Antibiotics for infection prevention after excision of the cervical transformation zone

Excision of the transformation zone of the cervix is the most commonly used approach to treat cervical precancerous lesions (cervical intraepithelial neoplasia (CIN)) to reduce the risk of developing cervical cancer. As the excision of the transformation zone leaves a raw area on the cervix, there is a risk of infection following the procedure. The incidence of infection after cold knife conization (CKC) is 36%, whereas the incidence for large loop excision of the transformation zone (LLETZ, also known as loop electrical excision procedure (LEEP)) is much lower (0.8% to 14.4%). Prophalytic antibiotics may prevent an infection developing and are often prescribed for CKC. However, there are no formal recommendations regarding the use of prophylactic antibiotics for infection prevention in women undergoing surgical excisional treatment for cervical precancerous lesions.

To evaluate the effectiveness and safety of antibiotics for infection prevention following excision of the cervical transformation zone.

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 4), MEDLINE, Embase, LILACS to May 2016. We also checked registers of clinical trials, citation lists of included studies, key textbooks and previous systematic reviews for potentially relevant studies SELECTION CRITERIA: We included randomised controlled trials (RCTs) evaluating the effectiveness and safety of prophylactic antibiotics versus a placebo or no treatment in women having excision of the cervical transformation zone, regardless of the type of surgical excisional method used.

We used standard methodological procedures expected by Cochrane. Two review authors independently selected potentially relevant trials, extracted data, and assessed risk of bias, compared results and resolved disagreements by discussion. We contacted investigators for additional data, where possible.

Of the 370 records that we identified as a result of the search (excluding duplicates), we regarded six abstracts and titles as potentially relevant studies. Of these six studies, three met the inclusion criteria involving 708 participants; most trials were at moderate or high risk of bias (risk mainly due to lack of blinding and high rate of incomplete data). We did not identify any ongoing trials. Although all included studies had been published in peer-reviewed journals at the time of the search and data extraction, numerical data regarding the outcome measured in one trial involving 77 participants were insufficient for inclusion in a meta-analyses.The difference in the rates of prolonged vaginal discharge or presumed cervicitis (one study; 348 participants; risk ratio (RR), 1.29; 95% confidence interval (CI) 0.72 to 2.31; low-quality evidence) and severe vaginal bleeding (two studies; 638 participants; RR 1.21; 95% CI 0.52 to 2.82; very low-quality evidence) among the two comparison groups did not reach the level for clinically important effect. In addition, there was no difference in adverse events related to antibiotics i.e. nausea/vomiting, diarrhoea, and headache among the two comparison groups (two studies; 638 participants; RR 1.69; 95% CI 0.85 to 3.34; very low-quality evidence). There were no differences in the incidence of fever (RR, 2.23; 95% CI 0.20 to 24.36), lower abdominal pain (RR, 1.03; 95% CI 0.61 to 1.72), unscheduled medical consultation (RR 2.68, 95% CI 0.97 to 7.41), and additional self-medication (RR 1.22; 95% CI 0.56 to 2.67) between the two comparison groups (one study; 290 participants; low to very low-quality evidence).

As only limited data are available from three trials with overall moderate to high risk of bias, there is insufficient evidence to support use of antibiotics to reduce infectious complications following excision of the cervical transformation zone. In addition, there were minimal data about antibiotic-related adverse events and no information on the risk of developing antibiotic resistance. Antibiotics given for infection prevention after excision of the cervical transformation zone should only be used in the context of clinical research, to avoid unnecessary prescription of antibiotics and to prevent further increases in antibiotic resistance.