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| Author(s): |
Samanta Rios Melo
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2017-07-26 |
| Examining board members: |
Julia Maria Matera;
Thais Andrade Costa Casagrande;
Durvanei Augusto Maria;
Genilson Fernandes de Queiroz;
Angelo João Stopiglia
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| Advisor: | Julia Maria Matera |
| Abstract | |
In most cases, proper surgical excision of mast cell tumors in dogs requires reconstructive techniques for the closure of the resulting wound, and it knowledge becomes essential for the surgeon. Achieving free margins has a significant influence on survival time, and should be the goal for most patients. The evaluation of the evolution of cutaneous flaps and the measurement of tissue adherence and vascularization at the intended site is extremely important for early diagnosis of defects in tissue implantation. There is no evidence in literature of studies related to evaluate tissue perfusion of skin flaps in companion animals, using thermography techniques. In this study, standard images and thermographic ones were obtained from 63 mast cell tumors from 60 dogs. The histological classification of the tumors in this study was significant in survival time (p <0.001). The prognostic score (0-13) proposed here, adapted from Melo et al. (2015), had also strong association with survival time (p <0.001). The presence of metastasis was observed in 17% of cases, and relapse in 14%. In both cases, 90% of the affected animals died. By means of statistical analyzes, we verified the association between these two factors (metastasis and relapse) in survival time (for both p <0.001). Within our study it was observed that in tumors with the presence of AIM (independent mast cell groups) there is a mortality risk 8.57 times higher than animals with free or even compromised margins. This risk is even greater than the risk of death in animals with relapse (HR 5,13). Also, VEGF-A was shown to be statistically significant at survival time; confirming previous studys and leading us to suggets once again the inclusion of this marker in the prognostic profile of mast cell tumors. All the tumors presented in this study had a thermographic analysis completed and documented. It is noted that even when considered central point or tumor area, 65 and 67% respectively, of the mast cell tumors were warmer than the surrounding healthy tissue. The cause of these temperature changes is not fully understood, but it is suggested to be associated with neoangiogenesis and local inflammation (XIE et al., 2004). By means of the statistical analyzes it is possible to affirm that the tumoral and non-tumoral regions are significantly different, as well as in the evaluation of the central point (SpT and SPNT) and in the evaluation of the tumoral area (TA and ANT) im comparison with healthy surrounding skin (p <0.001 ). Also through thermography, we could establish that skin flaps had a chance of dehiscence 5.57 times greater than the use of other techniques of reconstructive surgery. Finally, we were able to establish a thermal curve of evolution of the wounds of our study population, as well as to differentiate the thermal behavior when there is or not dehiscence. This may be useful for future studies or even clinical-surgical practice, in order to compare the evolution of patients with the curves previously established here, and it is feasible to predict wound healing. We believe, by means of this study, that the thermographic analysis of the evolution of cutaneous flaps can be used as corresponding to tissue perfusion, as indicated in the literature and be used as an early recognition tool for surgical wound dehiscence, as proposed by several authors (SALMI et al., 1995; EICHHORN et al., 2009; WEERD et al., 2009; WEERD et al., 2011). (AU) | |
| FAPESP's process: | 13/21044-6 - Vascularization analysis of pedicled skin flaps in dogs through thermographic camera |
| Grantee: | Samanta Rios Melo |
| Support Opportunities: | Scholarships in Brazil - Doctorate |