Cost savings analysis of intrawound vancomycin powder in posterior spinal surgery

The Effect of Topical Vancomycin Powder Application on the Rate of Intervertebral Fusion Following Lumbar Fusion: A Retrospective Study

PURPOSE

The occurrence of surgical site infection (SSI) after lumbar spinal fusion is a serious complication. Therefore, an increasing number of clinicians are applying vancomycin powder topically in the surgical field to reduce the incidence of SSI. However, there is concern that topical vancomycin powder application may affect intervertebral fusion. The purpose of this study was to analyse the effect of clinically relevant topical vancomycin doses on the rate of intervertebral fusion after lumbar fusion and to further investigate the effect of vancomycin powder on the prevention of SSI.

METHODS

The clinical data of 192 patients with degenerative lumbar spine disease admitted from January 2019 to June 2022, all of whom underwent posterior lumbar fusion, were retrospectively analysed. According to the infection prevention protocol, they were divided into a vancomycin group and a control group (no vancomycin), and the vancomycin group was sub-divided into 0.5 g, 1.0 g, and 1.5 g vancomycin groups. General information and surgical evaluation indexes were compared between the control and vancomycin groups and intervertebral fusion was compared between the vancomycin groups at 6 months and 12 months, postoperatively.

RESULTS

The rate of SSI in the vancomycin group was 0.0%, which was significantly lower than that in the control group (5.3%, P < 0.05), and intervertebral fusion was good in all 3 vancomycin groups at 6 months and 12 months postoperatively, with no statistically-significant differences (P > 0.05).

CONCLUSIONS

Topical application of 0.5 g, 1.0 g, or 1.5 g vancomycin powder did not affect the rates of intervertebral fusion after lumbar fusion. In addition, topical application of vancomycin powder significantly reduced the rates of SSI.

A meta-analysis examining the impact of intrawound treatment on reducing deep surgical site infections during instrumented spine surgery

The purpose of the meta-analysis was to evaluate and compare the effect of intrawound management on decreasing deep surgical site infections (SSIs) in instrumented spinal surgery (SS). The results of this meta-analysis were analysed, and the odds ratio (OR) and mean difference (MD) with 95% confidence intervals (CIs) were calculated using dichotomous or contentious random or fixed effect models. For the current meta-analysis, 29 examinations spanning from 2006 to 2022 were included, encompassing 11 181 people who had instrumented SS. Intrawound management had a significantly lower deep SSI when using vancomycin (OR, 0.34; 95% CI, 0.25-0.44, p < 0.001) and povidone-iodine as intrawound management (OR, 0.24; 95% CI, 0.13-0.42, p < 0.001) compared to control in instrumented SS subjects. The data that was looked at showed that using vancomycin and povidone-iodine as intrawound management had a much lower deep SSI than using a control group of instrumented SS subjects. However, given that some studies included a small number of subjects, attention should be given to their values.

Effects of Preoperative Use of Povidone-Iodine-Impregnated Dressing on Postoperative Rate of Surgical Site Infection in Patients Undergoing Posterolateral Lumbar Spinal Fusion Surgery: A Randomized, Nonblinded, Active-Controlled Trial

BACKGROUND AND OBJECTIVES

No study has evaluated the efficacy of using preoperative antiseptic dressings in reducing the rate of surgical site infection (SSI) in spine surgery thus far. To investigate the efficacy of the use of preoperative povidone-iodine-impregnated antiseptic dressings in patients undergoing instrumented posterolateral lumbar spinal fusion.

METHODS

This was a randomized, nonblinded, active-controlled, parallel-group clinical trial. Patients were randomly assigned to the 2 study groups, including treatment and control. Patients in the treatment group received povidone-iodine-impregnated antiseptic dressing applied to the anticipated incision site 12 hours before the operation. The control group merely received the standard perioperative care with no additional intervention or placebo. Patients were followed up for 90 days, and SSIs were recorded.

RESULTS

A total of 200 patients were included in this study (100 in each arm). Three cases of SSI were observed in the treatment group compared with 12 in the control one. A significant reduction in the postoperative rate of SSI was observed in the treatment group compared with the control one (P = .029). In addition to study intervention (P = .029), body mass index (P = .005), smoking status (P = .005), duration of the procedure (P = .003), American Society of Anesthesiologists class (P = .002), and diabetes mellitus (P < .001) were significantly associated with the postoperative rate of SSI.

CONCLUSION

To the best of our knowledge, this study for the first time showed that preoperative use of antiseptic dressings is significantly effective in reducing the rate of SSI in instrumented posterior lumbar spinal fusion surgery. Future studies are warranted to evaluate the efficacy of different preparations or the effectiveness of the present one in patients undergoing spine procedures with other surgical characteristics.

Effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery: A meta-analysis

We performed a meta-analysis to evaluate the effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery. A systematic literature search up to July 2022 was performed and 24 137 subjects with neurosurgery at the baseline of the studies; 10 496 of them were using the powdered vancomycin, and 13 641 were not using the powdered vancomycin as a control. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery using dichotomous methods with a random or fixed-effect model. The powdered vancomycin had significantly lower surgical site wound infections after spinal surgery (OR, 0.53; 95% CI, 0.41-0.70, P < .001), deep surgical site wound infections after spinal surgery (OR, 0.45; 95% CI, 0.35-0.57, P < .001), superficial surgical site wound infections after spinal surgery (OR, 0.60; 95% CI, 0.43-0.83, P = .002), and surgical site wound infections after cranial surgery (OR, 0.37; 95% CI, 0.22-0.61, P < .001) compared to control in subjects with neurosurgery. The powdered vancomycin had significantly lower surgical site wound infections after spinal surgery, deep surgical site wound infections after spinal surgery, superficial surgical site wound infections after spinal surgery, and surgical site wound infections after cranial surgery compared to control in subjects with neurosurgery. The analysis of outcomes should be done with caution even though the low number of studies with low sample size, 3 out of the 42 studies, in the meta-analysis, and a low number of studies in certain comparisons.

Prophylactic Application of Vancomycin Powder in Preventing Surgical Site Infections After Spinal Surgery

OBJECTIVE

We sought to analyze the preventive effect of local vancomycin powder application on surgical site infection (SSI) in spinal surgeries and provide the basis for future clinical practice.

METHODS

Through PubMed, Medline, Elsevier, and the Cochrane Library, with MeSH words "vancomycin powder," "local/intraoperative/topical/intra-wound," "spine/spinal/lumbar/cervical/thoracolumbar," "surgery," "infection," and "SSI," we searched for case-control research papers on the impact of prophylactic application of vancomycin powder on the incidence of SSI and compared the rate of infection using RevMan 5.3 meta-analysis software.

RESULTS

A total of 1950 publications were found using the mesh words, and 50 of those studies were selected for final analysis. There were 34,301 cases in total, including 14,793 cases in vancomycin group and 19,508 cases in the control group. Results of meta-analysis showed that the incidence of SSI was significantly lower in the prophylactic vancomycin powder group than the control group (P < 0.001). Further subgroup analysis showed that the incidence of SSI was significantly lower in the prophylactic vancomycin powder group than the control group in spine surgeries with internal fixation, deformity correction, and deep tissue infections (P < 0.001). Meanwhile, there were no significant differences between the 2 groups concerning patients undergoing noninstrumented spine surgeries and the incidence of superficial tissue infection.

CONCLUSIONS

Overall, prophylactic application of vancomycin powder in spinal surgery can significantly reduce the incidence of SSI in deep tissues, and this effect is more prominent in patients undergoing internal fixation and deformity correction surgeries.

Efficacy and safety of intrawound antibiotics in patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis: a nationwide database study

PURPOSE

To assess the efficacy and safety of intrawound antibiotics in posterior fusions for adolescent idiopathic scoliosis (AIS).

METHODS

The NSQIP-Pediatric databases 2016-2018 were utilized. Patients 10 years of age or older with AIS who underwent posterior fusion were selected and divided into two cohorts based on the receipt of intrawound antibiotics. Patient characteristics and complications were compared. Multivariate analyses were performed to determine the efficacy and safety of intrawound antibiotics.

RESULTS

A total of 4203 patients received intrawound antibiotics while 879 patients did not. The intrawound antibiotic group had longer constructs, higher blood loss, and longer operative times, factors historically associated with higher infection rates. Those that received intrawound antibiotics had SSI rate of 0.69%, while its counterpart had 0.57% (p = 0.689). The reoperation rates were 1.12% and 1.25% (p = 0.735), for those with and without intrawound antibiotics, respectively. In multivariate analyses, intrawound antibiotics use was not found to be a significant predictor for SSI, any complications, reoperation and readmission.

CONCLUSION

The current study represents the largest AIS surgery cohort studied to evaluate the efficacy of intrawound antibiotics. Our analysis failed to demonstrate association between the use of intrawound antibiotics and reduction in SSI. While other studies have reported seroma, wound dehiscence and renal failure with the practice, we did not observe an increased rate of such complications. This study highlights the difficulty of understanding the role for individual infection prevention measures in current surgical settings, where the SSI rate for the control group was substantially lower than 1%.

