Does Local Vancomycin Powder Impregnated with Autogenous Bone Graft and Bone Substitute Decrease the Risk of Deep Surgical Site Infection in Degenerative Lumbar Spine Fusion Surgery? - an Ambispective Study

Background:Deep surgical site infection (DSSI) is one of the most challenging complications in lumbar fusion surgery. Few investigations examined the effect of vancomycin powder mixed with ABG and bone substitutes on preventing DSSI in degenerative lumbar fusion surgeries as well as any interference with bony fusion. The aim of the study was to investigate the effects of autogenous bone graft (ABG) along with bone substitutes as a local vancomycin delivery system on preventing DSSI in lumbar instrumented fusion and compared with those who did not use vancomycin powder.Methods: From January, 2015 through December, 2015, a one-year prospective study using vancomycin powder mixed with ABG and bone substitute for degenerative lumbar fusion surgeries as vancomycin (V) group, 1 gm vancomycin for 2 and 3-level, and 2 gm for more than 3-level instrumentation. From December, 2013 through December 2014, patients received degenerative lumbar fusion surgeries without using vancomycin before the vancomycin protocol were retrospectively enrolled as non-vancomycin (NV) group. Vancomycin concentration was checked at post-operative days 1 and 3 for both the serum and drainage. Patients’ demographic data, microbiology reports, fusion status and functional outcomes were evaluated. Results:One hundred and ten patients were enrolled prospectively in the V group, and 86 for the NV group. After an average 41 months follow-up (range, 36-54), 3 patients (3.48%) developed postoperative DSSIs in the NV group, thereby requiring revision surgeries and parenteral antibiotics treatment versus no DSSIs (0%, 0/100) in the V group. (p=0.048). The postoperative serum vancomycin levels were undetectable and no vancomycin related side effects was encountered. The mean vancomycin concentration of drainage at postoperative days 1 and 3 were 517.96 ± 174.4 and 220.14 ± 102.3 mg/mL, respectively. At final follow-up, there was no statistical difference observed in terms of clinical and radiologic outcomes. Conclusions: Our vancomycin protocol may reduce the incidence of DSSI in degenerative lumbar fusion surgery without affecting bony fusion.

Role of topical vancomycin in reduction of postoperative infections in head trauma patients: A developing country experience

Background: Postoperative cranial wound infections are a major cause of morbidity, mortality, and financial burden, especially in developing countries. Methods: We prospectively studied 86 patients in a randomized trial; 39 patients received one gram of topical vancomycin powder in the subgaleal space while 47 matched control patients did not. Both groups received identical intraoperative and post-operative care. The primary outcome variable was the postoperative wound infections rate factored by cohort. Secondary outcomes were the timing of infection and the rate of adverse events. Results: Adding topical vancomycin was associated with a significantly lower rate of infection than the standard of care alone (2.6% [1/39] vs. 14.9% [7/47], P =.004). No adverse reactions occurred. Conclusion: Topical vancomycin is safe, and effective in the prevention of surgical site infections following craniotomy. These findings have broad consequences for neurosurgery practice, especially in developing countries with high incidence of head trauma.

Intra-wound vancomycin powder for the eradication of periprosthetic joint infection after debridement and implant exchange: experimental study in a rat model

Background Intra-wound vancomycin powder (VP) has been used in clinical practice to prevent periprosthetic joint infection (PJI) after primary knee/hip arthroplasty. The role of intra-wound VP in the setting of debridement and implant exchange after PJI remains undefined. This study aimed to explore the efficacy and safety of intra-wound VP in the control of methicillin-resistant S. aureus (MRSA) infection after debridement and implant exchange. Methods PJI modeling by knee prosthesis implantation and MRSA inoculation, debridement and implant exchange were performed in Wistar rats successively to mimic the one-stage exchange arthroplasty of PJI patients. Two weeks of systemic vancomycin (SV) or/and intraoperative intra-wound VP of single dosage were applied after revision surgery. Results No post-surgery deaths, incision complications and signs of drug toxicity were observed. The microbial counts of SV or intra-wound VP group were significantly reduced compared with the control group, while bacteria were still detected on the bone, soft-tissue and prosthesis. The elimination of bacterial counts, along with improvement of tissue inflammation and serum inflammatory markers, were observed in the rats with SV plus intra-wound VP. Serum levels of vancomycin in all groups were lower than that of causing nephrotoxicity, while no statistic difference was observed in the serum biochemical marker among the groups. Conclusions Intra-wound VP is effective after debridement and implant exchange in our current rat PJI model. Neither SV nor intra-wound VP alone could eradicate the bacteria within a two-weeks treatment course, while SV plus intra-wound VP could eliminate the MRSA infection, without notable hepatic or renal toxicity and any incision complications.

