Intrawound application of vancomycin for prophylaxis in instrumented thoracolumbar fusions: efficacy, drug levels, and patient outcomes

An intraoperative irrigation regimen to reduce the surgical site infection rate following adolescent idiopathic scoliosis surgery

INTRODUCTION

The aim of this study was to compare the efficacy of a gentamicin antibiotic intraoperative irrigation regimen (regimen A) with a povidone-iodine intraoperative irrigation regimen (regimen B) and to evaluate the ability of adjunctive local vancomycin powder (regimen C) to reduce the surgical site infection (SSI) rate following idiopathic scoliosis correction.

METHODS

This was a retrospective, single centre, two-surgeon cohort study of paediatric scoliosis procedures involving 118 patients under the age of 18 years who underwent correction for idiopathic scoliosis over a period of 42 months. Patients' baseline characteristics, pseudarthrosis and rates of SSI were compared.

RESULTS

Baseline characteristics were comparable in all three groups, with the exception of sex distribution. Over a quarter (27%) of patients with regimen B were male compared with 13% and 6% for regimens A and C respectively. Patients were mostly followed up for a minimum of 12 months. The SSI rate for both superficial and deep infections was higher with regimen A (26.7%) than with regimens B and C (7.0% and 6.3% respectively). The SSI rates for regimens B and C were comparable. No patients developed complications related to vancomycin toxicity, metalwork failure or pseudarthrosis.

CONCLUSIONS

Wound irrigation with a povidone-iodine solution reduces SSIs following adolescent idiopathic scoliosis surgery. The direct application of vancomycin powder to the wound is safe but does not reduce the SSI rate further in low risk patients. Additional studies are needed to elucidate whether it is effective at higher doses and in high risk patient groups.

Surgical Site Infections After Pediatric Spine Surgery

Surgical site infection (SSI) after spinal deformity surgery is a complication in the pediatric population resulting in high morbidity and cost. Despite modern surgical techniques and preventative strategies, the incidence remains substantial, especially in the neuromuscular population. This review focuses on recent advancements in identification of risk factors, prevention, diagnosis, and treatment strategies for acute and delayed pediatric spine infections. It reviews recent literature, including the best practice guidelines for infection prevention in high-risk patients. Targets of additional research are highlighted to assess efficacy of current practices to further reduce risk of SSI in pediatric patients with spinal deformity.

Risk factors for early implant-related surgical site infection

PURPOSE

To identify the risk factors and microbes associated with early implant-related surgical site infection (SSI).

METHODS

Records of 193 implant-related SSIs secondary to primary orthopaedic surgery were reviewed. Early and late SSI was defined as infection diagnosed within and after 3 months of surgery, respectively.

RESULTS

Of the 193 implant-related SSIs, 29 were superficial incisional, 127 were deep incisional, and 37 were organ/space-related. 144 (90%) out of 160 SSIs used cefazolin in their prophylactic antibiotic regimen. In univariate analysis, early SSI was associated with diabetes mellitus, American Society of Anesthesiologists (ASA) score of >2, emergency procedures, and lack of antibiotic prophylaxis. In multivariable analysis, early SSI was associated with an ASA score of >2 (p=0.016).

CONCLUSION

It is important to cross-check ASA score with co-morbidities to reduce early SSIs. Peri-operative optimisation and antibiotic prophylaxis should be administered prior to surgery. Appropriate modification of antibiotic prophylaxis should be considered.

Complications After Surgical Treatment of Adolescent Idiopathic Scoliosis

Even with current techniques and instrumentation, complications can occur after operative treatment of adolescent idiopathic scoliosis. The most dreaded complications-neurologic deficits-are relatively infrequent, occurring in 1% or less of patients. Nonneurologic deficits, such as infection, pseudarthrosis, curve progression, and proximal junctional kyphosis, are more frequent, but are much less likely to require reoperation or to cause poor functional outcomes. Understanding the potential complications of surgical treatment of pediatric spinal deformity is essential for surgical decision-making.

A Predictive Risk Index for 30-day Readmissions Following Surgical Treatment of Pediatric Scoliosis

BACKGROUND

Pediatric scoliosis often requires operative treatment, yet few studies have examined readmission rates in this patient population. The purpose of this study is to examine the incidence, reasons, and independent risk factors for 30-day unplanned readmissions following scoliosis surgery.

METHODS

A retrospective analysis of the American College of Surgeons National Surgical Quality Improvement-Pediatric database from 2012 to 2013 was performed. Patients undergoing spinal arthrodesis for progressive infantile scoliosis, idiopathic scoliosis, or scoliosis due to other medical conditions were identified and divided between 2 groups: patients with unplanned 30-day readmissions (Readmitted) and patients with no unplanned readmissions (Non-Readmitted). Multivariate logistic regression models were created to determine independent risk factors for readmissions.

RESULTS

A total of 3482 children were identified, of which 120 (3.4%) had an unplanned readmission. A majority of patients had a readmission due to a surgical site complication regardless of scoliosis etiology. Risk factors for readmission included obesity (P<0.001) and posterior fusion of 13 or more vertebrae (P=0.029) for idiopathic scoliosis, impaired cognition (P=0.009) for progressive infantile scoliosis, and pelvic fixation (P=0.025) and American Society of Anesthesiologist ≥3 (P=0.048) for scoliosis due to other conditions.

CONCLUSIONS

We present 30-day readmissions risk factors based on independent patient and procedural risk factors. This may be useful in the clinical management of patients following scoliosis surgery, specifically for the role of preoperative and predischarge risk stratification.

Prophylactic peri-operative local antibiotic irrigation

An extensive review of the spinal and arthroplasty literature was undertaken to evaluate the effectiveness of local antibiotic irrigation during surgery. The efficacy of antibiotic irrigation for the prevention of acute post-operative infection after total joint arthroplasty was evaluated retrospectively in 2293 arthroplasties (1990 patients) between January 2004 and December 2013. The mean follow-up was 73 months (20 to 139). One surgeon performed all the procedures with minimal post-operative infection.

The intra-operative protocol included an irrigation solution of normal saline with vancomycin 1000 mg/l and polymyxin 250 000 units/l at the rate of 2 l per hour. No patient required re-admission for primary infection or further antibiotic treatment. Two morbidly obese patients (two total hip arthroplasties) developed subcutaneous fat necrosis requiring debridement and one was revised because the deep capsular sutures were contaminated by the draining subcutaneous haematoma. One patient who had undergone total knee arthroplasty had unrecognised damage to the lateral superior geniculate artery and developed a haematoma that became infected secondarily four months after the surgery and underwent revision.

The use of antibiotic irrigation during arthroplasty surgery has been highly effective for the prevention of infection in the author’s practice. However, it should be understood that any routine prophylactic use of antibiotics may result in resistant organisms, and the wise stewardship of the use of antibiotics is an important part of surgical practice.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):23–6.

