Factors related to surgical site infection found in our study were classified as patient’s characteristics, procedures and appropriate antibiotic prophylaxis. For the patient’s characteristics, having the age of the patient more than 50 years old, comorbidity with hypertension and diabetes mellitus, having fasting blood sugar equally or more than 120 mg/dL, being in menopausal status and going to surgery for cancer condition, were significantly associated with surgical site infection. Procedures involving an explore laparotomy or opened procedures were significantly more associated compared to minimally invasive procedures. And lastly, not appropriate antibiotic prophylaxis given was significantly associated with infection.
Patient’s characteristics prone to postoperative surgical site infections have been proposed by many reports. These include, for example; high BMI, low hematocrit levels, uncontrolled diabetes, tobacco use, prolonged steroid use, prolonged hospital stay, and coincidental infections (3, 4).
The overall rate of surgical site infection for gynecologic procedures was 5.3% in our study. When the procedures were through exploratory laparotomy, the surgical site infection rate rose to 11.8%, while a rate of only 6.8% was found for laparoscopic procedures and none following hysteroscopy, even though there is no statistically significance between the route of procedures and the rate of SSI. In contrast to the previous study, minimal invasive surgery had more favorable outcomes in reducing surgical site infection(5, 6). The study of Uri P. D. et al. showed that the rate of surgical site infection following gynecological laparoscopic surgery could be more common than expected, with the post-site infection at about 10.2%, and any site infection at 16.3% in the study(7).
Focusing on the hysterectomy procedure (including benign and malignant conditions), transabdominal hysterectomy carried 7.84% risk of preoperative surgical site infection, while it was higher at 11.76% following laparoscopic hysterectomy in our study, even though there is no statistically significant. Previous reports of infection following hysterectomy were varied with transabdominal hysterectomy, ranging from 4.5-10.5% and laparoscopic hysterectomy, varying from 1.7-9% while 3.1-13% was reported following vaginal hysterectomy (3, 8).
Much research has been attempted to determine other possible factors related to preoperative gynecologic surgical site infection. Soper DE. Et al. published evidence that screening and treatment of bacterial vaginosis at the preoperative period was cost-effective for those undergoing hysterectomy, surgical abortion and cesarean delivery(9). Furthermore, Kara A M. et al have proposed a role for metronidazole adding to prophylaxis before hysterectomy as a result of a cost-effective study between bacterial vaginosis treatment and hysterectomy surgical site infection(10).
Choice of skin preparation solution, (alcohol-based chlorhexidine, alcohol-based povidone iodine, and water-based povidone iodine) has been studied to reduce gynecologic laparoscopic surgical site infection but it was shown that no solution had benefits over others(7).
Holly L. et al. had proposed the SSI-prevention bundles. The bundles comprise of appropriate prophylactic antibiotics, postoperative normothermia, oral antibiotics with mechanical bowel preparation, postoperative day#1 with glucose control (blood sugar ≤ 140 mg/dL, minimally invasive approach and short operative time less than 100 minutes(1).
As many factors worsen the risk of postoperative surgical site infection, one important modifiable factor is encouraging the surgeon to choose appropriate preoperative antibiotic prophylaxis based on standard recommendations. Our institute is the university hospital, and surprisingly nearly half (43.75%) of gynecologic operations were given not proper antibiotic prophylaxis based on standard recommendations. Mostly the reason for being misused is the inadequate dose of antibiotics (Eg.1 g instead of 2 g of cefazolin for normal weight patients). Non-appropriate antibiotic prophylaxis resulted in 12.24% of surgical site infections compared to none in groups receiving proper antibiotic prophylaxis.
Endorsing evidence-based SSI prevention strategies in routine practice could be the solution. The study of Joseph N. et al. on implementation of the WHO surgical safety checklist (SSC) to reduce cesarean surgical site infection showed positive outcomes. The results of antibiotic prophylaxis and SSI significantly improved(11). Matthew T. et al. showed the significant improvement in antibiotic infusion timing, antibiotic selection, and temperature management after endorsing WHO surgical safety checklist(12). The quality improvement project included the SSC, educational intervention, daily audit of charts and feedback to clinicians(11). The implementation interventions can be done with audit and feedback, organizational culture, monitoring performance, reminders and educational meetings(13).
An interesting point we focused on is why the surgeon’s preference of the antibiotic is not based on the standard recommendations published in ACOG, 2018(2). One focal point is that practicing for more than 3 years or in other words, post-graduation more than 3 years may result in lack of update in standard recommendations or newer guidelines, which can have a negative impact in practice.
The postgraduation interval related to physicians’ knowledge and attitude towards antibiotics used have been discussed. A previous study focused on the choice of malpractice antibiotics use and the post-graduation effect was also shown in Kose A. et al. study. The results from the study showed a negative impact on multidrug resistant bacteria related to misuse of antibiotics ordered by post-graduation doctors. As said “doctors forget their theoretical knowledge regarding rational antibiotic use and are unable to follow current developments due to the intensity of the work”. The result also suggested that the “sustainable training for rational antibiotics use for physicians after graduation can contribute positively to reduce of antimicrobial resistance rates and to be more conscious about the use of rational antibiotics”(14).
The knowledge of physicians compared between those recently graduated and those who graduated more than 3 years showed a significant weak negative correlation between age and knowledge score in a YO EC et al. study. The study was aimed to promote the benefits of a medical webinar to encourage physicians to maintain competence(15).
There are limitations of our study. First, we did focus only on procedures conducted in the major operating room and did not include the minor operations such as fractional curettage, cervical biopsy or LEEP to analyze. Further studies focusing on infection in minor procedures should be performed. Second, we have no case of vaginal operation during the period of study (such as vaginal hysterectomy). Third, there was bacterial culture confirmation only in two of the infected cases. And lastly, the sample size of our study is calculated based on the appropriate use of antibiotic prophylaxis. The small number of sample size is quite limit for the evaluation of many relevant factors.