Use of Topical Vancomycin Powder to Reduce Surgical Site Infections after Deep Brain Stimulation Surgery: UCSF Experience and Meta-Analysis

<b><i>Objective:</i></b> Surgical site infection (SSI) is the most common serious complication of deep brain stimulation (DBS) implantation surgery. Here, we report a single-surgeon experience on the efficacy of topical, intrawound vancomycin powder (VP) in reducing SSI for DBS surgery and present the first systematic review and meta-analysis examining the effect of topical vancomycin on SSI in patients after DBS surgery. <b><i>Methods:</i></b> For the retrospective review, all unique patients undergoing DBS surgery at UCSF for new hardware implantation or internal pulse generator (IPG) replacement by a single surgeon from September 2013 to March 2019, with at least 1 year of follow-up data, were included. For the meta-analysis, we included all primary studies that compared SSIs with and without application of topical vancomycin in DBS surgeries. <b><i>Results:</i></b> 368 unique patients met inclusion criteria; 195 patients received topical VP (VP group) and 173 did not (control). 99/195 patients in the VP group underwent new DBS implantation and 96/195 had IPG replacement. 71/173 patients in the control group had new DBS implantation and 102/173 had IPG replacement. There were 10 total cases of SSI: 4 patients from the VP group (3 new implants and 1 IPG replacement) and 6 patients from the control group (3 new implants and 3 IPG replacements), resulting in SSI rates of 2.1 and 3.5%, respectively (<i>p</i> value = 0.337). Including our retrospective analysis, 6 studies met inclusion criteria for the systematic review and meta-analysis. In the 4 studies that examined primary DBS implants, 479 total patients received topical VP and 436 did not; mean odds ratio for SSI with topical vancomycin was 0.802 (95% confidence interval [CI] 0.175–3.678). Across the 5 studies that examined IPG implantations or replacements, 606 total patients received topical VP while 1,173 patients did not; mean odds ratio for SSI with topical vancomycin was 0.492 (95% CI 0.164–1.475). In either case, topical VP application did not significantly decrease risk of SSI. <b><i>Conclusion:</i></b> Surgical infections after DBS surgery are uncommon events, with studies demonstrating mixed results on whether topical vancomycin reduces this risk. Our single-institution retrospective analysis and systematic review of prior studies both demonstrated no significant SSI rate reduction with topical VP. This is likely due to low baseline SSI rates, resulting in a small effect size for prevention. Given the cost-effectiveness, simplicity, and low risk, topical, intrawound VP remains a treatment option to further reduce risk of SSI, particularly in settings with higher baseline infection rates.

Intra-articular vancomycin for the prophylaxis of periprosthetic joint infection caused by methicillin-resistant S. aureus after total knee arthroplasty in a rat model: the dosage, efficacy, and safety

Although intra-articular vancomycin powder (VP) is sometimes applied before the closure of the incision to prevent periprosthetic joint infection (PJI) after joint replacement, the dosage, efficacy and safety remain controversial. This study aimed to explore the dosage, efficacy, and safety of intra-articular VP in the prophylaxis of infection after total knee arthroplasty (TKA) in a rat model. Sixty male rats were randomly divided into five groups after receiving TKA surgery: Control (no antibiotics); systemic vancomycin (SV) (intraperitoneal injection, 88 mg/kg, equal to 1g in a patient weighted 70kg); VP0.5, VP1.0 and VP2.0 (44 mg/kg, 88 mg/kg and 176 mg/kg respectively, intra-articular). All animals were inoculated in the knee with methicillin-resistant S. aureus (MRSA). General status, serum biomarkers, radiology, microbiological assay and histopathological tests were assessed within 14 days post-operatively. Compared with the Control and SV groups, bacterial counts, knee-width, tissue inflammation, and osteolysis were reduced in the VP0.5, VP1.0 and VP2.0 groups, without notable bodyweight loss and incision complications. Among all the VP groups, VP1.0 and VP2.0 groups presented superior outcomes in the knee-width and tissue inflammation than the VP0.5 group. Microbial culture indicated that no MRSA survived in the knee of VP1.0 and VP2.0 groups, while bacteria growth was observed in VP0.5 group. No obvious changes in the structure and functional biomarkers of liver and kidney were observed in both SV and VP groups. Therefore, intra-articular vancomycin powder at the dosage from 88 mg/kg to 176 mg/kg may be effective and safe in preventing PJI induced by methicillin-resistant S. aureus in the rat TKA model.