Reduction in CSF shunt infection over a 10-year period associated with the application of concentrated topical antibiotic powder directly to surgical wounds prior to closure

OBJECT

The application of concentrated topical antibiotic powder directly to surgical wounds has been associated with a reduction in wound infection in cardiac, spinal, and deep brain stimulator surgery. As a result of these findings, the corresponding author began systematically applying concentrated bacitracin powder directly to wounds during shunt surgery more than 5 years ago. The object of this study was to evaluate the effectiveness of concentrated bacitracin powder applied directly to wounds prior to closure during cranial shunt surgery and to evaluate the association between shunt infection and other risk factors. A single surgeon's cranial shunt surgery experience, equally divided between periods during which antibiotic powder was and was not applied, was studied to assess the effect of concentrated bacitracin powder application on shunt infection rates.

METHODS

This retrospective cohort study included all patients who underwent a cranial shunting procedure at All Children's Hospital performed by a single surgeon (G.F.T.) from 2001 to 2013. The surgeon applied bacitracin powder to all shunt wounds prior to closure between 2008 and 2013, whereas no antibiotic powder was applied to wounds prior to 2008. Both initial and revision shunting procedures were included, and all procedures were performed at a large children's hospital (All Children's Hospital). The primary outcome measure was shunt infection, which was defined using clinical criteria previously used by the Hydrocephalus Clinical Research Network. The association between bacitracin powder use and shunt infection was estimated using hazard ratios (HRs) and 95% CIs from Cox proportional hazard regression models.

RESULTS

A total of 47 infections out of 539 shunt operations occurred during the study period, resulting in an overall infection rate of 8.7%. Procedures performed before the use of concentrated bacitracin powder was instituted resulted in a 13% infection rate, whereas procedures performed after systematic use of bacitracin powder had been adopted experienced a 1% infection rate. Bacitracin powder use was associated with a reduced risk of shunt infection in univariate analysis (HR 0.11, 95% CI 0.03-0.34, p = 0.0002) and also in multivariate analysis (HR 0.12, 95% CI 0.04-0.41, p = 0.0006) when controlling for covariates that were associated with infection from the univariate analysis. The presence of a tracheostomy or a gastrostomy tube was also found to be independently associated with shunt infection in multivariate analysis (HR 3.15, 95% CI 1.05-9.50, p = 0.04, and HR 2.82, 95% CI 1.33-5.96, p = 0.007, respectively).

CONCLUSIONS

This study suggests, for the first time, that the systematic application of concentrated bacitracin powder to surgical wounds prior to closure during shunt surgery may be associated with a reduction in cranial shunt infection. This initial finding requires validation in a large prospective study before widespread application can be advocated.

Complications associated with bacitracin powder in surgical wounds

OBJECT

There has been renewed interest in the application of concentrated antibiotic powder to surgical wounds as a method to decrease infection rates. While there is substantial medical literature describing the effectiveness and complications associated with vancomycin and gentamycin powders, very little has been reported regarding the safety and effectiveness of bacitracin powder in surgical wounds. In this paper the authors report their detailed analysis of potential bacitracin powder-related complications in a population of pediatric patients who underwent shunt surgery.

METHODS

A detailed retrospective analysis was completed of all CSF shunt surgeries performed by the corresponding author at a large children's hospital between 2001 and 2013. This cohort consisted of many patients who were the subject of a previous report that showed the use of bacitracin powder in shunt wounds potentially decreased infection rates. Data were collected regarding the most common known complications of bacitracin, i.e., anaphylaxis, wound healing difficulties, and renal dysfunction. Data were stratified by typical demographic, medical, and surgical variables, including whether bacitracin powder was applied to wounds prior to closure.

RESULTS

A total of 597 patients were reviewed in the analysis: 389 underwent surgery without bacitracin powder and 208 had concentrated bacitracin powder applied to the wounds prior to closure. The application of bacitracin powder was not associated with anaphylaxis (n = 0 both groups) or with an increase in wound breakdown (n = 5 in the control group, n = 0 in the bacitracin powder group) or renal dysfunction (creatinine/estimated glomerular filtration rate) using both comparative and multivariate analyses between the 2 groups. The sample size evaluating renal function was significantly lower (range 6-320) than that of anaphylaxis and wound breakdown analysis because only clinical values acquired during the routine care of these patients were available for analysis. The only significant difference in demographics was the more frequent use of intrathecal vancomycin and gentamycin in patients who received bacitracin powder (n = 1 for controls, n = 21 for bacitracin powder). In the multivariate analysis, only 1 factor, surgery performed on a premature infant within the first 3 months of life, was independently associated with a change in creatinine at 3 months (creatinine decreased by 0.18) compared with the level before surgery (p < 0.0001). Bacitracin powder was not a significant factor.

CONCLUSIONS

To the authors' knowledge, this is the first study to systematically analyze the potential complications of concentrated bacitracin powder applied to surgical wounds. The use of topical bacitracin powder in CSF shunt wounds was not associated with anaphylaxis, wound breakdown, or renal dysfunction. Further study using standardized protocols is necessary before widespread use can be recommended.

Reducing surgical site infections following craniotomy: examination of the use of topical vancomycin

OBJECT

Although the use of topical vancomycin has been shown to be safe and effective for reducing postoperative infection rates in patients after spine surgery, its use in cranial wounds has not been studied systematically. The authors hypothesized that topical vancomycin, applied in powder form directly to the subgaleal space during closure, would reduce cranial wound infection rates.

METHODS

A cohort of 150 consecutive patients who underwent craniotomy was studied retrospectively. Seventy-five patients received 1 g of vancomycin powder applied in the subgaleal space at the time of closure. This group was compared with 75 matched-control patients who were accrued over the same time interval and did not receive vancomycin. The primary outcome measure was the presence of surgical site infection within 3 months. Secondary outcome measures included tissue pH from a subgaleal drain and vancomycin levels from the subgaleal space and serum.

RESULTS

Vancomycin was associated with significantly fewer surgical site infections (1 of 75) than was standard antibiotic prophylaxis alone (5 of 75; p < 0.05). Cultures were positive for typical skin flora species. As expected, local measured vancomycin concentrations peaked immediately after surgery (mean ± SD 499 ± 37 μg/ml) and gradually decreased over 12 hours. Vancomycin in the circulating serum remained undetectable. Subgaleal topical vancomycin was associated with a lower incidence of surgical site infections after craniotomy. The authors attribute this reduction in the infection rate to local vancomycin concentrations well above the minimum inhibitory concentration for antimicrobial efficacy.

CONCLUSIONS

Topical vancomycin is safe and effective for reducing surgical site infections after craniotomy. These data support the need for a prospective randomized examination of topical vancomycin in the setting of cranial surgery.

The management of periprosthetic infections in the future: a review of new forms of treatment

The number of arthroplasties being undertaken is expected to grow year on year, and periprosthetic joint infections will be an increasing socioeconomic burden. The challenge to prevent and eradicate these infections has resulted in the emergence of several new strategies, which are discussed in this review. Cite this article: Bone Joint J 2015;97-B:1162-9.

Local Injection of Aminoglycosides for Prophylaxis Against Infection in Open Fractures

BACKGROUND

The purpose of this study was to determine the efficacy of local wound cavity injections of aqueous aminoglycosides (gentamicin and tobramycin), in conjunction with systemic antibiotics, to lower the prevalence of infection in patients with open fractures.

