Univariate analysis showed that there was no statistical difference in gender, delay in surgery, TLC level at admission, DVT, medical history (diabetes, hypertension, heart disease, and cerebral apoplexy), and the number of co-morbidities (p > 0.05) between the living and dead groups, whereas there were significant differences in age, Hb, albumin, and malnutrition (p < 0.05; see Table 2). This evidence concerns the gene GSTM1 and Hypertension.