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.

Evaluating factors affecting length of hospital stay in patients with metastatic bone tumors.

BACKGROUND: Specific medical conditions known to increase LOS following orthopedic surgery including congestive heart failure, diabetes mellitus and COPD. It is also known that patient demographics such as increasing age and non-white race can negatively affect orthopedic surgical outcomes However, there is a lack of research examining the effect of these variables on patients with metastatic bone disease regarding length of hospital stay and ultimately economic burden following surgery. The aim of this study is to identify factors affecting LOS in patients following surgery for bone metastasis. METHODS: A retrospective chart review was used to extract data from 93 patients with an underlying diagnosis of bony metastatic cancer who underwent an orthopedic surgical procedure. Data collected included: length of hospital stay, demographic information (age, sex, race, BMI, smoking status), complications (infection, DVT, PE, fractures), pre-operative lab values (WBC, Albumin, Creatinine, HbA1c), primary cancer type, and surgical procedure measures to understand which factors affected LOS. RESULTS: Increased LOS in this specific patient population was found to be associated with pre-existing diabetes (P = 0.005), obesity (P = 0.025), multiple disease sites (P = 0.042), or disease at the femur (P = 0.035). Patients had a decreased LOS when undergoing a prophylactic procedure (3.53 days vs 5.51 days for non-prophylactic procedure). DISCUSSION: These findings allow providers to better communicate expectations regarding the duration of admission and allows for a better estimation of cost burden for patients and health systems. The present study demonstrates increased LOS in patients undergoing orthopedic procedures for metastatic bone disease who had pre-existing diabetes, obesity, multiple disease sites, disease in the femur, or surgery for a pathologic fracture (as opposed to a prophylactic procedure). Understanding the factors affecting LOS in this patient population can optimize preoperative care, improve communication between the patient and provider, and ultimately decrease financial burden.

Role of the twin-arginine translocase (tat) system in iron uptake in Listeria monocytogenes.

The twin-arginine translocase (Tat) complex is a unique system that translocates folded proteins across the cytoplasmic membrane. In this study, the Tat transporter system in Listeria monocytogenes was characterized to determine the role of Tat in the iron uptake pathway. A putative tatAC operon, containing conserved Fur-binding sequences in the promoter region, has been predicted to encode Tat-translocase components. Another operon, fepCAB, with a putative Fur-binding sequence in the promoter, close to TatAC, was identified in the complementary strands of L. monocytogenes. Electrophoretic mobility shift assay showed that the listerial Fur-repressor binds to the promoter of the tatAC operon, suggesting that tat is under Fur regulation. Using a heterologous system in a reporter assay, FepB was translocated across the membrane. Mutations in tatC and fepB were constructed to determine the roles of Tat and FepB, respectively. In a whole-cell ferric reductase assay, the fepB and tatC mutants were found to have reduced levels of ferric reductase activities compared with those of the isogenic parent strain. Although ferric reductase activity has been demonstrated in Listeria, a conventional ferric reductase encoding sequence does not appear to be present in its genome. Hence, we propose that fepB encodes a ferric reductase enzyme, which is translocated by the Tat-translocase system onto the bacterial cell surface, and plays an important role in the reductive iron uptake process in L. monocytogenes.