Use of intrawound vancomycin powder against postoperative infection after spine surgery

Off-label use of intravenous rifampicin during surgery: analysis of Australian surveillance data and retrospective audit at a tertiary hospital

Objective

To investigate the use of rifampicin vials in Australian operating theaters (OT) to determine the method of administration and rationale for use.

Methods

Retrospective (2022 and 2023) OT usage data for rifampicin 600 mg vials were analyzed to compare trends in use between Australian hospitals and between jurisdictions. An audit of rifampicin vials used in OT during 2023 was conducted at a large tertiary hospital.

Results

Fifty-nine of 248 hospitals (24%) contributing data to the National Antimicrobial Utilisation Surveillance Program recorded OT use of rifampicin vials during 2022 and 2023. Excluding hospitals with no usage, the median use was 7 vials/annum/per hospital (IQR: 2-32). A wide variation in use was seen between Australian states and territories. An audit of OT use in 2023 at a large tertiary hospital found poor documentation of topical use; in most cases, documentation was in the operation note only, with no documentation on the medication charts, medical notes, or the anesthetic record. Of 33 rifampicin vials used in 2023, documented topical use was identified for 10 individual patients only, 4 of whom had a confirmed Staphylococcus aureus infection (1 methicillin-resistant and 3 methicillin-susceptible).

Conclusion

Off-label, topical use of rifampicin during surgery is not uncommon in some Australian hospitals despite limited evidence of safety or efficacy. Given the potential for resistance, surgical use of rifampicin should be restricted to a named-patient basis, under the guidance of an infectious disease specialist/clinical microbiologist. Documentation of all medication use is recommended for patient safety.

Efficacy and Limitations of Continuous Local Antibiotic Perfusion in Treating Surgical Site Infections Following Instrumented Spinal Surgery: A Retrospective Multicenter Study

INTRODUCTION

Surgical site infection (SSI) is one of the most serious postoperative complications following instrumented spinal surgery. We previously reported the potential of continuous local antibiotic perfusion (CLAP) to retain implants for patients with SSI following instrumented spinal surgery. We conducted a retrospective multicenter study to elucidate the efficacy and limitations of CLAP for patients with SSI following instrumented spinal surgery.

METHODS

A total of 40 patients treated with CLAP for SSI after instrumented spinal surgery were included in this study. The implant retention rate was calculated. We investigated the influence of age, presence of diabetes, number of fused vertebrae, causative pathogens, duration from diagnosis to CLAP initiation, white blood cell (WBC) count (× 103/μL), and C-reactive protein (CRP) level on the development of SSI after CLAP. Patients were divided into two groups: a favorable outcome group (n = 28), in which SSI was promptly controlled after CLAP, and a poor outcome group (n = 12), in which additional surgery was required or fatal outcomes occurred after CLAP. The relationship between these two groups was evaluated.

RESULTS

In 13 of 40 patients, implants had already been removed before CLAP initiation. Excluding these cases, control of SSI with implant retention was achieved by CLAP in 22 of 27 patients (81%). In the poor outcome group, antibiotic-resistant pathogens were detected at a higher rate than in the favorable outcome group (p = 0.022), and the WBC counts at 1 week after CLAP were significantly increased compared with the favorable outcome group (poor outcome group 7.7 ± 2.4, favorable outcome group 5.8 ± 1.6; p = 0.013).

CONCLUSIONS

Application of CLAP enabled SSI control with a high rate of implant retention. However, detection of antibiotic-resistant pathogens and increased WBC count 1 week after initiating CLAP may predict poor control of SSI, even after CLAP.

Does the Application of Topical Vancomycin Reduce Surgical Site Infections in Spine Surgery? A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Surgical site infections (SSIs) represent a major challenge in spine surgery, leading to severe morbidity, mortality, and increased costs. The local application of antibiotics, particularly vancomycin, has emerged as a potential strategy. Individual randomized controlled trials (RCTs) have disagreed about the efficacy of topical vancomycin in preventing SSIs after spine surgery, and so a meta-analysis that pools data from those RCTs might be helpful to inform clinicians' decisions on the topic.