Effectiveness of Topical Vancomycin in the Prevention of Spinal Surgical Site Infections: A Retrospective Cohort Study

Introduction: The risk of surgical site infections (SSIs), particularly methicillin-resistant Staphylococcus aureus (MRSA) SSIs, post spinal surgeries is one of the most daunting experiences to patients and surgeons. In some practices, vancomycin powder is applied directly on the wound before skin closure to minimize the risk of SSIs; however, this practice is not supported by well-established evidence. This study sought to assess the effectiveness of topical (intra-wound) vancomycin in minimizing the risk of SSIs in patients who underwent spinal surgeries at a private Saudi hospital. Methodology: A retrospective cohort study was conducted using the hospital database. Patients who underwent spinal surgeries between September 2013 and September 2019 were included and followed-up for up to 30 (for surgeries without implantation) or 90 (for surgeries with implantation) days. The odds ratio (OR) of the first SSI observed in the follow-up period between vancomycin users versus nonusers was estimated using logistic regression adjusting for the measured confounders. A sensitivity analysis was conducted using a propensity score analysis. Result: We included 81 vancomycin users versus 375 nonusers with 28 infections. The adjusted OR of SSIs between the two groups was 0.40 (95% confidence interval [CI] 0.11–1.34). The result of the propensity score analysis was consistent (OR: 0.97 [95% CI 0.35–2.68]). Conclusion: We could not find a lower association of SSIs with intra-wound vancomycin in patients who underwent spinal surgeries. Conducting larger multicenter studies would add more emphasis to the findings of this study.

Intrawound Low-dose Vancomycin (250 mg) Powder has Lower Risk of Wound Dehiscence than Higher Doses in Spine Surgeries

Introduction: Surgical site infection post spinal surgery is a known complication which can be serious and may require aggressive intervention. Intrawound vancomycin powder application is an evolving method to prevent such complication. Although it has very low systemic complications, wound dehiscence with negative culture is reported in the literature. The aim of this study was to find the risk of wound dehiscence with low-dose intrawound vancomycin in comparison to 1 gr and its effectiveness in prevention of surgical site infection. Methodology: A chart review of all patients who underwent posterior thoracic, lumbar or sacral spine surgeries from December 2009 to September 2016 in a single center was done. Patients were categorized into three groups. First, patients who did not receive any intrawound vancomycin; second, patients who received high-dose vancomycin (1 gr); and third, patients who received low-dose vancomycin (250 mg). Additionally, patients’ demographic information, clinical data, and surgical variables were collected. Primary outcome was the presence of wound dehiscence or surgical site infection. Result: In total, 391 patients were included in this study, of which 56 (14.3%) received high-dose intrawound vancomycin, 126 (32.2%) received low dose, and 209 (53.5%) did not receive any. The overall incidence of wound dehiscence was 6.14% (24 out of 391 patients). Wound dehiscence was statistically and significantly higher (p = 0.039) in the high-dose vancomycin group in comparison to the patients who received low dose. The overall incidence of postoperative infection was 2.05% (eight patients). There was no statistically significant difference between the groups. Conclusion: The use of intrawound low-dose vancomycin (250 mg) has less wound dehiscence in comparison with other higher standard doses. Further trials are needed to evaluate the effectiveness of this dose in preventing postoperative infections.

Prophylactic Topical Antibiotics in Fracture Repair and Spinal Fusion

Introduction. The objective of this systematic review with meta-analysis is to determine whether prophylactic local antibiotics prevent surgical site infections (SSIs) in instrumented spinal fusions and traumatic fracture repair. A secondary objective is to investigate the effect of vancomycin, a common local antibiotic of choice, on the microbiology of SSIs. Methods. An electronic search of PubMed, EMBASE, and Web of Science databases and major orthopedic surgery conferences was conducted to identify studies that (1) were instrumented spinal fusions or fracture repair and (2) had a treatment group that received prophylactic local antibiotics. Both randomized controlled trials (RCTs) and comparative observational studies were included. Meta-analysis was performed separately for randomized and nonrandomized studies with subgroup analysis by study design and antibiotic. Results. Our review includes 44 articles (30 instrumented spinal fusions and 14 fracture repairs). Intrawound antibiotics significantly decreased the risk of developing SSIs in RCTs of fracture repair (RR 0.61, 95% CI: 0.40–0.93, I2 = 32.5%) but not RCTs of instrumented spinal fusion. Among observational studies, topical antibiotics significantly reduced the risk of SSIs in instrumented spinal fusions (OR 0.34, 95% CI: 0.27–0.43, I2 = 52.4%) and in fracture repair (OR 0.49, 95% CI: 0.37–0.65, I2 = 43.8%). Vancomycin powder decreased the risk of Gram-positive SSIs (OR 0.37, 95% CI: 0.27–0.51, I2 = 0.0%) and had no effect on Gram-negative SSIs (OR 0.95, 95% CI: 0.62–1.44, I2 = 0.0%). Conclusions. Prophylactic intrawound antibiotic administration decreases the risk of SSIs in fracture surgical fixation in randomized studies. Therapeutic efficacy in instrumented spinal fusion was seen in only nonrandomized studies. Vancomycin appears to be an effective agent against Gram-positive pathogens. There is no evidence that local vancomycin powder is associated with an increased risk for Gram-negative infection.