METHODS

Three hundred and fifty-one open fractures were identified by Current Procedural Terminology codes 11011 and 11012. Data on patient demographic characteristics, injury characteristics, infection, and fracture union were obtained from the electronic medical records. Patients in the control group (183 fractures) received systemic antibiotics only. Patients in the intervention group (168 fractures) received, in addition to systemic antibiotics, a locally administered aminoglycoside (2 mg/mL) at the time of the index surgical procedure. At the discretion of the attending surgeon, some wounds also received postoperative irrigations of aqueous aminoglycoside (n = 34). For wounds that could not be closed and wounds that received postoperative irrigations, negative pressure dressings were used.

RESULTS

The deep and superficial infection rate in the control group was 19.7% (thirty-six of 183 fractures), but it was significantly lower (p = 0.010) in the intervention group at 9.5% (sixteen of 168 fractures). When comparing only the deep infections, the infection rate in the control group was 14.2% (twenty-six of 183 fractures) compared with 6.0% (ten of 168 fractures) in the intervention group (p = 0.011). After multivariate analysis to adjust for possible confounding factors, the administration of local antibiotics was found to be an independent predictor of lower infection rates in both deep and superficial infections (odds ratio, 2.6 [95% confidence interval, 1.2 to 5.6]; p = 0.015) and deep infections only (odds ratio, 3.0 [95% confidence interval, 1.1 to 8.5]; p = 0.034). The use of local antibiotics did not have an impact on nonunion rate (p = 0.881), with a type-I error rate of α = 0.05 and 0.8 power.

CONCLUSIONS

This study suggests that local aqueous aminoglycoside administration as an adjunct to systemic antibiotics may be effective in lowering infection rates in open fractures; further research with higher-level research designs are needed.

Comparison of Intrawound Vancomycin Utility in Posterior Instrumented Spine Surgeries Between Patients With Tumor and Nontumor Patients

STUDY DESIGN

Retrospective cohort study of consecutive patients.

OBJECTIVE

To compare the efficacy of intrawound vancomycin to prevent postoperative surgical site infection (SSI) between patients with spinal tumor and nontumor spine patients.

SUMMARY OF BACKGROUND DATA

Recent studies have suggested that intrawound vancomycin is a promising method for reducing the SSI rate in spine surgery. However, the patient population in which it is most effective remains unknown.

METHODS

Medical records of a consecutive series of patients with tumor and nontumor spine patients who underwent open posterior instrumented surgeries at our institution between October 2011 and June 2014 were reviewed. 1 gram of vancomycin powder was evenly sprayed into the surgical site before drain placement. The SSI rates before and after vancomycin use were compared. Changes in SSI rates, which reflected the utility of vancomycin, were compared between patients with tumor and nontumor patients.

RESULTS

A total of 334 patients were enrolled including 25 patients with tumor and 129 nontumor patients in the "before" period, and 27 patients with tumor and 153 nontumor patients in the "after" period. Baseline characteristics in both patients with tumor and nontumor patients did not differ between periods. The SSI rate of nontumor patients was significantly reduced with intrawound vancomycin application (7.0% [9/129] vs. 0.7% [1/153], P = 0.011). However, the SSI rate in patients with tumor was not reduced (8.0% [2/25] vs. 14.8% [4/27], P = 0.442). 3 of the 4 patients with tumor who developed SSI after vancomycin use had previous radiotherapy, whereas only 1 SSI occurred in 14 patients with tumor without radiotherapy in the same period.

CONCLUSION

Intrawound vancomycin may be beneficial for nontumor spine patients who undergo open posterior instrumented surgeries, but may not for those with spinal tumors. The poor physical health status, major surgical trauma, and tumor-related adjuvant treatments of patients with spinal tumor may contribute to this disparity.

Complications from the use of intrawound vancomycin in lumbar spinal surgery: a systematic review

OBJECT

The use of intrawound vancomycin is rapidly being adopted for the prevention of surgical site infection (SSI) in spinal surgery. At operative closure, the placement of vancomycin powder in the wound bed—in addition to standard infection prophylaxis—can provide high concentrations of antibiotics with minimal systemic absorption. However, despite its popularity, to date the majority of studies on intrawound vancomycin are retrospective, and there are no prior reports highlighting the risks of routine treatment.

METHODS

A MEDLINE search for pertinent literature was conducted for studies published between 1966 and May 2015 using the following MeSH search terms: “intrawound vancomycin,” “operative lumbar spine complications,” and “nonoperative lumbar spine complications.” This was supplemented with references and known literature on the topic.

RESULTS

An advanced MEDLINE search conducted on May 6, 2015, using the search string “intrawound vancomycin” found 22 results. After a review of all abstracts for relevance to intrawound vancomycin use in spinal surgery, 10 studies were reviewed in detail. Three meta-analyses were evaluated from the initial search, and 2 clinical studies were identified. After an analysis of all of the identified manuscripts, 3 additional studies were included for a total of 16 studies. Fourteen retrospective studies and 2 prospective studies were identified, resulting in a total of 9721 patients. A total of 6701 (68.9%) patients underwent treatment with intrawound vancomycin. The mean SSI rate among the control and vancomycin-treated patients was 7.47% and 1.36%, respectively. There were a total of 23 adverse events: nephropathy (1 patient), ototoxicity resulting in transient hearing loss (2 patients), systemic absorption resulting in supratherapeutic vancomycin exposure (1 patient), and culture-negative seroma formation (19 patients). The overall adverse event rate for the total number of treated patients was 0.3%.

CONCLUSIONS

Intrawound vancomycin use appears to be safe and effective for reducing postoperative SSIs with a low rate of morbidity. Study disparities and limitations in size, patient populations, designs, and outcomes measures contribute significant bias that could not be fully rectified by this systematic review. Moreover, care should be exercised in the use of intrawound vancomycin due to the lack of well-designed, prospective studies that evaluate the efficacy of vancomycin and include the appropriate systems to capture drug-related complications.

PROPHYLAXIS OF SURGICAL SITE INFECTION WITH VANCOMYCIN IN 513 PATIENTS THAT UNDERWENT TO LUMBAR FUSION

Objective:To assess the prophylactic effects of local vancomycin on an infection of the surgical site in patients undergoing lumbar instrumented fusion.Methods:Retrospective study from January 2011 to June 2014 in patients with symptomatic and refractory lumbar spine stenosis and listhesis who underwent instrumented pedicle screw spinal fusion. Two groups of patient were analyzed, one using vancomycin on the surgical site, vancomycin group (VG) and the control group (CG) without topical vancomycin. The routine prophylactic procedures were performed in both groups: aseptic scrub technique, skin preparation, preoperative intravenous antibiotic therapy. The VG received a dose of 1g of vancomycin mixed with the bone graft every three spinal levels fused and the group consisted of 232 patients.Results:513 patients were analyzed, 232 in the VG and 281 in the CG. There was no statistical difference between the groups when the sex, mean surgery length, and mean bleeding volume were considered. The rate of infection for VG was reduced from 4.98% to 1.29% when compared with CG.Conclusion:The use of vancomycin added to the bone graft in posterior spinal fusion is associated with significantly lower rates of infection.