QUESTIONS/PURPOSES

This meta-analysis of RCTs asked: Does intrawound topical vancomycin reduce the risk of (1) SSIs, (2) deep SSIs, and (3) superficial SSIs in patients undergoing spine surgery?

METHODS

PubMed, Cochrane, and Google Scholar (pages 1-20) were searched up through March 13, 2024 (search performed on March 13, 2024). Inclusion criteria consisted of English or non-English-language RCTs comparing the implementation of topical vancomycin in spine surgery to its nonuse and assessing its efficacy in preventing SSI, while exclusion criteria consisted of nonrandomized comparative studies, single-arm noncomparative studies, comparative studies based on national databases or from the same center as other included studies, studies posted to preprint servers, studies reporting incomplete/nonrelevant outcomes, and studies adding another SSI preventive measure. The studies were assessed using the Cochrane Risk of Bias tool. Heterogeneity was evaluated by Q tests and I 2 statistics. We used a random-effects model when considerable heterogeneity was observed (all SSIs, deep SSIs); otherwise, a fixed-effects model was used (all SSIs subanalysis, superficial SSIs). Furthermore, the fragility index was calculated for each of the assessed outcomes when there was no difference between the two groups to assess how many patients were needed to experience the outcomes for a difference to become present. The studied outcomes were the risks of SSIs, deep SSIs, and superficial SSIs. Deep SSIs were defined by the included trials as SSIs underneath the fascia, otherwise they were considered superficial. Six RCTs representing a total of 2140 patients were included, with 1053 patients in the vancomycin group and 1087 in the control group. Using an alpha of 0.05, our meta-analysis had 80% power to detect a risk difference of 1.5% for the primary outcome between patients who did and did not receive vancomycin. The age of the patients in the vancomycin group ranged from 37 to 52 years, while the age in the control group ranged from 34 to 52 years. The surgical procedures consisted of both instrumented and noninstrumented spinal procedures. Overall, the risk of bias in the included studies was either low or unclear, with none of the studies having a high risk of bias in any of the assessed categories (selection bias, performance bias, detection bias, attrition bias, and reporting bias).

RESULTS

We found no difference in the risk of SSI between the vancomycin and control groups (3.0% [32 of 1053] versus 3.9% [42 of 1087], relative risk 0.74 [95% CI 0.35 to 1.57]; p = 0.43). Ten additional patients (4.8% infection risk) in the control group would need to experience an SSI for a difference to be observed between the two groups. We found no difference in the risk of deep SSI between the vancomycin and control groups (1.8% [15 of 812] versus 2.7% [23 of 860], relative risk 0.69 [95% CI 0.24 to 2.00]; p = 0.50). Seven additional patients (3.5% infection risk) in the control group would need to experience a deep SSI for a difference to be observed between the two groups. We found no difference in the risk of superficial SSI between the vancomycin and control groups (1.0% [6 of 620] versus 1.4% [9 of 662], relative risk 0.68 [95% CI 0.25 to 1.89]; p = 0.46). Seven additional patients (2.4% infection risk) in the control group would need to experience a superficial SSI for a difference to be observed between the two groups.

CONCLUSION

This meta-analysis of randomized trials examining use of topical vancomycin in spine surgery failed to show efficacy in reducing infection, and thus we do not recommend routine use of topical vancomycin for this indication. Future large-scale trials would be needed if surgeons believe that between-group differences smaller than those for which we were powered here (this meta-analysis had 80% power to detect a between-group difference of 1.5% in infection risk) are clinically important, and large database surveys may be informative in terms of assessing for postoperative adverse events associated with the use of vancomycin powder.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Vancomycin powder embedded in collagen sponge decreases the rate of prosthetic shoulder infection

BACKGROUND

Shoulder arthroplasty is a successful procedure to treat degenerative and traumatic diseases of the glenohumeral joint. Periprosthetic infection represents an infrequent but dreaded complication (2%-4%). Application of intrawound vancomycin powder seems to reduce periprosthetic infections, but limited information is available on its efficiency in shoulder arthroplasty. The purpose of this study was to evaluate if the vancomycin powder embedded in a collagen sponge could decrease the rate of prosthetic shoulder infection.

