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What are
Compromised Grafts & Flaps?
Compromised grafts and flaps refer to surgical tissue transfers that are experiencing inadequate blood supply, leading to potential tissue death and failure of the reconstructive procedure. This complication can occur in various types of reconstructive surgeries, including but not limited to plastic, orthopedic, and vascular procedures.
Common Sources of
Compromised Grafts & Flaps
Include:
Key characteristics of compromised grafts & flaps include:
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Inadequate perfusion or ischemia in the transferred tissue
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Venous congestion leading to edema and cyanosis
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Arterial insufficiency resulting in pallor and coolness
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Delayed capillary refill
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Impaired wound healing at graft or flap margins
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Risk of partial or complete tissue necrosis
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Potential for infection due to compromised tissue viability
Types of grafts and flaps that can be affected:
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Split-thickness skin grafts
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Full-thickness skin grafts
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Fasciocutaneous flaps
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Myocutaneous flaps
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Free tissue transfers (microsurgical flaps)
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Bone grafts
Factors that contribute to graft or flap compromise:
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Inadequate recipient bed preparation
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Technical errors in flap design or execution
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Vascular thrombosis (arterial or venous)
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Excessive tension on the flap
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Hematoma or seroma formation
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Infection
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Systemic factors (e.g., hypotension, vasopressor use)
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Patient-related factors (e.g., smoking, diabetes, peripheral vascular disease)
Early recognition and intervention in cases of compromised grafts and flaps are crucial for salvaging the transferred tissue and ensuring successful reconstruction.
How HBOT Helps with
Compromised Grafts & Flaps
Hyperbaric Oxygen Therapy (HBOT) has emerged as a valuable adjunctive treatment for compromised grafts and flaps. Here’s how HBOT specifically addresses the challenges of these surgical complications:
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Enhanced Tissue Oxygenation: HBOT dramatically increases oxygen levels in the compromised graft or flap, providing up to 20 times the normal oxygen concentration. This is crucial for tissues experiencing ischemia due to vascular compromise.
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Edema Reduction: The hyperbaric environment causes vasoconstriction in normal tissues, which helps reduce edema in the compromised graft or flap. This is particularly beneficial in cases of venous congestion, where edema can further compromise blood flow.
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Promotion of Neovascularization: HBOT stimulates the formation of new blood vessels (angiogenesis) in the compromised tissue and surrounding areas. This process is vital for improving long-term perfusion of the graft or flap.
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Enhancement of Fibroblast Activity: Increased oxygen levels stimulate fibroblast proliferation and collagen deposition, which are essential for wound healing at the graft or flap margins and integration with surrounding tissues.
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Improvement of Microcirculation: HBOT enhances the plasticity of red blood cells, allowing them to more easily navigate through narrowed or compromised vessels in the graft or flap.
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Reduction of Ischemia-Reperfusion Injury: In cases where blood flow is restored to the compromised graft or flap, HBOT helps mitigate the additional damage that can occur during reperfusion by modulating the inflammatory response.
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Potentiation of Antibiotic Efficacy: For infected grafts or flaps, HBOT can enhance the effectiveness of antibiotics, particularly in hypoxic areas where antibiotics might otherwise have reduced efficacy.
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Preservation of Marginal Tissue: By improving oxygenation, HBOT can help preserve tissue at the margins of the graft or flap that might otherwise become necrotic, potentially increasing the overall survival area.
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Stimulation of Stem Cell Mobilization: HBOT has been shown to mobilize stem cells from the bone marrow, which may contribute to tissue repair and regeneration in the compromised graft or flap.
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Enhancement of White Blood Cell Function: HBOT improves the oxygen-dependent killing capacity of neutrophils, which is crucial for preventing and combating infections in compromised grafts and flaps.
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Modulation of Nitric Oxide Production: HBOT influences nitric oxide synthesis, which plays a role in vasodilation and tissue perfusion, potentially benefiting compromised grafts and flaps with marginal blood supply.
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Synergy with Surgical Interventions: When surgical revision of a compromised graft or flap is necessary, preoperative HBOT can improve tissue conditions, potentially enhancing the success of the revision procedure.
What Happens in Our Bodies During HBOT for
Compromised Grafts & Flaps
During HBOT treatment for compromised grafts and flaps, several physiological processes occur that specifically address the unique challenges of these surgical complications:
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Hyperoxia Induction in Ischemic Tissues: Blood oxygen levels increase dramatically, with oxygen dissolved directly in the plasma. This is particularly crucial for the compromised graft or flap tissue, which may be receiving inadequate blood supply.