Combined local and systemic antibiotic treatment is effective against experimental Staphylococcus aureus peri-implant biofilm infection

We hypothesized that systemic ceftriaxone and high concentration local antibiotics might eradicate peri-implant sepsis. Experiment 1: Eighty-four implants inoculated with biofilm-forming Staphylococcus aureus were treated in vitro with gentamicin, vancomycin, gentamicin + rifampin, or vancomycin + rifampin for 2, 4, or 8 days. Experiment 2: Forty-five implants were wired in vivo to rat femurs and inoculated with 1 × 10(6) CFU S. aureus. After 48 h, rats were treated once daily for 5 days with systemic ceftriaxone, local tobramycin or ceftriaxone, and tobramycin. Experiment 3: Forty implants with established S. aureus biofilms were wired in vivo to rat femurs. After 48 h, rats were treated with systemic ceftriaxone alone or in combination with local gentamicin, gentamicin and rifampin, or vancomycin. Experiment 1: 100% of implants treated in vitro with gentamicin were sterile after 48 h. The other treatments did not become sterile until 4 days. Experiment 2: No implant was culture negative. The combination of systemic ceftriaxone and local tobramycin was significantly better than others (p < 0.008). Experiment 3: Systemic ceftriaxone alone was ineffective. All implants treated with systemic ceftriaxone and local gentamicin were sterile (p < 0.001), the other groups were less effective.

The use of local vancomycin powder in degenerative spine surgery

PURPOSE

Wound infection after spine surgery is a debilitating complication. Local placement of vancomycin powder into the surgical wounds prior to closing of the fascia has been introduced as a method to reduce deep infection rates.

METHODS

The infection rates of all the patients who were treated with intra-operative local vancomycin between June 2012 and June 2013 were compared to all cases that were not treated with vancomycin between January 2009 and December 2010. Patients for both groups were operated by four senior, fellowship-trained spine surgeons with a combined experience of 55 years of practice at a referral orthopedic center. Patients' charts and microbiology reports were reviewed.

RESULTS

1224 cases were performed with the use of vancomycin. The average age was 56.3 years (SD -13.2; NS). The male to female ratio was 1:1.12 (NS). 2253 cases were performed without the use of vancomycin. The average patient age was 57.1 years (SD 14.5). The male to female ratio was 1:1.14. There were 30 cases of deep infections needing a surgical irrigation and debridement without vancomycin versus 5 when vancomycin was used (P = 0.04). Infections in patients treated with vancomycin were not vancomycin-resistant bacteria.

CONCLUSION

In conclusion, the use of vancomycin reduces the rate of deep wound infections and irrigation and debridement procedures after spine surgery in a referral center among surgeons with a high surgical volume.

Principles of Antibiotic Prophylaxis in Total Joint Arthroplasty: Current Concepts

Infection is a rare, serious complication following total joint arthroplasty and constitutes a considerable emotional and financial burden for patients, surgeons, and healthcare systems. Prevention of surgical site and periprosthetic joint infections is crucial. This requires knowledge of the microorganisms that commonly cause these infections, including Staphylococcus species. Selection of the appropriate antibiotic regimen to treat infection remains controversial, but cefazolin and cefuroxime are the most commonly recommended antibiotics for prophylaxis. Appropriate timing of administration before surgery, with redosing performed as needed, can help to ensure optimal antibiotic concentration during surgery. Given the increasing evidence that S aureus colonization is a risk factor for periprosthetic joint infection, an exploration of the potential benefits of preoperative S aureus carrier screening and decolonization protocols is warranted. The use of antibiotic-loaded bone cement in primary total joint arthroplasty and antibiotic powder at wound closure are other controversial topics that require additional research.

Efficacy of Antibiotics Sprayed into Surgical Site for Prevention of the Contamination in the Spinal Surgery

Study Design

Retrospective study.

Purpose

To evaluate the effect of intraoperative wound application of vancomycin on preventing surgical wound contamination during instrumented lumbar spinal surgery.

Overview of Literature

Postoperative infection is the one of the most devastating complications of lumbar surgery. There are a few reports showing the benefits of intraoperative wound application of vancomycin during spinal surgery. However, there is no report about the effectiveness of local vancomycin instillation in prevention of surgical wound contamination.

Methods

Eighty-six patients underwent instrumented lumbar spinal surgery. Mean patient age was 65.19 years (range, 23-83 years). There were 67 females and 19 males. During surgery, vancomycin powder was applied into the surgical site before closure in 43 patients (antibiotic group) and vancomycin powder was not applied into the surgical site before closure in 43 patients (control group). The tip of the surgical drain was cultured to evaluate surgical wound contamination. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were measured on the first, third, seventh, and fourteenth day after the operation.

Results

We found two patients with a positive culture from the tip of surgical drains in the antibiotic group, and one patient with a positive culture from the tip of the surgical drain in the control group. Postoperative ESR and CRP levels did not show significant differences between the two groups. On the third postoperative day, ESR in patients of the antibiotic group was more significantly decreased than that in patients of the control group, while CRP level did not show a significant difference between the two groups.

Conclusions

There was no evidence to suggest that intraoperative vancomycin application is effective in decreasing the risk of postoperative wound infection after instrumented posterior lumbar fusion surgery.

Application of Intrawound Vancomycin Powder during Spine Surgery in a Patient with Dialysis-Dependent Renal Failure

Surgical site infections (SSIs) after spinal surgery are a serious complication that can be minimized with prophylaxis. Vancomycin is a common agent used in the prevention of SSI. Given that vancomycin is renally cleared, its use requires careful observation in dialysis-dependent patients due to toxicity at supratherapeutic levels. Since minimum inhibitory concentrations (MICs) for vancomycin have increased due to the emergence of resistant pathogens, the use of vancomycin in such patients is further complicated. Local instillation of vancomycin powder is thought to provide additional protection against SSI and have lower systemic absorption. We present a patient with end-stage renal disease that developed progressively debilitating cervical spondylotic myelopathy necessitating multilevel laminectomy and instrumented fusion. Prior to closure, 1 gram of vancomycin powder was sprinkled into the surgical incision. Postoperative serum vancomycin levels were well below those associated with nephrotoxicity and ototoxicity. Based on this experience, we reviewed the relevant guidelines that were designed to prevent postoperative infections in such dialysis-dependent patients. Intrawound application of vancomycin may be a legitimate and safe option for SSI prophylaxis in patients with renal failure on dialysis.

Should we add vancomycin antibiotic powder to prevent post operative infection in spine surgery?

Intravenous antibiotic prophylaxis is routinely administered to prevent surgical site infection in spinal surgery. Adding intrawound vancomycin powder before surgical closure might further decrease infection risk. However, its use is controversial. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified six systematic reviews that considered 16 studies, including one randomized controlled trial. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded vancomycin probably does not decrease the risk of infection in low risk surgery, but there is uncertainty about its effects in populations or surgeries with a higher risk because the certainty of the evidence is very low.

Cost and quality of life outcome analysis of postoperative infections after subaxial dorsal cervical fusions

OBJECT

Infections following spine surgery negatively affect patient quality of life (QOL) and impose a significant financial burden on the health care system. Postoperative wound infections occur at higher rates following dorsal cervical procedures than ventral procedures. Quantifying the health outcomes and costs associated with infections following dorsal cervical procedures may help to guide treatment strategies to minimize the deleterious consequences of these infections. Therefore, the goals of this study were to determine the cost and QOL outcomes affecting patients who developed deep wound infections following subaxial dorsal cervical spine fusions.

