Recent studies have supported the basis of our study findings, suggesting the addition of metronidazole to the antibiotic regimen at time of hysterectomy can decrease postoperative complications. One study indicated that metronidazole substantially reduced the incidence of postoperative surgical site infections compared to cefazolin alone( SSI ~ 2.3- 2.8 % vs 4.5-4.9 %, adjusted odds ratio ~ 0.40, p <. 001) based on a sample size of greater than 3,000 patients. 12 Other studies have supported these findings when examining risk of pelvic infection following minimally invasive hysterectomy for gynecologic malignancy. 13 Another study indicated that there was no statistically significant reduction in postoperative complications with administration of vaginal metronidazole five days prior to hysterectomy. 14 This lack of reduction in complications may indicate that vaginal metronidazole alone may not be effective for all patients and that targeted screening for BV may be of benefit. Perioperative infection prevention with hysterectomy continues to be imperative to continue reducing the most significant cause of morbidity in gynecologic surgery, prompting further exploration of ways we can continue to reduce its incidence.
The improved outcomes associated with perioperative BV screening is promising, but the argument may arise that routine screening presents a financial challenge within patient care. Diagnosis requires wet mount or genital culture, which could increase patient cost and may not be covered by insurance. Wet mount microscopy is convenient and is more cost effective compared to genital culture, however accuracy can be limited especially if there is a delay in testing samples. 2 Genital cultures are more specific to organisms such as Gardnerella, but are almost twice the cost of a wet mount. 11 Despite this knowledge, the benefits of screening likely outweigh the negatives, with the ability to reduce number of postoperative SSIs, the workup related to diagnosis of infections, and potential hospital admissions or surgical procedures needed for management.
A similar discussion can be applied to the use of antibiotics in treatment of positive screening for BV. Antibiotics given orally or intravenously are very effective in reducing the risk of infection, however they contribute to antimicrobial resistance when used more routinely and can cause side effects such as gastrointestinal symptoms. 1 In opposition, topical treatments, such as intravaginal metronidazole or clindamycin, allow for localized treatment without systemic absorption. 6, 7 After completion of our study, we aimed to determine associated institutional costs related to implementation of our proposed interventions. A five-day course of intravaginal metronidazole gel might cost approximately $ 30 compared to $ 7.25 for a single intravenous dose. Alternatively, oral metronidazole for five days costs around $ 8.65. Evaluating the costs and benefits along with clinical effectiveness can help inform protocols and promote proper antibiotic use regarding methods of administration and optimization for length of treatment. This information also suggests the potential to perform a cost-effective analysis to further delineate overall impact on a more standardized level.
While this study highlights the prevalence of BV within our patient population and the potential of treating with metronidazole to prevent postoperative infection, it is important to acknowledge its limitations. This single-institution pilot study with a relatively small sample size poses the need for further validation of results by repeating this study on a larger scale. We were unable to perform further statistical analysis due to our small sample size and low frequency of associated outcomes, with only one pelvic abscess occurring within the data set. Variability in surgical technique among 10 different surgeons should also be noted and could influence the risk of infection. The use of wet mount microscopy and genital culture are the standard for BV diagnosis, however they rely on human interpretation and execution, which was reflected in the loss of six patients from our data collection due to not collecting the swabs prior to vaginal prep. Incorporation of a control group without treatment of BV could help determine if a more causative correlation exists between BV treatment and postoperative outcomes. Further studies could also expand to performing BV screening on further modalities of hysterectomy, including transabdominal and supracervical approaches, which carry alternative risks of postoperative infection compared to laparoscopic and vaginal approaches.
Overall, our findings demonstrate the clinical importance of early identification and treatment of BV at the time of or before hysterectomy and how this aligns with national guidelines. Implementation of routine screening and treatment has the potential to reduce the risk of SSIs and improve gynecological surgery outcomes. Further investigation can be made into the overall cost effectiveness of perioperative BV screening and how we can optimize treatment prior to surgery, focusing on the timing and length of treatment to prevent development of SSI related to BV.
CONCLUSION
BV is a prevalent vaginal condition caused by an imbalance in the normal vaginal microbiota. Although BV is generally considered benign, it has been associated with development of SSI following hysterectomy, which is one of the most common sources of postoperative morbidity in gynecology. This association has prompted recommendations from ACOG to consider BV screening prior to gynecologic surgeries, including hysterectomy. 5 Our pilot study highlighted the prevalence of BV perioperatively to hysterectomy at our academic institution and our findings suggest the potential of treatment of BV at time of surgery to reduce postoperative infection. Further research is needed to expand support of these findings as well as optimize the method and treatment duration with metronidazole while balancing cost effectiveness in patients that receive treatment.
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