Impact of Plastic Surgery and an Enhanced Prophylaxis Protocol on Cervical Spine Surgery Infection

Background: Reduction of surgical site infections (SSIs) is important in improving cervical spine surgery outcomes. Plastic surgery involvement and an enhanced modified prophylaxis protocol may reduce infection rates. Methods: A total of 962 cervical spine operations were conducted by a single surgeon (TFC). An enhanced modified prophylaxis protocol and plastic surgery were used in some operations. Differences in infection rates, surgical approach, previous operations, prophylaxis use, and plastic surgery involvement were compared using Fisher’s exact tests and multivariate linear regression. Results: Four patients (0.42%) experienced SSIs. All 4 infections involved the standard protocol, posterior approach, and did not involve plastic surgery. The infection rate was lower in the enhanced protocol group when compared to the standard protocol (β −0.78, 95% CI −1.23 to −0.33, P = .0008). The enhanced protocol group had an increased percentage of operations with plastic surgery (β 0.19, 95% CI 0.10 to 0.28, P < .0001). The infection rate among the plastics group was 0.00% compared to 0.60% for the non-plastics group ( P = .32). The plastics group had a lower rate of anterior approach when compared to the non-plastics group (β −0.20, 95% CI −0.24 to −0.15, P = .049). Among the posterior approach group, procedures with plastic surgery had an infection rate of 0.00% compared to 2.53% without plastic surgery ( P = .13). Conclusion: The enhanced protocol was associated with a lower SSI rate and increased plastic surgery involvement. Posterior approaches were associated with increased infection rates and the likelihood of utilizing plastic surgery. Both the enhanced protocol and plastic surgery may decrease infection.

Cefazolin prophylaxis in spine surgery: patients are frequently underdosed and at increased risk for infection

BACKGROUND CONTEXT

Perioperative antibiotics are critical in reducing the risk of postoperative spine infections. However, the efficacy and optimal weight-based prophylactic cefazolin dosing is unclear.

PURPOSE

To determine (1) if inadequate weight-based prophylactic dosing of cefazolin affects infection rates after spinal fusions, and (2) identify the optimal dosing of cefazolin.

STUDY DESIGN/SETTING

Single center retrospective cohort PATIENT SAMPLE: Patients undergoing posterior cervical or lumbar spinal fusion between January 2000 and October 2020 OUTCOME MEASURES: Postoperative surgical site infection status METHODS: Patients were grouped based on our institutionally derived dosing adequacy standards, 1 g for <60 kg, 2 g for 60 to 120 kg, and 3 g for >120 kg. Univariate comparisons and multivariate regressions identified the effect of inadequate dosing on infection rate. Patients were subsequently regrouped into cefazolin dose (grams) administered and logistic regression and receiver operating characteristic curves were compiled to determine the probability of infection based on cefazolin dose and patient weight. Alpha was set at 0.05.

RESULTS

A total of 2,643 patients met inclusion criteria and 95 infections (3.6%) were identified. The infection rate was higher in the inadequate dosing group (5.86% vs. 2.58%, p<.001). Adequate dosing was a predictor of decreased infections after lumbar fusion (OR: 0.43, p<.001), but not posterior cervical fusions (OR: 0.47, p=.065). Patients were subsequently regrouped into 1 g or 2 g of cefazolin administered resulting in a 5.01% and 2.77% infection rate, respectively (p=.005). The area under the curve (AUC) and 95% confidence interval for one (0.850 [0.777-0.924]) and two (0.575 [0.493-0.657]) g of cefazolin demonstrated lower infection rates for patients given 2 g cefazolin.

CONCLUSIONS

Patients receiving an inadequate weight-based dose of preoperative cefazolin had an increased risk of infection following spinal fusion surgery. Two grams prophylactic cefazolin significantly reduces the likelihood of infection.

Vancomycin Soaking Is Highly Cost-Effective in Primary ACLR Infection Prevention: A Cost-Effectiveness Study

BACKGROUND

Although presoaking grafts in vancomycin has been demonstrated to be effective in observational studies for anterior cruciate ligament reconstruction (ACLR) infection prevention, the economic benefit of the technique is uncertain.

PURPOSE

To 1) determine the cost-effectiveness of vancomycin presoaking during primary ACLR to prevent postoperative joint infections and 2) to establish the break-even cost-effectiveness threshold of the technique and determine its cost-effectiveness across various international health care settings.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 2.

METHODS

A Markov model was used to determine cost-effectiveness and the incremental cost-effectiveness ratio of additional vancomycin presoaking compared with intravenous antibiotic prophylaxis alone. A repeated search of the PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials databases, using the same criteria as a recent meta-analysis, was completed. A repeated meta-analysis of 9 cohort studies (level 3 evidence) was completed to determine the odds ratio of infection with vancomycin presoaking compared with intravenous antibiotics alone. Estimated costs of the vancomycin technique, treatment of infection, and further surgery were sourced from local hospitals and literature. Transitional probabilities for further surgery, including revision reconstruction and primary arthroplasty, were obtained from the literature. Probabilistic sensitivity analyses and a 1-way sensitivity analysis were performed to evaluate the ACLR infection rate break-even threshold for which the vancomycin technique would be no longer cost-effective.

RESULTS

The vancomycin soaking technique provides expected cost savings of $660 (USA), A$581 (Australia), and €226 (Spain) per patient. There was an improvement in the quality-adjusted life-years of 0.007 compared with intravenous antibiotic prophylaxis alone (4.297 vs 4.290). If the infection rate is below 0.014% with intravenous antibiotics alone, the vancomycin wrap would no longer be cost-effective.

CONCLUSION

The vancomycin presoaking technique is a highly cost-effective method to prevent postoperative septic arthritis after primary ACLR.

Role of intra-discal Vancomycin instillation in prevention post-operative discitis

Background

Post discectomy discitis is regarded as the most disabling cause of failed back surgery. Value of local intra-operative application of antibiotics in prevention of such complication has been a matter of debate. We evaluate the role of intraoperative intra-discal vancomycin powder instillation as a prophylaxis in prevention of postoperative discitis in patients undergoing microscopic discectomy. We allocated 100 patients undergoing discectomy equally into two groups. In the first group, a local Vancomycin powder was inserted into the disc space after finishing discectomy, and in the second group, nothing was inserted.

Results

The postoperative discitis was reported in 6 cases; of them, two patients were in the Vancomycin group (4%), while four patients were in the non-Vancomycin group (8%).

Conclusions

We concluded that the intra-operative prophylaxis, with intra-discal Vancomycin, decreased the incidence of postoperative discitis but without significant statistical difference. We advocate using local vancomycin especially in high risk patients for prevention of post discectomy discitis.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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 (p 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.

CONCLUSION

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.

Topical Vancomycin for Prevention of Surgical Site Infection after Craniotomy, Meta-analysis and Systematic Literature Review

OBJECTIVE AND DESIGN

There is no consensus among neurosurgeons regarding whether the application of topical vancomycin after performing craniotomy has a role in reduction of the risk surgical site infection and consequently reduction of treatment costs. In order to compare the rate of surgical site infections after craniotomies with and without the use of topical vancomycin, a meta-analysis of the available studies in the literature was carried out.

MATERIALS AND METHODS

Multiple electronic health databases were searched to identify all the studies published from July 1988 to July 2021 that examined the role of application of topical vancomycin in reduction of the risk of surgical site infection after craniotomy (cSSIs). Effect sizes were expressed in pooled odds ratio (OR) estimates and due to heterogeneity between studies, random effect of the inverse variance weighted method was used to perform the meta-analysis.

RESULTS

Three observational retrospective cohort studies and one prospective controlled cohort study were identified, comparing the incidence of surgical site infection after 605 craniotomies in which topical vancomycin was used and after 716 craniotomies in which no such intervention was done. Meta-analysis showed that topical vancomycin decreased incidence of cSSIs (odds ratio, 0.13; 95% confidence interval, 0.04 - 0.43).

CONCLUSIONS

The results of this meta-analysis suggest that the use of topical vancomycin after performing craniotomies is safe and effective in decreasing the incidence of cSSIs, however there is a need to perform randomized controlled trials to strongly support this conclusion.

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, I 2 = 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, I 2 = 52.4%) and in fracture repair (OR 0.49, 95% CI: 0.37-0.65, I 2 = 43.8%). Vancomycin powder decreased the risk of Gram-positive SSIs (OR 0.37, 95% CI: 0.27-0.51, I 2 = 0.0%) and had no effect on Gram-negative SSIs (OR 0.95, 95% CI: 0.62-1.44, I 2 = 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.

Invasive Staphylococcus aureus Infection among Patients Undergoing Elective, Posterior, Instrumented Spinal Fusion Surgeries: A Retrospective Cohort Study

Background: Post-surgical invasive Staphylococcus aureus infections among spinal fusion patients are serious complications that can worsen clinical outcomes and increase healthcare utilization. Risk of such infections at the population level remains unknown. This study assessed the post-surgical risk of invasive Staphylococcus aureus infections among patients undergoing elective posterior instrumented spinal fusion surgeries in 129 U.S. hospitals. Patients and Methods: This retrospective cohort study analyzed adult patients ≥18 years of age who underwent thoracolumbar/lumbar and cervical fusion surgeries during 2010 - 2014 using the Premier Healthcare Database, the largest hospital discharge database in the United States. Risks of blood stream infection (BSI), deep or organ/space surgical site infections (SSI) caused by Staphylococcus aureus during 90 and 180 days post-index surgery were estimated. Infections were identified based on positive culture results, related International Classification of Diseases, Ninth Revision (ICD-9) procedure codes, and specific claims information. Results: Among 11,236 patients with thoracolumbar/lumbar fusion, 90- and 180-day BSI/SSI infection risks were higher for multilevel than single level fusion (90-day, 1.52% vs. 1.07%, p = 0.05; 180-day, 1.66% vs. 1.07%, p = 0.014). Among 1,641 patients with cervical fusion, 90- and 180-day BSI/SSI infection risks were also higher in multilevel fusions but not statistically significant (90-day, 1.66% vs. 0.52%, p = 0.350; 180-day, 1.80% vs. 0.51%, p = 0.241). The risk for SSI/BSI was more than twice as high among multilevel thoracolumbar/lumbar fusion patients with more than two comorbidities than those with no comorbidity at both 90-day (2.78% vs. 1.00%, p < 0.05) and 180-day (3.01% vs. 1.10%, p < 0.05). Similar trend without statistical significance was seen in multilevel cervical fusion cohort (90-day, 2.91% vs. 1.25%, p > 0.05; 180-day, 3.88% vs. 1.41%, p > 0.05). Conclusions: The risk of BSI/SSI infection for elective posterior instrumented spinal fusions ranged between 0.5% and 2%. Higher risk was observed in multilevel thoracolumbar/lumbar surgery, with infection risk greatest in patients with more than two comorbidities. These real-world findings highlight the need for additional measures, in addition to antibiotic prophylaxis, to reduce invasive Staphylococcus aureus infections in this setting.