METHODS

A retrospective analysis of 827 patients undergoing total shoulder arthroplasty was performed. The study involved a control group of 405 patients and a group of 422 with the intraoperative insertion of intrawound vancomycin powder. Incidence of periprosthetic infection was evaluated comparing the 2 groups at a minimum follow-up of 12 months. Patient demographics, comorbidities, and perioperative information were compared between the 2 groups.

RESULTS

No infection was observed in the group treated with intrawound vancomycin, and 13 cases of infection were observed in the control group (3.2%) (P value <.001) without subacromial vancomycin application. No wound complications requiring revision were observed as a result of intrawound vancomycin application.

DISCUSSION AND CONCLUSION

Intrawound vancomycin powder significantly reduces the rate of periprosthetic shoulder infections without any increase in local and systemic aseptic complications at a minimum follow-up of 12 months. Our results support the use of intrawound local vancomycin for prophylaxis of shoulder periprosthetic infections.

Combined photothermal and sonodynamic therapy using a 2D black phosphorus nanosheets loaded coating for efficient bacterial inhibition and bone-implant integration

Surgical site infection (SSI) remains a major threat for implant failure in orthopedics. Herein, we report a dual-functional coating on Ti implants (named Ti/PDA/BP) with the integration of two-dimensional (2D) photo-sono sensitive black phosphorus nanosheets (BPNSs) and polydopamine (PDA) for efficient bacterial inhibition and bone-implant integration. For the first time, we employ BPNSs as generators of reactive radicals (ROS) under ultrasound (US) stimuli for implant associated infection. Additionally, the application of PDA improves the stability of BPNSs, the biocompatibility and photothermal performance of this hybrid coating. The as-prepared Ti/PDA/BP coating exhibits superior biocompatibility, bioactivity, photothermal and sonodynamic conversion abilities. Owing to the synergistic effect of hyperthermia and ·OH, Ti/PDA/BP damages the membrane and antioxidant system of Staphylococcus aureus, reaching a high antibacterial activity of 96.6% in vitro and 97.3% in vivo with rapid 10 min NIR irradiation and 20 min US treatment. In addition, we firstly unveil the significant effect of Ti/PDA/BP-based sonodynamic therapy (SDT) on bacterial membrane and oxidative stress at the transcriptome level. Moreover, the Ti/PDA/BP coating remarkably promotes osteogenesis in vitro and bone-implant osseointegration in vivo. Overall, development of Ti/PDA/BP bioactive coating provides a new strategy for combating the implant associated infection.

The Effect of Local Administration of Vancomycin Suspended in Fibrin Glue for Prevention of Surgical Site Infection After Spinal Instrumentation: Comparison by Probability of Treatment Weighting Model

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To compare the surgical site infection (SSI) rate in patients undergoing spinal instrumentation surgery who received vancomycin suspended in fibrin glue at the surgical site and those who did not.

SUMMARY OF BACKGROUND DATA

The intrawound application of vancomycin powder for preventing SSI after spinal surgery remains controversial. Vancomycin suspended in fibrin glue is another option for local administration that may be effective. The present study assessed whether vancomycin suspended in fibrin glue could prevent SSI after spinal instrumentation surgery.

MATERIALS AND METHODS

We enrolled patients who underwent posterior spinal instrumentation surgery with or without fusion for degenerative conditions, spinal trauma, or tumor. A multiple logistic regression model with inverse probability of treatment weighting based on propensity score was used to assess the efficacy of vancomycin suspended in fibrin glue and to account for confounding. A secondary multivariate logistic regression analysis was performed to identify the risk factors associated with SSI.

RESULTS

Of the 264 patients enrolled in this study, 134 underwent application of vancomycin suspended in fibrin glue at the surgical site and 130 did not. The incidence of SSI was lower in patients who were treated with vancomycin suspended in fibrin glue (2.2% vs. 8.5%) even after inverse probability of treatment weighting adjustment (adjusted odds ratio: 0.25; 95% CI, 0.0768-0.91; P =0.03). Multivariate logistic regression analysis showed that the treatment with vancomycin suspended in fibrin glue was significantly associated with a lower odds of SSI (odds ratio: 0.2; 95% CI, 0.05-0.85; P =0.03).

