Abstract: Fluorescent Angiography Demonstrates Changes in Wound Microvasculature As a Result of Hyperbaric Oxygen Therapy (Plastic Surgery The Meeting)

Monday, September 26, 2016: 1:50 PM

Sarah Cecilia Sorice, MD , Plastic and Reconstructive Surgery, Stanford University, Palo Alto, CA

Torbjörn Lundh, PhD , Vascular Surgery, Stanford University, Palo Alto, CA

Alexander Y Li, MS , Plastic and Reconstructive Surgery, Stanford University, Palo Alto, CA

Kristine Rustad, MD , Plastic and Reconstructive Surgery, Stanford University, Palo Alto, CA

Subhro Sen, MD , Plastic and Reconstructive Surgery, Stanford University, Palo Alto, CA

Jeanie Parsley , Advanced Wound Care Center, Stanford University, Redwood City, CA

Robert Robertson, RN , Stanford Advanced Wound Care Center, Redwood City, CA

Venita Chandra, MD , Vascular Surgery, Stanford University, Palo Alto, CA

Geoffrey C. Gurtner, MD , Plastic and Reconstructive Surgery, Stanford University, Stanford, CA

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Background: The efficacy of hyperbaric oxygen therapy (HBOT) to facilitate wound healing in diabetic lower extremity ulcers is well established. The impact of HBOT however, on tissue perfusion and flow is not known. The purpose of this pilot study was to ascertain the effects of HBOT on the microvasculature of chronic wounds as assessed by fluorescent angiography.

Methods: Patients underwent fluorescent angiography at 6 different time points: immediately prior and immediately after the first, second and 20th HBOT treatments. Photo imaging with infrared camera began concurrently with the initiation of the IC- GreenTM injection and lasted for 2.5 minutes. All videos were analyzed via MATLAB. The wound bed and the peri-wound area were then outlined as masks for the image analysis. The 1st and 2nd derivative were subsequently taken to define 4 time points of interest: the onset of inflow, the time of maximal inflow, the time of peak intensity, and the time of maximal outflow.

Results: Immediately after HBOT, there was evidence of increased flow. The maximum rate of arterial inflow and venous outflow occurred increasingly earlier in response to each successive HBOT. Interestingly, the onset of arterial inflow also occurred earlier after the initial HBO treatment when compared with pretreatment and remained stable immediately prior to the second HBO treatment indicating the post HBO associated vasodilitory effects are sustained for at least 24 hours.

In addition, the time interval between the maximum rate of arterial inflow and venous outflow was shortened in response to cumulative treatments of HBOT, suggesting decreased overall time in the capillary bed. After prolonged treatments with HBOT, all four time points occurred significantly later and overall intensity decreased as compared to baseline and the initial two HBO treatments potentially indicating vascular redistribution via neo-angiogenesis. This correlated well with decreasing wound size.

Conclusion: This pilot study demonstrates that hyperbaric oxygen therapy appears to immediately impact the microcirculation both on an inflow (arterial) and outflow (venous) level. This effect also appears to be cumulative and sustained for at least 24 hours. Long term HBOT may affect the architecture of the peri-wound microvasculature by inducing capillary neo-angiogenesis. This work offers an insight into the potential mechanism of HBOT and may direct future applications.

29651 Fluorescent Angiography Demonstrates Changes in Wound Microvasculature As a Result of Hyperbaric Oxygen Therapy