Page 67 - Effects of radiotherapy and hyperbaric oxygen therapy on oral microcirculation Renee Helmers

HBOT and vascular regeneration in oral mucosal flaps
Differences in diving times, depth, and frequency of HBOT make it difficult
to compare studies, since a higher dose of oxygen and tissue pO2 determines
the degree of angiogenic potency and wound healing.4,8,23 Determining wound
oximetry might give a good prediction for wound healing.4,23 With this in mind, it
would be advantageous to combine wound oximetry with SDF-measurements
in the future. Higher oxygen tension in wounds might be correlated with a
particular percentage in FCD expression, this might aid in predicting in which
wounds HBOT is most beneficial, creating a clear indication for HBO treatment.
It is interesting to point out that stress may have a negative influence in animal 3 wounds by diverting oxygen supply from a wound region to accommodate
other physiological needs.5 Following the findings of Gajendrareddy et al., best
efforts were practiced in order to decrease stress to a very minimum to provide
the best possible environment for our animal groups. Transportation to the
hyperbaric tank, oxygen gas inflow, and other miscellaneous noises were kept
at an absolute minimum to evade anxiety in the animals; no alarming behavior
or distress was observed in any of the animals.
In routine practice, patients who are at risk of developing ORN are treated preventively, both pre- and postoperatively with HBOT. However, despite these preventive practices, no direct evidence-based consensus currently exists that specifies in which patients HBOT is truly indicated; such a consensus could strategically alleviate patients from being subjected to expensive and lengthy therapeutic sessions that are unsubstantiated by a lack of both consistent and convincing data that clearly defines predictable outcomes. Our results indicate that vascular regeneration can be accelerated by HBO; however, care should be taken when trying to extrapolate data from the present study to other anatomical tissues. Although keratinized epithelial tissues such as in the oral mucosa and the skin share similar histological constructions and follow similar wound healing patterns, both tissues may respond differently to HBOT regimens.
In conclusion, the present study introduces for the first time quantification of postoperative microcirculatory regeneration with SDF imaging in keratinized oral mucosal surgical flaps treated with HBOT. Our results, characterized by a rise in FCD, appears to share a similar trend with findings from other experimental studies reporting an improvement in wound blood perfusion in response to HBOT. While it may be true that elevating tissue pO2 in ischemic wounds with poor vascularity provides the necessary oxygenation for angiogenesis and cellular proliferation, it is important to emphasize consistency in selecting
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