METHODS

The authors identified 22 (4.0%) of 551 patients undergoing dorsal cervical fusions who developed deep wound infections requiring surgical debridement. These patients were individually matched with control patients who did not develop infections. Health outcomes were assessed using the EQ-5D, Pain Disability Questionnaire (PDQ), Patient Health Questionnaire (PHQ-9), and visual analog scale (VAS). QOL outcome measures were collected preoperatively and after 6 and 12 months. Health resource utilization was recorded from patient electronic medical records over an average follow-up of 18 months. Direct costs were estimated using Medicare national payment amounts, and indirect costs were based on patients' missed workdays and income.

RESULTS

No significant differences in preoperative QOL scores were found between the 2 cohorts. At 6 months postsurgery, the noninfection cohort had significant pre- to postoperative improvement in EQ-5D (p = 0.02), whereas the infection cohort did not (p = 0.2). The noninfection cohort also had a significantly higher 6-month postoperative EQ-5D scores than the infection cohort (p = 0.04). At 1 year postsurgery, there was no significant difference in EQ-5D scores between the groups. Health care–associated costs for the infection cohort were significantly higher ($16,970 vs $7658; p < 0.0001). Indirect costs for the infection cohort and the noninfection cohort were $6495 and $2756, respectively (p = 0.03). Adjusted for inflation, the total costs for the infection cohort were $21,778 compared with $9159 for the noninfection cohort, reflecting an average cost of $12,619 associated with developing a postoperative deep wound infection (p < 0.0001).

CONCLUSIONS

Dorsal cervical infections temporarily decrease patient QOL postoperatively, but with no long-term impact; they do, however, dramatically increase the cost of care. Knowledge of the financial burden of wound infections following dorsal cervical fusion may stimulate the development and use of improved prophylactic and therapeutic techniques to manage this serious complication.

Intrasite vancomycin powder for the prevention of surgical site infection in spine surgery: a systematic literature review

BACKGROUND CONTEXT

Deep surgical site infections (SSIs) following spinal surgery are a significant burden to the patient, patient's family, and the health-care system. Because of increasing pressures to reduce SSIs and control costs, some spine surgeons have begun placing lyophilized vancomycin powder directly into the surgical wound at the conclusion of the procedure. However, the literature supporting this practice remains limited.

PURPOSE

To review the current literature examining the use of prophylactic intrasite vancomycin powder to control SSIs in spinal surgery and determine if any standard recommendations can be made.

STUDY DESIGN

A systematic review.

METHODS

Ovid Medline and PubMed were searched to identify English language articles.

RESULTS

No current guidelines are available for the use of intrasite vancomycin powder in preventing SSIs, and no standard dosage for the drug exists. Based on the limited literature and evidence currently available, there appears to be a protective effect of intrasite vancomycin powder on the incidence of SSI, without evidence of side effects. However, case reports do exist describing the systemic side effects after intrasite vancomycin powder during spine surgery.

CONCLUSIONS

The interpretation of the available evidence supporting the use of intrasite vancomycin powder in surgical wounds is limited, and its extrapolation should be performed with caution. Despite the lack of significant high-quality evidence available in the literature, many surgeons have adopted this practice; anecdotally, it continues to provide protection from infection without apparent significant risk of side effects.

What is new in the diagnosis and prevention of spine surgical site infections

BACKGROUND CONTEXT

Surgical site infection (SSI) after spinal surgery can result in several serious secondary complications, such as pseudoarthrosis, neurological injury, paralysis, sepsis, and death. There is an increasing body of literature on risk factors, diagnosis, and specific intraoperative interventions, including attention to sterility of instrumentation, application of minimally invasive fusion techniques, intraoperative irrigation, and application of topical antibiotics, that hold the most promise for reduction of SSI.

PURPOSE

The purpose of this review is to identify and summarize the recent literature on the incidence, risk factors, diagnosis, prevention, and treatment of SSIs after adult spine surgery.

STUDY DESIGN

The study design included systematic review and literature synthesis.

METHODS

For the systematic reviews, a search was performed in Medline and Scopus using keywords derived from a preliminary review of the literature and Medline MeSH terms. These studies were then manually filtered to meet the study criteria outlined in each section. Studies were excluded via predetermined criteria, and the majority of articles reviewed were excluded.

RESULTS

There are a number of patient- and procedure-specific risk factors for SSI. Surgical site infection appears to have significant implications from the patients' perspective on outcome of care. Diagnosis of SSI appears to rely primarily on clinical factors, while laboratory values such as C-reactive protein are not universally sensitive. Similarly, novel methods of perioperative infection prophylaxis such as local antibiotic administration appear to be modestly effective.

CONCLUSIONS

Surgical site infections are a common multifactorial problem after spine surgery. There is compelling evidence that improved risk stratification, detection, and prevention will reduce SSIs.

Experience with intrawound vancomycin powder for posterior cervical fusion surgery

OBJECT

Recent studies have reported that the local delivery of vancomycin powder is associated with a decrease in spinal surgical site infection. This retrospective cohort study compares posterior cervical fusion cases before and after the routine application of spinal vancomycin powder to evaluate the ability of local vancomycin powder to prevent deep wound infection after posterior cervical spinal fusion.

METHODS

Posterior cervical fusion spinal surgeries performed at a single institution were reviewed from January 2011 to July 2013. Each cohort's baseline characteristics, operative data, and rates of wound infection were compared. Associations between infection and vancomycin powder, with and without propensity score adjustment for risk factors, were determined using logistic regression.

RESULTS

A total of 289 patients (174 untreated and 115 treated with vancomycin powder) were included in the study. The cohorts were similar in terms of baseline and operative variables. No significant change in deep wound infection rate was seen between the control group (6.9%) and intervention group (5.2%, p = 0.563). Logistic regression, with and without propensity score adjustment, demonstrated that the use of vancomycin powder did not impact the development of surgical site infection (OR 0.743 [95% CI 0.270–2.04], p = 0.564) and (OR 0.583 [95% CI 0.198–1.718], p = 0.328), respectively.

CONCLUSIONS

Within the context of an ongoing debate on the effectiveness of locally administered vancomycin powder, the authors found no significant difference in the incidence of deep wound infection rates after posterior cervical fusion surgery with routine use of locally applied vancomycin powder. Future prospective randomized series are needed to corroborate these results.

Prospective multicenter surveillance and risk factor analysis of deep surgical site infection after posterior thoracic and/or lumbar spinal surgery in adults

BACKGROUND

Surgical site infection is a serious and significant complication after spinal surgery and is associated with high morbidity rates, high healthcare costs and poor patient outcomes. Accurate identification of risk factors is essential for developing strategies to prevent devastating infections. The purpose of this study was to identify independent risk factors for surgical site infection among posterior thoracic and/or lumbar spinal surgery in adult patients using a prospective multicenter surveillance research method.

METHODS

From July 2010 to June 2012, we performed a prospective surveillance study in adult patients who had developed surgical site infection after undergoing thoracic and/or lumbar posterior spinal surgery at 11 participating hospitals. Detailed preoperative and operative patient characteristics were prospectively recorded using a standardized data collection format. Surgical site infection was based on the definition established by the Centers for Disease Control and Prevention.