Health and Economic Outcomes of Posterior Spinal Fusion for Children With Neuromuscular Scoliosis

OBJECTIVES

Neuromuscular scoliosis (NMS) can result in severe disability. Nonoperative management minimally slows scoliosis progression, but operative management with posterior spinal fusion (PSF) carries high risks of morbidity and mortality. In this study, we compare health and economic outcomes of PSF to nonoperative management for children with NMS to identify opportunities to improve care.

METHODS

We performed a cost-effectiveness analysis. Our decision analytic model included patients aged 5 to 20 years with NMS and a Cobb angle ≥50°, with a base case of 15-year-old patients. We estimated costs, life expectancy, quality-adjusted life-years (QALYs), and incremental cost-effectiveness from published literature and conducted sensitivity analyses on all model inputs.

RESULTS

We estimated that PSF resulted in modestly decreased discounted life expectancy (10.8 years) but longer quality-adjusted life expectancy (4.84 QALYs) than nonoperative management (11.2 years; 3.21 QALYs). PSF costs $75 400 per patient. Under base-case assumptions, PSF costs $50 100 per QALY gained. Our findings were sensitive to quality of life (QoL) and life expectancy, with PSF favored if it significantly increased QoL.

CONCLUSIONS

In patients with NMS, whether PSF is cost-effective depends strongly on the degree to which QoL improved, with larger improvements when NMS is the primary cause of debility, but limited data on QoL and life expectancy preclude a definitive assessment. Improved patient-centered outcome assessments are essential to understanding the effectiveness of NMS treatment alternatives. Because the degree to which PSF influences QoL substantially impacts health outcomes and varies by patient, clinicians should consider shared decision-making during PSF-related consultations.

A meta-analysis of the local application of vancomycin powder to prevent surgical site infection after spinal surgeries

Objective

This study aimed to systematically analyze the effectiveness and safety of the local application of vancomycin powder to prevent surgical site infection (SSI) after spinal surgeries and provide guidance for clinical practice.

Methods

Two researchers independently searched PubMed, Web of Science, Elsevier, and China National Knowledge Infrastructure using the MeSH terms “spinal surgery,” “vancomycin,” “local,” “topical,” “prophylactic,” “surgical site infection,” and “SSI” to identify studies published between January 2010 and January 2020 on the local application of vancomycin powder for preventing SSI after spinal surgeries. The outcome assessment indicators were analyzed using RevMan 5.3 software.

Results

Three randomized controlled trials, two prospective studies, and 26 retrospective studies were included in the current research. The results of the meta-analysis revealed significant differences between the vancomycin and control groups (non-vancomycin group) concerning the incidence of SSI (risk ratio = 0.39, 95% confidence interval = 0.28–0.55, Z = 5.46), indicating that local application of vancomycin powder can significantly reduce the incidence of SSI.

Conclusion

Local application of vancomycin powder is an effective and safe method to prevent SSI after spinal surgeries.

Efficiency of Topical Rifampin on Infection in Open Neural Tube Defects: A randomized controlled trial

Objectives: Neural tube defects are the second most common congenital malformation in humans. Despite significant decreases in neural tube defects and related mortality and morbidity with recent developments, infections remain an important problem. Research on the role of topical therapy for managing neural tube defects and associated infections in the neonatal period has been limited. This randomized controlled trial aimed to investigate the efficiency of topical Rifampin on infection control in paraplegic newborns with open neural tube defects.Methods: Thirty-seven patients who underwent an operation for neural tube defects were included. Topical Rifampin and cefotaxime were administered to 19 patients constituting the case group and local saline and cefotaxime were administered to a control group. Patients were examined for ventriculoperitoneal shunt infection/dysfunction, surgical site infection, urinary tract infection, and sepsis.Results: None of the patients using topical rifampin had ventriculoperitoneal shunt infection/dysfunction, surgical site infection, urinary tract infection, or sepsis. In the control group, ventriculoperitoneal shunt infection/dysfunction was found in 4 (22.2%) cases, surgical site infection in 3 (27.7%), urinary tract infection in 3 (27.7%), and sepsis in 5 (27.7%), with statistically significant differences between the groups (p = 0.01, p = 0.032, p = 0.032, and p = 0.002, respectively). No local or systemic side effect was observed regarding rifampin use.Conclusion: Topical Rifampin is effective in minimizing complications like sepsis, surgical site infection, urinary tract infection, and ventriculoperitoneal shunt infection due to neural tube defect operations. Further research with larger numbers of cases is needed to implement this practice routinely.

Intrawound vancomycin application after spinal surgery: a propensity score-matched cohort analysis

OBJECTIVE

Surgical site infection (SSI) following spine surgery is associated with increased morbidity and healthcare costs. In an effort to reduce SSI rates, the application of intrawound vancomycin powder has gained popularity. However, there is limited high-quality evidence to support the safety and efficacy of this practice. The authors sought to determine if intrawound application of vancomycin powder improves 90-day overall SSI rates.

METHODS

The authors performed a retrospective, vancomycin exposure-matched cohort study at a single tertiary care hospital over 21 months. They included all patients undergoing elective spinal surgery and stratified the patients into two groups: those who received intrawound vancomycin powder application and those who received no application of vancomycin powder. The primary outcome of interest was the 90-day overall SSI rate. Secondary outcomes included rates of superficial SSI, deep SSI, wound disruption, and a post hoc analysis of the microbiology and minimum inhibitory concentrations. Baseline patient demographics, clinical presentation, comorbidities, perioperative factors, and 90-day postoperative outcomes were manually abstracted from patient charts. To mitigate bias, we performed 1:1 matching after calculating propensity scores and identified 1 patient from the no-vancomycin cohort for each patient in the vancomycin cohort.

RESULTS

A total of 997 patients met our inclusion criteria (473 patients receiving vancomycin and 524 patients not receiving vancomycin). Propensity score matching produced 221 matched pairs. Risk-adjusted analysis demonstrated similar overall SSI rates between the groups (OR 1.9, p = 0.329). On unadjusted analysis, the overall 90-day SSI rate was greater in the vancomycin group (n = 10 [4.5%]) than in the no-vancomycin group (n = 5 [2.3%]) (p < 0.001), as were the superficial SSI rate (7 [3.2%] vs 4 [1.8%], p < 0.001), deep SSI rate (3 [1.4%] vs 1 [0.5%], p < 0.001), and wound disruption rate (5 [2.3%] vs 1 [0.5%], p < 0.001). No cultured isolate demonstrated vancomycin resistance.

CONCLUSIONS

The authors observed no difference in SSI rates after the intrawound application of vancomycin powder during spine surgery. Vancomycin use did not contribute to antimicrobial resistance; however, it may select out gram-negative bacteria and increase rates of wound disruption.

Comparison of two fluorescent probes in preclinical non-invasive imaging and image-guided debridement surgery of Staphylococcal biofilm implant infections

Implant-associated infections are challenging to diagnose and treat. Fluorescent probes have been heralded as a technologic advancement that can improve our ability to non-invasively identify infecting organisms, as well as guide the inexact procedure of surgical debridement. This study’s purpose was to compare two fluorescent probes for their ability to localize Staphylococcus aureus biofilm infections on spinal implants utilizing noninvasive optical imaging, then assessing the broader applicability of the more successful probe in other infection animal models. This was followed by real-time, fluorescence image-guided surgery to facilitate debridement of infected tissue. The two probe candidates, a labelled antibiotic that targets peptidoglycan (Vanco-800CW), and the other, a labelled antibody targeting the immunodominant Staphylococcal antigen A (1D9-680), were injected into mice with spine implant infections. Mice were then imaged noninvasively with near infrared fluorescent imaging at wavelengths corresponding to the two probe candidates. Both probes localized to the infection, with the 1D9-680 probe showing greater fidelity over time. The 1D9-680 probe was then tested in mouse models of shoulder implant and allograft infection, demonstrating its broader applicability. Finally, an image-guided surgery system which superimposes fluorescent signals over analog, real-time, tissue images was employed to facilitate debridement of fluorescent-labelled bacteria.

Efficacy of prophylactic application of vancomycin powder in preventing surgical site infections after instrumented spinal surgery: A retrospective analysis of patients with high-risk conditions

OBJECTIVE

This study aimed to determine the efficacy of prophylactic use of vancomycin powder against surgical site infections in patients with high-risk conditions who underwent posterior spinal instrumentation.

METHODS

Data obtained from 209 patients who underwent posterior spinal instrumentation at a single institution from 2014 to 2017 were retrospectively reviewed. Patients were then divided into two groups: control group, including 107 patients (61 females, 46 males; mean age=54 years; age range=16-85 years), and treatment group, including 102 patients (63 females, 39 males; mean age=53 years; age range=14-90 years). All patients received the same standard prophylactic antibiotic regimen. In addition to the prophylactic antibiotic, vancomycin powder was applied locally to the surgical site in the treatment group. All patients were followed up for at least 90 days postoperatively. Infections were categorized as superficial and deep infections. Subgroup analysis of high-risk patients (Syrian refugees) was also performed.