CONCLUSIONS

The administration of vancomycin suspended in fibrin glue was significantly associated with a lower likelihood of SSI in patients undergoing spinal instrumentation surgery.

Effect of Vancomycin Applied to the Surgical Site on Fracture Healing in a Diabetic Rat Model

BACKGROUND

Prophylactic vancomycin treatment decreases the prevalence of surgical site and deep infections by >70% in diabetic patients undergoing reconstructive foot and ankle surgery. Thus, determining whether clinically relevant local vancomycin doses affect diabetic fracture healing is of medical interest. We hypothesized that application of vancomycin powder to the fracture site during surgery would not affect healing outcomes, but continuous exposure of vancomycin would inhibit differentiation of osteoblast precursor cells and their osteogenic activity in vitro.

METHODS

The vancomycin dose used to treat the diabetic rats was a modest increase to routine surgical site vancomycin application of 1 to 2 g for a 70-kg adult (21 mg/kg). After femur fracture in BB-Wistar type 1 diabetic rats, powdered vancomycin (25 mg/kg) was administered to the fracture site. Bone marrow and periosteal cells isolated from diabetic bones were cultured and treated with increasing levels of vancomycin (0, 5, 50, 500, or 5000 µg/mL).

RESULTS

Radiographic scoring, micro-computed tomography (µCT) analysis, and torsion mechanical testing failed to identify any statistical difference between the vancomycin-treated and the untreated fractured femurs 6 weeks postfracture. Low to moderate levels of vancomycin treatment (5 and 50 µg/mL) did not impair cell viability, osteoblast differentiation, or calcium deposition in either the periosteum or bone marrow-derived cell cultures. In contrast, high doses of vancomycin (5000 µg/mL) did impair viability, differentiation, and calcium deposition.

CLINICAL RELEVANCE

In this diabetic rodent fracture model, vancomycin powder application at clinically relevant doses did not affect fracture healing or osteogenesis.

Effects of different doses of vancomycin powder in total knee and hip arthroplasty on the periprosthetic joint infection rate: a systematic review and meta-analysis

BACKGROUND

Periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) is a serious complication for patients. Some joint surgeons have tried to use vancomycin powder (VP) in total knee and total hip arthroplasty to prevent postoperative PJI, but its effect is still not clear. At present, there is no meta-analysis that specifically analyses the effect of different doses of vancomycin powder on the incidence of PJI.

METHODS

We carried out a search based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and identified the studies we needed. Review Manager (RevMan) 5.3 software was employed for statistical analysis.

RESULTS

The analysis of primary TKA (PTKA) showed that using 1 g (RR 0.38, 95% CI 0.22-0.67 [P = 0.0008]) and 2 g (RR 0.48, 95% CI 0.31-0.74 [P = 0.0008]) of vancomycin powder in primary TKA (PTKA) could all significantly prevent PJI. The analysis of primary THA (PTHA) showed that using 1 g (RR 0.37, 95% CI 0.17-0.80 [P = 0.01]) of vancomycin powder effectively decreased the incidence of PJI, while using 2 g (RR 1.02, 95% CI 0.53-1.97 [P = 0.94]) of vancomycin powder had no significant effect on preventing PJI. Because the data were abnormal, we believed the conclusion that using 2 g of vancomycin powder in primary THA had no effect on preventing PJI was doubtful. Using vancomycin powder in revision TKA (RTKA) significantly reduced the PJI rate (RR 0.33, 95% CI 0.14-0.77 [P = 0.01]), similar to revision THA (RTHA) (RR 0.37, 95% CI 0.14-0.96 [P = 0.04]).

CONCLUSIONS

In primary TKA, both 1 g and 2 g of vancomycin powder can effectively prevent PJI. In primary THA, using 1 g of vancomycin powder is a better choice, while the effect of using 2 g of vancomycin powder is not clear, and a more prospective randomized controlled trial should be done to verify it. In revision TKA and revision THA, vancomycin powder is a good choice to prevent PJI.

Does the use of intrawound povidone-iodine irrigation and local vancomycin powder impact surgical site infection rate in adolescent idiopathic scoliosis surgery?