RESULTS

A total of 2,736 consecutive adult patients were enrolled, of which 24 (0.9%) developed postoperative deep surgical site infection. Multivariate regression analysis indicated four independent risk factors. Preoperative steroid therapy (P = 0.001), spinal trauma (P = 0.048) and gender (male) (P = 0.02) were statistically significant independent patient-related risk factors, whereas an operating time ≥3 h (P < 0.001) was a surgery-related independent risk factor.

CONCLUSION

Preoperative steroid therapy, spinal trauma, male gender and an operating time ≥3 h were independent risk factors for deep surgical site infection after thoracic and/or lumbar spinal surgery in adult patients. Identification of these risk factors can be used to develop protocols aimed at decreasing the risk of surgical site infection.

The use of vancomycin powder in modern spine surgery: systematic review and meta-analysis of the clinical evidence

BACKGROUND

Surgical-site infections (SSIs) can lead to greater postoperative morbidity, mortality, and health care costs. Despite current prophylactic measures, rates of SSIs have been reported in up to 15% of patients undergoing spine surgery. The adjunctive local application of vancomycin powder in spine surgery is a low-cost strategy to help reduce SSIs. Vancomycin is active against skin pathogens that can potentially contaminate the wound during spinal surgery. The local application of vancomycin in its powder form ensures adequate surgical-site concentrations while minimizing adverse effects caused by undetectable systemic distribution. However, clinical studies have produced conflicting results, and the clinical evidence behind the use of vancomycin powder in modern spinal surgery practices is not clear.

PURPOSE

To examine the current clinical evidence on the use of vancomycin powder in spine surgery.

STUDY DESIGN

Systematic review and meta-analysis of literature.

METHODS

A comprehensive search of the English literature was conducted with PubMed (MEDLINE). The inclusion criteria consisted of intrawound vancomycin powder use in spine surgery as a prophylactic agent for SSIs. Studies that investigated nonspine surgeries, selected patients on the basis of clinical suspicion, or included patients with infections were excluded. Studies that compared intrawound vancomycin in spine surgery against their standard practice were pooled in the meta-analysis using a random-effects model.

RESULTS

A total of 671 abstracts were reviewed, and 18 papers met inclusion/exclusion criteria and were included in this review. These included 1 randomized controlled trial, 13 comparative studies, and 4 case series. The level of evidence in hierarchical order was as follows: 1 level II, 13 level III, and 4 level IV. Fourteen of the studies, 1 randomized controlled trial and 13 comparative studies, were eligible for the meta-analysis. The odds of developing a deep infection with intrawound vancomycin powder were 0.23 times the odds of experiencing an infection without intrawound vancomycin (95% confidence interval 0.11-0.50, P = 0.0002, I(2) = 47%). For combined superficial and deep infections the odds ratio was 0.43 (95% confidence interval 0.22-0.82, P = 0.01, I(2) = 36%).

CONCLUSIONS

Numerous clinical studies have confirmed the safety of using vancomycin powder in the surgical site. The pooled clinical data supports the use of vancomycin to prevent SSIs in adult spine surgeries. The majority of the supporting literature is class III evidence. Existing studies use different definitions for surgical site infections and different pre-, peri-, and postoperative antibiotic regimens. Further high-quality investigations should use standardized protocols to confirm these findings.

A meta-analysis of spinal surgical site infection and vancomycin powder

Object

Surgical site infection (SSI) is a serious and costly complication of spinal surgery. There have been several conflicting reports on the use of intrawound vancomycin powder in decreasing SSI in spine surgery. The purpose of this study is to answer the question: “Does intrawound vancomycin powder reduce the rate of SSIs in spine surgery?”

Methods

A comprehensive search of multiple electronic databases and bibliographies was conducted to identify clinical studies that evaluated the rates of SSI with and without the use of intrawound vancomycin powder in spine surgery. Independent reviewers extracted data and graded the quality of each paper that met inclusion criteria. A random effects meta-analysis was then performed.

Results

The search identified 9 retrospective cohort studies (Level III evidence) and 1 randomized controlled trial (Level II evidence). There were 2574 cases and 106 infections in the control group (4.1%) and 2518 cases and 33 infections (1.3%) in the treatment group, yielding a pooled absolute risk reduction and relative risk reduction of 2.8% and 68%, respectively. The meta-analysis revealed the use of vancomycin powder to be protective in preventing SSI (relative risk = 0.34, 95% confidence interval 0.17–0.66, p = 0.021). The number needed to treat to prevent 1 SSI was 36. A subgroup analysis found that patients who had implants had a reduced risk of SSI with vancomycin powder (p = 0.023), compared with those who had noninstrumented spinal operations (p = 0.226).

Conclusions

This meta-analysis suggests that the use of vancomycin powder may be protective against SSI in open spinal surgery; however, the exact population in which it should be used is not clear. This benefit may be most appreciated in higher-risk populations or in facilities with a high baseline rate of infection.

Sterile Seroma Resulting from Multilevel XLIF Procedure as Possible Adverse Effect of Prophylactic Vancomycin Powder: A Case Report

Study Design Case report.

Objective The objective of this study was to present the unusual case of a 59-year-old woman with a reoccurring sterile postoperative seroma.

Methods A patient was observed postoperatively for any complications or adverse side effects resulting from an initial multilevel anterior/posterior lumbar fusion surgery where 2 g (1 g combined with the bone graft used for posterolateral fusion and 1 g placed in the soft tissues) of prophylactic vancomycin powder was placed within the soft tissues posteriorly before wound closure. The patient's progress was monitored through 6 months following the initial procedure. Six weeks postoperatively, the patient sustained a fall and had increased pain. Magnetic resonance imaging, computed tomography, and X-rays demonstrated a displaced sacral fracture, a large epidural fluid collection, and severe compression of the thecal sac at the lumbar operative sites (L3–5).

Results On the basis of the aforementioned imaging studies and the patient's progressive neurologic deficit, it was apparent at the 6-week follow-up that emergent surgical intervention was necessary. Drainage and examination of an epidural fluid collection along with treatment of a displaced sacral fracture (S1–S2) were performed. The patient had an uneventful postoperative course with resolution of her back pain and neurologic deficit; however, recurrence of the epidural fluid collection requiring serial aspirations confounded the patients' clinical presentation.

Conclusions With the recurrent nature of the seroma being unusual, the cause of the fluid collection and formation is undetermined. With lack of bone morphogenetic protein usage, and few confounding variables accountable, an acute allergic response to topical vancomycin powder is a possible etiology. Analysis with larger patient populations comparing postoperative adverse effects of prophylactic vancomycin powder is recommended.

Topical intrawound application of vancomycin powder in addition to intravenous administration of antibiotics: A meta-analysis on the deep infection after spinal surgeries

BACKGROUND

The intrawound application of vancomycin powder in addition to intravenous administration of antibiotics has been reported to be an easy and cost-efficient technique for reducing the deep infection, which is a serious complication of spinal surgeries. The aim of the present meta-analysis was to derive a preliminary estimation on the clinical performance of this technique.

HYPOTHESIS

The intrawound application of vancomycin powder in addition to intravenous administration of antibiotics may significantly reduce the risk of deep infection after spinal surgeries.

MATERIALS AND METHODS

Studies were identified from PubMed and EMBASE searches. After comprehensive review, data were extracted from eligible studies. A meta-analysis was performed to generate pooled odds ratio (OR) of this technique.