RESULTS

The infection rates were 1.96% (two patients) in the treatment group and 6.54% (seven patients) in the control group. A significant decrease in the infection rates was observed with local vancomycin powder application. Advanced age (>46 years) and prolonged surgical duration (>140 min) were found to be the main risk factors for surgical site infections (p=0.004 and p=0.028, respectively). The infection rates were 3.22% and 8.11% in the treatment and control groups of refugees, respectively. There were three superficial and four deep infections in the control group and one superficial and one deep infection in the treatment group. A dominance of staphylococcus infections was observed in the control group, whereas no significant dominance was observed in the treatment group. Three patients in the control group and one patient in the treatment group received implant removal.

CONCLUSION

Evidence from this study has revealed that local application of vancomycin powder reduces the rate of surgical site infections after instrumented spinal surgery. The benefit of vancomycin application may be most appreciated in higher risk populations or in clinics with high baseline rates of infection.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

The Cost-Effectiveness of Vancomycin Powder in Lumbar Laminectomy

STUDY DESIGN

Break-even cost analysis.

OBJECTIVE

The goal of this study is to examine the cost-effectiveness of vancomycin powder for preventing infection following lumbar laminectomy.

METHODS

The product cost of vancomycin powder was obtained from our institution's purchasing records. Infection rates and revision costs for lumbar laminectomy and lumbar laminectomy with fusion were obtained from the literature. A break-even analysis was then performed to determine the absolute risk reduction (ARR) in infection rate to make prophylactic application of vancomycin powder cost-effective. Analysis of lumbar laminectomy with fusion was performed for comparison.

RESULTS

Costing $3.06 per gram at our institution, vancomycin powder was determined to be cost-effective in lumbar laminectomy if the infection rate of 4.2% decreased by an ARR of 0.015%. Laminectomy with fusion was also determined to be cost-effective at the same cost of vancomycin powder if the infection rate of 8.5% decreased by an ARR of 0.0034%. The current highest cost reported in the literature, $44.00 per gram of vancomycin powder, remained cost-effective with ARRs of 0.21% and 0.048% for laminectomy and laminectomy with fusion, respectively. Varying the baseline infection rate did not influence the ARR for either procedure when the analysis was performed using the product cost of vancomycin at our institution.

CONCLUSIONS

This break-even analysis demonstrates that prophylactic vancomycin powder can be highly cost-effective for lumbar laminectomy. At our institution, vancomycin powder is economically justified if it prevents at least one infection out of 6700 lumbar laminectomy surgeries.

A Cost-Effectiveness Analysis of Smoking-Cessation Interventions Prior to Posterolateral Lumbar Fusion

BACKGROUND

Smoking cessation represents an opportunity to reduce both short and long-term effects of smoking on complications after lumbar fusion and smoking-related morbidity and mortality. However, the cost-effectiveness of smoking-cessation interventions prior to lumbar fusion is not fully known.

METHODS

We created a decision-analytic Markov model to evaluate the cost-effectiveness of 5 smoking-cessation strategies (behavioral counseling, nicotine replacement therapy [NRT], bupropion or varenicline monotherapy, and a combined intervention) prior to single-level, instrumented lumbar posterolateral fusion (PLF) from the health payer perspective. Probabilities, costs, and utilities were obtained from published sources. We calculated the costs and quality-adjusted life years (QALYs) associated with each strategy over multiple time horizons and accounted for uncertainty with probabilistic sensitivity analyses (PSAs) consisting of 10,000 second-order Monte Carlo simulations.

RESULTS

Every smoking-cessation intervention was more effective and less costly than usual care at the lifetime horizon. In the short term, behavioral counseling, NRT, varenicline monotherapy, and the combined intervention were also cost-saving, while bupropion monotherapy was more effective but more costly than usual care. The mean lifetime cost savings for behavioral counseling, NRT, bupropion monotherapy, varenicline monotherapy, and the combined intervention were $3,291 (standard deviation [SD], $868), $2,571 (SD, $479), $2,851 (SD, $830), $6,767 (SD, $1,604), and $34,923 (SD, $4,248), respectively. The minimum efficacy threshold (relative risk for smoking cessation) for lifetime cost savings varied from 1.01 (behavioral counseling) to 1.15 (varenicline monotherapy). A PSA revealed that the combined smoking-cessation intervention was always more effective and less costly than usual care.

CONCLUSIONS

Even brief smoking-cessation interventions yield large short-term and long-term cost savings. Smoking-cessation interventions prior to PLF can both reduce costs and improve patient outcomes as health payers/systems shift toward value-based reimbursement (e.g., bundled payments) or population health models.

LEVEL OF EVIDENCE

Economic Level II. See Instructions for Authors for a complete description of levels of evidence.

[The effectiveness of local application of vancomycin powder in the prevention of surgical site infections in spine surgery: a meta-analysis]

OBJECTIVE

To perform a meta-analysis of studies examining the effectiveness of the local application of vancomycin powder for the prophylaxis of surgical site infections (SSIs) in spine surgery.

MATERIAL AND METHODS

Retrospective cohort studies and prospective randomized clinical trials were searched for in the Pubmed, EMBASE, Cochrane Library and eLibrary databases published from 2008 to December 2018. For the resulting variables, the odds ratio and 95% confidence interval were calculated using random and fixed effects models. Estimation of the degree of heterogeneity is estimated using the coefficient I². Statistically significant differences were considered differences p<0.05.

RESULTS

The meta-analysis included 28 clinical studies that included the results of the local application of vancomycin powder in 17,469 patients after performing various spinal surgical interventions. Two publications had a prospective, randomized, controlled study design. Topical application of vancomycin powder reduces the incidence of SSIs after spine surgery (p<0.0001). The use of vancomycin powder reduces the incidence of SSIs in patients operated on with stabilizing implants (p=0.004). On the other hand, the topical application of vancomycin powder did not affect the prevalence of SSIs in respondents who were operated on without the use of stabilizing implants (p=0.12) or due to deformities of the spine (p=0.06).

CONCLUSION

Topical application of vancomycin powder is highly effective in preventing the development of SSIs in patients after spinal surgical interventions.

Progress not panacea: vancomycin powder efficacy and dose evaluated in an in vivo mouse model of spine implant infection

BACKGROUND

Intrawound vancomycin powder (VP) has been rapidly adopted in spine surgery with apparent benefit demonstrated in limited, retrospective studies. Randomized trials, basic science, and dose response studies are scarce.

PURPOSE

This study aims to test the efficacy and dose effect of VP over an extended time course within a randomized, controlled in vivo animal experiment.

STUDY DESIGN/SETTING

Randomized controlled experiment utilizing a mouse model of spine implant infection with treatment groups receiving vancomycin powder following bacterial inoculation.

METHODS

Utilizing a mouse model of spine implant infection with bioluminescent Staphylococcus aureus, 24 mice were randomized into 3 groups: 10 infected mice with VP treatment (+VP), 10 infected mice without VP treatment (No-VP), and 4 sterile controls (SC). Four milligrams of VP (mouse equivalent of 1 g in a human) were administered before wound closure. Bioluminescence imaging was performed over 5 weeks to quantify bacterial burden. Electron microscopy (EM), bacterial colonization assays (Live/Dead) staining, and colony forming units (CFU) analyses were completed. A second dosing experiment was completed with 34 mice randomized into 4 groups: control, 2 mg, 4 mg, and 8 mg groups.

RESULTS

The (+VP) treatment group exhibited significantly lower bacterial loads compared to the control (No-VP) group, (p<.001). CFU analysis at the conclusion of the experiment revealed 20% of mice in the +VP group and 67% of mice in the No-VP group had persistent infections, and the (+VP) treatment group had significantly less mean number of CFUs (p<.03). EM and Live/Dead staining revealed florid biofilm formation in the No-VP group. Bioluminescence was suppressed in all VP doses tested compared with sterile controls (p<.001). CFU analysis revealed a 40%, 10%, and 20% persistent infection rate in the 2 mg, 4 mg, and 8 mg dose groups, respectively. CFU counts across dosing groups were not statistically different (p=.56).

CONCLUSIONS

Vancomycin powder provided an overall infection prevention benefit but failed to eradicate infection in all mice. Furthermore, the dose when halved also demonstrated an overall protective benefit, albeit at a lower rate.

CLINICAL SIGNIFICANCE

Vancomycin powder is efficacious but should not be viewed as a panacea for perioperative infection prevention. Dose alterations can be considered, especially in patients with kidney disease or at high risk for seroma.

Preoperative Versus Extended Postoperative Antimicrobial Prophylaxis of Surgical Site Infection During Spinal Surgery: A Comprehensive Systematic Review and Meta-Analysis

Introduction

Surgical site infection (SSI) following spinal surgery is a major source of postoperative morbidity. Although studies have demonstrated perioperative antimicrobial prophylaxis (AMP) to be beneficial in the prevention of SSI among spinal surgery patients, consensus is lacking over whether preoperative or extended postoperative AMP is most efficacious. To date, no meta-analysis has investigated the comparative efficacy of these two temporally variable AMP protocols in spinal surgery. We undertook a systemic review and meta-analysis to determine whether extended postoperative AMP is associated with a difference in the rate of SSI occurrence among adult patients undergoing spinal surgery.

Methods

Embase and MEDLINE databases were systematically searched for clinical trials and cohort studies directly comparing SSI rates among adult spinal surgery patients receiving either preoperative or extended postoperative AMP. Quality of evidence of the overall study population was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group approach. Random effects meta-analyses were performed utilizing both pooled and stratified data based on instrumentation use.