PURPOSE

Surgical site infection (SSI) is a major complication after adolescent idiopathic scoliosis (AIS) surgery, with an incidence ranging from 0.5 to 7%. Intraoperative wound decontamination with povidone-iodine (PVP-I) irrigation and/or vancomycin powder in adult spinal surgery has gained attention in the literature with controversial results. The aim of this study was to investigate the impact of using intrawound PVP-I irrigation and local vancomycin powder (LVP) on the incidence of early SSI in AIS surgery.

METHODS

All AIS patients who underwent posterior spinal fusion between October 2016 and December 2019 were retrospectively reviewed. The incidence of early SSI was reported and compared between 2 groups defined by the treating spinal surgeons' preferences: group 1-intrawound irrigation with 2L of PVP-I and application of 3 g LVP before closure and control group 2-patients that did not receive either of these measures.

RESULTS

Nine early cases of SSI (2.9%) were reported among the 307 AIS posterior spinal fusion patients. Incidence of SSI in group 1 (2/178 = 1.1%) was significantly lower than in group 2 (7/129 = 5.4%; p = 0.04). There were no adverse reactions to the use of PVP-I and LVP in our study. At latest follow-up, rate of surgical revision for mechanical failure with pseudarthrosis was significantly lower in group 1 (2/178 = 1.1%) than in group 2 (9/129 = 7.0%; p = 0.01).

CONCLUSION

Intraoperative use of intrawound PVP-I irrigation and vancomycin powder is associated with a significant reduction of early SSI after AIS spine surgery.

LEVEL OF EVIDENCE IV

Retrospective study.

Continuous local antibiotic perfusion for patients with surgical site infection after instrumented spinal surgery; a novel technique to retain the implants

OBJECTIVES

To describe the novel technique of continuous local antibiotic perfusion (CLAP) for a surgical site infection (SSI) after instrumented spinal surgery.

METHODS

CLAP was applied to 4 continuous patients at our institution who developed SSI after instrumented spinal surgery.

RESULTS

All 4 patients were successfully treated and the infection was controlled. The implant was retained in all patients. The duration of CLAP ranged from 2 to 3 weeks. The blood level of the antibiotic used (gentamicin) at 1 week after the initiation of CLAP did not increase in any patient. No other adverse events occurred in any patient. Dramatic improvements in laboratory parameters, including the white blood cell (WBC) counts and C-reactive protein (CRP) levels were seen in every patient at 1 week after the initiation of CLAP.

CONCLUSIONS

CLAP controlled the infection without severe adverse events in all 4 patients, and the implants were retained. Despite its cost and the discomfort of patients, CLAP may become an option for the treatment of SSIs after instrumented spinal surgery. A large number of case series are needed to verify the efficacy of CLAP for patients with SSIs after instrumented spinal surgery.

Surgeon practice patterns for pre-soaking ACL tendon grafts in vancomycin: a survey of the ACL study group

PURPOSE

To survey members of The ACL study group to determine the current practice patterns surrounding the technique of pre-soaking ACL grafts in vancomycin.

METHODS

A web-based questionnaire was distributed to members of the ACL Study Group. Questions included the use of vancomycin solution for graft soaking during ACL reconstruction, their protocol for soaking the graft, vancomycin concentration utilized, graft choices, and concerns with the technique.

RESULTS

Sixty-six (57%) ACL surgeons completed the survey. Approximately one-third (37.9%) of respondents currently pre-soak their ACL grafts in vancomycin prior to implantation, with 60% of these surgeons being from Europe. Seventy-six percent have adopted this practice within the past 5 years. The majority of surgeons wrap the graft in a vancomycin-soaked gauze prior to implantation (56%), soak for a variable amount of time before implantation (56%), use a concentration of 5 mg/mL (68%), and soak hamstring grafts (92%). Concerns included the mechanical properties of the graft (35%), cost of vancomycin (23%), availability (12%), and antibiotic resistance (9%).

CONCLUSION

This survey demonstrates that 37.9% of ACL study group members currently utilize vancomycin to pre-soak ACL tendon grafts as a means to decrease post-operative infection risk, with the majority of surgeons having implemented this practice within the past 5 years. The biggest concern towards using vancomycin was the mechanical properties of the graft after soaking.

