Evaluation Of Wound Healing After OCT Monitoring Of Chronic Skin Ulcer

Background and PurPoseChronic skin ulcer is a common and refractory disease. Qufushengji (Eliminating slough and promoting granulation) is the core theory of traditional Chinese medicine (TCM) which directs surgical treatment on chronic skin ulcer. Since the existing optical techniques have many advantages, such as the high resolution that cannot meet the detection requirements, we used optical imaging by Optical Coherence Tomography (OCT) with high speed, throughput and high adaptability, based on superluminescent light emitting diode (SLED) light sources.In this study, the optical imaging with benefits of non-contact, non-invasive, high sensitive and repeatable, were used to dynamically observe the evolution pattern of "slough" and "granulation" in the ulcer wound to evaluate the therapeutic effect of TCM on chronic skin ulcer. We tried to establish the optical detection index system of "slough" and "granulation" to resolve the defect of the evaluation method of chronic skin ulcer therapeutic effect which is subjective now. This was a new attempt for combining optical detection and TCM. And the optical index system of "slough" and "granulation" in the ulcer wound corresponding to TCM concepts would be built for further interpretation of the healing regularity of "slough vanishing and granulation arising" for chronic skin ulcers. This study would provide scientific evidence for the surgical ulcer treatment in TCM based on the theory of qufushengji, and would lay the foundation for the establishment of objective evaluation standard of therapeutic effect for chronic skin ulcers.MethodsFirstly, Using OCT to monitor the healing processes of the skin wound:In this experiment, we created the modes of skin wounds in the rats. Let the wound heals spontaneously. Then we monitored the healing processes of skin wounds in the rats after one hour,3 days,6 days,9 days and 15 days. The attenuation coefficient during prosess of wound healing was obtained by OCT single scattering model.The wound pathomorphology was observed after fixing wound with formalin solution and HE staining.Secondly, we monitored the process of tissue healing of mouse skin in vivo after skin damage based on optical coherence tomography. SD rats (n= 80) were randomly divided into 2 groups, including model group of chronic skin ulcers, preparation group with consecutive medicinal administration for 15 days. OCT monitor the healing processes of skin wounds in the rats on 3 days,6 days,9 days and 15 days. The treatment processes of ulcers based on the theory of qufushengji were monitored from imaging structure, the attenuation coefficient, and the histological examination results.Thirdly, monitoring the process of tissue healing of human chronic skin ulcers in vivo based on OCT and TCM symptom standardization. The optical detection index system of "slough" and "granulation" were used to evaluate the morphology of wounds.Finally, Zhuhong Ointment was applied everyday on ulcers, which were established on the absence skin, foreign body and staphylococcal infection. The levels of MCP-1, TNF-a, IL-10, PDGF-AB, TGF-β1, VEGF and EGF were tested after administration for 3 days,6 days,9 days and 15 days.Results1, The change of attenuation coefficient was consistent with the result of the corresponding histological result. The attenuation coefficient during process of wound healing decreased firstly, and then increased. Compared with the normal skin, the level of attenuation coefficient of "slough" increased obviously; the level of attenuation coefficient of "granulation" decreased obviously.2, The wound and morphological of "slough" and "granulation" were changed obviously by Zhuhong Ointment treatment. OCT dynamically observed the evolution pattern of "slough" and "granulation" in the ulcer wound. Compared with model group of chronic skin ulcers, after consecutive medicinal administration for 3 days, the level of attenuation coefficient of "slough" increased obviously, than decreased obviously on 6 days and 9days; the level of attenuation coefficient of "granulation" increased on 15 days.3, Monitoring the changing process of human chronic wounds after consecutive medicinal administration for 9 days, the level of attenuation coefficient of "slough" reduced gradually. And this renovated process was in accord with the change of quantitative score of traditional Chinese medicine in real time.4, Compared with ulcer model group, The level of MCP-1 increased on 6 days,while it dropped down obviously on 9 days; The level of TNF-a increased obviously on 3 days,while it dropped down on 15 days; There was no statistical difference in IL-10; The level of PDGF-AB increased obviously on 9 days, while it dropped down on 15 days; The level of TGF-β1 decreased obviously on 9 days; The level of VEGF increased obviously on 3 days,6 days and 9 days, while it decreased on 15 days; The level of EGF increased obviously on 3 days,6 days and 15 days.Conclusion:1, The result demonstrated of OCT can be used to diagnose the "slough" and "granulation" and this renovated process in real time.2, Establish the optical detection index of "slough" and "granulation" in chronic skin ulcers.3, The optical index system of "slough" and "granulation" in the ulcer wound corresponding to TCM concepts can be built for monitoring the healing processes of the skin wound in vivo.