Results

Five studies met inclusion criteria. No individual study demonstrated a significant difference in the rate of SSI occurrence between preoperative and extended postoperative AMP protocols. The GRADE quality of evidence was low. Among the overall cohort of 2824 patients, 96% underwent lumbar spinal surgery. Pooled SSI rates were 1.38% (26/1887) for patients receiving extended postoperative AMP and 1.28% (12/937) for patients only receiving preoperative AMP. The risk of SSI development among patients receiving extended postoperative AMP was not significantly different from the risk of SSI development among patients only receiving preoperative AMP [RR (risk ratio), 1.11; 95% CI (confidence interval) 0.53–2.36; p = 0.78]. The difference in risk of SSI development when comparing extended postoperative AMP to preoperative AMP was also not significant for both instrumented (RR, 0.92; 95% CI 0.15–5.75; p = 0.93) and non-instrumented spinal surgery (RR, 1.25; 95% CI 0.49–3.17; p = 0.65). There was no evidence of heterogeneity of treatment effects for all meta-analyses.

Conclusion

Preoperative AMP appears to provide equivalent protection against SSI development when compared to extended postoperative AMP. Prudent antibiotic use is also known to decrease hospital length of stay, healthcare expenditure, and risk of complications. However, until higher-quality evidence becomes available regarding AMP in spinal surgery, surgeons should continue to exercise discretion and clinical judgment when weighing the effects of patient comorbidities and complications before determining the optimal duration of perioperative AMP.

Electronic supplementary material

The online version of this article (10.1007/s12325-020-01371-5) contains supplementary material, which is available to authorized users.

Paraspinous Muscle Flaps for the Treatment of Complex Spinal Wounds

MINI: This retrospective case series investigated paraspinous flaps for coverage of complex spinal wounds. 6.90% of patients developed postoperative wound infections and 0.00% of patients required instrumentation removal for infection. This suggests that these flaps may offer a long-term solution in wound management for patients with repeated spinal operations.

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To investigate the efficacy and complication profile of the use of paraspinous muscle flaps for closure of complex spinal wounds.

SUMMARY OF BACKGROUND DATA

Paraspinous muscle flap closure offers an innovative option in difficult-to-manage post-spinal surgery wounds. Current literature reports are mixed in terms of success and complication rates of these flap procedures, with most sources citing a wound complication rate of 20%.

METHODS

This case series investigated the hospital course of 58 patients undergoing paraspinous flap closure after spinal surgery between the years 2014 and 2018. Information gathered includes: demographics, surgery indication, location, and length of incision on the spine, nutrition labs, previous spinal surgeries, preoperative wound class, operative times, length of hospital stay, and complication rates including reoperation, wound infection, and other postoperative complications.

RESULTS

Of the 58 patients undergoing spinal muscle flap closure, 51 (87.93%) had undergone previous spinal surgery with an average of 2.12 previous surgeries in these patients. Mean albumin and prealbumin were 2.62 and 13.75, respectively. 4/58 (6.90%) developed a wound infection or experienced a continuation of their chronic osteomyelitis. Of the 57 patients that had spinal instrumentation, three (5.26%) had spinal implants removed at the time of surgery and two (3.51%) had it removed or replaced later for mechanical complications. No patients had instrumentation removed for chronic infections. One (1.72%) experienced reoperation for wound-related complications. These rates are lower than most complication rates in the current literature.

CONCLUSION

The plastic and reconstructive paraspinous muscle flap has promising results as a closure option for complex spinal wounds following neurosurgical cases. Further investigation is called for to determine the applicability of these results to the general population.

LEVEL OF EVIDENCE

4.

Seromas Following Pediatric Spinal Deformity Surgery: Is Operative Management Necessary?

BACKGROUND

Seromas are known complications after pediatric spinal deformity surgery. Although many surgeons perform an early debridement to prevent deep surgical site infections (SSIs), a less invasive approach to seroma management has not been studied. We hypothesized that a conservative approach to seroma management would be safe and yield equivalent outcomes.

METHODS

We performed a retrospective review of patients who developed a postoperative seroma with or without nonpurulent drainage. Inclusion criteria were patients below 21 years who underwent primary posterior spinal fusion from 1996 to 2016 and developed a postoperative wound seroma. Seromas were clinically defined as an afebrile patient with a fluid collection that was soft and nontender to palpation and without induration or erythema. Growing spine surgeries and revision procedures were excluded from this study.

RESULTS

Twenty-five of 790 total patients with a mean follow-up of 57.8 months (±48.5 mo) developed a seroma. Seromas were identified at a mean of 13.6 days postoperatively and resolved after a mean of 12.2 days following the presentation. Seromas occurred in 12 patients with idiopathic scoliosis, 12 with neuromuscular scoliosis, and 1 patient with Scheuermann kyphosis. All cases were managed conservatively with monitoring of the incision without an operative procedure. In cases of spontaneous drainage, a sterile dressing was applied to the wound and changed as needed until drainage ceased. Two patients underwent bedside needle aspiration and 5 patients received prophylactic antibiotics at the treating surgeon's discretion. All cases resolved spontaneously without development of an acute SSI. Three cases subsequently developed a late SSI (range, 18 to 38 mo postoperatively). Two had idiopathic scoliosis and 1 had neuromuscular scoliosis. None of these seromas drained spontaneously.

CONCLUSIONS

Conservative management of postoperative seromas after pediatric spinal deformity surgery is appropriate. It is unclear if seromas contributed to the development of the 3 late infections. Further studies are needed regarding the relationship of late infections in seroma patients.

LEVEL OF EVIDENCE

Level IV-case series.

Current Strategies in Prevention of Postoperative Infections in Spine Surgery

STUDY DESIGN

Narrative review.

OBJECTIVES

Postoperative surgical site infections (SSIs) are among the most common acute complications in spine surgery and have a devastating impact on outcomes. They can lead to increased morbidity and mortality as well as greater economic burden. Hence, preventive strategies to reduce the rate of SSIs after spine surgery have become vitally important. The purpose of this article was to summarize and critically analyze the available evidence related to current strategies in the prevention of SSIs after spine surgery.

METHODS

A literature search utilizing Medline database was performed. Relevant studies from all the evidence levels have been included. Recommendations to decrease the risk of SSIs have been provided based on the results from studies with the highest level of evidence.

RESULTS

SSI prevention occurs at each phase of care including the preoperative, intraoperative, and postoperative periods. Meticulous patient selection, tight glycemic control in diabetics, smoking cessation, and screening/eradication of Staphylococcus aureus are some of the main preoperative patient-related preventive strategies. Currently used intraoperative measures include alcohol-based skin preparation, topical vancomycin powder, and betadine irrigation of the surgical site before closure. Postoperative infection prophylaxis can be performed by administration of silver-impregnated or vacuum dressings, extended intravenous antibiotics, and supplemental oxygen therapy.

CONCLUSIONS

Although preventive strategies are already in use alone or in combination, further high-level research is required to prove their efficacy in reducing the rate of SSIs in spine surgery before evidence-based standard infection prophylaxis guidelines can be built.

Spinal Fusion Surgery and Local Antibiotic Administration: A Systematic Review on Key Points From Preclinical and Clinical Data

STUDY DESIGN

Systematic review.

OBJECTIVE

The present review of clinical and preclinical in vivo studies focused on the local antibiotic administration for surgical site infection (SSI) in spinal fusion procedures and identifying new approaches or research direction able to release antibiotics in the infected environment.

SUMMARY OF BACKGROUND DATA

SSI is a severe complication of spinal fusion procedures that represents a challenging issue for orthopedic surgeons. SSIs can range from 0.7% to 2.3% without instrumentation up to 6.7% with the use of instrumentation with significant implications in health care costs and patient management.

METHOD

A systematic search was carried out by two independent researchers according to the PRISMA statement in three databases (www.pubmed.com, www.scopus.com and www.webofknowledge.com) to identify preclinical in vivo and clinical reports in the last 10 years. Additionally, to evaluate ongoing clinical trials, three of the major clinical registry websites were also checked (www.clinicaltrials.gov, www.who.int/ictrp, https://www.clinicaltrialsregister.eu).

RESULTS

After screening, a total of 43 articles were considered eligible for the review: 36 clinical studies and seven preclinical studies. In addition, six clinical trials were selected from the clinical registry websites.

CONCLUSION

The results reported that the topical vancomycin application seem to represent a strategy to reduce SSI incidence in spine surgery. However, the use of local vancomycin as a preventive approach for SSIs in spine surgery is mostly based on retrospective studies with low levels of evidence and moderate/severe risk of bias that do not allow to draw a clear conclusion. This review also underlines that several key points concerning the local use of antibiotics in spinal fusion still remains to be defined to allow this field to make a leap forward that would lead to the identification of specific approaches to counteract the onset of SSIs.

LEVEL OF EVIDENCE

4.

Acoustic Parameters for Optimal Ultrasound-Triggered Release from Novel Spinal Hardware Devices

Post-operative infection is a catastrophic complication of spinal fusion surgery, with rates as high as 10%, and existing preventative measures (i.e., peri-operative antibiotics) are only partially successful. To combat this clinical problem, we have designed a drug delivery system around polyether ether ketone clips to be used for prophylactic post-surgical release of antibiotics upon application of ultrasound. The overall hypothesis is that antimicrobial release from this system will aggressively combat post-surgical bacterial survival. This study investigated a set of acoustic parameters optimized for in vitro ultrasound-triggered coating rupture and subsequent release of encapsulated prophylactic antibiotics. We determined that a transducer frequency of 1.7 MHz produced the most consistent burst release and that, at this frequency, a pulse repetition frequency of 6.4 kHz and acoustic output power of 100% (3.41 MPa) produced the greatest release, representing an important proof of principle and the basis for continued development of this novel drug delivery system.

