic postoperative wound delay, routine cosmetic recovery, and uncomplicated incisions.
Reviews of acute surgical wounds have repeatedly noted a lack of sufficiently large, high-quality randomized trials. Some small studies and observational reports describe improved healing in selected wound complications, but differences in surgical procedures, patient selection, timing, and treatment protocols limit broad conclusions. (PubMed)
This uncertainty makes disciplined selection important. HBOT should be used because the patient has a plausible oxygen-responsive condition and a defined salvage or healing objective, not merely because the wound is difficult.
Risks and Treatment Burden
HBOT is generally well tolerated in appropriately screened patients, but it has recognized risks.
Potential adverse effects include:
- Middle-ear or sinus barotrauma
- Claustrophobia or confinement anxiety
- Temporary myopic vision changes
- Blood glucose instability
- Pulmonary oxygen effects
- Rare oxygen-induced seizure
An untreated pneumothorax is generally considered an absolute contraindication. Pulmonary disease, difficulty equalizing ear pressure, unstable heart failure, seizure risk, medication concerns, and implanted devices require individualized assessment. Pressure-related barotrauma and oxygen-related neurologic, pulmonary, and ophthalmologic effects are the principal categories of hyperbaric complications. (NCBI)
The treatment course may also require daily travel while the patient continues dressing changes, surgical appointments, antibiotics, rehabilitation, or home health care. The expected benefit should justify this burden.
Coordinating HBOT with the Surgical Team
Hyperbaric treatment should remain integrated with the surgeon’s plan. The operating surgeon understands the reconstruction, tissue planes, implants, closure tension, and consequences of additional debridement. The wound and hyperbaric teams contribute assessment of oxygenation, infection, tissue viability, and treatment response.
Strong communication is particularly important when decisions are time sensitive. A threatened flap may require immediate operative revision. A necrotizing infection may require another debridement. A wound in irradiated tissue may need staged reconstruction. Chamber scheduling must accommodate these priorities rather than compete with them.
For appropriately selected patients, HBOT may improve the environment in which healing occurs. It can increase oxygen delivery to compromised tissue, support angiogenesis and immune function, and help preserve selected grafts, flaps, or surgical wounds.
Its value depends on using it for the right wound, at the right time, with the structural, vascular, infectious, and metabolic causes of failure addressed simultaneously.
