Is Implant Washing and Wound Irrigation with Rifampicin Effective for Preventing Surgical Site Infections in Lumbar Instrumentation?

Irrigation techniques used in spine surgery for surgical site infection prophylaxis: a systematic review and meta-analysis

Background

The greater likelihood of morbidity, mortality, length of hospital stays and poorer long-term outcomes as a result of surgical site infections secondary to spinal surgery makes prophylactic measures an imperative focus. Therefore, the aim of this review was to evaluate the available research related to the efficacy of different intraoperative irrigation techniques used in spinal surgery for surgical site infection (SSI) prophylaxis.

Methods

We performed a comprehensive search using Ovid Medline, EMBASE, Web of Science and the Cochrane library pertaining to this topic. Our meta-analysis was conducted according to PRISMA guidelines. The inclusion criteria consist of spine surgeries with intraoperative use of any wound irrigation technique, comparison groups with a different intraoperative irrigation technique or no irrigation, SSI identified with bacterial cultures or clinically in the postoperative period, reported SSI rates. Data extracted from eligible studies included, but was not limited to, SSI rates, irrigation technique and control technique. Exclusion criteria consist of articles with no human subjects, reviews, meta-analyses and case control studies and no details about SSI identification or rates. Pooled risk ratios were calculated. A meta-analysis was performed with a forest plot to determine risk estimates’ heterogeneity with I² index, Q-statistic, and p value under a random-effects model. Funnel plot was used to assess publication bias. All databases were last checked on January, 2022. PROBAST tool was used to assess both risk of bias and applicability concerns.

Results

After reviewing 1494 titles and abstracts, 18 articles met inclusion criteria. They included three prospective randomized-controlled trials, 13 retrospective cohort studies, two prospective cohort studies. There were 54 (1.8%) cases of SSIs in the povidone-iodine irrigation group (N = 2944) compared to 159 (4.6%) in the control group (N = 3408). Using intraoperative povidone-iodine wound irrigation produced an absolute risk reduction of 2.8%. Overall risk ratio was 0.32 (95% CI 0.20–0.53, p < 0.00001). In a global analysis, study heterogeneity and synthesizing mostly retrospective data were primary limitations.

Conclusion

The most evidence exists for povidone-iodine and has Level 2 evidence supporting SSI reduction during spinal surgery. Other antiseptic solutions such as dilute chlorhexidine lack published evidence in this patient population which limits the ability to draw conclusions related to its use in spinal surgery.

Level of Evidence

II – Systematic Review with Meta-Analysis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05763-2.

Wound irrigation for preventing surgical site infections

Wound irrigation (i.e. washing out a wound before wound closure) aims to reduce the microbial burden by removing tissue debris, metabolic waste, and tissue exudate from the surgical field before site closure. Although it is a popular procedure in every day surgical practice, the lack of procedure standardization, leads to studies with high heterogeneity and often controversial results. Thus, there are studies that advocate its use, while others discourage its implementation in clinical practice to reduce the risk of surgical site infection. The present article reviews the current literature on wound irrigation for preventing surgical site infections. Several irrigants are presented. Chlorexidine is generally considered to be less effective than povidone-iodine, while antibiotics are not that common nowadays, as they require prolonged exposure with the target to act. Hydrogen peroxide has several potential complications, which eliminate its use. Any differences in the incidence of surgical site infections between different irrigants, especially between antibacterial and non-bacterial ones, should be viewed sceptically. More randomized controlled studies are needed to provide better quality of evidence regarding the irrigants' effectiveness and safety.