Evaluation of Cumulative and Conditional Antibiotic Release from Vancomycin-Embedded Fibrin Sealant and Its Antibacterial Activity : An In Vitro Study

Objective

Fibrin sealants have been used for hemostasis, sealant for cerebrospinal fluid leakage, and adhesive barrier in neurosurgery. Further, as its clinical use and role of an effective drug delivery vehicle have been proposed. This study was performed to measure antibacterial activity and continuous local antibiotic release from different concentrations of vancomycin-impregnated fibrin sealant in vitro.

Methods

Antibacterial activity was investigated by disk diffusion test by measuring the diameter of the growth inhibition zone of bacteria (methicillin-resistant Staphylococcus aureus, ATCC29213) from vancomycin-embedded fibrin sealant disc diluted at five different concentrations (C1–C5; 8.33, 4.167, 0.83, 0.083, and 0.0083 mg/disc, respectively). Continuous and conditioned release of vancomycin concentration (for 2 weeks and for 5 days, respectively) were also measured using high-performance liquid chromatography (HPLC) method. To mimic the physiologic wound conditions with in vitro, conditioned vancomycin release in phosphate buffer solution (PBS) was measured and replaced PBS for five consecutive days, half a day or completely daily.

Results

In the disk diffusion test, the mean diameters of bacterial inhibition zone were 2.54±0.07 cm, 2.61±0.12 cm, and 2.13±0.15 cm (C1, C2, and C3 respectively) but 1.67±0.06 cm and 1.23±0.15 cm in C4 and C5, respectively. Continuous elution test elicited the peak release of vancomycin from the fibrin sealant at 48 hours, with continued release until 2 weeks. However, conditioned vancomycin release decreased to half or more on day 2, however, the sustainable release was measured over the therapeutic dose (10–20 μg/mL) for 5 days and 4 days in assays of half and total exchange of PBS.

Conclusion

This study suggests that fibrin sealant can provide an efficient vehicle for antibiotic drug release in a wide range of neurosurgical procedures and the safe and effective therapeutic dose will be at the concentration embedded of 4.167 mg/disc or more of vancomycin.

Vancomycin powder for the prevention of surgical site infection in posterior elective spinal surgery

OBJECTIVE

To assess the effectiveness and safety of vancomycin powder as surgical site infection (SSI) prophylaxis in posterior bilateral elective spinal surgery.

MATERIALS AND METHODS

Single-center quasi-experimental pre and postintervention comparative cohort study. The post-intervention group received standard intravenous antibiotic prophylaxis plus 1g of vancomycin powder into the surgical field before wound closure, and the pre-intervention group only the intravenous prophylaxis.

RESULTS

150 patients were included in each group. Twelve SSI (7 superficial and 5 deep) occurred in the post-intervention group and 16 SSI (7 superficial and 9 deep) in the pre-intervention group. The risk of deep SSI decreased from 6.0% to 3.3% (OR 0,54, 95%CI 0.17-1.65, p=0.411) with vancomycin powder. The percentage of deep SSI due to gram negative-positive germs were 80%-20% and 33%-67% for the post- and pre-intervention groups, respectively (p=0.265). No local or systemic adverse effects occurred attributable to vancomycin powder.

CONCLUSION

In posterior elective spinal surgery, prophylaxis with vancomycin powder did not result in a significantly reduced incidence of superficial and deep SSI. There was a trend towards a higher incidence of deep SSI caused by gram negative microorganisms among those treated with vancomycin.

The efficacy of intrawound vancomycin powder and povidone-iodine irrigation to prevent surgical site infections in complex instrumented spine surgery

BACKGROUND CONTEXT

Surgical site infections (SSIs) are notorious complications in spinal surgery and cause substantial patient morbidity. Intraoperative decontamination of the wound with povidone-iodine irrigation or vancomycin powder has gained attention lately, but the efficacy of either intervention is unclear.

PURPOSE

To determine the efficacy of intrawound povidone-iodine or vancomycin in reducing the incidence of deep- and superficial SSIs in instrumented spinal surgery.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

A retrospective chart review was performed including all consecutive adult patients undergoing open, posterior, instrumented spinal surgery at any level between January 2012 and August 2017.

OUTCOME MEASURES

The presence of SSI was evaluated according to the criteria published by the Centers for Disease Control and Prevention. The SSIs were divided into deep SSIs (below the muscular fascia) and superficial SSIs (above the muscular fascia).

METHODS

A retrospective cohort without intrawound treatment was compared with two separate, consecutive intervention groups. One intrawound group received 1.3g/L povidone-iodine irrigation and the other received 1-2 grams of intrawound vancomycin powder at the end of surgery. Incidence of SSIs, as well as demographic, surgical and patient-related variables were registered and compared between groups. In patients with SSI, additional microbiological data were collected.

RESULTS

In total, 853 patients were included. In the control group (N=257), 25 (9.7%) patients developed a deep and 13 (5.1%) developed a superficial SSI. In the povidone-iodine group (N=217), 21 (9.7%) patients developed a deep and two (0.9%) developed a superficial SSI. Compared with the control group, there was no significant difference in the incidence of deep SSIs (risk ratio [RR]: 1.00, 95% CI 0.57-1.73), although the number of superficial SSIs was reduced significantly (RR 0.18, 95% CI 0.04-0.80). In the vancomycin group (N=379), 19 (5.0%) patients developed a deep and six (1.6%) developed a superficial SSI. Both deep (RR: 0.52, 95% CI 0.29-0.92) and superficial SSIs (RR: 0.31, 95% CI 0.12-0.81) were significantly reduced in the vancomycin group compared with the control group, even when correcting for several risk factors associated with SSIs in a multivariable logistic regression analysis. There were no significant differences in complications between the 3 groups. No gram-negative selection or vancomycin-resistance was seen in the vancomycin group.

CONCLUSIONS

Intrawound application of vancomycin was associated with a significant reduction in both deep and superficial SSIs in instrumented spinal surgery. A 1.3g/L intrawound povidone-iodine solution did not show a reduction in deep SSIs, although a reduction of superficial SSIs was observed.

Efficacy and Cost-effectiveness of Topical Vancomycin Powder in Primary Cementless Total Hip Arthroplasty

Topical vancomycin has been shown to effectively reduce infections after spinal surgery while remaining safe and cost-effective; however, there are few studies evaluating topical vancomycin in total hip arthroplasty. The authors hypothesized that the incidence of periprosthetic joint infection would decrease with the use of topical vancomycin in total hip arthroplasty and that topical vancomycin would be cost-effective. A retrospective patient chart review was performed to evaluate consecutive primary cementless total hip arthroplasties performed in the authors' hospital system between April 2015 and December 2016. Demographic data were collected. Periprosthetic joint infection was defined by Musculoskeletal Infection Society criteria. Statistical analysis included t test, Fisher's exact test, and logistic regression. The costs of vancomycin and postoperative infection were used to determine the absolute risk reduction (1/number needed to treat) threshold needed for topical vancomycin to be cost-effective. In this study, 309 patients (55.7%) undergoing total hip arthroplasty were treated with topical vancomycin, and 246 patients (44.3%) did not receive treatment. There were 2 infections in the vancomycin group (0.6% incidence), and 4 in the no vancomycin group (1.6% incidence). There was no statistical difference in infection rate between the 2 cohorts (P=.414). The absolute risk reduction was 0.98%, and the number needed to treat with topical vancomycin was 102 patients to prevent 1 periprosthetic joint infection. Topical vancomycin ($12 per vial) resulted in an expected cost savings of $904 per patient. Topical vancomycin is inexpensive and cost-effective. Although not statistically significant, the topical vancomycin group had a 60% lower incidence of infection. Further research regarding appropriate prophylactic topical and intravenous antibiotic use is needed prior to widespread adoption. [Orthopedics. 2019; 42(5):e430-e436.].

USE OF INTRAOPERATORY VANCOMYCIN IN SPINAL SURGERIES

ABSTRACT Objectives: Despite the use of systemic antibiotic prophylaxis, infection is still a challenge for spine surgeons, with high morbidity and mortality, long hospitalization, delayed rehabilitation, and a greater number of interventions. The purpose of this cross-sectional retrospective case-control study was to compare the incidence of postoperative infection in individuals who received a systemic antibiotic as the sole prophylactic method with those who received vancomycin in the operative wound in association with systemic antibiotic prophylaxis in spinal surgery. Methods: We evaluated 2694 medical records of individuals submitted to posterior spinal surgery in the thoracolumbar segment in the period from January 2012 to June 2017, 1360 in the treatment group and 1334 in the control group. Results: Nineteen (1.39%) of the treatment group progressed with surgical site infection, compared to 42 (3.14%) of the control group. Conclusions: There was a significant reduction in the postoperative infection rate with the use of vancomycin (p=0.0379). Level of Evidence III; Case-Control Study.

Application of Vancomycin Powder to Reduce Surgical Infection and Deep Surgical Infection in Spinal Surgery: A Meta-analysis

STUDY DESIGN

This was a meta-analysis study.

OBJECTIVE

Our meta-analysis study aimed to evaluate the efficacy of vancomycin powder to reduce the surgical site infection (SSI) in spinal surgery.

SUMMARY OF BACKGROUND DATA

The SSI is a potential and devastating complication after spinal surgery. Local application of vancomycin powder is an attractive adjunctive therapy to reduce SSI in spinal surgery.

