IJCS | Volume 33, Nº1, January / February 2019

28 Table 2 - Postoperative data of the patients MS group (n = 17) MI group (n = 17) p-value Surgery (n/%) Mitral valve replacement 7/41.2 8/47.1 0.300 Atrial septal defect closure 6/35.3 8/47.1 Mitral reconstruction 4/23.5 1/5.9 Procedure time (minutes) 194.7 ± 60 251.0 ± 52.3 0.006* Extracorporeal circulation time (minutes) 101.8 ± 35.4 118.4 ± 26.1 0.100 Cross-clamp time (minutes) 78.2 ± 33.5 88.5 ± 21.9 0.300 ICU time (hours) 52.2 ± 16.8 33.7 ± 12.7 0.001* Hospital length of stay (days) 6 ± 1.4 3.5 ± 0.9 0.001* MS: median sternotomy; MI: minithoracotomy; n: number of patients; %: frequency; ICU: intensive care unit. *p < 0.05 between groups, unpaired Student’s t-test for continuous variables and z test for categorical variables; 95% confidence level. Figure 1 - Number of pain sites in patients undergoing minimally invasive cardiac surgery and median sternotomy on the third and seventh postoperative days. Box plot of the number of pain sites reported by 34 patients (17 patients subjected to minimally invasive cardiac surgery, MI, and 17 to median sternotomy, MS) on the third (3 rd ) and seventh (7 th ) postoperative days. Circles and triangles represent outliers. *p < 0.05 between groups, unpaired Student’s t-test at 95% confidence level. Silva et al. Minimally invasive surgery–pain investigation Int J Cardiovasc Sci. 2020;33(1):24-33 Original Article patients in the MS group and 16 patients in the MI group were receiving pain medications (p = 0.3052). On the 7 th PO day, 16 patients in the MS group and only six in the MI group were receiving pain medications (p = 0.0003). Discussion The present study showed that, in patients undergoing surgical treatment for mitral valve and septal defects,