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Edema Reduction Through Vasoconstriction: HBOT causes vasoconstriction in normal tissues, which helps reduce edema in the compromised graft or flap without compromising oxygen delivery. This is especially beneficial in cases of venous congestion.
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Stimulation of Angiogenic Factors: The alternating hyperoxic and relative hypoxic states during and after HBOT stimulate the release of angiogenic factors such as VEGF (Vascular Endothelial Growth Factor). This promotes the formation of new blood vessels in and around the compromised graft or flap.
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Enhancement of Fibroblast and Collagen Synthesis: Increased oxygen levels stimulate fibroblast activity and collagen production. This is crucial for the integration of the graft or flap with surrounding tissues and overall wound healing.
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Improvement of Microvascular Blood Flow: HBOT enhances the plasticity of red blood cells and reduces blood viscosity, improving microcirculation in the compromised graft or flap.
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Modulation of Ischemia-Reperfusion Injury: In cases where blood flow is restored to the compromised graft or flap, HBOT helps prevent additional damage that can occur during reperfusion by modulating the inflammatory response and reducing free radical damage.
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Enhancement of Leukocyte Function: HBOT improves the oxygen-dependent killing capacity of neutrophils, which is crucial for preventing and combating infections in the compromised graft or flap.
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Stimulation of Stem Cell Mobilization: The hyperbaric environment activates and mobilizes stem cells from the bone marrow, which may migrate to the compromised graft or flap and contribute to tissue repair.
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Modulation of Nitric Oxide Production: HBOT influences nitric oxide synthesis, which plays a role in vasodilation and tissue perfusion. This can be particularly beneficial for grafts or flaps with marginal blood supply.
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Potentiation of Antibiotic Activity: For cases involving infection, HBOT enhances the efficacy of certain antibiotics, particularly in hypoxic areas of the compromised graft or flap.
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Reduction of Lactate Levels: HBOT helps reduce tissue lactate levels, which can accumulate in ischemic tissues of the compromised graft or flap, potentially improving the local metabolic environment.
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Enhancement of Growth Factor Activity: The hyperoxic environment can enhance the activity of various growth factors involved in wound healing and tissue repair, benefiting the integration and survival of the graft or flap.
Protocol
HBOT treatment for compromised grafts and flaps typically involves pressurizing the chamber to 2.0-2.5 atmospheres absolute (ATA) for about 90-120 minutes. Treatments are usually administered daily, often twice daily in severe cases, with the total number of sessions ranging from 10 to 20 or more, depending on the clinical response of the graft or flap.
It’s important to note that the physiological responses to HBOT in compromised grafts and flaps can continue for some time after each treatment session. The cumulative effect of multiple treatments leads to sustained improvements in tissue oxygenation, angiogenesis, and cellular function, ultimately enhancing the chances of graft or flap survival and successful integration.
References
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Thom, S. R. (2011). Hyperbaric oxygen: its mechanisms and efficacy. Plastic and Reconstructive Surgery, 127(Suppl 1), 131S-141S.
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Friedman, H. I., Fitzmaurice, M., Lefaivre, J. F., Vecchiolla, T., & Clarke, D. (2006). An evidence-based appraisal of the use of hyperbaric oxygen on flaps and grafts. Plastic and Reconstructive Surgery, 117(7S), 175S-190S.
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Zamboni, W. A., Browder, L. K., & Martinez, J. (2003). Hyperbaric oxygen and wound healing. Clinics in Plastic Surgery, 30(1), 67-75.
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Larson, J. V., Steensma, E. A., Flikkema, R. M., & Norman, E. M. (2013). The application of hyperbaric oxygen therapy in the management of compromised flaps. Undersea & Hyperbaric Medicine, 40(6), 499-504.
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Nemiroff, P. M., & Lungu, A. L. (1987). The influence of hyperbaric oxygen and irradiation on vascularity in skin flaps: a controlled study. Surgical Forum, 38, 565-567.
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Waterhouse, M. A., Zamboni, W. A., & Brown, R. E. (1993). The use of HBO in compromised free tissue transfer and replantation: a clinical review. Undersea & Hyperbaric Medicine, 20(SUPPL), 64.
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Mathieu, D., Marroni, A., & Kot, J. (2017). Tenth European Consensus Conference on Hyperbaric Medicine: recommendations for accepted and non-accepted clinical indications and practice of hyperbaric oxygen treatment. Diving and Hyperbaric Medicine, 47(1), 24-32.
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Guo, S., & DiPietro, L. A. (2010). Factors affecting wound healing. Journal of Dental Research, 89(3), 219-229.