METHODS

Studies were identified from PubMed, The Cochrane Library, AMED, Web of Science, Scopus, Ovid, EMBASE, and Ebsco Medline. The fixed-effects model was used to compute the merge of relative risk and 95% confidence interval (CI). Heterogeneity tests were checked by I statistics. Subgroup analysis was performed to determine whether vancomycin powder was beneficial, that could reduce the SSI in spinal surgery, or not. Publication bias was explored by funnel plot.

RESULTS

We included 21 studies for final analysis. In our analysis, application of vancomycin powder was associated with a significantly reduced risk of SSI and deep SSI. Pooled relative risks showed significant changes: SSI, 0.36 (95% CI: 0.27-0.47, P=0.000), SSI in the instrumented group, 0.35 (95% CI: 0.25-0.49, P=0.000), SSI in the noninstrumented group, 0.39 (95% CI: 0.24-0.65, P=0.000), deep SSI, 0.28 (95% CI: 0.18-0.44, P=0.000), and the incidence pseudoarthrosis, 0.88 (95% CI: 0.35-2.21, P=0.784). In the subgroup analysis, vancomycin powder showed beneficial effects to SSI in the instrumented group. Pooled the heterogeneity: SSI (P=0.124, I=30.0%), SSI in the instrumented group (P=0.366, I=8.2%), SSI in the noninstrumented group (P=0.039, I=60.5%), deep SSI (P=0.107, I=33.5%).

CONCLUSIONS

The application of vancomycin powder could decrease the SSI and deep SSI in spinal surgery. In the subgroup, vancomycin powder is beneficial to the SSI in the instrumented group. The available evidence is too limited to make the conclusion that the use of vancomycin powder causes pseudoarthrosis in spinal surgery, its extrapolation should be carefully executed.

Evaluation of bacterial presence on lead X-ray aprons utilised in the operating room via IBIS and standard culture methods

Background

Despite precautions, surgical procedures carry risk of infection. Radiation-protective lead aprons worn by operating personnel are a potential source of bacterial contamination and have not been fully evaluated.

Aim/objective

To evaluate lead aprons as a source of bacterial contamination, identify organisms most commonly found on this source, and devise a method with which to lower the risk of contamination.

Methods

In this basic science study, 20 randomly selected lead X-ray aprons were swabbed at three time points. The experimental treatment was with a hospital-grade disinfectant wipe. The samples were assessed for bacterial growth via traditional plating methods and mass spectrometry. Plates were graded on a scale of 0 to 4+ based on the number of quadrants with growth. Growth on one quadrant or more was considered contaminated.

Findings/results

Bacteria were initially detected via IBIS on a majority of the aprons (32/40), most commonly Staphylococcus epidermidis and Propionibacterium acnes. Virulent organisms cultured were Methicillin-resistant Staphylococcus epidermidis (MRSE), Neisseria, Streptococcus viridans and pseudomonas. MRSE were detected on 5/20 of the samples. Immediately after treatment, the majority of aprons showed less bacterial contamination (0/20 standard culture positive; 13/20 IBIS positive) with some recurrence at the 6-h time point (2/20 standard culture positive, 16/20 IBIS positive). All MRSE detected initially was eradicated.

Discussion

Lead X-ray aprons worn in the operating room harbour bacteria. Disinfecting before use may prevent the introduction of virulent organisms to patients. Our proposed method of sanitising with a disinfectant wipe is quick and effective.

Intrawound Treatment for Prevention of Surgical Site Infections in Instrumented Spinal Surgery: A Systematic Comparative Effectiveness Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

To determine the efficacy of intrawound treatments in reducing deep surgical site infections (SSIs) in instrumented spinal surgery.

METHODS

The electronic databases MEDLINE, EMBASE, and Cochrane were systematically searched for intrawound treatments for the prevention of SSIs in clean instrumented spine surgery. Both randomized controlled trials and comparative cohort studies were included. The results of included studies were pooled for meta-analysis.

RESULTS

After full text- and reference screening, 20 articles were included. There were 2 randomized controlled trials and 18 observational studies. Sixteen studies investigated the use of intrawound antibiotics, and 4 studies investigated the use of intrawound antiseptics. The relative risk of deep SSI for any treatment was 0.26 (95% confidence interval [CI] 0.16-0.44, P < .0001), a significant reduction compared with controls receiving no treatment. For patients treated with local antibiotics the relative risk was 0.29 (95% CI 0.17-0.51, P < .0001), and patients treated with local antiseptics had a relative risk of 0.14 (95% CI 0.05-0.44, P = .0006).

CONCLUSIONS

Both the use of antibiotic and antiseptic intrawound prophylactics was associated with a significant 3 to 7 times reduction of deep SSIs in instrumented spine surgery. No adverse events were reported in the included studies.

Intrawound Antibiotic Powder Decreases Frequency of Deep Infection and Severity of Heterotopic Ossification in Combat Lower Extremity Amputations

BACKGROUND

Amputations sustained owing to combat-related blast injuries are at high risk for deep infection and development of heterotopic ossification, which can necessitate reoperation and place immense strain on the patient. Surgeons at our institution began use of intrawound antibiotic powder at the time of closure in an effort to decrease the rate of these surgical complications after initial and revision amputations, supported by compelling clinical evidence and animal models of blast injuries. Antibiotic powder may be useful in reducing the risk of these infections, but human studies on this topic thus far have been inconclusive.

PURPOSE

We sought to determine whether administration of intrawound antibiotic powder at the time of closure would (1) decrease the risk of subsequent deep infections of major lower-extremity combat-related amputations, and (2) limit formation and decrease severity of heterotopic ossification common in the combat-related traumatic residual limb.

METHODS

Between 2009 and 2015, 252 major lower extremity initial and revision amputations were performed by a single surgeon. Revision cases were excluded if performed specifically to address deep infection, leaving 223 amputations (88.5%) for this retrospective analysis. We reviewed medical records to collect patient information, returns to the operating room for subsequent infection, and microbiologic culture results. We also reviewed radiographs taken at least 3 months after surgery to determine the presence and severity of heterotopic ossification using the Walter Reed classification system. We grouped cases according to whether limbs underwent initial or revision amputations, and whether the limbs had a history of a prior infection. Apart from the use of antibiotic powder and duration of followup, the groups did not differ in terms of age, mechanism of injury, or sex. We then calculated the absolute risk reduction for infection and heterotopic ossification and the number needed to treat to prevent an infection.

RESULTS

Overall, administration of antibiotic powder resulted in a 13% absolute risk reduction of deep infection (14 of 82 [17%] versus 42 of 141 [30%]; p = 0.03; 95% CI, 0.20%-24.72%). In revision amputation surgery, the absolute risk reduction of infection with antibiotic powder use was 16% overall (eight of 58 versus 17 of 57; 95% CI, 1.21%-30.86%), and 25% for previously infected limbs (eight of 46 versus 14 of 33; 95% CI, 4.93%-45.14%). The number needed to treat to prevent one additional deep infection in amputation surgery is eight in initial amputations, seven in revision amputations, and four for revision amputation surgery on previously infected limbs. With the numbers available, we observed no reduction in the risk of heterotopic ossification with antibiotic powder use, but severity was decreased in the treatment group in terms of the number of residual limbs with moderate or severe heterotopic ossification (three of 12 versus 19 of 34; p = 0.03).

CONCLUSIONS

Our findings show that administration of intrawound antibiotic powder reduces deep infection in residual limbs of combat amputees, particularly in the setting of revision amputation surgery in apparently aseptic residual limbs at the time of the surgery. Furthermore, administration of antibiotic powder for amputations at time of initial closure decreases the severity of heterotopic ossification formation, providing a low-cost adjunct to decrease the risk of two complications common to amputation surgery.Level of Evidence Level III, therapeutic study.

Perioperative Catheter Use as a Risk Factor for Surgical Site Infection After Cervical Surgery: An Analysis of 39,893 Patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To demonstrate the relationship between perioperative use of catheters and the incidence of surgical site infection (SSI) after cervical spine surgery, after adjusting for patient's age, severity of comorbidity, surgical approach, and use of instrumentation.

SUMMARY OF BACKGROUND DATA

Although the association between SSI and the use of arterial catheters (ACs) or central venous catheters (CVCs) is established in cardiac surgery, the relation in the cervical spine was not well elucidated.

METHODS

A private insurance database was analyzed. The incidence of SSI within 1 month postoperatively and the crude odds ratio (cOR) and 95% confidence interval (95% CI) were calculated based on the use of catheters. Subsequently, logistic regression analysis was performed to identify independent factors for SSI. Independent variables of the regression analysis included Charlson comorbidity index with the score of age, the use of CVC, the use of AC, surgical approach (anterior or posterior), and instrumentation (fusion or decompression alone).

RESULTS

A total of 39,893 patients received cervical surgery between 2007 and 2015. Of these, 1.6% patients experienced an SSI. The incidence of SSI in patients treated with and without AC was 3.2% and 1.3%, respectively (cOR 2.44, 95% CI: 2.05-2.99, P < 0.001). Likewise, incidence of SSI in patients with and without CVC was 5.8% and 1.5%, respectively (cOR 2.61, 95% CI: 2.97-5.55, P < 0.001). Multivariate logistic regression analysis demonstrated that the adjusted OR was 1.66 in CVC use (95% CI: 1.08-2.46, P = 0.016), whereas the AC use was not significant variable (P = 0.086).

CONCLUSION

The use of CVC can be a potential risk factor for SSI regardless of age, severity of comorbidity, surgical approach, or presence of instrumentation. Although the essential benefits of catheters are undisputed, our data can bring up the surgeon's attention to appropriate management of the CVC.

LEVEL OF EVIDENCE

3.