LEVEL OF EVIDENCE

IV.

Significantly Lower Infection Risk for Anterior Cruciate Ligament Grafts Presoaked in Vancomycin Compared With Unsoaked Grafts: A Systematic Review and Meta-analysis

PURPOSE

To compare postoperative infection rates following ACL reconstruction performed with grafts presoaked in vancomycin versus those without vancomycin.

METHODS

A systematic review was performed using PRISMA guidelines. PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched for therapeutic level I to III studies that compared outcomes of presoaking ACL grafts with vancomycin versus without vancomycin in human patients. Included graft types were tendon autografts or allografts, and included studies documented infection with a minimum follow-up of 30 days. Postoperative infection rates and knee-specific patient-reported outcome scores were extracted from each study and compared between groups. Study methodological quality was analyzed using the Methodological Index for Non-Randomized Studies (MINORS) and Modified Coleman Methodology Score (MCMS). Infection rates and retear rates were pooled and weighted for meta-analysis using a random-effects model. All P values were reported with an α level of 0.05 set as significant.

RESULTS

The initial search yielded 144 articles (44 duplicates, 100 screened, 29 full-text review). Ten articles (21,368 subjects [7,507 vancomycin and 13,861 no vancomycin], 67% males, mean ± standard deviation age 29.5 ± 1.5 years) were included and analyzed. Eight of the 10 studies included only autografts, with 94.5% of grafts being hamstring autografts. Soaking grafts in vancomycin resulted in significantly fewer infections (0.013% versus 0.77%; odds ratio 0.07; 95% confidence interval 0.03, 0.18; P < .001). Only 2 studies included patient-reported outcomes, and both demonstrated no difference in International Knee Documentation Committee scores 1 year after surgery for patients with grafts presoaked in vancomycin versus without vancomycin.

CONCLUSIONS

Soaking ACL tendon grafts with vancomycin before implantation is associated with a nearly 15 times decrease in odds of infection compared with grafts not soaked in vancomycin. Few studies investigated patient-reported outcomes and retear rates after soaking ACL grafts in vancomycin.

LEVEL OF EVIDENCE

III, systematic review of level III studies.

Soaking of Autologous Tendon Grafts in Vancomycin Before Implantation Does Not Lead to Tenocyte Cytotoxicity

BACKGROUND

Surgical site infections (SSIs) after anterior cruciate ligament (ACL) reconstruction procedures are an unfortunate complication. Soaking grafts in vancomycin before implantation has been reported to reduce the incidence of postoperative SSI after ACL reconstruction. There is potential for vancomycin to compromise graft integrity because of tenocyte toxicity.

PURPOSE

To examine the in vitro toxicity of varying doses of vancomycin on human tenocytes.

STUDY DESIGN

Controlled laboratory study.

METHODS

Human patellar tenocytes were isolated and expanded in vitro. Tenocytes in culture were exposed to vancomycin at 5 different concentrations (400, 1600, 3200, 6400, and 12,800 μg/mL) and 3 time intervals (2, 6, and 24 hours). The control for all series was tenocyte exposure to only culture medium for each time interval. After treatment, a 10% Cell Counting Kit-8 solution in cellular growth medium was applied to the cells to examine cytotoxicity. A live/dead assay was used to assess tenocyte viability through fluorescence microscopy and flow cytometry. Results were analyzed statistically using multivariable logistic regression models with Tukey honest significant difference post hoc tests.

RESULTS

Vancomycin did not cause significant changes in tenocyte viability after 2 and 6 hours of incubation at any concentration between 0 and 12,800 µg/mL. Incubation with vancomycin for 24 hours led to a significant decrease in cell viability at higher concentrations.

CONCLUSION

Tenocytes derived from human patellar tendons exposed to relatively high concentrations of vancomycin for short periods of time do not demonstrate significant cell death and toxicity.

CLINICAL RELEVANCE

Exposing tendons to vancomycin for a short period of time, such as before ACL reconstruction, is not likely to cause tenocyte toxicity because of vancomycin administration.