SUBSTANTIATION OF THE METHOD OF APPLYING RELEASING INCISIONS TO REPLACE SKIN DEFECTS AFTER MASTECTOMY IN PATIENTS WITH DECAYING BREAST CANCER
The problem of postoperative skin defect is relevant in Oncology, and especially in the surgical treatment of breast cancer. Aim: topographic-anatomical and technical justification of the technique of releasing incisions when replacing significant skin defects of the anterior chest wall after radical mastectomy. This work included data on 81 patients who were treated in the Oncology Department of the North-Western State Medical University named after I.I. Mechnikov and City clinical oncology center from 2003 to 2011. The Age of patients varied from 33 to 91 years, with a median of 59 (95% CI 54-64) years, and an average age of 60 (95% CI 57-63) years. There were 20 (24,7%) patients under the age of 50, 50-59 ? 22 (27,2%), 60-69 ? 16 (19,8%) and 70 years and older ? 23 (28,4%) patients. Basically, patients underwent modified radical mastectomy ? 66 (81.5%), simple mastectomy was performed in 4 (4.9%) patients, and sanitary amputation ? in 11 (13.6%) women. The Abaqus CAE software and the Solidworks 2016 software package were used for mathematical modeling, comprehensive study and analysis of the proposed method of orientation of lax sections. The overall 3-year survival rate of patients was 68,4 ± 5,3%. Events (relapses, progression) were 9 (11%). They occurred within a period of 8 to 106 months (average-28,5 months, median-17 months). Event-free survival rate was 62,6 + 5,5%. If radical surgery was possible, the survival rate was 72.1 ± 5.6%, if it was not possible, it decreased to 45,5 ± 15% (Chi-square = 3,6388, df = 1, log-rank test = 0,0493). For the purpose of virtual simulation of the application of the technique of releasing incisions, шn the Abaqus CAE mathematical modeling environment, virtual mathematical models were created: a, b and c. It is shown that the critical value of the voltage in model a is higher (374,4 PA) than in model b (365,4 PA) and similar model c (330,0 PA). The model we proposed demonstrates a greater ability to deform: the value of the deformation scale factor is +3.485 e+03; the model b shows result +3.461 e+03 and +3.355 e+03 for the c model. Applying a series of releasing incisions is one of the best ways to solve the problem of closing extensive skin defects of the anterior chest wall and healing the wound after undergoing a radical mastectomy. The proposed mathematical model of orientation and location of releasing incisions allows to reduce the operating trauma.