RESULTS

Eight studies (4592 patients) were included. The pooled OR (95% CI) was 0.22 (0.07-0.63). I(2) value was 65.2% (P=0.005). The pooled ORs were stable in sensitivity analyses. No analysis of subgroup, meta-regression or publication bias was performed because of inadequate included studies.

DISCUSSION

The intrawound application of vancomycin powder in addition to intravenous administration of antibiotics may significantly reduce the risk of deep infection after spinal surgeries. Further studies with large sample size and high quality are needed to provide more evidences.

LEVEL OF EVIDENCE

II.

Cost savings analysis of intrawound vancomycin powder in posterior spinal surgery

BACKGROUND CONTEXT

Recent studies have shown that prophylactic use of intrawound vancomycin in posterior instrumented spine surgery substantially decreases the incidence of wound infections requiring repeat surgery. Significant cost savings are thought to be associated with the use of vancomycin in this setting.

PURPOSE

To elucidate cost savings associated with the use of intrawound vancomycin in posterior spinal surgeries using a budget-impact model.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Data from a cohort of 303 patients who underwent spinal surgery (instrumented and noninstrumented) over 2 years were analyzed; 96 of these patients received prophylactic intrawound vancomycin powder in addition to normal intravenous (IV) antibiotic prophylaxis, and 207 received just routine IV antibiotic prophylaxis. Patients requiring repeat surgical procedures for infection were identified, and the costs of these additional procedures were elucidated.

OUTCOME MEASURE

Cost associated with the additional procedure to remediate infection in the absence of vancomycin prophylaxis.

METHODS

We retrospectively reviewed the cost of return procedures for treatment of surgical site infection (SSI). The total reimbursement received by the health care facility was used to model the costs associated with repeat surgery, and this cost was compared with the cost of a single local application of vancomycin costing about $12.

RESULTS

Of the 96 patients in the treatment group, the return-to-surgery rate for SSI was 0. In the group without vancomycin, seven patients required a total of 14 procedures. The mean cost per episode of surgery, based on the reimbursement, the health care facility received was $40,992 (range, $14,459-$114,763). A total of $573,897 was spent on 3% of the 207-patient cohort that did not receive intrawound vancomycin, whereas a total of $1,152 ($12×96 patients) was spent on the cohort treated with vancomycin.

CONCLUSIONS

This study shows a reduction in SSIs requiring a return-to-surgery-with large cost savings-with use of intrawound vancomycin powder. In our study population, the cost savings totaled more than half a million dollars.

Local intrawound vancomycin powder decreases the risk of surgical site infections in complex adult deformity reconstruction: a cost analysis

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

To evaluate the rate of surgical site infections (SSIs) and cost-effectiveness of the use of intraoperative vancomycin powder in thoracolumbar adult deformity procedures.

SUMMARY OF BACKGROUND DATA

The rates of SSI remain unacceptably high in adult spinal deformity surgery despite routine intravenous antibiotics. Vancomycin powder applied directly to the wound intraoperatively has shown promise for decreasing SSI in spine surgery.

METHODS

Adults who underwent adult deformity reconstruction by 2 surgeons between 2008 and 2012 with a minimum of 3 months of clinical follow-up were retrospectively reviewed. The patients were subdivided into those who had received only routine perioperative intravenous antibiotics (control) and those who received intravenous antibiotics and 2 g of vancomycin powder applied into the surgical wound. The primary outcome was SSI within 90 days. Secondary outcomes included surgical/clinical parameters and SSI-related medical costs based on hospital billing records.

RESULTS

Two hundred fifteen patients were evaluated-controls (n=64) and vancomycin powder group (n=151). The average number of levels fused was 10 (5-17, control) and 12 (5-19, vancomycin). The mean follow-up was 34 months (3-68 mo, control) and 18 months (3-35 mo, vancomycin) (P<0.05). There were significantly fewer hospital readmissions within 90 days for SSI in patients who received vancomycin powder (2.6%; 4/151) compared with controls (10.9%; 7/64) (P=0.01). There were no reported adverse events related to the intrawound vancomycin use. The average cost per patient of treating a postoperative SSI was higher in the control group ($34,388) than in the study group ($28,169). With the use of vancomycin powder, there was a cost saving of $244,402 per 100 complex spinal procedures.

CONCLUSION

Local application of vancomycin powder significantly decreased SSI for adults undergoing spinal reconstructive surgery. This resulted in cost savings of $244,402 per 100 thoracolumbar adult deformity procedures.

LEVEL OF EVIDENCE

3.

Safety of topical vancomycin for pediatric spinal deformity: nontoxic serum levels with supratherapeutic drain levels

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

To establish if drain levels exceed the minimum inhibitory concentrations for common pathogens (methicillin-resistant Staphylococcus aureus, methicillin-sensitive Staphylococcus aureus, and Propionibacterium acnes-2 μg/mL; Staphylococcus epidermidis, Enterococcus faecalis-4 μg/mL). Evaluate the safety of topical vancomycin in pediatric patients undergoing spinal deformity surgery and determine if postoperative serum levels approach toxicity (25 μg/mL).

SUMMARY OF BACKGROUND DATA

The application of topical vancomycin powder has decreased postoperative wound infections in retrospective analyses in the adult population with minimal local and systemic risks. The safety and efficacy of vancomycin powder has not been completely evaluated in the pediatric population after deformity surgery.

METHODS

Topical vancomycin powder (1 g) was applied during wound closure after instrumented posterior spinal fusion. All patients received intravenous perioperative antibiotics and a subfascial drain was used. Serum and drain vancomycin levels were collected immediately postoperatively and during the first 2 postoperative days (PODs). Complications were recorded.

RESULTS

The study population consisted of 25 patients with a mean age of 13.5 years (9.5-17.1 yr) and mean ± standard deviation body weight of 44.5 ± 18 kg. Underlying diagnoses included: adolescent idiopathic scoliosis (12), neuromuscular scoliosis (10), and kyphosis (3). Mean serum vancomycin levels trended downward from 2.5 μg/mL (POD 0) to 1.9 μg/mL (POD 1) to 1.1 μg/mL (POD 2). Mean drain levels also trended downward from 403 μg/mL (POD 0) to 251 μg/mL (POD 1) to 115 μg/mL (POD 2). No vancomycin toxicity or deep wound infections were observed. One patient with neuromuscular scoliosis developed a superficial wound dehiscence that was managed with dressing changes.

CONCLUSION

Topical application of vancomycin powder in pediatric spinal deformity surgery produced local levels well above the minimum inhibitory concentration for common pathogens and serum levels below the toxicity threshold (25 μg/mL). There were no deep wound or antibiotic related complications.

LEVEL OF EVIDENCE

3.

Risk factors for mediastinitis following cardiac surgery: the importance of managing obesity

BACKGROUND

Mediastinitis is a devastating complication of cardiac surgery. Previous studies have often observed small populations, been retrospective in design, and used a variety of definitions for mediastinitis.

AIM

To identify risk factors for mediastinitis, and strategies to minimize its incidence.

METHODS

A prospective cohort study of 4883 adult patients who underwent cardiac surgery between October 2003 and February 2009, comparing pre- and peri-operative risk factors, microbial aetiology, requirement for re-admission, length of stay and mortality between patients with and without mediastinitis.