Does intrawound vancomycin powder reduce surgical site infection after posterior instrumented spinal surgery? A propensity score-matched analysis

BACKGROUND CONTEXT

Recent reports suggested that placing vancomycin powder into surgical wounds before closure can prevent surgical site infections (SSIs) in spinal surgery.

PURPOSE

The present study aimed to evaluate if intrawound vancomycin powder could prevent SSIs after spinal surgery with posterior instrumentation.

STUDY DESIGN

This is a multicenter retrospective cohort study using propensity score matching.

PATIENT SAMPLE

We reviewed all spinal surgeries performed with posterior instrumentation from July 2012 to December 2014 at 11 institutions among patients aged ≥15 years.

OUTCOME MEASURES

The incidence of SSIs was compared between patients who received intrawound vancomycin powder (vancomycin group) and those who did not (control group).

METHODS

Demographic and operative data and microbiological findings of SSI cases were analyzed. After a preliminary whole-cohort analysis, we performed one-to-one propensity score matching to adjust for the differences between the two groups and then compared the incidence of SSIs between the matched groups. No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.

RESULTS

A total of 2,859 patients were included in the study. In the vancomycin and control groups (n=694 and n=2165, respectively), 12 (1.73%) and 21 (0.97%) patients developed SSIs, respectively, but the difference was not statistically significant (p=.10, chi-square test). During the propensity score-matched analysis, 507 pairs were analyzed. No significant change in the rate of SSIs was seen between the vancomycin and control groups (8 SSIs [1.58%] vs. 9 SSIs [1.78%], respectively; p=.81, chi-square test). Microbiological analysis revealed that 5 of 12 (42%) and 11 of 21 (52%) SSIs in the vancomycin and control groups, respectively, were caused by Staphylococcus (p=.72, Fisher exact test).

CONCLUSIONS

Intrawound application of vancomycin powder was not associated with a significant decrease in the incidence of SSIs after posterior instrumented spinal surgeries in a propensity score-matched analysis. However, the rate of infections caused by Staphylococcus species was lower in the vancomycin group.

Cost-effectiveness of pre-operative Staphylococcus aureus screening and decolonization

OBJECTIVE

We developed a decision analytic model to evaluate the impact of a preoperative Staphylococcus aureus decolonization bundle on surgical site infections (SSIs), health-care-associated costs (HCACs), and deaths due to SSI.

METHODS

Our model population comprised US adults undergoing elective surgery. We evaluated 3 self-administered preoperative strategies: (1) the standard of care (SOC) consisting of 2 disinfectant soap showers; (2) the "test-and-treat" strategy consisting of the decolonization bundle including chlorhexidine gluconate (CHG) soap, CHG mouth rinse, and mupirocin nasal ointment for 5 days) if S. aureus was found at any of 4 screened sites (nasal, throat, axillary, perianal area), otherwise the SOC; and (3) the "treat-all" strategy consisting of the decolonization bundle for all patients, without S. aureus screening. Model parameters were derived primarily from a randomized controlled trial that measured the efficacy of the decolonization bundle for eradicating S. aureus.

RESULTS

Under base-case assumptions, the treat-all strategy yielded the fewest SSIs and the lowest HCACs, followed by the test-and-treat strategy. In contrast, the SOC yielded the most SSIs and the highest HCACs. Consequently, relative to the SOC, the average savings per operation was $217 for the treat-all strategy and $123 for the test-and-treat strategy, and the average savings per per SSI prevented was $21,929 for the treat-all strategy and $15,166 for the test-and-treat strategy. All strategies were sensitive to the probability of acquiring an SSI and the increased risk if SSI if the patient was colonized with SA.

CONCLUSION

We predict that the treat-all strategy would be the most effective and cost-saving strategy for preventing SSIs. However, because this strategy might select more extensively for mupirocin-resistant S. aureus and cause more medication adverse effects than the test-and-treat approach or the SOC, additional studies are needed to define its comparative benefits and harms.

Effect of intrawound vancomycin application in spinal surgery on the incidence of surgical site infection: a meta-analysis

Background

Despite great advances in aseptic surgical techniques, surgical site infection (SSI) is still one of the main complications after spine surgery. SSI can bring tremendous physical, psychological, and economic challenges to patients. Intrawound vancomycin application is a much disputed method for the prevention of SSI after spine surgery.

Objective

The aim of this study is to review the current literature for studies on the intra-wound application of vancomycin powder and to analyze its effectiveness in the prevention of postoperative SSI.

Methods

PubMed, Medline, Elsevier, and CNKI were searched for the key words “vancomycin”, “local/intraoperative/topical/intra-wound”, “spine/spinal/lumbar/cervical/thoracolumbar surgery”, “infection”, and “SSI” in published studies on the effectiveness of intrawound vancomycin application to prevent postoperative SSI. RevMan 5.3 was used to compare the data extracted from the studies included.

Results

A total of 27 studies involving 17,321 patients were included in the final analysis. Among those patients, 7,423 patients were treated with vancomycin to prevent SSI, with 9,898 in control groups. SSI incidence after surgery in experimental groups was 0.39 times as high as control groups, and this difference was statistically significant (P<0.01). Among patients who underwent internal fixation, vancomycin application significantly reduced the incidence of postoperative SSI (OR 0.31 95% CI 0.19–0.50; P<0.01). Meanwhile, vancomycin did not affect SSI incidence in patients who did not receive internal fixation (P=0.17) or received deformity correction (P=0.25).

Conclusion

SSI incidence after spinal surgery can be significantly reduced by intrawound application of vancomycin in most circumstances. This method can be applied in various spinal procedures involving instrumentation to prevent postoperative SSI.

Use of Intrawound Antibiotics in Orthopaedic Surgery

Intrawound antibiotics have been used in orthopaedic surgery procedures to prevent the development of surgical site infections. Local delivery of antibiotic powder has demonstrated a notable reduction in surgical site infection in rabbit and rodent in vivo models, as well as in other surgical fields, including vascular, colorectal, cardiothoracic, and dermatologic surgery. Intrawound antibiotic powder has been used in many orthopaedic applications, including spine surgery, total joint arthroplasty, trauma, foot and ankle reconstruction, and elbow surgery. Although the theory behind the use of intrawound antibiotic powder is promising, it has potential adverse effects, including antibiotic resistance, circulatory collapse, and decreased bone healing. In addition, most studies in the orthopaedic literature on the use of intrawound antibiotic powder are retrospective in nature.

An Analysis of Implant Retention and Antibiotic Suppression in Instrumented Spine Infections: A Preliminary Data Set of 67 Patients

Background

It is unclear whether patients can be taken off suppressive antibiotics with infected retained instrumentation. This study aimed to retrospectively analyze the perioperative course and antibiotic regimen that led to the clinical intervention of patients with infected spinal instrumentation.

Methods

Consecutive adult patients with spine instrumentation who suffered surgical site infections (SSI) requiring debridement were retrospectively analyzed. The patients were grouped into 4 cohorts based on their clinical intervention: removal of instrumentation, reinstrumentation, retention of instrumentation with continued antibiotic suppression, and retention of instrumentation with no antibiotic suppression. Patient factors, infection factors, debridement, and antibiosis were compared.

Results

Of the 67 patients with SSI after spine surgery and instrumentation, 19 (28%) had their instrumentation removed, 6 (9%) had their instrumentation exchanged, 25 (37%) had their instrumentation retained and were on antibiotic suppression, and 17 (25%) had their instrumentation retained without any suppression. Those who had their instrumentation removed had a later presentation of their infection averaging 85 days (range 6-280 days) postoperatively. There was an earlier presentation for those who retained their implants, with suppression averaging 19 days (range 9-39) and no suppression averaging 29 days (range 6-90 days) post operatively (P < .001).

Conclusions

None of the patients with retained instrumentation without suppression had recurrence of infections after long-term follow-up. Lifelong antibiotic suppression may not be required with SSI that present early after early aggressive debridement. Patients with infections detected later are difficult to treat without removal of their original instrumentation.

Clinical Relevance

This study presents the outcomes of surgical and antibiotic factors in patients with infected spinal instrumentation.

Prevention of Surgical Site Infections: A Systematic Review of Cost Analyses in the Use of Prophylactic Antibiotics

Introduction: The preoperative phase is an important period in which to prevent surgical site infections (SSIs). Prophylactic antibiotic use helps to reduce SSI rates, leading to reductions in hospitalization time and cost. In clinical practice, besides effectiveness and safety, the selection of prophylactic antibiotic agents should also consider the evidence with regard to costs and microbiological results. This review assessed the current research related to the use of antibiotics for SSI prophylaxis from an economic perspective and the underlying epidemiology of microbiological findings.

Methods: A literature search was carried out through PubMed and Embase databases from 1 January 2006 to 31 August 2017. The relevant studies which reported the use of prophylactic antibiotics, SSI rates, and costs were included for analysis. The causing pathogens for SSIs were categorized by sites of the surgery. The quality of reporting on each included study was assessed with the “Consensus on Health Economic Criteria” (CHEC).

Results: We identified 20 eligible full-text studies that met our inclusion criteria, which were subsequently assessed, studies had in a reporting quality scored on the CHEC list averaging 13.03 (8–18.5). Of the included studies, 14 were trial-based studies, and the others were model-based studies. The SSI rates ranged from 0 to 71.1% with costs amounting to US$480-22,130. Twenty-four bacteria were identified as causative agents of SSIs. Gram negatives were the dominant causes of SSIs especially in general surgery, neurosurgery, cardiothoracic surgery, and obstetric cesarean sections.

Conclusions: Varying results were reported in the studies reviewed. Yet, information from both trial-based and model-based costing studies could be considered in the clinical implementation of proper and efficient use of prophylactic antibiotics to prevent SSIs and antimicrobial resistance.