Background: Two recent randomized controlled trials demonstrated the beneficial effects of subcutaneous drainage in preventing incisional surgical site infection (SSI) in colorectal surgery. This study aimed to evaluate the efficacy of subcutaneous suction drains (SSDs) compared with primary skin closure (PC) in class 4 dirty wound surgery. Patients and Methods: Eighty-one patients undergoing open gastrointestinal surgery with class 4 dirty wounds were enrolled in this study, 30 of whom underwent SSD insertion, whereas the other 51 were treated with PC. Because several studies have reported that the median onset of the development of incisional SSI was eight to 13 days after surgery, we used a two-week placement of an SSD. Comparison of patients treated with SSD and PC and multivariable analysis were performed to test the ability of SSD in decreasing the SSI rate. Results: No differences were observed between the two groups in terms of gender, body mass index, American Society of Anesthesiology score, steroid use, presence of diabetes mellitus, peri-operative transfusion, and surgery type. Surgical site infection incidence was lower in the SSD group (6.6%; 2/30) than that in the PC group (23.5%; 12/51; p = 0.069). Multivariable analysis revealed that the presence of diabetes mellitus was an important independent risk factor for incisional SSI, and the placement of an SSD has substantial preventive effects on incisional SSI (p = 0.018 and p = 0.014, respectively). Conclusions: This study suggested the potential importance of a two-week placement of an SSD for preventing incisional SSI in class 4 dirty wound surgery.
Keywords: class 4 surgery; prevention; subcutaneous suction drain; surgical site infection.