FINDINGS

Ninety (1.8%) patients were diagnosed with mediastinitis. Microbial aetiology was defined for 75 patients. Staphlyocococcus aureus was the most common isolate (30 episodes; 15 due to meticillin-resistant S. aureus). Univariate analysis revealed the following pre-operative factors associated with mediastinitis: age; body mass index; diabetes; modified logistic European System for Cardiac Operative Risk Evaluation score; urgent admission; and longer pre-operative stay (P < 0.05). Associated peri-operative factors were: combined coronary artery bypass grafting plus aortic valve replacement; longer aortic cross-clamp time; and longer cardiopulmonary bypass time (P < 0.005). Multi-variate analysis revealed that higher body mass index, combined coronary artery bypass grafting plus aortic valve replacement, and older age were associated with mediastinitis (P < 0.05). Mediastinitis was associated with re-admission to hospital, longer inpatient stay and reduced long-term survival (P < 0.05).

CONCLUSION

Mediastinitis is associated with worse short-term outcomes (re-admission, length of stay) and reduced long-term survival. Obesity is the only modifiable pre-operative risk factor for mediastinitis. It may be possible to reduce risk through pre-operative weight loss programmes before elective surgery.

Complications and outcomes of complex spine reconstructions in poliomyelitis-associated spinal deformities: a single-institution experience

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To share our institutional experience with spinal reconstruction for deformity correction in patients with a history of poliomyelitis.

SUMMARY OF BACKGROUND DATA

Polio and postpolio syndrome are not uncommonly related to a paralytic spinal deformity. Limited modern data exist regarding outcomes and complications after spinal reconstruction in this population.

METHODS

A clinical database was reviewed for patients undergoing spinal reconstruction for polio-associated spinal deformity at our institution from 1985 to 2012. Relevant demographic, medical, surgical, and postoperative information were collected from medical records and analyzed. Preoperative and last follow-up Scoliosis Research Society-22 Questionnaire scores were recorded.

RESULTS

A total of 22 patients with polio who underwent surgical deformity correction were identified. Mean age was 49 years (range, 12-74 yr), and 15 patients (68%) were female. Preoperative motor deficit was present in 14 of 22 (64%) patients. All patients underwent instrumented spinal fusion (mean, 13 vertebral levels, range, 3-18). Ten (10/22, 45%) patients developed major complications, and 4 patients (4/22, 18%) developed new postoperative neurological deficits. Neurological monitoring yielded a 13% false-negative rate. At 2-year follow-up, 20 of 22 patients maintained an average coronal correction of 25° (33%, P = 0.001) and sagittal correction of 25° (34%, P = 0.003). Minimum 2-year follow-up data were available for 11 of 22 (50%) patients. At an average of 72 months of follow-up (range, 28-134 mo), the mean Scoliosis Research Society-22 Questionnaire pain subscore improved from a mean of 2.75 to 3.6 (P = 0.012); self-image from 2.8 to 3.7 (P = 0.041); function from 3.1 to 3.8 (P = 0.036); satisfaction from 2.1 to 3.9 (P = 0.08); and mental health from 3.7 to 4.5 (P = 0.115).

CONCLUSION

Spine reconstruction for poliomyelitis-associated deformity was associated with high complication rates (54%) and sometimes unreliable neurological monitoring data. Despite this, patients undergoing spine reconstructions had significantly improved outcome scores. These data may help surgeons to appropriately counsel this complicated patient population.

Establishing a role for vancomycin powder application for prosthetic joint infection prevention-results of a wear simulation study

Topical vancomycin powder (VP) has shown efficacy and safety in decreasing post-operative spine infections. VP use in arthroplasty has not been established. Concerns remain for third-body wear with the addition of crystalline substrate at the implant interface. The study's purpose was to compare wear behavior of CoCr on UHMWPE to identical wear couples with VP. A six-station wear simulator was utilized and cyclic articulations were run for 10 million cycles (Mc). UHMWPE wear was measured using photography, stereomicroscopy, and gravimetric measurement. There were no differences in wear mark length (P = 0.43), width (P = 0.49), or gravimetric wear at 10 Mc (P = 0.98). VP and control groups lost 0.32 and 0.33 mg, respectively. VP may have a role in PJI prevention. A well-designed clinical study is needed.

Efficacy of intraoperative vancomycin powder use in intrathecal baclofen pump implantation procedures: single institutional series in a high risk population

We aimed to assess the efficacy of intraoperative vancomycin powder in intrathecal baclofen pump placement patients, a high risk population. A retrospective review was conducted using prospectively collected data at an academic tertiary care unit. The neurosurgical adult patient population was queried for all intrathecal baclofen pump implantation procedures. Patients were then reviewed for the use of intraoperative crystalline vancomycin powder. Those with a history of prior surgical site infection, chronic systemic infections or osteomyelitis were excluded. Anhydrous, crystalline vancomycin was utilized in the wound bed after completion of implantation, distributed evenly in the case of multiple incisions. Patients received 500 mg or 1,000 mg of crystallized vancomycin, evenly distributed through the wound layers based on a 70 kg weight cutoff. Intraoperative institutional standards of infection prophylaxis were unchanged throughout the study period. Infection rate of baclofen pump placement prior to the use of vancomycin powder from 2001-2009 at the same institution was monitored. Wound infection rate was tracked for a 12 month postoperative period. Six patients out of 26 baclofen pump implantations (23%) in this cohort were identified to have seven infections despite vancomycin powder placement in the lumbar and catheter wounds. Prior infection rates have been investigated for intrathecal drug delivery systems from 2001 to 2009 at the same institution with an overall infection rate of 3% (8/274). The use of vancomycin powder in patients with implants in this series did not reduce infection rates compared to published historical controls, and was elevated compared to institutional controls. Further prospective study of this high risk patient population is warranted.

Surgeon practices regarding infection prevention for growth friendly spinal procedures

PURPOSE

The rate of infection in patients having growth sparing surgery for early onset scoliosis has been reported up to 25 % during the course of treatment. A recent study demonstrated significant variability in the approach to infection prevention in adolescent and neuromuscular scoliosis. The purpose of this study is to conduct a similar survey in order to understand approaches used by experienced pediatric spinal surgeons with regard to infection prevention in growth friendly spinal procedures.

MATERIALS AND METHODS

After preliminary internal testing of a survey by the authors, a final 21-question survey was created and approved by the authors and electronically distributed to all members of the Chest Wall Spinal Deformity Study Group and the Growing Spine Study Group (n = 57). A total of 40 responses were obtained (70 %).

RESULTS

Significant variability in practice was demonstrated across the majority of the questions answered. Several of the questions demonstrated relative equipoise between practices, including preoperative MRSA screening, preoperative chlorhexidine baths, postoperative antibiotic duration after insertion, use of topical antibiotics, use of drains, use of IV gram negative coverage or vancomycin, and skin preparation.

CONCLUSION

Other studies have demonstrated that variability in practice may have a negative impact on clinical outcomes, so one could postulate that steps that can reduce variability in the current population may help improve outcomes in this population. Areas of clinical equipoise can be used to help design and direct multicenter studies with an ultimate goal of reducing infections in this population.

LEVEL OF EVIDENCE

Level V.